bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/Link.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2009 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.internal.motif.*;
 import org.eclipse.swt.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.events.*;

 /**
  * Instances of this class represent a selectable
  * user interface object that displays a text with
  * links.
  * <p>
  * <dl>
  * <dt><b>Styles:</b></dt>
  * <dd>(none)</dd>
  * <dt><b>Events:</b></dt>
  * <dd>Selection</dd>
  * </dl>
  * <p>
  * IMPORTANT: This class is <em>not</em> intended to be subclassed.
  * </p>
  *
  * @see <a href="http://www.eclipse.org/swt/snippets/#link">Link snippets</a>
  * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
  * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
  *
  * @since 3.1
  * @noextend This class is not intended to be subclassed by clients.
  */
 public class Link extends Control {
 	String text;
 	TextLayout layout;
 	Color linkColor, disabledColor;
 	Point [] offsets;
 	Point selection;
 	String [] ids;
 	int [] mnemonics;
 	int focusIndex;

 	static final RGB LINK_FOREGROUND = new RGB (0, 51, 153);
 	static final RGB LINK_DISABLED_FOREGROUND = new RGB (172, 168, 153);

 /**
  * 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 Widget#checkSubclass
  * @see Widget#getStyle
  */
 public Link (Composite parent, int style) {
 	super (parent, style);
 }
 /**
  * Adds the listener to the collection of listeners who will
  * be notified when the control is selected by the user, by sending
  * it one of the messages defined in the <code>SelectionListener</code>
  * interface.
  * <p>
  * <code>widgetSelected</code> is called when the control is selected by the user.
  * <code>widgetDefaultSelected</code> is not called.
  * </p>
  *
  * @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 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);
 }
 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;
 	int width, height;
 	int layoutWidth = layout.getWidth ();
 	//TEMPORARY CODE
 	if (wHint == 0) {
 		layout.setWidth (1);
 		Rectangle rect = layout.getBounds ();
 		width = 0;
 		height = rect.height;
 	} else {
 		layout.setWidth (wHint);
 		Rectangle rect = layout.getBounds ();
 		width = rect.width;
 		height = rect.height;
 	}
 	layout.setWidth (layoutWidth);
 	if (wHint != SWT.DEFAULT) width = wHint;
 	if (hHint != SWT.DEFAULT) height = hHint;
 	int border = getBorderWidth ();
 	width += border * 2;
 	height += border * 2;
 	return new Point (width, height);
 }
 void createHandle (int index) {
 	state |= THEME_BACKGROUND;
 	int [] argList = {
 		OS.XmNancestorSensitive, 1,
 		OS.XmNborderWidth, (style & SWT.BORDER) != 0 ? 1 : 0,
 		OS.XmNmarginWidth, 0,
 		OS.XmNmarginHeight, 0,
 		OS.XmNresizePolicy, OS.XmRESIZE_NONE,
 		OS.XmNtraversalOn, 0,
 	};
 	handle = OS.XmCreateDrawingArea (parent.handle, null, argList, argList.length / 2);
 	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
 	layout = new TextLayout (display);
 	linkColor = new Color (display, LINK_FOREGROUND);
 	disabledColor = new Color (display, LINK_DISABLED_FOREGROUND);
 	offsets = new Point [0];
 	ids = new String [0];
 	mnemonics = new int [0];
 	selection = new Point (-1, -1);
 	focusIndex = -1;
 }
 void createWidget (int index) {
 	super.createWidget (index);
 	text = "";
 	//TODO - accessibility
 }
 void enableWidget (boolean enabled) {
 	super.enableWidget (enabled);
 	TextStyle linkStyle = new TextStyle (null, enabled ? linkColor : disabledColor, null);
 	linkStyle.underline = true;
 	for (int i = 0; i < offsets.length; i++) {
 		Point point = offsets [i];
 		layout.setStyle (linkStyle, point.x, point.y);
 	}
 	redraw ();
 }
 String getNameText () {
 	return getText ();
 }
 Rectangle [] getRectangles (int linkIndex) {
 	int lineCount = layout.getLineCount ();
 	Rectangle [] rects = new Rectangle [lineCount];
 	int [] lineOffsets = layout.getLineOffsets ();
 	Point point = offsets [linkIndex];
 	int lineStart = 1;
 	while (point.x > lineOffsets [lineStart]) lineStart++;
 	int lineEnd = 1;
 	while (point.y > lineOffsets [lineEnd]) lineEnd++;
 	int index = 0;
 	if (lineStart == lineEnd) {
 		rects [index++] = layout.getBounds (point.x, point.y);
 	} else {
 		rects [index++] = layout.getBounds (point.x, lineOffsets [lineStart]-1);
 		rects [index++] = layout.getBounds (lineOffsets [lineEnd-1], point.y);
 		if (lineEnd - lineStart > 1) {
 			for (int i = lineStart; i < lineEnd - 1; i++) {
 				rects [index++] = layout.getLineBounds (i);
 			}
 		}
 	}
 	if (rects.length != index) {
 		Rectangle [] tmp = new Rectangle [index];
 		System.arraycopy (rects, 0, tmp, 0, index);
 		rects = tmp;
 	}
 	return rects;
 }
 /**
  * Returns the receiver's text, which will be an empty
  * string if it has never been set.
