/*******************************************************************************
 * Copyright (c) 2000, 2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.events.*;

/**
 * Instances of this class provide a selectable user interface object
 * that displays a hierarchy of items and issues notification when an
 * item in the hierarchy is selected.
 * <p>
 * The item children that may be added to instances of this class
 * must be of type <code>TreeItem</code>.
 * </p><p>
 * Style <code>VIRTUAL</code> is used to create a <code>Tree</code> whose
 * <code>TreeItem</code>s are to be populated by the client on an on-demand basis
 * instead of up-front.  This can provide significant performance improvements for
 * trees that are very large or for which <code>TreeItem</code> population is
 * expensive (for example, retrieving values from an external source).
 * </p><p>
 * Here is an example of using a <code>Tree</code> with style <code>VIRTUAL</code>:
 * <code><pre>
 *  final Tree tree = new Tree(parent, SWT.VIRTUAL | SWT.BORDER);
 *  tree.setItemCount(20);
 *  tree.addListener(SWT.SetData, new Listener() {
 *      public void handleEvent(Event event) {
 *          TreeItem item = (TreeItem)event.item;
 *          TreeItem parentItem = item.getParentItem();
 *          String text = null;
 *          if (parentItem == null) {
 *              text = "node " + tree.indexOf(item);
 *          } else {
 *              text = parentItem.getText() + " - " + parentItem.indexOf(item);
 *          }
 *          item.setText(text);
 *          System.out.println(text);
 *          item.setItemCount(10);
 *      }
 *  });
 * </pre></code>
 * </p><p>
 * Note that although this class is a subclass of <code>Composite</code>,
 * it does not make sense to add <code>Control</code> children to it,
 * or set a layout on it.
 * </p><p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SINGLE, MULTI, CHECK, FULL_SELECTION, VIRTUAL</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection, DefaultSelection, Collapse, Expand, SetData, MeasureItem, EraseItem, PaintItem</dd>
 * </dl>
 * </p><p>
 * Note: Only one of the styles SINGLE and MULTI may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */
public class Tree extends Composite {
	int /*long*/ modelHandle, checkRenderer;
	int columnCount, sortDirection;
	int /*long*/ ignoreCell;
	TreeItem[] items;
	TreeColumn [] columns;
	TreeColumn sortColumn;
	TreeItem currentItem;
	ImageList imageList, headerImageList;
	boolean firstCustomDraw;
	boolean modelChanged;
	boolean expandAll;
	int drawState, drawFlags;
	GdkColor drawForeground;
	boolean ownerDraw, ignoreSize;
	
	static final int ID_COLUMN = 0;
	static final int CHECKED_COLUMN = 1;
	static final int GRAYED_COLUMN = 2;
	static final int FOREGROUND_COLUMN = 3;
	static final int BACKGROUND_COLUMN = 4;
	static final int FONT_COLUMN = 5;
	static final int FIRST_COLUMN = FONT_COLUMN + 1;
	static final int CELL_PIXBUF = 0;
	static final int CELL_TEXT = 1;
	static final int CELL_FOREGROUND = 2;
	static final int CELL_BACKGROUND = 3;
	static final int CELL_FONT = 4;
	static final int CELL_TYPES = CELL_FONT + 1;

/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>SWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together 
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>SWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a composite control which will be the parent of the new instance (cannot be null)
 * @param style the style of control to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see SWT#SINGLE
 * @see SWT#MULTI
 * @see SWT#CHECK
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Tree (Composite parent, int style) {
	super (parent, checkStyle (style));
}

void _addListener (int eventType, Listener listener) {
	super._addListener (eventType, listener);
	if (!ownerDraw) {
		switch (eventType) {
			case SWT.MeasureItem:
			case SWT.EraseItem:
			case SWT.PaintItem:
				ownerDraw = true;
				recreateRenderers ();
				break;
		}
	}
}

TreeItem _getItem (int /*long*/ iter) {
	int id = getId (iter, true);
	if (items [id] != null) return items [id];
	int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, iter);
	int depth = OS.gtk_tree_path_get_depth (path);
	int [] indices = new int [depth];
	OS.memmove (indices, OS.gtk_tree_path_get_indices (path), 4*depth);
	int /*long*/ parentIter = 0;
	if (depth > 1) {
		OS.gtk_tree_path_up (path);
		parentIter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
		OS.gtk_tree_model_get_iter (modelHandle, parentIter, path);
	}
	items [id] = new TreeItem (this, parentIter, SWT.NONE, indices [indices.length -1], false);
	OS.gtk_tree_path_free (path);
	if (parentIter != 0) OS.g_free (parentIter);
	return items [id];
}

TreeItem _getItem (int /*long*/ parentIter, int index) {
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	OS.gtk_tree_model_iter_nth_child(modelHandle, iter, parentIter, index);
	int id = getId (iter, true);
	OS.g_free (iter);
	if (items [id] != null) return items [id];
	return items [id] = new TreeItem (this, parentIter, SWT.NONE, index, false);
}

int getId (int /*long*/ iter, boolean queryModel) {
	if (queryModel) {
		int[] value = new int[1];
		OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, value, -1);
		if (value [0] != -1) return value [0];
	}
	// find next available id
	int id = 0;
	while (id < items.length && items [id] != null) id++;
	if (id == items.length) {
		TreeItem [] newItems = new TreeItem [items.length + 4];
		System.arraycopy (items, 0, newItems, 0, items.length);
		items = newItems;
	}
	OS.gtk_tree_store_set (modelHandle, iter, ID_COLUMN, id, -1);
	return id;
}

static int checkStyle (int style) {
	/*
	* To be compatible with Windows, force the H_SCROLL
	* and V_SCROLL style bits.  On Windows, it is not
	* possible to create a tree without scroll bars.
	*/
	style |= SWT.H_SCROLL | SWT.V_SCROLL;
	/* GTK is always FULL_SELECTION */
	style |= SWT.FULL_SELECTION;
	return checkBits (style, SWT.SINGLE, SWT.MULTI, 0, 0, 0, 0);
}

int /*long*/ cellDataProc (int /*long*/ tree_column, int /*long*/ cell, int /*long*/ tree_model, int /*long*/ iter, int /*long*/ data) {
	if (cell == ignoreCell) return 0;
	TreeItem item = _getItem (iter);
	if (item != null) OS.g_object_set_qdata (cell, Display.SWT_OBJECT_INDEX2, item.handle);
	boolean isPixbuf = OS.GTK_IS_CELL_RENDERER_PIXBUF (cell);
	if (!(isPixbuf || OS.GTK_IS_CELL_RENDERER_TEXT (cell))) return 0;
	int modelIndex = -1;
	boolean customDraw = false;
	if (columnCount == 0) {
		modelIndex = Tree.FIRST_COLUMN;
		customDraw = firstCustomDraw;
	} else {
		TreeColumn column = (TreeColumn) display.getWidget (tree_column);
		if (column != null) {
			modelIndex = column.modelIndex;
			customDraw = column.customDraw;
		}
	}
	if (modelIndex == -1) return 0;
	boolean setData = false;
	if ((style & SWT.VIRTUAL) != 0) {
		/*
		* Feature in GTK.  On GTK before 2.4, fixed_height_mode is not
		* supported, and the tree asks for the data of all items.  The
		* fix is to only provide the data if the row is visible.
		*/
		if (OS.GTK_VERSION < OS.VERSION (2, 3, 2)) {
			int /*long*/ path = OS.gtk_tree_model_get_path (tree_model, iter);
			OS.gtk_widget_realize (handle);
			GdkRectangle visible = new GdkRectangle ();
			OS.gtk_tree_view_get_visible_rect (handle, visible);
			GdkRectangle area = new GdkRectangle ();
			OS.gtk_tree_view_get_cell_area (handle, path, tree_column, area);
			OS.gtk_tree_path_free (path);			
			if (area.y + area.height < 0 || area.y + visible.y > visible.y + visible.height ) {
				/* Give an image from the image list to make sure the row has
				* the correct height.
				*/
				if (imageList != null && imageList.pixbufs.length > 0) {
					if (isPixbuf) OS.g_object_set (cell, OS.pixbuf, imageList.pixbufs [0], 0);
				}
				return 0;
			}
		}
		if (!item.cached) {
			//lastIndexOf = index [0];
			setData = checkData (item);
		}
	}
	int /*long*/ [] ptr = new int /*long*/ [1];
	if (setData) {
		if (isPixbuf) {
			ptr [0] = 0;
			OS.gtk_tree_model_get (tree_model, iter, modelIndex + CELL_PIXBUF, ptr, -1);
			OS.g_object_set (cell, OS.pixbuf, ptr[0], 0);
		} else {
			ptr [0] = 0;
			OS.gtk_tree_model_get (tree_model, iter, modelIndex + CELL_TEXT, ptr, -1); 
			if (ptr [0] != 0) {
				OS.g_object_set (cell, OS.text, ptr[0], 0);
				OS.g_free (ptr[0]);
			}
		}
	}
	if (customDraw) {
		/*
		 * Bug on GTK. Gtk renders the background on top of the checkbox and pixbuf.
		 * This only happens in version 2.2.1 and earlier. The fix is not to set the background.   
		 */
		if (OS.GTK_VERSION > OS.VERSION (2, 2, 1)) {
			if (!ownerDraw) {
				ptr [0] = 0;
				OS.gtk_tree_model_get (tree_model, iter, modelIndex + CELL_BACKGROUND, ptr, -1);
				if (ptr [0] != 0) {
					OS.g_object_set (cell, OS.cell_background_gdk, ptr[0], 0);
				}
			}
		}
		if (!isPixbuf) {
			ptr [0] = 0;
			OS.gtk_tree_model_get (tree_model, iter, modelIndex + CELL_FOREGROUND, ptr, -1);
			if (ptr [0] != 0) {
				OS.g_object_set (cell, OS.foreground_gdk, ptr[0], 0);
			}
			ptr [0] = 0;
			OS.gtk_tree_model_get (tree_model, iter, modelIndex + CELL_FONT, ptr, -1);
			if (ptr [0] != 0) {
				OS.g_object_set (cell, OS.font_desc, ptr[0], 0);
			}
		}
	}
	if (setData) {
		ignoreCell = cell;
		setScrollWidth (tree_column, item);
		ignoreCell = 0;
	}
	return 0;
}

boolean checkData (TreeItem item) {
	if (item.cached) return true;
	if ((style & SWT.VIRTUAL) != 0) {
		item.cached = true;
		TreeItem parentItem = item.getParentItem ();
		Event event = new Event ();
		event.item = item;
		event.index = parentItem == null ? indexOf (item) : parentItem.indexOf (item);
		int mask = OS.G_SIGNAL_MATCH_DATA | OS.G_SIGNAL_MATCH_ID;
		int signal_id = OS.g_signal_lookup (OS.row_changed, OS.gtk_tree_model_get_type ());
		OS.g_signal_handlers_block_matched (modelHandle, mask, signal_id, 0, 0, 0, handle);
		currentItem = item;
		sendEvent (SWT.SetData, event);
		currentItem = null;
		//widget could be disposed at this point
		if (isDisposed ()) return false;
		OS.g_signal_handlers_unblock_matched (modelHandle, mask, signal_id, 0, 0, 0, handle);
		if (item.isDisposed ()) return false;
	}
	return true;
}

protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the user changes the receiver's selection, by sending
 * it one of the messages defined in the <code>SelectionListener</code>
 * interface.
 * <p>
 * When <code>widgetSelected</code> is called, the item field of the event object is valid.
 * If the receiver has the <code>SWT.CHECK</code> style and the check selection changes,
 * the event object detail field contains the value <code>SWT.CHECK</code>.
 * <code>widgetDefaultSelected</code> is typically called when an item is double-clicked.
 * The item field of the event object is valid for default selection, but the detail field is not used.
 * </p>
 *
 * @param listener the listener which should be notified when the user changes the receiver's selection
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Selection, typedListener);
	addListener (SWT.DefaultSelection, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when an item in the receiver is expanded or collapsed
 * by sending it one of the messages defined in the <code>TreeListener</code>
 * interface.
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see TreeListener
 * @see #removeTreeListener
 */
public void addTreeListener(TreeListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Expand, typedListener);
	addListener (SWT.Collapse, typedListener);
}

int calculateWidth (int /*long*/ column, int /*long*/ iter) {
	OS.gtk_tree_view_column_cell_set_cell_data (column, modelHandle, iter, false, false);
	/*
	* Bug in GTK.  The width calculated by gtk_tree_view_column_cell_get_size()
	* always grows in size regardless of the text or images in the table.
	* The fix is to determine the column width from the cell renderers.
	*/
	// Code intentionally commented
	//int [] width = new int [1];
	//OS.gtk_tree_view_column_cell_get_size (column, null, null, null, width, null);
	//return width [0];
	
	int width = 0;
	int [] w = new int [1];
	if (OS.gtk_tree_view_get_expander_column (handle) == column) {		
		OS.gtk_widget_style_get (handle, OS.expander_size, w, 0);
		width += w [0] + TreeItem.EXPANDER_EXTRA_PADDING;
	}
	OS.gtk_widget_style_get(handle, OS.focus_line_width, w, 0);
	width += 2 * w [0];
	int /*long*/ list = OS.gtk_tree_view_column_get_cell_renderers (column);
	if (list == 0) return 0;
	int /*long*/ temp = list;
	while (temp != 0) {
		int /*long*/ renderer = OS.g_list_data (temp);
		if (renderer != 0) {
			OS.gtk_cell_renderer_get_size (renderer, handle, null, null, null, w, null);
			width += w [0];
		}
		temp = OS.g_list_next (temp);
	}
	OS.g_list_free (list);
	return width;
}

