package org.eclipse.swt.widgets;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved
 */

import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;

/**
 * Instances of this class represent a selectable user interface object
 * corresponding to a tab for a page in a tab folder.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */

public class TabItem extends Item {
	TabFolder parent;
	Control control;
	String toolTipText;

public TabItem (TabFolder parent, int style) {
	super (parent, style);
	this.parent = parent;
	parent.createItem (this, parent.getItemCount ());
}


public TabItem (TabFolder parent, int style, int index) {
	super (parent, style);
	this.parent = parent;
	parent.createItem (this, index);
}

protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

/**
 * Returns the control that is used to fill the client area of
 * the tab folder when the user selects the tab item.  If no
 * control has been set, return <code>null</code>.
 * <p>
 * @return the control
 *
 * @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 Control getControl () {
	checkWidget();
	return control;
}

public Display getDisplay () {
	TabFolder parent = this.parent;
	if (parent == null) error (SWT.ERROR_WIDGET_DISPOSED);
	return parent.getDisplay ();
}
/**
 * Returns the receiver's parent, which must be a <code>TabFolder</code>.
 *
 * @return the receiver's parent
 *
 * @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 TabFolder getParent () {
	checkWidget();
	return parent;
}

/**
 * Returns the receiver's tool tip text, or null if it has
 * not been set.
 *
 * @return the receiver's tool tip text
 *
 * @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 String getToolTipText () {
	checkWidget();
	return toolTipText;
}

void releaseChild () {
	super.releaseChild ();
	int index = parent.indexOf (this);
	if (index == parent.getSelectionIndex ()) {
		if (control != null) control.setVisible (false);
	}
	parent.destroyItem (this);
}

void releaseWidget () {
	super.releaseWidget ();
	control = null;
	parent = null;
}

/**
 * Sets the control that is used to fill the client area of
 * the tab folder when the user selects the tab item.
 * <p>
 * @param control the new control (or null)
 *
 * @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 setControl (Control control) {
	checkWidget();
	if (control != null && control.parent != parent) {
		error (SWT.ERROR_INVALID_PARENT);
	}
	Control oldControl = this.control, newControl = control;
	this.control = control;
	int index = parent.indexOf (this);
	if (index != parent.getSelectionIndex ()) {
		if (newControl != null) newControl.setVisible (false);
		return;
	}
	if (newControl != null) {
		newControl.setBounds (parent.getClientArea ());
		newControl.setVisible (true);
	}
	if (oldControl != null) oldControl.setVisible (false);
}

public void setImage (Image image) {
	checkWidget();
	int index = parent.indexOf (this);
	if (index == -1) return;
	super.setImage (image);
	int hwnd = parent.handle;
	TCITEM tcItem = new TCITEM ();
	tcItem.mask = OS.TCIF_IMAGE;
	tcItem.iImage = parent.imageIndex (image);
	OS.SendMessage (hwnd, OS.TCM_SETITEM, index, tcItem);
}
public void setText (String string) {
	checkWidget();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	int index = parent.indexOf (this);
	if (index == -1) return;
	super.setText (string);
	int hwnd = parent.handle;
	int hHeap = OS.GetProcessHeap ();
	byte [] buffer = Converter.wcsToMbcs (0, string, false);
	int pszText = OS.HeapAlloc (hHeap, OS.HEAP_ZERO_MEMORY, buffer.length + 1);
	OS.MoveMemory (pszText, buffer, buffer.length); 
	TCITEM tcItem = new TCITEM ();
	tcItem.mask = OS.TCIF_TEXT;
	tcItem.pszText = pszText;
	int result = OS.SendMessage (hwnd, OS.TCM_SETITEM, index, tcItem);
	OS.HeapFree (hHeap, 0, pszText);
}

/**
 * Sets the receiver's tool tip text to the argument, which
 * may be null indicating that no tool tip text should be shown.
 *
 * @param string the new tool tip text (or null)
 *
 * @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 setToolTipText (String string) {
	checkWidget();
	toolTipText = string;
}

}