  *
  * @return the receiver's 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 getText () {
 	checkWidget ();
 	return text;
 }
 void releaseWidget () {
 	super.releaseWidget ();
 	if (layout != null) layout.dispose ();
 	layout = null;
 	if (linkColor != null) linkColor.dispose ();
 	linkColor = null;
 	if (disabledColor != null) disabledColor.dispose ();
 	disabledColor = null;
 	offsets = null;
 	ids = null;
 	mnemonics = null;
 	text = null;
 }
 /**
  * Removes the listener from the collection of listeners who will
  * be notified when the control is selected by the user.
  *
  * @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);
 	if (eventTable == null) return;
 	eventTable.unhook (SWT.Selection, listener);
 	eventTable.unhook (SWT.DefaultSelection, listener);
 }
 String parse (String string) {
 	int length = string.length ();
 	offsets = new Point [length / 4];
 	ids = new String [length / 4];
 	mnemonics = new int [length / 4 + 1];
 	StringBuffer result = new StringBuffer ();
 	char [] buffer = new char [length];
 	string.getChars (0, string.length (), buffer, 0);
 	int index = 0, state = 0, linkIndex = 0;
 	int start = 0, tagStart = 0, linkStart = 0, endtagStart = 0, refStart = 0;
 	while (index < length) {
 		char c = Character.toLowerCase (buffer [index]);
 		switch (state) {
 			case 0:
 				if (c == '<') {
 					tagStart = index;
 					state++;
 				}
 				break;
 			case 1:
 				if (c == 'a') state++;
 				break;
 			case 2:
 				switch (c) {
 					case 'h':
 						state = 7;
 						break;
 					case '>':
 						linkStart = index  + 1;
 						state++;
 						break;
 					default:
 						if (Character.isWhitespace(c)) break;
 						else state = 13;
 				}
 				break;
 			case 3:
 				if (c == '<') {
 					endtagStart = index;
 					state++;
 				}
 				break;
 			case 4:
 				state = c == '/' ? state + 1 : 3;
 				break;
 			case 5:
 				state = c == 'a' ? state + 1 : 3;
 				break;
 			case 6:
 				if (c == '>') {
 					mnemonics [linkIndex] = parseMnemonics (buffer, start, tagStart, result);
 					int offset = result.length ();
 					parseMnemonics (buffer, linkStart, endtagStart, result);
 					offsets [linkIndex] = new Point (offset, result.length () - 1);
 					if (ids [linkIndex] == null) {
 						ids [linkIndex] = new String (buffer, linkStart, endtagStart - linkStart);
 					}
 					linkIndex++;
 					start = tagStart = linkStart = endtagStart = refStart = index + 1;
 					state = 0;
 				} else {
 					state = 3;
 				}
 				break;
 			case 7:
 				state = c == 'r' ? state + 1 : 0;
 				break;
 			case 8:
 				state = c == 'e' ? state + 1 : 0;
 				break;
 			case 9:
 				state = c == 'f' ? state + 1 : 0;
 				break;
 			case 10:
 				state = c == '=' ? state + 1 : 0;
 				break;
 			case 11:
 				if (c == '"') {
 					state++;
 					refStart = index + 1;
 				} else {
 					state = 0;
 				}
 				break;
 			case 12:
 				if (c == '"') {
 					ids[linkIndex] = new String (buffer, refStart, index - refStart);
 					state = 2;
 				}