/**
 * Clears the item at the given zero-relative index in the receiver.
 * The text, icon and other attributes of the item are set to the default
 * value.  If the tree was created with the <code>SWT.VIRTUAL</code> style,
 * these attributes are requested again as needed.
 *
 * @param index the index of the item to clear
 * @param all <code>true</code> if all child items of the indexed item should be
 * cleared recursively, and <code>false</code> otherwise
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see SWT#VIRTUAL
 * @see SWT#SetData
 * 
 * @since 3.2
 */
public void clear(int index, boolean all) {
	checkWidget ();
	clear (0, index, all);
}

void clear (int /*long*/ parentIter, int index, boolean all) {
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	OS.gtk_tree_model_iter_nth_child(modelHandle, iter, parentIter, index);
	int[] value = new int[1];
	OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, value, -1);
	if (value [0] != -1) {
		TreeItem item = items [value [0]];
		item.clear ();
	}
	if (all) clearAll (all, iter);
	OS.g_free (iter);
}

/**
 * Clears all the items in the receiver. The text, icon and other
 * attributes of the items are set to their default values. If the
 * tree was created with the <code>SWT.VIRTUAL</code> style, these
 * attributes are requested again as needed.
 * 
 * @param all <code>true</code> if all child items should be cleared
 * recursively, and <code>false</code> otherwise
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see SWT#VIRTUAL
 * @see SWT#SetData
 * 
 * @since 3.2
 */
public void clearAll (boolean all) {
	checkWidget ();
	clearAll (all, 0);
}
void clearAll (boolean all, int /*long*/ parentIter) {
	int length = OS.gtk_tree_model_iter_n_children (modelHandle, parentIter);
	if (length == 0) return;
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	boolean valid = OS.gtk_tree_model_iter_children (modelHandle, iter, parentIter);
	int[] value = new int[1];
	while (valid) {
		OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, value, -1);
		if (value [0] != -1) {
			TreeItem item = items [value [0]];
			item.clear ();
		}
		if (all) clearAll (all, iter);
		valid = OS.gtk_tree_model_iter_next (modelHandle, iter);
	}
	OS.g_free (iter);
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	if (wHint != SWT.DEFAULT && wHint < 0) wHint = 0;
	if (hHint != SWT.DEFAULT && hHint < 0) hHint = 0;
	Point size = computeNativeSize (handle, wHint, hHint, changed);
	Rectangle trim = computeTrim (0, 0, size.x, size.y);
	size.x = trim.width;
	size.y = trim.height;
	return size;
}

void copyModel (int /*long*/ oldModel, int oldStart, int /*long*/ newModel, int newStart, int /*long*/ [] types, int /*long*/ oldParent, int /*long*/ newParent, int modelLength) {
	int /*long*/ iter = OS.g_malloc(OS.GtkTreeIter_sizeof ());
	if (OS.gtk_tree_model_iter_children (oldModel, iter, oldParent))  {
		int /*long*/ [] oldItems = new int /*long*/ [OS.gtk_tree_model_iter_n_children (oldModel, oldParent)];
		int oldIndex = 0;
		do {
			int /*long*/ newItem = OS.g_malloc (OS.GtkTreeIter_sizeof ());
			if (newItem == 0) error (SWT.ERROR_NO_HANDLES);	
			OS.gtk_tree_store_append (newModel, newItem, newParent);
			int [] index = new int [1];
			OS.gtk_tree_model_get (oldModel, iter, ID_COLUMN, index, -1);
			TreeItem item = null;
			if (index [0] != -1) {
				item = items [index [0]];
				if (item != null) {
					int /*long*/ oldItem = item.handle;
					oldItems[oldIndex++] = oldItem;
					int /*long*/ [] ptr = new int /*long*/ [1];
					for (int j = 0; j < FIRST_COLUMN; j++) {
						OS.gtk_tree_model_get (oldModel, oldItem, j, ptr, -1);
						OS.gtk_tree_store_set (newModel, newItem, j, ptr [0], -1);
						if (types [j] == OS.G_TYPE_STRING ()) OS.g_free ((ptr [0]));
					}
					for (int j= 0; j<modelLength - FIRST_COLUMN; j++) {
						OS.gtk_tree_model_get (oldModel, oldItem, oldStart + j, ptr, -1);
						OS.gtk_tree_store_set (newModel, newItem, newStart + j, ptr [0], -1);
						if (types [j] == OS.G_TYPE_STRING ()) OS.g_free ((ptr [0]));
					}
				}
			} else {
				OS.gtk_tree_store_set (newModel, newItem, ID_COLUMN, -1, -1);
			}
			// recurse through children
			copyModel(oldModel, oldStart, newModel, newStart, types, iter, newItem, modelLength);
			
			if (item!= null) {
				item.handle = newItem;
			} else {
				OS.g_free (newItem);
			}
		} while (OS.gtk_tree_model_iter_next(oldModel, iter));
		for (int i = 0; i < oldItems.length; i++) {
			int /*long*/ oldItem = oldItems [i];
			if (oldItem != 0) {
				OS.gtk_tree_store_remove (oldModel, oldItem);
				OS.g_free (oldItem);
			}
		}
	}
	OS.g_free (iter);
}

void createColumn (TreeColumn column, int index) {
/*
* Bug in ATK. For some reason, ATK segments fault if 
* the GtkTreeView has a column and does not have items.
* The fix is to insert the column only when an item is 
* created.
*/
	
	int modelIndex = FIRST_COLUMN;
	if (columnCount != 0) {
		int modelLength = OS.gtk_tree_model_get_n_columns (modelHandle);
		boolean [] usedColumns = new boolean [modelLength];
		for (int i=0; i<columnCount; i++) {
			int columnIndex = columns [i].modelIndex;
			for (int j = 0; j < CELL_TYPES; j++) {
				usedColumns [columnIndex + j] = true;
			}
		}
		while (modelIndex < modelLength) {
			if (!usedColumns [modelIndex]) break;
			modelIndex++;
		}
		if (modelIndex == modelLength) {
			int /*long*/ oldModel = modelHandle;
			int /*long*/[] types = getColumnTypes (columnCount + 4); // grow by 4 rows at a time
			int /*long*/ newModel = OS.gtk_tree_store_newv (types.length, types);
			if (newModel == 0) error (SWT.ERROR_NO_HANDLES);
			copyModel (oldModel, FIRST_COLUMN, newModel, FIRST_COLUMN, types, (int /*long*/)0, (int /*long*/)0, modelLength);
			OS.gtk_tree_view_set_model (handle, newModel);
			OS.g_object_unref (oldModel);
			modelHandle = newModel;
		}
	}
	int /*long*/ columnHandle = OS.gtk_tree_view_column_new ();
	if (columnHandle == 0) error (SWT.ERROR_NO_HANDLES);
	if (index == 0 && columnCount > 0) {
		TreeColumn checkColumn = columns [0];
		createRenderers (checkColumn.handle, checkColumn.modelIndex, false, checkColumn.style);
	}
	createRenderers (columnHandle, modelIndex, index == 0, column == null ? 0 : column.style);
	/*
	* Use GTK_TREE_VIEW_COLUMN_GROW_ONLY on GTK versions < 2.3.2
	* because fixed_height_mode is not supported.
	*/
	boolean useVirtual = (style & SWT.VIRTUAL) != 0 && OS.GTK_VERSION >= OS.VERSION (2, 3, 2);
	if (!useVirtual && columnCount == 0) {
		OS.gtk_tree_view_column_set_sizing (columnHandle, OS.GTK_TREE_VIEW_COLUMN_GROW_ONLY);
	} else {
		OS.gtk_tree_view_column_set_sizing (columnHandle, OS.GTK_TREE_VIEW_COLUMN_FIXED);
		if (columnCount != 0) OS.gtk_tree_view_column_set_visible (columnHandle, false);
	}
	OS.gtk_tree_view_column_set_resizable (columnHandle, true);
	OS.gtk_tree_view_column_set_clickable (columnHandle, true);
	OS.gtk_tree_view_column_set_min_width (columnHandle, 0);
	OS.gtk_tree_view_insert_column (handle, columnHandle, index);
	if (column != null) {
		column.handle = columnHandle;
		column.modelIndex = modelIndex;
	}
	/* Disable searching when using VIRTUAL */
	if ((style & SWT.VIRTUAL) != 0) {
		/*
		* Bug in GTK. Until GTK 2.6.5, calling gtk_tree_view_set_enable_search(FALSE)
		* would prevent the user from being able to type in text to search the tree.
		* After 2.6.5, GTK introduced Ctrl+F as being the key binding for interactive
		* search. This meant that even if FALSE was passed to enable_search, the user
		* can still bring up the search pop up using the keybinding. GTK also introduced
		* the notion of passing a -1 to gtk_set_search_column to disable searching
		* (including the search key binding).  The fix is to use the right calls
		* for the right version.
		*/
		if (OS.GTK_VERSION >= OS.VERSION (2, 6, 5)) {
			OS.gtk_tree_view_set_search_column (handle, -1); 
		} else {
			OS.gtk_tree_view_set_enable_search (handle, false);
		}
	} else {
		/* Set the search column whenever the model changes */
		int firstColumn = columnCount == 0 ? FIRST_COLUMN : columns [0].modelIndex;
		OS.gtk_tree_view_set_search_column (handle, firstColumn + CELL_TEXT);
	}
}

void createHandle (int index) {
	state |= HANDLE;
	fixedHandle = OS.g_object_new (display.gtk_fixed_get_type (), 0);
	if (fixedHandle == 0) error (SWT.ERROR_NO_HANDLES);
	OS.gtk_fixed_set_has_window (fixedHandle, true);
	scrolledHandle = OS.gtk_scrolled_window_new (0, 0);
	if (scrolledHandle == 0) error (SWT.ERROR_NO_HANDLES);
	int /*long*/ [] types = getColumnTypes (1);
	modelHandle = OS.gtk_tree_store_newv (types.length, types);
	if (modelHandle == 0) error (SWT.ERROR_NO_HANDLES);
	handle = OS.gtk_tree_view_new_with_model (modelHandle);
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
	if ((style & SWT.CHECK) != 0) {
		checkRenderer = OS.gtk_cell_renderer_toggle_new ();
		if (checkRenderer == 0) error (SWT.ERROR_NO_HANDLES);
		OS.g_object_ref (checkRenderer);
	}
	createColumn (null, 0);
	OS.gtk_container_add (fixedHandle, scrolledHandle);
	OS.gtk_container_add (scrolledHandle, handle);

	int mode = (style & SWT.MULTI) != 0 ? OS.GTK_SELECTION_MULTIPLE : OS.GTK_SELECTION_BROWSE;
	int /*long*/ selectionHandle = OS.gtk_tree_view_get_selection (handle);
	OS.gtk_tree_selection_set_mode (selectionHandle, mode);
	OS.gtk_tree_view_set_headers_visible (handle, false);	
	int hsp = (style & SWT.H_SCROLL) != 0 ? OS.GTK_POLICY_AUTOMATIC : OS.GTK_POLICY_NEVER;
	int vsp = (style & SWT.V_SCROLL) != 0 ? OS.GTK_POLICY_AUTOMATIC : OS.GTK_POLICY_NEVER;
	OS.gtk_scrolled_window_set_policy (scrolledHandle, hsp, vsp);
	if ((style & SWT.BORDER) != 0) OS.gtk_scrolled_window_set_shadow_type (scrolledHandle, OS.GTK_SHADOW_ETCHED_IN);
	/* Disable searching when using VIRTUAL */
	if ((style & SWT.VIRTUAL) != 0) {
		/* The fixed_height_mode property only exists in GTK 2.3.2 and greater */
		if (OS.GTK_VERSION >= OS.VERSION (2, 3, 2)) {
			OS.g_object_set (handle, OS.fixed_height_mode, true, 0);
		}
		/*
		* Bug in GTK. Until GTK 2.6.5, calling gtk_tree_view_set_enable_search(FALSE)
		* would prevent the user from being able to type in text to search the tree.
		* After 2.6.5, GTK introduced Ctrl+F as being the key binding for interactive
		* search. This meant that even if FALSE was passed to enable_search, the user
		* can still bring up the search pop up using the keybinding. GTK also introduced
		* the notion of passing a -1 to gtk_set_search_column to disable searching
		* (including the search key binding).  The fix is to use the right calls
		* for the right version.
		*/
		if (OS.GTK_VERSION >= OS.VERSION (2, 6, 5)) {
			OS.gtk_tree_view_set_search_column (handle, -1); 
		} else {
			OS.gtk_tree_view_set_enable_search (handle, false);
		};
	}
}

void createItem (TreeColumn column, int index) {
	if (!(0 <= index && index <= columnCount)) error (SWT.ERROR_INVALID_RANGE);
	if (index == 0) {
		// first column must be left aligned
		column.style &= ~(SWT.LEFT | SWT.RIGHT | SWT.CENTER);
		column.style |= SWT.LEFT;
	}
	if (columnCount == 0) {
		column.handle = OS.gtk_tree_view_get_column (handle, 0);
		OS.gtk_tree_view_column_set_sizing (column.handle, OS.GTK_TREE_VIEW_COLUMN_FIXED);
		OS.gtk_tree_view_column_set_visible (column.handle, false);
		column.modelIndex = FIRST_COLUMN;
		createRenderers (column.handle, column.modelIndex, true, column.style);
		column.customDraw = firstCustomDraw;
		firstCustomDraw = false;
	} else {
		createColumn (column, index);
	}
	int /*long*/ boxHandle = OS.gtk_hbox_new (false, 3);
	if (boxHandle == 0) error (SWT.ERROR_NO_HANDLES);
	int /*long*/ labelHandle = OS.gtk_label_new_with_mnemonic (null);
	if (labelHandle == 0) error (SWT.ERROR_NO_HANDLES);
	int /*long*/ imageHandle = OS.gtk_image_new ();
	if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
	OS.gtk_container_add (boxHandle, imageHandle);
	OS.gtk_container_add (boxHandle, labelHandle);
	OS.gtk_widget_show (boxHandle);
	OS.gtk_widget_show (labelHandle);
	column.labelHandle = labelHandle;
	column.imageHandle = imageHandle;	
	OS.gtk_tree_view_column_set_widget (column.handle, boxHandle);
	int /*long*/ widget = OS.gtk_widget_get_parent (boxHandle);
	while (widget != handle) {
		if (OS.GTK_IS_BUTTON (widget)) {
			column.buttonHandle = widget;
			break;
		}
		widget = OS.gtk_widget_get_parent (widget);
	}
	if (columnCount == columns.length) {
		TreeColumn [] newColumns = new TreeColumn [columns.length + 4];
		System.arraycopy (columns, 0, newColumns, 0, columns.length);
		columns = newColumns;
	}
	System.arraycopy (columns, index, columns, index + 1, columnCount++ - index);
	columns [index] = column;
	if ((state & FONT) != 0) {
		column.setFontDescription (getFontDescription ());
	}
	if (columnCount >= 1) {
		for (int i=0; i<items.length; i++) {
			TreeItem item = items [i];
			if (item != null) {
				Font [] cellFont = item.cellFont;
				if (cellFont != null) {
					Font [] temp = new Font [columnCount];
					System.arraycopy (cellFont, 0, temp, 0, index);
					System.arraycopy (cellFont, index, temp, index+1, columnCount-index-1);
					item.cellFont = temp;
				}
			}
		}
	}
}