 				break;
 			case 13:
 				if (Character.isWhitespace (c)) {
 					state = 0;
 				} else if (c == '='){
 					state++;
 				}
 				break;
 			case 14:
 				state = c == '"' ? state + 1 : 0;
 				break;
 			case 15:
 				if (c == '"') state = 2;
 				break;
 			default:
 				state = 0;
 				break;
 		}
 		index++;
 	}
 	if (start < length) {
 		int tmp = parseMnemonics (buffer, start, tagStart, result);
 		int mnemonic = parseMnemonics (buffer, Math.max (tagStart, linkStart), length, result);
 		if (mnemonic == -1) mnemonic = tmp;
 		mnemonics [linkIndex] = mnemonic;
 	} else {
 		mnemonics [linkIndex] = -1;
 	}
 	if (offsets.length != linkIndex) {
 		Point [] newOffsets = new Point [linkIndex];
 		System.arraycopy (offsets, 0, newOffsets, 0, linkIndex);
 		offsets = newOffsets;
 		String [] newIDs = new String [linkIndex];
 		System.arraycopy (ids, 0, newIDs, 0, linkIndex);
 		ids = newIDs;
 		int [] newMnemonics = new int [linkIndex + 1];
 		System.arraycopy (mnemonics, 0, newMnemonics, 0, linkIndex + 1);
 		mnemonics = newMnemonics;
 	}
 	return result.toString ();
 }
 int parseMnemonics (char[] buffer, int start, int end, StringBuffer result) {
 	int mnemonic = -1, index = start;
 	while (index < end) {
 		if (buffer [index] == '&') {
 			if (index + 1 < end && buffer [index + 1] == '&') {
 				result.append (buffer [index]);
 				index++;
 			} else {
 				mnemonic = result.length();
 			}
 		} else {
 			result.append (buffer [index]);
 		}
 		index++;
 	}
 	return mnemonic;
 }
 boolean setBounds (int x, int y, int width, int height, boolean move, boolean resize) {
 	boolean changed = super.setBounds (x, y, width,height, move, resize);
 	if (changed && resize) {
 		layout.setWidth (width > 0 ? width : -1);
 		redraw ();
 	}
 	return changed;
 }
 public void setFont (Font font) {
 	super.setFont (font);
 	layout.setFont (this.font);
 	int xDisplay = OS.XtDisplay (handle);
 	if (xDisplay == 0) return;
 	int xWindow = OS.XtWindow (handle);
 	if (xWindow == 0) return;
 	OS.XClearArea (xDisplay, xWindow, 0, 0, 0, 0, true);
 }
 void setForegroundPixel (int pixel) {
 	super.setForegroundPixel (pixel);
 	int xDisplay = OS.XtDisplay (handle);
 	if (xDisplay == 0) return;
 	int xWindow = OS.XtWindow (handle);
 	if (xWindow == 0) return;
 	OS.XClearArea (xDisplay, xWindow, 0, 0, 0, 0, true);
 }
 /**
  * Sets the receiver's text.
  * <p>
  * The string can contain both regular text and hyperlinks.  A hyperlink
  * is delimited by an anchor tag, &lt;A&gt; and &lt;/A&gt;.  Within an
  * anchor, a single HREF attribute is supported.  When a hyperlink is
  * selected, the text field of the selection event contains either the
  * text of the hyperlink or the value of its HREF, if one was specified.
  * In the rare case of identical hyperlinks within the same string, the
  * HREF attribute can be used to distinguish between them.  The string may
  * include the mnemonic character and line delimiters. The only delimiter
  * the HREF attribute supports is the quotation mark (").