void createItem (TreeItem item, int /*long*/ parentIter, int index) {
	int count = OS.gtk_tree_model_iter_n_children (modelHandle, parentIter);
	if (index == -1) index = count;
	if (!(0 <= index && index <= count)) error (SWT.ERROR_INVALID_RANGE);
	item.handle = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	if (item.handle == 0) error(SWT.ERROR_NO_HANDLES);
	/*
	* Feature in GTK.  It is much faster to append to a tree store
	* than to insert at the end using gtk_tree_store_insert(). 
	*/
	if (index == count) {
		OS.gtk_tree_store_append (modelHandle, item.handle, parentIter);
	} else {
		OS.gtk_tree_store_insert (modelHandle, item.handle, parentIter, index);
	}
	int id = getId (item.handle, false);
	items [id] = item;
	modelChanged = true;
}

void createRenderers (int /*long*/ columnHandle, int modelIndex, boolean check, int columnStyle) {
	OS.gtk_tree_view_column_clear (columnHandle);
	if ((style & SWT.CHECK) != 0 && check) {
		OS.gtk_tree_view_column_pack_start (columnHandle, checkRenderer, false);
		OS.gtk_tree_view_column_add_attribute (columnHandle, checkRenderer, OS.active, CHECKED_COLUMN);
		/*
		* Feature in GTK. The inconsistent property only exists in GTK 2.2.x.
		*/
		if (OS.GTK_VERSION >= OS.VERSION (2, 2, 0)) {
			OS.gtk_tree_view_column_add_attribute (columnHandle, checkRenderer, OS.inconsistent, GRAYED_COLUMN);
		}
		/*
		* Bug in GTK. GTK renders the background on top of the checkbox.
		* This only happens in version 2.2.1 and earlier. The fix is not to set the background.   
		*/
		if (OS.GTK_VERSION > OS.VERSION (2, 2, 1)) {
			if (!ownerDraw) OS.gtk_tree_view_column_add_attribute (columnHandle, checkRenderer, OS.cell_background_gdk, BACKGROUND_COLUMN);
		}
		if (ownerDraw) {
			OS.gtk_tree_view_column_set_cell_data_func (columnHandle, checkRenderer, display.cellDataProc, handle, 0);
			OS.g_object_set_qdata (checkRenderer, Display.SWT_OBJECT_INDEX1, columnHandle);
		}
	}
	int /*long*/ pixbufRenderer = ownerDraw ? OS.g_object_new (display.gtk_cell_renderer_pixbuf_get_type (), 0) : OS.gtk_cell_renderer_pixbuf_new ();
	if (pixbufRenderer == 0) error (SWT.ERROR_NO_HANDLES);
	int /*long*/ textRenderer = ownerDraw ? OS.g_object_new (display.gtk_cell_renderer_text_get_type (), 0) : OS.gtk_cell_renderer_text_new ();
	if (textRenderer == 0) error (SWT.ERROR_NO_HANDLES);
	
	if (ownerDraw) {
		OS.g_object_set_qdata (pixbufRenderer, Display.SWT_OBJECT_INDEX1, columnHandle);
		OS.g_object_set_qdata (textRenderer, Display.SWT_OBJECT_INDEX1, columnHandle);
	}

	/*
	* Feature in GTK.  When a tree view column contains only one activatable
	* cell renderer such as a toggle renderer, mouse clicks anywhere in a cell
	* activate that renderer. The workaround is to set a second  cell renderer
	* to be activatable.
	*/
	if ((style & SWT.CHECK) != 0 && check) {
		OS.g_object_set (pixbufRenderer, OS.mode, OS.GTK_CELL_RENDERER_MODE_ACTIVATABLE, 0);
	}

	/* Set alignment */
	if ((columnStyle & SWT.RIGHT) != 0) {
		OS.g_object_set(textRenderer, OS.xalign, 1f, 0);
		OS.gtk_tree_view_column_pack_end (columnHandle, textRenderer, true);
		OS.gtk_tree_view_column_pack_end (columnHandle, pixbufRenderer, false);
		OS.gtk_tree_view_column_set_alignment (columnHandle, 1f);
	} else if ((columnStyle & SWT.CENTER) != 0) {
		OS.g_object_set(textRenderer, OS.xalign, 0.5f, 0);
		OS.gtk_tree_view_column_pack_start (columnHandle, pixbufRenderer, false);
		OS.gtk_tree_view_column_pack_end (columnHandle, textRenderer, true);
		OS.gtk_tree_view_column_set_alignment (columnHandle, 0.5f);
	} else {
		OS.gtk_tree_view_column_pack_start (columnHandle, pixbufRenderer, false);
		OS.gtk_tree_view_column_pack_start (columnHandle, textRenderer, true);
		OS.gtk_tree_view_column_set_alignment (columnHandle, 0f);
	}

	/* Add attributes */
	OS.gtk_tree_view_column_add_attribute (columnHandle, pixbufRenderer, OS.pixbuf, modelIndex + CELL_PIXBUF);
	/*
	 * Bug on GTK. Gtk renders the background on top of the pixbuf.
	 * This only happens in version 2.2.1 and earlier. The fix is not to set the background.   
	 */
	if (OS.GTK_VERSION > OS.VERSION (2, 2, 1)) {
		if (!ownerDraw) {
			OS.gtk_tree_view_column_add_attribute (columnHandle, pixbufRenderer, OS.cell_background_gdk, BACKGROUND_COLUMN);
			OS.gtk_tree_view_column_add_attribute (columnHandle, textRenderer, OS.cell_background_gdk, BACKGROUND_COLUMN);
		}
	}
	OS.gtk_tree_view_column_add_attribute (columnHandle, textRenderer, OS.text, modelIndex + CELL_TEXT);
	OS.gtk_tree_view_column_add_attribute (columnHandle, textRenderer, OS.foreground_gdk, FOREGROUND_COLUMN);
	OS.gtk_tree_view_column_add_attribute (columnHandle, textRenderer, OS.font_desc, FONT_COLUMN);
	
	boolean customDraw = firstCustomDraw;
	if (columnCount != 0) {
		for (int i=0; i<columnCount; i++) {
			if (columns [i].handle == columnHandle) {
				customDraw = columns [i].customDraw;
				break;
			}
		}
	}
	if ((style & SWT.VIRTUAL) != 0 || customDraw || ownerDraw) {
		OS.gtk_tree_view_column_set_cell_data_func (columnHandle, textRenderer, display.cellDataProc, handle, 0);
		OS.gtk_tree_view_column_set_cell_data_func (columnHandle, pixbufRenderer, display.cellDataProc, handle, 0);
	}
}

void createWidget (int index) {
	super.createWidget (index);
	items = new TreeItem [4];
	columns = new TreeColumn [4];
	columnCount = 0;
}

GdkColor defaultBackground () {
	return display.COLOR_LIST_BACKGROUND;
}

GdkColor defaultForeground () {
	return display.COLOR_LIST_FOREGROUND;
}

void deregister () {
	super.deregister ();
	display.removeWidget (OS.gtk_tree_view_get_selection (handle));
	if (checkRenderer != 0) display.removeWidget (checkRenderer);
}

/**
 * Deselects all selected items in the receiver.
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void deselectAll() {
	checkWidget();
	boolean fixColumn = showFirstColumn ();
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	OS.gtk_tree_selection_unselect_all (selection);
	OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	if (fixColumn) hideFirstColumn ();
}

void destroyItem (TreeColumn column) {
	int index = 0;
	while (index < columnCount) {
		if (columns [index] == column) break;
		index++;
	}
	if (index == columnCount) return;
	int /*long*/ columnHandle = column.handle;
	if (columnCount == 1) {
		firstCustomDraw = column.customDraw;
	}
	System.arraycopy (columns, index + 1, columns, index, --columnCount - index);
	columns [columnCount] = null;
	OS.gtk_tree_view_remove_column (handle, columnHandle);
	if (columnCount == 0) {
		int /*long*/ oldModel = modelHandle;
		int /*long*/[] types = getColumnTypes (1);
		int /*long*/ newModel = OS.gtk_tree_store_newv (types.length, types);
		if (newModel == 0) error (SWT.ERROR_NO_HANDLES);
		copyModel(oldModel, column.modelIndex, newModel, FIRST_COLUMN, types, (int /*long*/)0, (int /*long*/)0, FIRST_COLUMN + CELL_TYPES);
		OS.gtk_tree_view_set_model (handle, newModel);
		OS.g_object_unref (oldModel);
		modelHandle = newModel;
		createColumn (null, 0);
		
	} else {
		for (int i=0; i<items.length; i++) {
			TreeItem item = items [i];
			if (item != null) {
				int /*long*/ iter = item.handle;
				int modelIndex = column.modelIndex;
				OS.gtk_tree_store_set (modelHandle, iter, modelIndex + CELL_PIXBUF, 0, -1);
				OS.gtk_tree_store_set (modelHandle, iter, modelIndex + CELL_TEXT, 0, -1);
				OS.gtk_tree_store_set (modelHandle, iter, modelIndex + CELL_FOREGROUND, 0, -1);
				OS.gtk_tree_store_set (modelHandle, iter, modelIndex + CELL_BACKGROUND, 0, -1);
				OS.gtk_tree_store_set (modelHandle, iter, modelIndex + CELL_FONT, 0, -1);
				
				Font [] cellFont = item.cellFont;
				if (cellFont != null) {
					if (columnCount == 0) {
						item.cellFont = null;
					} else {
						Font [] temp = new Font [columnCount];
						System.arraycopy (cellFont, 0, temp, 0, index);
						System.arraycopy (cellFont, index + 1, temp, index, columnCount - index);
						item.cellFont = temp;
					}
				}
			}
		}
		if (index == 0) {
			// first column must be left aligned and must show check box
			TreeColumn firstColumn = columns [0];
			firstColumn.style &= ~(SWT.LEFT | SWT.RIGHT | SWT.CENTER);
			firstColumn.style |= SWT.LEFT;
			createRenderers (firstColumn.handle, firstColumn.modelIndex, true, firstColumn.style);
		}
	}
	/* Disable searching when using VIRTUAL */
	if ((style & SWT.VIRTUAL) != 0) {
		/*
		* Bug in GTK. Until GTK 2.6.5, calling gtk_tree_view_set_enable_search(FALSE)
		* would prevent the user from being able to type in text to search the tree.
		* After 2.6.5, GTK introduced Ctrl+F as being the key binding for interactive
		* search. This meant that even if FALSE was passed to enable_search, the user
		* can still bring up the search pop up using the keybinding. GTK also introduced
		* the notion of passing a -1 to gtk_set_search_column to disable searching
		* (including the search key binding).  The fix is to use the right calls
		* for the right version.
		*/
		if (OS.GTK_VERSION >= OS.VERSION (2, 6, 5)) {
			OS.gtk_tree_view_set_search_column (handle, -1); 
		} else {
			OS.gtk_tree_view_set_enable_search (handle, false);
		}
	} else {
		/* Set the search column whenever the model changes */
		int firstColumn = columnCount == 0 ? FIRST_COLUMN : columns [0].modelIndex;
		OS.gtk_tree_view_set_search_column (handle, firstColumn + CELL_TEXT);
	}
}


void destroyItem (TreeItem item) {
	/*
	* Bug in GTK.  GTK segment faults when a root tree item
	* is destroyed when the tree is expanded and the last leaf of
	* the root is selected.  This only happens in versions earlier
	* than 2.0.6.  The fix is to collapse the tree item being destroyed
	* when it is a root, before it is destroyed.
	*/
	if (OS.GTK_VERSION < OS.VERSION (2, 0, 6)) {
		int length = OS.gtk_tree_model_iter_n_children (modelHandle, 0);
		if (length > 0) {
			int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
			boolean valid = OS.gtk_tree_model_iter_children (modelHandle, iter, 0);
			while (valid) {
				if (item.handle == iter) {
					item.setExpanded (false);
					break;
				}
				valid = OS.gtk_tree_model_iter_next (modelHandle, iter);
			}
			OS.g_free (iter);
		}
	}
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	OS.gtk_tree_store_remove (modelHandle, item.handle);
	OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	modelChanged = true;
}

boolean dragDetect (int x, int y, boolean filter, boolean [] consume) {
	boolean selected = false;
	if (filter) {
		int /*long*/ [] path = new int /*long*/ [1];
		if (OS.gtk_tree_view_get_path_at_pos (handle, x, y, path, null, null, null)) {
			if (path [0] != 0) {
				int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
				if (OS.gtk_tree_selection_path_is_selected (selection, path [0])) selected = true;
				OS.gtk_tree_path_free (path [0]);
			}
		} else {
			return false;
		}
	}
	boolean dragDetect = super.dragDetect (x, y, filter, consume);
	if (dragDetect && selected && consume != null) consume [0] = true;
	return dragDetect;
}

int /*long*/ eventWindow () {
	return paintWindow ();
}

void fixChildren (Shell newShell, Shell oldShell, Decorations newDecorations, Decorations oldDecorations, Menu [] menus) {
	super.fixChildren (newShell, oldShell, newDecorations, oldDecorations, menus);
	for (int i=0; i<columnCount; i++) {
		TreeColumn column = columns [i];
		if (column.toolTipText != null) {
			column.setToolTipText(oldShell, null);
			column.setToolTipText(newShell, column.toolTipText);
		}
	}
}

GdkColor getBackgroundColor () {
	return getBaseColor ();
}

public Rectangle getClientArea () {
	checkWidget ();
	forceResize ();
	OS.gtk_widget_realize (handle);
	int /*long*/ fixedWindow = OS.GTK_WIDGET_WINDOW (fixedHandle);
	int /*long*/ binWindow = OS.gtk_tree_view_get_bin_window (handle);
	int [] binX = new int [1], binY = new int [1];
	OS.gdk_window_get_origin (binWindow, binX, binY);
	int [] fixedX = new int [1], fixedY = new int [1];
	OS.gdk_window_get_origin (fixedWindow, fixedX, fixedY);
	int /*long*/ clientHandle = clientHandle ();
	int width = (state & ZERO_WIDTH) != 0 ? 0 : OS.GTK_WIDGET_WIDTH (clientHandle);
	int height = (state & ZERO_HEIGHT) != 0 ? 0 : OS.GTK_WIDGET_HEIGHT (clientHandle);
	return new Rectangle (fixedX [0] - binX [0], fixedY [0] - binY [0], width, height);
}

/**
 * Returns the column at the given, zero-relative index in the
 * receiver. Throws an exception if the index is out of range.
 * Columns are returned in the order that they were created.
 * If no <code>TreeColumn</code>s were created by the programmer,
 * this method will throw <code>ERROR_INVALID_RANGE</code> despite
 * the fact that a single column of data may be visible in the tree.
 * This occurs when the programmer uses the tree like a list, adding
 * items but never creating a column.
 *
 * @param index the index of the column to return
 * @return the column at the given index
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see Tree#getColumnOrder()
 * @see Tree#setColumnOrder(int[])
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(boolean)
 * @see SWT#Move
 * 
 * @since 3.1
 */
public TreeColumn getColumn (int index) {
	checkWidget();
	if (!(0 <= index && index < columnCount)) error (SWT.ERROR_INVALID_RANGE);
	return columns [index];
}

/**
 * Returns the number of columns contained in the receiver.
 * If no <code>TreeColumn</code>s were created by the programmer,
 * this value is zero, despite the fact that visually, one column
 * of items may be visible. This occurs when the programmer uses
 * the tree like a list, adding items but never creating a column.
 *
 * @return the number of columns
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public int getColumnCount () {
	checkWidget();
	return columnCount;
}

/**
 * Returns an array of zero-relative integers that map
 * the creation order of the receiver's items to the
 * order in which they are currently being displayed.
 * <p>
 * Specifically, the indices of the returned array represent
 * the current visual order of the items, and the contents
 * of the array represent the creation order of the items.
 * </p><p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver. 
 * </p>
 *
 * @return the current visual order of the receiver's items
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see Tree#setColumnOrder(int[])
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(boolean)
 * @see SWT#Move
 * 
 * @since 3.2
 */
public int [] getColumnOrder () {
	checkWidget ();
	if (columnCount == 0) return new int [0];
	int /*long*/ list = OS.gtk_tree_view_get_columns (handle);
	if (list == 0) return new int [0];
	int  i = 0, count = OS.g_list_length (list);
	int [] order = new int [count];
	int /*long*/ temp = list;
	while (temp != 0) {
		int /*long*/ column = OS.g_list_data (temp);
		if (column != 0) {
			for (int j=0; j<columnCount; j++) {
				if (columns [j].handle == column) {
					order [i++] = j;
					break;
				}
			}
		}
		temp = OS.g_list_next (temp);
	}
	OS.g_list_free (list);
	return order;
}

int /*long*/[] getColumnTypes (int columnCount) {
	int /*long*/[] types = new int /*long*/ [FIRST_COLUMN + (columnCount * CELL_TYPES)];
	// per row data
	types [ID_COLUMN] = OS.G_TYPE_INT ();
	types [CHECKED_COLUMN] = OS.G_TYPE_BOOLEAN (); 
	types [GRAYED_COLUMN] = OS.G_TYPE_BOOLEAN ();
	types [FOREGROUND_COLUMN] = OS.GDK_TYPE_COLOR ();
	types [BACKGROUND_COLUMN] = OS.GDK_TYPE_COLOR ();
	types [FONT_COLUMN] = OS.PANGO_TYPE_FONT_DESCRIPTION ();
	// per cell data
	for (int i=FIRST_COLUMN; i<types.length; i+=CELL_TYPES) {
		types [i + CELL_PIXBUF] = OS.GDK_TYPE_PIXBUF ();
		types [i + CELL_TEXT] = OS.G_TYPE_STRING ();
		types [i + CELL_FOREGROUND] = OS.GDK_TYPE_COLOR ();
		types [i + CELL_BACKGROUND] = OS.GDK_TYPE_COLOR ();
		types [i + CELL_FONT] = OS.PANGO_TYPE_FONT_DESCRIPTION ();
	}
	return types;
}

/**
 * Returns an array of <code>TreeColumn</code>s which are the
 * columns in the receiver. Columns are returned in the order
 * that they were created.  If no <code>TreeColumn</code>s were
 * created by the programmer, the array is empty, despite the fact
 * that visually, one column of items may be visible. This occurs
 * when the programmer uses the tree like a list, adding items but
 * never creating a column.
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver. 
 * </p>
 *
 * @return the items in the receiver
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see Tree#getColumnOrder()
 * @see Tree#setColumnOrder(int[])
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(boolean)
 * @see SWT#Move
 * 
 * @since 3.1
 */
public TreeColumn [] getColumns () {
	checkWidget();
	TreeColumn [] result = new TreeColumn [columnCount];
	System.arraycopy (columns, 0, result, 0, columnCount);
	return result;
}

TreeItem getFocusItem () {
	int /*long*/ [] path = new int /*long*/ [1];
	OS.gtk_tree_view_get_cursor (handle, path, null);
	if (path [0] == 0) return null;
	TreeItem item = null;
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	if (OS.gtk_tree_model_get_iter (modelHandle, iter, path [0])) {
		int [] index = new int [1];
		OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
		if (index [0] != -1) item = items [index [0]]; //TODO should we be creating this item when index is -1?
	}
	OS.g_free (iter);
	OS.gtk_tree_path_free (path [0]);
	return item;	
} 

GdkColor getForegroundColor () {
	return getTextColor ();
}

/**
 * Returns the width in pixels of a grid line.
 *
 * @return the width of a grid line in pixels
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public int getGridLineWidth () {
	checkWidget();
	return 0;
}

/**
 * Returns the height of the receiver's header 
 *
 * @return the height of the header or zero if the header is not visible
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1 
 */
public int getHeaderHeight () {
	checkWidget ();
	if (!OS.gtk_tree_view_get_headers_visible (handle)) return 0;
	if (columnCount > 0) {
		GtkRequisition requisition = new GtkRequisition ();
		int height = 0;
		for (int i=0; i<columnCount; i++) {
			int /*long*/ buttonHandle = columns [i].buttonHandle;
			if (buttonHandle != 0) {
				OS.gtk_widget_size_request (buttonHandle, requisition);
				height = Math.max (height, requisition.height);
			}
		}
		return height;
	}
	OS.gtk_widget_realize (handle);
	int /*long*/ fixedWindow = OS.GTK_WIDGET_WINDOW (fixedHandle);
	int /*long*/ binWindow = OS.gtk_tree_view_get_bin_window (handle);
	int [] binY = new int [1];
	OS.gdk_window_get_origin (binWindow, null, binY);
	int [] fixedY = new int [1];
	OS.gdk_window_get_origin (fixedWindow, null, fixedY);
	return binY [0] - fixedY [0];
}

/**
 * Returns <code>true</code> if the receiver's header is visible,
 * and <code>false</code> otherwise.
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, this method
 * may still indicate that it is considered visible even though
 * it may not actually be showing.
 * </p>
 *
 * @return the receiver's header's visibility state
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public boolean getHeaderVisible () {
	checkWidget();
	return OS.gtk_tree_view_get_headers_visible (handle);
}

/**
 * Returns the item at the given, zero-relative index in the
 * receiver. Throws an exception if the index is out of range.
 *
 * @param index the index of the item to return
 * @return the item at the given index
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public TreeItem getItem (int index) {
	checkWidget();
	if (!(0 <= index && index < OS.gtk_tree_model_iter_n_children (modelHandle, 0)))  {
		error (SWT.ERROR_INVALID_RANGE);
	}
	return _getItem (0, index);
}

/**
 * Returns the item at the given point in the receiver
 * or null if no such item exists. The point is in the
 * coordinate system of the receiver.
 * <p>
 * The item that is returned represents an item that could be selected by the user.
 * For example, if selection only occurs in items in the first column, then null is 
 * returned if the point is outside of the item. 
 * Note that the SWT.FULL_SELECTION style hint, which specifies the selection policy,
 * determines the extent of the selection.
 * </p>
 *
 * @param point the point used to locate the item
 * @return the item at the given point, or null if the point is not in a selectable item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public TreeItem getItem (Point point) {
	checkWidget ();
	if (point == null) error (SWT.ERROR_NULL_ARGUMENT);
	int /*long*/ [] path = new int /*long*/ [1];
	OS.gtk_widget_realize (handle);
	int /*long*/ [] columnHandle = new int /*long*/ [1];
	if (!OS.gtk_tree_view_get_path_at_pos (handle, point.x, point.y, path, columnHandle, null, null)) return null;
	if (path [0] == 0) return null;
	TreeItem item = null;
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	if (OS.gtk_tree_model_get_iter (modelHandle, iter, path [0])) {
		boolean overExpander = false;
		if (OS.gtk_tree_view_get_expander_column (handle) == columnHandle [0]) {
			int [] buffer = new int [1];
			GdkRectangle rect = new GdkRectangle ();
			OS.gtk_tree_view_get_cell_area (handle, path [0], columnHandle [0], rect);
			if (OS.GTK_VERSION < OS.VERSION (2, 8, 18)) {
				OS.gtk_widget_style_get (handle, OS.expander_size, buffer, 0);
				int expanderSize = buffer [0] + TreeItem.EXPANDER_EXTRA_PADDING;
				overExpander = point.x < rect.x + expanderSize;
			} else {
				overExpander = point.x < rect.x;
			}
		}
		if (!overExpander) {
			item = _getItem (iter);
		}
	}
	OS.g_free (iter);
	OS.gtk_tree_path_free (path [0]);
	return item;
}

/**
 * Returns the number of items contained in the receiver
 * that are direct item children of the receiver.  The
 * number that is returned is the number of roots in the
 * tree.
 *
 * @return the number of items
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getItemCount () {
	checkWidget ();
	return OS.gtk_tree_model_iter_n_children (modelHandle, 0);
}

/**
 * Returns the height of the area which would be used to
 * display <em>one</em> of the items in the tree.
 *
 * @return the height of one item
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getItemHeight () {
	checkWidget ();
	int itemCount = OS.gtk_tree_model_iter_n_children (modelHandle, 0);
	if (itemCount == 0) {
		int /*long*/ column = OS.gtk_tree_view_get_column (handle, 0);
		int [] w = new int [1], h = new int [1];
		ignoreSize = true;
		OS.gtk_tree_view_column_cell_get_size (column, null, null, null, w, h);
		ignoreSize = false;
		return h [0];
	} else {
		int height = 0;
		int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
		OS.gtk_tree_model_get_iter_first (modelHandle, iter);
		int columnCount = Math.max (1, this.columnCount);
		for (int i=0; i<columnCount; i++) {
			int /*long*/ column = OS.gtk_tree_view_get_column (handle, i);
			OS.gtk_tree_view_column_cell_set_cell_data (column, modelHandle, iter, false, false);
			int [] w = new int [1], h = new int [1];
			OS.gtk_tree_view_column_cell_get_size (column, null, null, null, w, h);
			height = Math.max (height, h [0]);
		}
		OS.g_free (iter);
		return height;
	}
}

/**
 * Returns a (possibly empty) array of items contained in the
 * receiver that are direct item children of the receiver.  These
 * are the roots of the tree.
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver. 
 * </p>
 *
 * @return the items
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public TreeItem [] getItems () {
	checkWidget();
	return getItems (0);
}

TreeItem [] getItems (int /*long*/ parent) {
	int length = OS.gtk_tree_model_iter_n_children (modelHandle, parent);
	TreeItem[] result = new TreeItem [length];
	if (length == 0) return result;
	if ((style & SWT.VIRTUAL) != 0) {
		for (int i=0; i<length; i++) {
			result [i] = _getItem (parent, i);
		}
	} else {
		int i = 0;
		int[] index = new int [1];
		int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
		boolean valid = OS.gtk_tree_model_iter_children (modelHandle, iter, parent);
		while (valid) {
			OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
			result [i++] = items [index [0]];
			valid = OS.gtk_tree_model_iter_next (modelHandle, iter);
		}
		OS.g_free (iter);
	}
	return result;
}

/**
 * Returns <code>true</code> if the receiver's lines are visible,
 * and <code>false</code> otherwise.
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, this method
 * may still indicate that it is considered visible even though
 * it may not actually be showing.
 * </p>
 *
 * @return the visibility state of the lines
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public boolean getLinesVisible() {
	checkWidget();
	return OS.gtk_tree_view_get_rules_hint (handle);
}

/**
 * Returns the receiver's parent item, which must be a
 * <code>TreeItem</code> or null when the receiver is a
 * root.
 *
 * @return the receiver's parent item
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public TreeItem getParentItem () {
	checkWidget ();
	return null;
}

int /*long*/ getPixbufRenderer (int /*long*/ column) {
	int /*long*/ list = OS.gtk_tree_view_column_get_cell_renderers (column);
	if (list == 0) return 0;
	int count = OS.g_list_length (list);
	int /*long*/ pixbufRenderer = 0;
	int i = 0;
	while (i < count) {
		int /*long*/ renderer = OS.g_list_nth_data (list, i);
		 if (OS.GTK_IS_CELL_RENDERER_PIXBUF (renderer)) {
			pixbufRenderer = renderer;
			break;
		}
		i++;
	}
	OS.g_list_free (list);
	return pixbufRenderer;
}

/**
 * Returns an array of <code>TreeItem</code>s that are currently
 * selected in the receiver. The order of the items is unspecified.
 * An empty array indicates that no items are selected. 
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its selection, so modifying the array will
 * not affect the receiver. 
 * </p>
 * @return an array representing the selection
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public TreeItem[] getSelection () {
	checkWidget();
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	if (OS.GTK_VERSION < OS.VERSION (2, 2, 0)) {
		display.treeSelectionLength  = 0;
		display.treeSelection = new int [items.length];
		OS.gtk_tree_selection_selected_foreach (selection, display.treeSelectionProc, handle);
		TreeItem [] result = new TreeItem [display.treeSelectionLength];
		for (int i=0; i<result.length; i++) result [i] = items [display.treeSelection [i]];
		return result;
	}
	/*
	* Bug in GTK.  gtk_tree_selection_get_selected_rows() segmentation faults
	* in versions smaller than 2.2.4 if the model is NULL.  The fix is
	* to give a valid pointer instead.
	*/
	int /*long*/ [] model = OS.GTK_VERSION < OS.VERSION (2, 2, 4) ? new int /*long*/ [1] : null;
	int /*long*/ list = OS.gtk_tree_selection_get_selected_rows (selection, model);
	if (list != 0) {
		int count = OS.g_list_length (list);
		TreeItem [] treeSelection = new TreeItem [count];
		int length = 0;
		for (int i=0; i<count; i++) {
			int /*long*/ data = OS.g_list_nth_data (list, i);
			int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
			if (OS.gtk_tree_model_get_iter (modelHandle, iter, data)) {
				treeSelection [length] = _getItem (iter);
				length++;
			}
			OS.g_free (iter);
		}
		OS.g_list_free (list);
		if (length < count) {
			TreeItem [] temp = new TreeItem [length];
			System.arraycopy(treeSelection, 0, temp, 0, length);
			treeSelection = temp;
		}
		return treeSelection;
	}
	return new TreeItem [0];
}
	
/**
 * Returns the number of selected items contained in the receiver.
 *
 * @return the number of selected items
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getSelectionCount () {
	checkWidget();
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	if (OS.GTK_VERSION < OS.VERSION (2, 2, 0)) {
		display.treeSelectionLength = 0;
		display.treeSelection = null;
		OS.gtk_tree_selection_selected_foreach (selection, display.treeSelectionProc, handle);
		return display.treeSelectionLength;
	}
	return OS.gtk_tree_selection_count_selected_rows (selection);
}

/**
 * Returns the column which shows the sort indicator for
 * the receiver. The value may be null if no column shows
 * the sort indicator.
 *
 * @return the sort indicator 
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see #setSortColumn(TreeColumn)
 * 
 * @since 3.2
 */
public TreeColumn getSortColumn () {
	checkWidget ();
	return sortColumn;
}

/**
 * Returns the direction of the sort indicator for the receiver. 
 * The value will be one of <code>UP</code>, <code>DOWN</code> 
 * or <code>NONE</code>.
 *
 * @return the sort direction
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @see #setSortDirection(int)
 * 
 * @since 3.2
 */
public int getSortDirection () {
	checkWidget ();
	return sortDirection;
}

int /*long*/ getTextRenderer (int /*long*/ column) {
	int /*long*/ list = OS.gtk_tree_view_column_get_cell_renderers (column);
	if (list == 0) return 0;
	int count = OS.g_list_length (list);
	int /*long*/ textRenderer = 0;
	int i = 0;
	while (i < count) {
		int /*long*/ renderer = OS.g_list_nth_data (list, i);
		 if (OS.GTK_IS_CELL_RENDERER_TEXT (renderer)) {
			textRenderer = renderer;
			break;
		}
		i++;
	}
	OS.g_list_free (list);
	return textRenderer;
}

/**
 * Returns the item which is currently at the top of the receiver.
 * This item can change when items are expanded, collapsed, scrolled
 * or new items are added or removed.
 *
 * @return the item at the top of the receiver 
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 2.1
 */
public TreeItem getTopItem () {
	checkWidget ();
	int /*long*/ [] path = new int /*long*/ [1];
	OS.gtk_widget_realize (handle);
	if (!OS.gtk_tree_view_get_path_at_pos (handle, 1, 1, path, null, null, null)) return null;
	if (path [0] == 0) return null;
	TreeItem item = null;
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof());
	if (OS.gtk_tree_model_get_iter (modelHandle, iter, path [0])) {
		item = _getItem (iter);
	}
	OS.g_free (iter);
	OS.gtk_tree_path_free (path [0]);
	return item;
}

int /*long*/ gtk_button_press_event (int /*long*/ widget, int /*long*/ event) {
	GdkEventButton gdkEvent = new GdkEventButton ();
	OS.memmove (gdkEvent, event, GdkEventButton.sizeof);
	if (gdkEvent.window != OS.gtk_tree_view_get_bin_window (handle)) return 0;
	int /*long*/ result = super.gtk_button_press_event (widget, event);
	if (result != 0) return result;
	/*
	* Feature in GTK.  In a multi-select tree view, when multiple items are already
	* selected, the selection state of the item is toggled and the previous selection 
	* is cleared. This is not the desired behaviour when bringing up a popup menu.
	* Also, when an item is reselected with the right button, the tree view issues
	* an unwanted selection event. The workaround is to detect that case and not
	* run the default handler when the item is already part of the current selection.
	*/
	int button = gdkEvent.button;
	if (button == 3 && gdkEvent.type == OS.GDK_BUTTON_PRESS) {
		int /*long*/ [] path = new int /*long*/ [1];
		if (OS.gtk_tree_view_get_path_at_pos (handle, (int)gdkEvent.x, (int)gdkEvent.y, path, null, null, null)) {
			if (path [0] != 0) {
				int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
				if (OS.gtk_tree_selection_path_is_selected (selection, path [0])) result = 1;
				OS.gtk_tree_path_free (path [0]);
			}
		}
	}
	
	/*
	* Feature in GTK.  When the user clicks in a single selection GtkTreeView
	* and there are no selected items, the first item is selected automatically
	* before the click is processed, causing two selection events.  The is fix
	* is the set the cursor item to be same as the clicked item to stop the
	* widget from automatically selecting the first item.
	*/
	if ((style & SWT.SINGLE) != 0 && getSelectionCount () == 0) {
		int /*long*/ [] path = new int /*long*/ [1];
		if (OS.gtk_tree_view_get_path_at_pos (handle, (int)gdkEvent.x, (int)gdkEvent.y, path, null, null, null)) {
			if (path [0] != 0) {
				int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
				OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
				OS.gtk_tree_view_set_cursor (handle, path [0], 0, false);
				OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
				OS.gtk_tree_path_free (path [0]);
			}
		}
	}
	/*
	* Bug in GTK. GTK segments fault, if the GtkTreeView widget is
	* not in focus and all items in the widget are disposed before
	* it finishes processing a button press.  The fix is to give
	* focus to the widget before it starts processing the event.
	*/
	if (!OS.GTK_WIDGET_HAS_FOCUS (handle)) {
		OS.gtk_widget_grab_focus (handle);
	}
	return result;
}

int /*long*/ gtk_button_release_event (int /*long*/ widget, int /*long*/ event) {
	int /*long*/ window = OS.GDK_EVENT_WINDOW (event);
	if (window != OS.gtk_tree_view_get_bin_window (handle)) return 0;
	return super.gtk_button_release_event (widget, event);
}

int /*long*/ gtk_changed (int /*long*/ widget) {
	TreeItem item = getFocusItem ();
	if (item != null) {
		Event event = new Event ();
		event.item = item;
		postEvent (SWT.Selection, event);
	}
	return 0;
}

int /*long*/ gtk_expand_collapse_cursor_row (int /*long*/ widget, int /*long*/ logical, int /*long*/ expand, int /*long*/ open_all) {
	// FIXME - this flag is never cleared.  It should be cleared when the expand all operation completes.
	if (expand != 0 && open_all != 0) expandAll = true;
	return 0;
}

int /*long*/ gtk_key_press_event (int /*long*/ widget, int /*long*/ eventPtr) {
	int /*long*/ result = super.gtk_key_press_event (widget, eventPtr);
	if (result != 0) return result;
	if (OS.GTK_VERSION < OS.VERSION (2, 2 ,0)) {
		/*
		* Feature in GTK 2.0.x.  When an item is default selected using
		* the return key, GTK does not issue notification. The fix is
		* to issue this notification when the return key is pressed.
		*/
		GdkEventKey keyEvent = new GdkEventKey ();
		OS.memmove (keyEvent, eventPtr, GdkEventKey.sizeof);
		int key = keyEvent.keyval;
		switch (key) {
			case OS.GDK_Return:
			case OS.GDK_KP_Enter: {
				Event event = new Event ();
				event.item = getFocusItem (); 
				postEvent (SWT.DefaultSelection, event);
				break;
			}
		}
	}
	return result;
}

int /*long*/ gtk_motion_notify_event (int /*long*/ widget, int /*long*/ event) {
	int /*long*/ window = OS.GDK_EVENT_WINDOW (event);
	if (window != OS.gtk_tree_view_get_bin_window (handle)) return 0;
	return super.gtk_motion_notify_event (widget, event);
}

int /*long*/ gtk_popup_menu (int /*long*/ widget) {
	int /*long*/ result = super.gtk_popup_menu (widget);
	/*
	* Bug in GTK.  The context menu for the typeahead in GtkTreeViewer
	* opens in the bottom right corner of the screen when Shift+F10
	* is pressed and the typeahead window was not visible.  The fix is
	* to prevent the context menu from opening by stopping the default
	* handler.
	* 
	* NOTE: The bug only happens in GTK 2.6.5 and lower.
	*/
	return OS.GTK_VERSION < OS.VERSION (2, 6, 5) ? 1 : result;
}

int /*long*/ gtk_row_activated (int /*long*/ tree, int /*long*/ path, int /*long*/ column) {
	if (path == 0) return 0;
	TreeItem item = null;
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	if (OS.gtk_tree_model_get_iter (modelHandle, iter, path)) {
		int [] index = new int [1];
		OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
		item = items [index [0]];
	}
	OS.g_free (iter);
	Event event = new Event ();
	event.item = item;
	postEvent (SWT.DefaultSelection, event);
	return 0;
}

int /*long*/ gtk_test_collapse_row (int /*long*/ tree, int /*long*/ iter, int /*long*/ path) {
	int [] index = new int [1];
	OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
	TreeItem item = items [index [0]];
	Event event = new Event ();
	event.item = item;
	boolean oldModelChanged = modelChanged;
	modelChanged = false;
	sendEvent (SWT.Collapse, event);
	/*
	* Bug in GTK.  Collapsing the target row during the test_collapse_row
	* handler will cause a segmentation fault if the animation code is allowed
	* to run.  The fix is to block the animation if the row is already
	* collapsed.
	*/
	boolean changed = modelChanged || !OS.gtk_tree_view_row_expanded (handle, path);
	modelChanged = oldModelChanged;
	if (isDisposed () || item.isDisposed ()) return 1;
	/*
	* Bug in GTK.  Expanding or collapsing a row which has no more
	* children causes the model state to become invalid, causing
	* GTK to give warnings and behave strangely.  Other changes to
	* the model can cause expansion to fail when using the multiple
	* expansion keys (such as *).  The fix is to stop the expansion
	* if there are model changes.
	* 
	* Note: This callback must return 0 for the collapsing
	* animation to occur.
	*/
	if (changed) {
		OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, TEST_COLLAPSE_ROW);
		OS.gtk_tree_view_collapse_row (handle, path);
		OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, TEST_COLLAPSE_ROW);
		return 1;
	}
	return 0;
}

int /*long*/ gtk_test_expand_row (int /*long*/ tree, int /*long*/ iter, int /*long*/ path) {
	int [] index = new int [1];
	OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
	TreeItem item = items [index [0]];
	Event event = new Event ();
	event.item = item;
	boolean oldModelChanged = modelChanged;
	modelChanged = false;
	sendEvent (SWT.Expand, event);
	/*
	* Bug in GTK.  Expanding the target row during the test_expand_row
	* handler will cause a segmentation fault if the animation code is allowed
	* to run.  The fix is to block the animation if the row is already
	* expanded.
	*/
	boolean changed = modelChanged || OS.gtk_tree_view_row_expanded (handle, path);
	modelChanged = oldModelChanged;
	if (isDisposed () || item.isDisposed ()) return 1;
	/*
	* Bug in GTK.  Expanding or collapsing a row which has no more
	* children causes the model state to become invalid, causing
	* GTK to give warnings and behave strangely.  Other changes to
	* the model can cause expansion to fail when using the multiple
	* expansion keys (such as *).  The fix is to stop the expansion
	* if there are model changes.
	* 
	* Bug in GTK.  test-expand-row does not get called for each row
	* in an expand all operation.  The fix is to block the initial
	* expansion and only expand a single level.
	* 
	* Note: This callback must return 0 for the collapsing
	* animation to occur.
	*/
	if (changed || expandAll) {
		OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, TEST_EXPAND_ROW);
		OS.gtk_tree_view_expand_row (handle, path, false);
		OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, TEST_EXPAND_ROW);
		return 1;
	}
	return 0;
}

int /*long*/ gtk_toggled (int /*long*/ renderer, int /*long*/ pathStr) {
	int /*long*/ path = OS.gtk_tree_path_new_from_string (pathStr);
	if (path == 0) return 0;
	TreeItem item = null;
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof());
	if (OS.gtk_tree_model_get_iter (modelHandle, iter, path)) {
		item = _getItem (iter);
	}
	OS.g_free (iter);
	OS.gtk_tree_path_free (path);
	if (item != null) {
		item.setChecked (!item.getChecked ());
		Event event = new Event ();
		event.detail = SWT.CHECK;
		event.item = item;
		postEvent (SWT.Selection, event);
	}
	return 0;
}

void gtk_widget_size_request (int /*long*/ widget, GtkRequisition requisition) {
	/*
	 * Bug in GTK.  For some reason, gtk_widget_size_request() fails
	 * to include the height of the tree view items when there are
	 * no columns visible.  The fix is to temporarily make one column
	 * visible. 
	 */
	if (columnCount == 0) {
		super.gtk_widget_size_request (widget, requisition);
		return;
	}
	int /*long*/ columns = OS.gtk_tree_view_get_columns (handle), list = columns;
	boolean fixVisible = columns != 0;
	while (list != 0) {
		int /*long*/ column = OS.g_list_data (list);
		if (OS.gtk_tree_view_column_get_visible (column)) {
			fixVisible = false;
			break;
		}
		list = OS.g_list_next (list);
	}
	int /*long*/ columnHandle = 0;
	if (fixVisible) {
		columnHandle = OS.g_list_data (columns);
		OS.gtk_tree_view_column_set_visible (columnHandle, true);
	}
	super.gtk_widget_size_request (widget, requisition);
	if (fixVisible) {
		OS.gtk_tree_view_column_set_visible (columnHandle, false);
	}
	if (columns != 0) OS.g_list_free (columns);
}

void hideFirstColumn () {
	int /*long*/ firstColumn = OS.gtk_tree_view_get_column (handle, 0);
	OS.gtk_tree_view_column_set_visible (firstColumn, false);	
}
	
void hookEvents () {
	super.hookEvents ();
	int /*long*/ selection = OS.gtk_tree_view_get_selection(handle);
	OS.g_signal_connect_closure (selection, OS.changed, display.closures [CHANGED], false);
	OS.g_signal_connect_closure (handle, OS.row_activated, display.closures [ROW_ACTIVATED], false);
	OS.g_signal_connect_closure (handle, OS.test_expand_row, display.closures [TEST_EXPAND_ROW], false);
	OS.g_signal_connect_closure (handle, OS.test_collapse_row, display.closures [TEST_COLLAPSE_ROW], false);
	OS.g_signal_connect_closure (handle, OS.expand_collapse_cursor_row, display.closures [EXPAND_COLLAPSE_CURSOR_ROW], false);
	if (checkRenderer != 0) {
		OS.g_signal_connect_closure (checkRenderer, OS.toggled, display.closures [TOGGLED], false);
	}
}

/**
 * Searches the receiver's list starting at the first column
 * (index 0) until a column is found that is equal to the 
 * argument, and returns the index of that column. If no column
 * is found, returns -1.
 *
 * @param column the search column
 * @return the index of the column
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the column is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public int indexOf (TreeColumn column) {
	checkWidget();
	if (column == null) error (SWT.ERROR_NULL_ARGUMENT);
	for (int i=0; i<columnCount; i++) {
		if (columns [i] == column) return i;
	}
	return -1;
}

/**
 * Searches the receiver's list starting at the first item
 * (index 0) until an item is found that is equal to the 
 * argument, and returns the index of that item. If no item
 * is found, returns -1.
 *
 * @param item the search item
 * @return the index of the item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public int indexOf (TreeItem item) {
	checkWidget();
	if (item == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (item.isDisposed()) error (SWT.ERROR_INVALID_ARGUMENT);
	int index = -1;
	int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, item.handle);
	int depth = OS.gtk_tree_path_get_depth (path);
	if (depth == 1) {
		int /*long*/ indices = OS.gtk_tree_path_get_indices (path);
		if (indices != 0) {	
			int[] temp = new int[1];
			OS.memmove (temp, indices, 4);
			index = temp[0];
		}
	}
	OS.gtk_tree_path_free (path);
	return index;
}

boolean mnemonicHit (char key) {
	for (int i=0; i<columnCount; i++) {
		int /*long*/ labelHandle = columns [i].labelHandle;
		if (labelHandle != 0 && mnemonicHit (labelHandle, key)) return true;
	}
	return false;
}

boolean mnemonicMatch (char key) {
	for (int i=0; i<columnCount; i++) {
		int /*long*/ labelHandle = columns [i].labelHandle;
		if (labelHandle != 0 && mnemonicMatch (labelHandle, key)) return true;
	}
	return false;
}

int /*long*/ paintWindow () {
	OS.gtk_widget_realize (handle);
	return OS.gtk_tree_view_get_bin_window (handle);
}

void recreateRenderers () {
	if (checkRenderer != 0) {
		display.removeWidget (checkRenderer);
		OS.g_object_unref (checkRenderer);
		checkRenderer = ownerDraw ? OS.g_object_new (display.gtk_cell_renderer_toggle_get_type(), 0) : OS.gtk_cell_renderer_toggle_new ();
		if (checkRenderer == 0) error (SWT.ERROR_NO_HANDLES);
		OS.g_object_ref (checkRenderer);
		display.addWidget (checkRenderer, this);
		OS.g_signal_connect_closure (checkRenderer, OS.toggled, display.closures [TOGGLED], false);
	}
	if (columnCount == 0) {
		createRenderers (OS.gtk_tree_view_get_column (handle, 0), Tree.FIRST_COLUMN, true, 0);
	} else {
		for (int i = 0; i < columnCount; i++) {
			TreeColumn column = columns [i];
			createRenderers (column.handle, column.modelIndex, i == 0, column.style);
		}
	}
}

void redrawBackgroundImage () {
	Control control = findBackgroundControl ();
	if (control != null && control.backgroundImage != null) {
		redrawWidget (0, 0, 0, 0, true, false, false);
	}
}

void register () {
	super.register ();
	display.addWidget (OS.gtk_tree_view_get_selection (handle), this);
	if (checkRenderer != 0) display.addWidget (checkRenderer, this);
}

void releaseItem (TreeItem item, boolean release) {
	int [] index = new int [1];
	OS.gtk_tree_model_get (modelHandle, item.handle, ID_COLUMN, index, -1);
	if (index [0] == -1) return;
	if (release) item.release (false);
	items [index [0]] = null;
}

void releaseItems (int /*long*/ parentIter) {
	int[] index = new int [1];
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	boolean valid = OS.gtk_tree_model_iter_children (modelHandle, iter, parentIter);
	while (valid) {
		releaseItems (iter);
		if (!isDisposed ()) {
			OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
			if (index [0] != -1) {
				TreeItem item = items [index [0]];
				if (item != null) releaseItem (item, true);
			}
		}
		valid = OS.gtk_tree_model_iter_next (modelHandle, iter);
	}
	OS.g_free (iter);
}

void releaseChildren (boolean destroy) {
	if (items != null) {
		for (int i=0; i<items.length; i++) {
			TreeItem item = items [i];
			if (item != null && !item.isDisposed ()) {
				item.release (false);
			}
		}
		items = null;
	}
	if (columns != null) {
		for (int i=0; i<columnCount; i++) {
			TreeColumn column = columns [i];
			if (column != null && !column.isDisposed ()) {
				column.release (false);
			}
		}
		columns = null;
	}
	super.releaseChildren (destroy);
}

void releaseWidget () {
	super.releaseWidget ();
	if (modelHandle != 0) OS.g_object_unref (modelHandle);
	modelHandle = 0;
	if (checkRenderer != 0) OS.g_object_unref (checkRenderer);
	checkRenderer = 0;
	if (imageList != null) imageList.dispose ();
	if (headerImageList != null) headerImageList.dispose ();
	imageList = headerImageList = null;
	currentItem = null;
}

void remove (int /*long*/ parentIter, int start, int end) {
	if (start > end) return;
	int itemCount = OS.gtk_tree_model_iter_n_children (modelHandle, parentIter);
	if (!(0 <= start && start <= end && end < itemCount)) {
		error (SWT.ERROR_INVALID_RANGE);
	}
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
	int index = start;
	for (int i = start; i <= end; i++) {
		OS.gtk_tree_model_iter_nth_child (modelHandle, iter, parentIter, index);
		int[] value = new int[1];
		OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, value, -1);
		TreeItem item = value [0] != -1 ? items [value [0]] : null;
		if (item != null && !item.isDisposed ()) {
			item.dispose ();
		} else {
			OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
			OS.gtk_tree_store_remove (modelHandle, iter);
			OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
		}
	}
	OS.g_free (iter);
}

/**
 * Removes all of the items from the receiver.
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void removeAll () {
	checkWidget ();
	for (int i=0; i<items.length; i++) {
		TreeItem item = items [i];
		if (item != null && !item.isDisposed ()) item.release (false);
	}
	items = new TreeItem[4];
	/*
	* Bug in GTK.  In version 2.3.2, when the property fixed-height-mode
	* is set and there are items in the list, OS.gtk_tree_store_clear()
	* segment faults.  The fix is to create a new empty model instead.
	*/
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	/*
	* Bug in GTK.  In version 2.8, when gtk_tree_view_set_model() is called, GTK
	* does not remove the timer used to show animation when expanding a node. This
	* can cause two possible crashes. The first one happens when the timer expires and
	* it accesses the expanding node which has been already destroyed. The second one
	* happens if a new item is created and destroyed before the timer expires. The fix 
	* is to remove the timer by disposing the first item in the tree.  
	*/
	if (OS.GTK_VERSION < OS.VERSION(2, 10, 0)) {
		if (OS.gtk_tree_model_iter_n_children (modelHandle, 0) != 0) {
			int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
			OS.gtk_tree_model_iter_nth_child (modelHandle, iter, 0, 0);
			OS.gtk_tree_store_remove (modelHandle, iter);
			OS.g_free (iter);
		}
	}
	// TODO verify if true for tree store
	//OS.gtk_tree_store_clear (modelHandle);
	int /*long*/ oldModel = modelHandle;
	int /*long*/[] types = getColumnTypes (Math.max (1,columnCount));
	int /*long*/ newModel = OS.gtk_tree_store_newv (types.length, types);
	if (newModel == 0) error (SWT.ERROR_NO_HANDLES);
	OS.gtk_tree_view_set_model (handle, newModel);
	OS.g_object_unref (oldModel);
	modelHandle = newModel;
	OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	
	/* Disable searching when using VIRTUAL */
	if ((style & SWT.VIRTUAL) != 0) {
		/*
		* Bug in GTK. Until GTK 2.6.5, calling gtk_tree_view_set_enable_search(FALSE)
		* would prevent the user from being able to type in text to search the tree.
		* After 2.6.5, GTK introduced Ctrl+F as being the key binding for interactive
		* search. This meant that even if FALSE was passed to enable_search, the user
		* can still bring up the search pop up using the keybinding. GTK also introduced
		* the notion of passing a -1 to gtk_set_search_column to disable searching
		* (including the search key binding).  The fix is to use the right calls
		* for the right version.
		*/
		if (OS.GTK_VERSION >= OS.VERSION (2, 6, 5)) {
			OS.gtk_tree_view_set_search_column (handle, -1); 
		} else {
			OS.gtk_tree_view_set_enable_search (handle, false);
		}
	} else {
		/* Set the search column whenever the model changes */
		int firstColumn = columnCount == 0 ? FIRST_COLUMN : columns [0].modelIndex;
		OS.gtk_tree_view_set_search_column (handle, firstColumn + CELL_TEXT);
	}
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the user changes the receiver's selection.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SelectionListener
 * @see #addSelectionListener
 */
public void removeSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection, listener);	
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when items in the receiver are expanded or collapsed.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see TreeListener
 * @see #addTreeListener
 */
public void removeTreeListener(TreeListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Expand, listener);
	eventTable.unhook (SWT.Collapse, listener);
}

int /*long*/ rendererGetSizeProc (int /*long*/ cell, int /*long*/ widget, int /*long*/ cell_area, int /*long*/ x_offset, int /*long*/ y_offset, int /*long*/ width, int /*long*/ height) {
	int /*long*/ g_class = OS.g_type_class_peek_parent (OS.G_OBJECT_GET_CLASS (cell));
	GtkCellRendererClass klass = new GtkCellRendererClass ();
	OS.memmove (klass, g_class);
	int /*long*/ result = OS.call (klass.get_size, cell, handle, cell_area, x_offset, y_offset, width, height);
	if (!ignoreSize && OS.GTK_IS_CELL_RENDERER_TEXT (cell)) {
		int /*long*/ iter = OS.g_object_get_qdata (cell, Display.SWT_OBJECT_INDEX2);
		TreeItem item = null;
		if (iter != 0) item = _getItem (iter);
		if (item != null) {
			int columnIndex = 0;
			if (columnCount > 0) {
				int /*long*/ columnHandle = OS.g_object_get_qdata (cell, Display.SWT_OBJECT_INDEX1);
				for (int i = 0; i < columnCount; i++) {
					if (columns [i].handle == columnHandle) {
						columnIndex = i;
						break;
					}				
				}
			}
			if (hooks (SWT.MeasureItem)) {
				int [] contentWidth = new int [1], contentHeight = new int  [1];
				if (width != 0) OS.memmove (contentWidth, width, 4);
				if (height != 0) OS.memmove (contentHeight, height, 4);
				Image image = item.getImage (columnIndex);
				int imageWidth = 0;
				if (image != null) {
					Rectangle bounds = image.getBounds ();
					imageWidth = bounds.width;
				}
				contentWidth [0] += imageWidth;
				GC gc = new GC (this);
				gc.setFont (item.getFont (columnIndex));
				Event event = new Event ();
				event.item = item;
				event.index = columnIndex;
				event.gc = gc;
				event.width = contentWidth [0];
				event.height = contentHeight [0];
				sendEvent (SWT.MeasureItem, event);
				gc.dispose ();
				contentWidth [0] = event.width - imageWidth;
				contentHeight [0] = event.height;
				if (width != 0) OS.memmove (width, contentWidth, 4);
				if (height != 0) OS.memmove (height, contentHeight, 4);
			}
		}
	}
	return result;
}

int /*long*/ rendererRenderProc (int /*long*/ cell, int /*long*/ window, int /*long*/ widget, int /*long*/ background_area, int /*long*/ cell_area, int /*long*/ expose_area, int /*long*/ flags) {
	TreeItem item = null;
	int /*long*/ iter = OS.g_object_get_qdata (cell, Display.SWT_OBJECT_INDEX2);
	if (iter != 0) item = _getItem (iter);
	int /*long*/ columnHandle = OS.g_object_get_qdata (cell, Display.SWT_OBJECT_INDEX1);
	int columnIndex = 0;
	if (columnCount > 0) {
		for (int i = 0; i < columnCount; i++) {
			if (columns [i].handle == columnHandle) {
				columnIndex = i;
				break;
			}				
		}
	}
	if (item != null) {
		if (OS.GTK_IS_CELL_RENDERER_TOGGLE (cell) || (OS.GTK_IS_CELL_RENDERER_PIXBUF (cell) && (columnIndex != 0 || (style & SWT.CHECK) == 0))) {
			drawFlags = (int)/*64*/flags;
			drawState = SWT.FOREGROUND;
			int /*long*/ [] ptr = new int /*long*/ [1];
			OS.gtk_tree_model_get (modelHandle, item.handle, Tree.BACKGROUND_COLUMN, ptr, -1);
			if (ptr [0] == 0) {
				int modelIndex = columnCount == 0 ? Tree.FIRST_COLUMN : columns [columnIndex].modelIndex;
				OS.gtk_tree_model_get (modelHandle, item.handle, modelIndex + Tree.CELL_BACKGROUND, ptr, -1);
			}
			if (ptr [0] != 0) drawState |= SWT.BACKGROUND;
			if ((flags & OS.GTK_CELL_RENDERER_SELECTED) != 0) drawState |= SWT.SELECTED;
			if ((flags & OS.GTK_CELL_RENDERER_FOCUSED) != 0) drawState |= SWT.FOCUSED;			
			
			GdkRectangle rect = new GdkRectangle ();
			int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, iter);
			OS.gtk_tree_view_get_background_area (handle, path, columnHandle, rect);
			OS.gtk_tree_path_free (path);
			
			if ((drawState & SWT.SELECTED) == 0) {
				Control control = findBackgroundControl ();
				if (control != null && control.backgroundImage != null) {
					OS.gdk_window_clear_area (window, rect.x, rect.y, rect.width, rect.height);
				}
			}

			if (hooks (SWT.EraseItem)) {
				boolean wasSelected = false; 
				if ((drawState & SWT.SELECTED) != 0) {
					wasSelected = true;
					OS.gdk_window_clear_area (window, rect.x, rect.y, rect.width, rect.height);
				}
				GC gc = new GC (this);
				if ((drawState & SWT.SELECTED) != 0) {
					gc.setBackground (display.getSystemColor (SWT.COLOR_LIST_SELECTION));
					gc.setForeground (display.getSystemColor (SWT.COLOR_LIST_SELECTION_TEXT));
				} else {
					gc.setBackground (item.getBackground (columnIndex));
					gc.setForeground (item.getForeground (columnIndex));
				}
				gc.setFont (item.getFont (columnIndex));
				gc.setClipping (rect.x, rect.y, rect.width, rect.height);
				Event event = new Event ();
				event.item = item;
				event.index = columnIndex;
				event.gc = gc;
				event.x = rect.x;
				event.y = rect.y;
				event.width = rect.width;
				event.height = rect.height;
				event.detail = drawState;
				sendEvent (SWT.EraseItem, event);
				drawForeground = null;
				drawState = event.doit ? event.detail : 0;
				drawFlags &= ~(OS.GTK_CELL_RENDERER_FOCUSED | OS.GTK_CELL_RENDERER_SELECTED);
				if ((drawState & SWT.SELECTED) != 0) drawFlags |= OS.GTK_CELL_RENDERER_SELECTED;
				if ((drawState & SWT.FOCUSED) != 0) drawFlags |= OS.GTK_CELL_RENDERER_FOCUSED;
				if ((drawState & SWT.SELECTED) != 0) {
					int /*long*/ style = OS.gtk_widget_get_style (widget);					
					//TODO - parity and sorted
					byte[] detail = Converter.wcsToMbcs (null, "cell_odd", true);
					OS.gtk_paint_flat_box (style, window, OS.GTK_STATE_SELECTED, OS.GTK_SHADOW_NONE, rect, widget, detail, rect.x, rect.y, rect.width, rect.height);
				} else {
					if (wasSelected) drawForeground = gc.getForeground ().handle;
				}
				gc.dispose();
			}
		}
	}
	int /*long*/ result = 0;
	if ((drawState & SWT.BACKGROUND) != 0 && (drawState & SWT.SELECTED) == 0) {
		GC gc = new GC (this);
		gc.setBackground (item.getBackground (columnIndex));
		GdkRectangle rect = new GdkRectangle ();
		OS.memmove (rect, background_area, GdkRectangle.sizeof);
		gc.fillRectangle (rect.x, rect.y, rect.width, rect.height);
		gc.dispose ();
	}
	if ((drawState & SWT.FOREGROUND) != 0 || OS.GTK_IS_CELL_RENDERER_TOGGLE (cell)) {
		int /*long*/ g_class = OS.g_type_class_peek_parent (OS.G_OBJECT_GET_CLASS (cell));
		GtkCellRendererClass klass = new GtkCellRendererClass ();
		OS.memmove (klass, g_class);
		if (drawForeground != null && OS.GTK_IS_CELL_RENDERER_TEXT (cell)) {
			OS.g_object_set (cell, OS.foreground_gdk, drawForeground, 0);
		}
		result = OS.call (klass.render, cell, window, handle, background_area, cell_area, expose_area, drawFlags);
	}
	if (item != null) {
		if (OS.GTK_IS_CELL_RENDERER_TEXT (cell)) {
			if (hooks (SWT.PaintItem)) {
				GdkRectangle rect = new GdkRectangle ();
				int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, iter);
				OS.gtk_tree_view_get_cell_area (handle, path, columnHandle, rect);
				OS.gtk_tree_path_free (path);
				if (OS.GTK_VERSION < OS.VERSION (2, 8, 18) && OS.gtk_tree_view_get_expander_column (handle) == columnHandle) {
					int [] buffer = new int [1];
					OS.gtk_widget_style_get (handle, OS.expander_size, buffer, 0);
					rect.x += buffer [0] + TreeItem.EXPANDER_EXTRA_PADDING;
					rect.width -= buffer [0] + TreeItem.EXPANDER_EXTRA_PADDING;
					//OS.gtk_widget_style_get (handle, OS.horizontal_separator, buffer, 0);
					//rect.x += buffer[0];
					//rect.width -= buffer [0]; // TODO Is this required for some versions?
				}
				ignoreSize = true;
				int [] contentX = new int [1], contentWidth = new int [1];
				OS.gtk_cell_renderer_get_size (cell, handle, null, null, null, contentWidth, null);
				OS.gtk_tree_view_column_cell_get_position (columnHandle, cell, contentX, null);
				ignoreSize = false;
				Image image = item.getImage (columnIndex);
				int imageWidth = 0;
				if (image != null) {
					Rectangle bounds = image.getBounds ();
					imageWidth = bounds.width;
				}
				contentX [0] -= imageWidth;
				contentWidth [0] += imageWidth;
				GC gc = new GC (this);
				if ((drawState & SWT.SELECTED) != 0) {
					gc.setBackground (display.getSystemColor (SWT.COLOR_LIST_SELECTION));
					gc.setForeground (display.getSystemColor (SWT.COLOR_LIST_SELECTION_TEXT));
				} else {
					gc.setBackground (item.getBackground (columnIndex));
					Color foreground = drawForeground != null ? Color.gtk_new (display, drawForeground) : item.getForeground (columnIndex);
					gc.setForeground (foreground);
				}
				gc.setFont (item.getFont (columnIndex));
				gc.setClipping (rect.x, rect.y, rect.width, rect.height);
				Event event = new Event ();
				event.item = item;
				event.index = columnIndex;
				event.gc = gc;
				event.x = rect.x + contentX [0];
				event.y = rect.y;
				event.width = contentWidth [0];
				event.height = rect.height;
				event.detail = drawState;
				sendEvent (SWT.PaintItem, event);	
				gc.dispose();
			}
		}
	}
	return result;
}

void resetCustomDraw () {
	if ((style & SWT.VIRTUAL) != 0 || ownerDraw) return;
	int end = Math.max (1, columnCount);
	for (int i=0; i<end; i++) {
		boolean customDraw = columnCount != 0 ? columns [i].customDraw : firstCustomDraw;
		if (customDraw) {
			int /*long*/ column = OS.gtk_tree_view_get_column (handle, i);
			int /*long*/ textRenderer = getTextRenderer (column);
			OS.gtk_tree_view_column_set_cell_data_func (column, textRenderer, 0, 0, 0);
			if (columnCount != 0) columns [i].customDraw = false;
		}
	}
	firstCustomDraw = false;
}

/**
 * Display a mark indicating the point at which an item will be inserted.
 * The drop insert item has a visual hint to show where a dragged item 
 * will be inserted when dropped on the tree.
 * 
 * @param item the insert item.  Null will clear the insertion mark.
 * @param before true places the insert mark above 'item'. false places 
 *	the insert mark below 'item'.
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setInsertMark (TreeItem item, boolean before) {
	checkWidget ();
	if (item == null) {
		OS.gtk_tree_view_unset_rows_drag_dest(handle);
		return;
	}
	if (item.isDisposed()) error (SWT.ERROR_INVALID_ARGUMENT);
	if (item.parent != this) return;
	Rectangle rect = item.getBounds();
	int /*long*/ [] path = new int /*long*/ [1];
	OS.gtk_widget_realize (handle);
	if (!OS.gtk_tree_view_get_path_at_pos(handle, rect.x, rect.y, path, null, null, null)) return;
	if (path [0] == 0) return;
	int position = before ? OS.GTK_TREE_VIEW_DROP_BEFORE : OS.GTK_TREE_VIEW_DROP_AFTER;
	OS.gtk_tree_view_set_drag_dest_row(handle, path[0], position);
	OS.gtk_tree_path_free (path [0]);
}

void setItemCount (int /*long*/ parentIter, int count) {
	int itemCount = OS.gtk_tree_model_iter_n_children (modelHandle, parentIter);
	if (count == itemCount) return;
	boolean isVirtual = (style & SWT.VIRTUAL) != 0;
	if (!isVirtual) setRedraw (false);
	remove (parentIter, count, itemCount - 1);
	if (isVirtual) {
		for (int i=itemCount; i<count; i++) {
			int /*long*/ iter = OS.g_malloc (OS.GtkTreeIter_sizeof ());
			if (iter == 0) error (SWT.ERROR_NO_HANDLES);
			OS.gtk_tree_store_append (modelHandle, iter, parentIter);
			OS.gtk_tree_store_set (modelHandle, iter, ID_COLUMN, -1, -1);
			OS.g_free (iter);
		}
	} else {
		for (int i=itemCount; i<count; i++) {
			new TreeItem (this, parentIter, SWT.NONE, i, true);
		}
	}
	if (!isVirtual) setRedraw (true);
	modelChanged = true;
}

/**
 * Sets the number of root-level items contained in the receiver.
 *
 * @param count the number of items
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @since 3.2
 */
public void setItemCount (int count) {
	checkWidget ();
	count = Math.max (0, count);
	setItemCount (0, count);
}
/**
 * Selects all of the items in the receiver.
 * <p>
 * If the receiver is single-select, do nothing.
 * </p>
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void selectAll () {
	checkWidget();
	if ((style & SWT.SINGLE) != 0) return;
	boolean fixColumn = showFirstColumn ();
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	OS.gtk_tree_selection_select_all (selection);
	OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	if (fixColumn) hideFirstColumn ();
}

void setBackgroundColor (GdkColor color) {
	super.setBackgroundColor (color);
	OS.gtk_widget_modify_base (handle, 0, color);
}

void setBackgroundPixmap (int /*long*/ pixmap) {
	super.setBackgroundPixmap (pixmap);
	int /*long*/ window = paintWindow ();
	if (window != 0) OS.gdk_window_set_back_pixmap (window, 0, true);	
}

int setBounds (int x, int y, int width, int height, boolean move, boolean resize) {
	int result = super.setBounds (x, y, width, height, move, resize);
	/*
	* Bug on GTK.  The tree view sometimes does not get a paint
	* event or resizes to a one pixel square when resized in a new
	* shell that is not visible after any event loop has been run.  The
	* problem is intermittent. It doesn't seem to happen the first time
	* a new shell is created. The fix is to ensure the tree view is realized
	* after it has been resized.
	*/
	OS.gtk_widget_realize (handle);
	/*
	* Bug in GTK.  An empty GtkTreeView fails to repaint the focus rectangle
	* correctly when resized on versions before 2.6.0.  The fix is to force
	* the widget to redraw.
	*/
	if (OS.GTK_VERSION < OS.VERSION (2, 6, 0) && OS.gtk_tree_model_iter_n_children (modelHandle, 0) == 0) {
		redraw (false);
	}
	return result;
}

/**
 * Sets the order that the items in the receiver should 
 * be displayed in to the given argument which is described
 * in terms of the zero-relative ordering of when the items
 * were added.
 *
 * @param order the new order to display the items
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item order is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item order is not the same length as the number of items</li>
 * </ul>
 * 
 * @see Tree#getColumnOrder()
 * @see TreeColumn#getMoveable()
 * @see TreeColumn#setMoveable(boolean)
 * @see SWT#Move
 * 
 * @since 3.2
 */
public void setColumnOrder (int [] order) {
	checkWidget ();
	if (order == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (columnCount == 0) {
		if (order.length > 0) error (SWT.ERROR_INVALID_ARGUMENT);
		return;
	}
	if (order.length != columnCount) error (SWT.ERROR_INVALID_ARGUMENT);
	boolean [] seen = new boolean [columnCount];
	for (int i = 0; i<order.length; i++) {
		int index = order [i];
		if (index < 0 || index >= columnCount) error (SWT.ERROR_INVALID_RANGE);
		if (seen [index]) error (SWT.ERROR_INVALID_ARGUMENT);
		seen [index] = true;
	}
	int /*long*/ baseColumn = 0;
	for (int i=0; i<order.length; i++) {
		int /*long*/ column = columns [order [i]].handle;
		OS.gtk_tree_view_move_column_after (handle, column, baseColumn);
		baseColumn = column;
	}
}

void setFontDescription (int /*long*/ font) {
	super.setFontDescription (font);
	TreeColumn[] columns = getColumns ();
	for (int i = 0; i < columns.length; i++) {
		if (columns[i] != null) {
			columns[i].setFontDescription (font);
		}
	}
}

/**
 * Marks the receiver's header as visible if the argument is <code>true</code>,
 * and marks it invisible otherwise. 
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, marking
 * it visible may not actually cause it to be displayed.
 * </p>
 *
 * @param show the new visibility state
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public void setHeaderVisible (boolean show) {
	checkWidget ();
	OS.gtk_tree_view_set_headers_visible (handle, show);
}

/**
 * Marks the receiver's lines as visible if the argument is <code>true</code>,
 * and marks it invisible otherwise. 
 * <p>
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, marking
 * it visible may not actually cause it to be displayed.
 * </p>
 *
 * @param show the new visibility state
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.1
 */
public void setLinesVisible (boolean show) {
	checkWidget();
	OS.gtk_tree_view_set_rules_hint (handle, show);
}

void setParentBackground () {
	super.setParentBackground ();
	int /*long*/ window = paintWindow ();
	if (window != 0) OS.gdk_window_set_back_pixmap (window, 0, true);
}

void setParentWindow (int /*long*/ widget) {
	int /*long*/ window = eventWindow ();
	OS.gtk_widget_set_parent_window (widget, window);
}

void setScrollWidth (int /*long*/ column, TreeItem item) {
	if (columnCount != 0 || currentItem == item) return;
	/*
	* Use GTK_TREE_VIEW_COLUMN_GROW_ONLY on GTK versions < 2.3.2
	* because fixed_height_mode is not supported.
	*/
	if (((style & SWT.VIRTUAL) != 0) && OS.GTK_VERSION < OS.VERSION (2, 3, 2)) return;
	int width = OS.gtk_tree_view_column_get_fixed_width (column);
	int itemWidth = calculateWidth (column, item.handle);
	if (width < itemWidth) {
		OS.gtk_tree_view_column_set_fixed_width (column, itemWidth);
	}
}

/**
 * Sets the receiver's selection to the given item.
 * The current selection is cleared before the new item is selected.
 * <p>
 * If the item is not in the receiver, then it is ignored.
 * </p>
 *
 * @param item the item to select
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.2
 */
public void setSelection (TreeItem item) {
	checkWidget ();
	if (item == null) error (SWT.ERROR_NULL_ARGUMENT);
	setSelection (new TreeItem [] {item});
}

/**
 * Sets the receiver's selection to be the given array of items.
 * The current selection is cleared before the new items are selected.
 * <p>
 * Items that are not in the receiver are ignored.
 * If the receiver is single-select and multiple items are specified,
 * then all items are ignored.
 * </p>
 *
 * @param items the array of items
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the array of items is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if one of the items has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Tree#deselectAll()
 */
public void setSelection (TreeItem [] items) {
	checkWidget ();
	if (items == null) error (SWT.ERROR_NULL_ARGUMENT);
	deselectAll ();
	int length = items.length;
	if (length == 0 || ((style & SWT.SINGLE) != 0 && length > 1)) return;
	boolean fixColumn = showFirstColumn ();
	int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
	OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	boolean first = true;
	for (int i = 0; i < length; i++) {
		TreeItem item = items [i];
		if (item == null) continue;
		if (item.isDisposed ()) break;
		if (item.parent != this) continue;
		int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, item.handle);
		showItem (path, false);
		if (first) {
			OS.gtk_tree_view_set_cursor (handle, path, 0, false);
		}
		OS.gtk_tree_selection_select_iter (selection, item.handle);
		OS.gtk_tree_path_free (path);
		first = false;
	}
	OS.g_signal_handlers_unblock_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, CHANGED);
	if (fixColumn) hideFirstColumn ();
}

/**
 * Sets the column used by the sort indicator for the receiver. A null
 * value will clear the sort indicator.  The current sort column is cleared 
 * before the new column is set.
 *
 * @param column the column used by the sort indicator or <code>null</code>
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the column is disposed</li> 
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.2
 */
public void setSortColumn (TreeColumn column) {
	checkWidget ();
	if (column != null && column.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
	if (sortColumn != null && !sortColumn.isDisposed()) {
		OS.gtk_tree_view_column_set_sort_indicator (sortColumn.handle, false);
	}
	sortColumn = column;
	if (sortColumn != null && sortDirection != SWT.NONE) {
		OS.gtk_tree_view_column_set_sort_indicator (sortColumn.handle, true);
		OS.gtk_tree_view_column_set_sort_order (sortColumn.handle, sortDirection == SWT.DOWN ? 0 : 1);
	}
}

/**
 * Sets the direction of the sort indicator for the receiver. The value 
 * can be one of <code>UP</code>, <code>DOWN</code> or <code>NONE</code>.
 *
 * @param direction the direction of the sort indicator 
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 * 
 * @since 3.2
 */
public void setSortDirection  (int direction) {
	checkWidget ();
	if (direction != SWT.UP && direction != SWT.DOWN && direction != SWT.NONE) return;
	sortDirection = direction;
	if (sortColumn == null || sortColumn.isDisposed ()) return;
	if (sortDirection == SWT.NONE) {
		OS.gtk_tree_view_column_set_sort_indicator (sortColumn.handle, false);
	} else {
		OS.gtk_tree_view_column_set_sort_indicator (sortColumn.handle, true);
		OS.gtk_tree_view_column_set_sort_order (sortColumn.handle, sortDirection == SWT.DOWN ? 0 : 1);
	}
}

/**
 * Sets the item which is currently at the top of the receiver.
 * This item can change when items are expanded, collapsed, scrolled
 * or new items are added or removed.
 *
 * @param item the item to be shown
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Tree#getTopItem()
 * 
 * @since 2.1
 */
public void setTopItem (TreeItem item) {
	if (item == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (item.isDisposed ()) error(SWT.ERROR_INVALID_ARGUMENT);
	if (item.parent != this) return;
	int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, item.handle);
	showItem (path, false);
	OS.gtk_tree_view_scroll_to_cell (handle, path, 0, true, 0f, 0f);
	if (OS.GTK_VERSION < OS.VERSION (2, 8, 0)) {
		/*
		* Bug in GTK.  According to the documentation, gtk_tree_view_scroll_to_cell
		* should vertically scroll the cell to the top if use_align is true and row_align is 0.
		* However, prior to version 2.8 it does not scroll at all.  The fix is to determine
		* the new location and use gtk_tree_view_scroll_to_point.
		* If the widget is a pinhead, calling gtk_tree_view_scroll_to_point
		* will have no effect. Therefore, it is still neccessary to call 
		* gtk_tree_view_scroll_to_cell.
		*/
		OS.gtk_widget_realize (handle);
		GdkRectangle cellRect = new GdkRectangle ();
		OS.gtk_tree_view_get_cell_area (handle, path, 0, cellRect);
		int[] tx = new int[1], ty = new int[1];
		OS.gtk_tree_view_widget_to_tree_coords(handle, cellRect.x, cellRect.y, tx, ty);
		OS.gtk_tree_view_scroll_to_point (handle, -1, ty[0]);
	}
	OS.gtk_tree_path_free (path);
}

/**
 * Shows the column.  If the column is already showing in the receiver,
 * this method simply returns.  Otherwise, the columns are scrolled until
 * the column is visible.
 *
 * @param column the column to be shown
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @since 3.1
 */
public void showColumn (TreeColumn column) {
	checkWidget ();
	if (column == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (column.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
	if (column.parent != this) return;
	/*
	* This code is intentionally commented. According to the
	* documentation, gtk_tree_view_scroll_to_cell should scroll the
	* minimum amount to show the column but instead it scrolls strangely.
	*/
	//OS.gtk_tree_view_scroll_to_cell (handle, 0, column.handle, false, 0, 0);
	OS.gtk_widget_realize (handle);
	GdkRectangle cellRect = new GdkRectangle ();
	OS.gtk_tree_view_get_cell_area (handle, 0, column.handle, cellRect);
	GdkRectangle visibleRect = new GdkRectangle ();
	OS.gtk_tree_view_get_visible_rect (handle, visibleRect);
	if (cellRect.x < visibleRect.x) {
		OS.gtk_tree_view_scroll_to_point (handle, cellRect.x, -1);
	} else {
		int width = Math.min (visibleRect.width, cellRect.width);
		if (cellRect.x + width > visibleRect.x + visibleRect.width) {
			int tree_x = cellRect.x + width - visibleRect.width;
			OS.gtk_tree_view_scroll_to_point (handle, tree_x, -1);
		}
	}
}

boolean showFirstColumn () {	
	/*
	* Bug in GTK.  If no columns are visible, changing the selection
	* will fail.  The fix is to temporarily make a column visible. 
	*/
	int columnCount = Math.max (1, this.columnCount);
	for (int i=0; i<columnCount; i++) {
		int /*long*/ column = OS.gtk_tree_view_get_column (handle, i);
		if (OS.gtk_tree_view_column_get_visible (column)) return false;
	}
	int /*long*/ firstColumn = OS.gtk_tree_view_get_column (handle, 0);
	OS.gtk_tree_view_column_set_visible (firstColumn, true);
	return true;
}

/**
 * Shows the selection.  If the selection is already showing in the receiver,
 * this method simply returns.  Otherwise, the items are scrolled until
 * the selection is visible.
 *
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Tree#showItem(TreeItem)
 */
public void showSelection () {
	checkWidget();
	TreeItem [] items = getSelection ();
	if (items.length != 0 && items [0] != null) showItem (items [0]);
}

void showItem (int /*long*/ path, boolean scroll) {
	int depth = OS.gtk_tree_path_get_depth (path);
	if (depth > 1) {
		int [] indices = new int [depth - 1];
		int /*long*/ indicesPtr = OS.gtk_tree_path_get_indices (path);
		OS.memmove (indices, indicesPtr, indices.length * 4);
		int /*long*/ tempPath = OS.gtk_tree_path_new ();
		for (int i=0; i<indices.length; i++) {
			OS.gtk_tree_path_append_index (tempPath, indices [i]);
			OS.gtk_tree_view_expand_row (handle, tempPath, false);
		}
		OS.gtk_tree_path_free (tempPath);		
	}
	if (scroll) {
		OS.gtk_widget_realize (handle);
		GdkRectangle cellRect = new GdkRectangle ();
		OS.gtk_tree_view_get_cell_area (handle, path, 0, cellRect);
		boolean isHidden = cellRect.y == 0 && cellRect.height == 0;
		int [] tx = new int [1], ty = new int [1];
		OS.gtk_tree_view_widget_to_tree_coords (handle, cellRect.x, cellRect.y, tx, ty);
		GdkRectangle visibleRect = new GdkRectangle ();
		OS.gtk_tree_view_get_visible_rect (handle, visibleRect);
		if (!isHidden) {
			if (ty[0] < visibleRect.y || ty[0] + cellRect.height > visibleRect.y + visibleRect.height) {
				isHidden = true;
			} 
		}
		if (isHidden) {
			/*
			* This code intentionally commented.
			* Bug in GTK.  According to the documentation, gtk_tree_view_scroll_to_cell
			* should scroll the minimum amount to show the cell if use_align is false.
			* However, what actually happens is the cell is scrolled to the top.
			* The fix is to determine the new location and use gtk_tree_view_scroll_to_point.
			* If the widget is a pinhead, calling gtk_tree_view_scroll_to_point
			* will have no effect. Therefore, it is still neccessary to 
			* call gtk_tree_view_scroll_to_cell.
			*/
			//	OS.gtk_tree_view_scroll_to_cell (handle, path, 0, depth != 1, 0.5f, 0.0f);
			if (depth != 1) {
				OS.gtk_tree_view_scroll_to_cell (handle, path, 0, true, 0.5f, 0.0f);
			} else {
				if (ty[0] < visibleRect.y ) {
					OS.gtk_tree_view_scroll_to_point (handle, -1, ty[0]);
				} else {
					int height = Math.min (visibleRect.height, cellRect.height);
					if (ty[0] + height > visibleRect.y + visibleRect.height) {
						OS.gtk_tree_view_scroll_to_point (handle, -1, ty[0] + cellRect.height - visibleRect.height);
					}
				}
			}
		}
	}
}

/**
 * Shows the item.  If the item is already showing in the receiver,
 * this method simply returns.  Otherwise, the items are scrolled
 * and expanded until the item is visible.
 *
 * @param item the item to be shown
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the item is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the item has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see Tree#showSelection()
 */
public void showItem (TreeItem item) {
	checkWidget ();
	if (item == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (item.isDisposed ()) error(SWT.ERROR_INVALID_ARGUMENT);
	if (item.parent != this) return;
	int /*long*/ path = OS.gtk_tree_model_get_path (modelHandle, item.handle);
	showItem (path, true);
	OS.gtk_tree_path_free (path);
}

int /*long*/ treeSelectionProc (int /*long*/ model, int /*long*/ path, int /*long*/ iter, int[] selection, int length) {
	if (selection != null) {
		int [] index = new int [1];
		OS.gtk_tree_model_get (modelHandle, iter, ID_COLUMN, index, -1);
		selection [(int)/*64*/length] = index [0];
	}
	return 0;
}

void updateScrollBarValue (ScrollBar bar) {
	super.updateScrollBarValue (bar);
	/*
	* Bug in GTK. Scrolling changes the XWindow position
	* and makes the child widgets appear to scroll even
	* though when queried their position is unchanged.
	* The fix is to queue a resize event for each child to
	* force the position to be corrected.
	*/
	int /*long*/ parentHandle = parentingHandle ();
	int /*long*/ list = OS.gtk_container_get_children (parentHandle);
	if (list == 0) return;
	int /*long*/ temp = list;
	while (temp != 0) {
		int /*long*/ widget = OS.g_list_data (temp);
		if (widget != 0) OS.gtk_widget_queue_resize  (widget);
		temp = OS.g_list_next (temp);
	}
	OS.g_list_free (list);
}

}