  * </p>
  *
  * @param string the new text
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_NULL_ARGUMENT - if the text 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 void setText (String string) {
 	checkWidget ();
 	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
 	if (string.equals (text)) return;
 	text = string;
 	layout.setText (parse (string));
 	focusIndex = offsets.length > 0 ? 0 : -1;
 	selection.x = selection.y = -1;
 	int [] argList = new int [] {OS.XmNtraversalOn, offsets.length > 0 ? 1 : 0};
 	OS.XtSetValues (handle, argList, argList.length / 2);
 	int [] argList1 = {OS.XmNsensitive, 0};
 	OS.XtGetValues (handle, argList1, argList1.length / 2);
 	boolean enabled = argList1 [1] != 0;
 	TextStyle linkStyle = new TextStyle (null, enabled ? linkColor : disabledColor, null);
 	linkStyle.underline = true;
 	for (int i = 0; i < offsets.length; i++) {
 		Point point = offsets [i];
 		layout.setStyle (linkStyle, point.x, point.y);
 	}
 	TextStyle mnemonicStyle = new TextStyle (null, null, null);
 	mnemonicStyle.underline = true;
 	for (int i = 0; i < mnemonics.length; i++) {
 		int mnemonic  = mnemonics [i];
 		if (mnemonic != -1) {
 			layout.setStyle (mnemonicStyle, mnemonic, mnemonic);
 		}
 	}
 	redraw ();
 }
 int traversalCode (int key, XKeyEvent event) {
 	if (offsets.length == 0) return 0;
 	int bits = super.traversalCode (key, event);
 	if (event != null && key == OS.XK_Tab) {
 		boolean next = (event.state & OS.ShiftMask) == 0;
 		if (next && focusIndex < offsets.length - 1) {
 			return bits & ~SWT.TRAVERSE_TAB_NEXT;
 		}
 		if (!next && focusIndex > 0) {
 			return bits & ~SWT.TRAVERSE_TAB_PREVIOUS;
 		}
 	}
 	return bits;
 }
 int XButtonPress (int w, int client_data, int call_data, int continue_to_dispatch) {
 	int result = super.XButtonPress (w, client_data, call_data, continue_to_dispatch);
 	if (result != 0) return result;
 	XButtonEvent xEvent = new XButtonEvent ();
 	OS.memmove (xEvent, call_data, XButtonEvent.sizeof);
 	if (xEvent.button == 1) {
 		int offset = layout.getOffset (xEvent.x, xEvent.y, null);
 		int oldSelectionX = selection.x;
 		int oldSelectionY = selection.y;
 		selection.x = offset;
 		selection.y = -1;
 		if (oldSelectionX != -1 && oldSelectionY != -1) {
 			if (oldSelectionX > oldSelectionY) {
 				int temp = oldSelectionX;
 				oldSelectionX = oldSelectionY;
 				oldSelectionY = temp;
 			}
 			Rectangle rect = layout.getBounds (oldSelectionX, oldSelectionY);
 			redraw (rect.x, rect.y, rect.width, rect.height, false);
 		}
 		for (int j = 0; j < offsets.length; j++) {
 			Rectangle [] rects = getRectangles (j);
 			for (int i = 0; i < rects.length; i++) {
 				Rectangle rect = rects [i];
 				if (rect.contains (xEvent.x, xEvent.y)) {
 					focusIndex = j;
 					redraw ();
 					return result;
 				}
 			}
 		}
 	}
 	return result;
 }
 int XButtonRelease (int w, int client_data, int call_data, int continue_to_dispatch) {
 	int result = super.XButtonRelease (w, client_data, call_data, continue_to_dispatch);
 	if (result != 0) return result;
 	if (focusIndex == -1) return result;
 	XButtonEvent xEvent = new XButtonEvent ();
 	OS.memmove (xEvent, call_data, XButtonEvent.sizeof);
 	if (xEvent.button == 1) {
 		Rectangle [] rects = getRectangles (focusIndex);
 		for (int i = 0; i < rects.length; i++) {
 			Rectangle rect = rects [i];
 			if (rect.contains (xEvent.x, xEvent.y)) {
 				Event event = new Event ();
 				event.text = ids [focusIndex];
 				notifyListeners (SWT.Selection, event);
 				return result;
 			}
 		}
 	}
 	return result;
 }
 int XExposure (int w, int client_data, int call_data, int continue_to_dispatch) {
 	XExposeEvent xEvent = new XExposeEvent ();
 	OS.memmove (xEvent, call_data, XExposeEvent.sizeof);
 	int xDisplay = OS.XtDisplay (handle);
 	if (xDisplay == 0) return 0;
 	int damageRgn = OS.XCreateRegion ();
 	OS.XtAddExposureToRegion (call_data, damageRgn);
 	GCData data = new GCData ();
 	data.damageRgn = damageRgn;
 	GC gc = GC.motif_new (this, data);
 	OS.XSetRegion (xDisplay, gc.handle, damageRgn);
 	int selStart = selection.x;
 	int selEnd = selection.y;
 	if (selStart > selEnd) {
 		selStart = selection.y;
 		selEnd = selection.x;
 	}
 	// temporary code to disable text selection
 	selStart = selEnd = -1;
 	int [] argList = {OS.XmNsensitive, 0};
 	OS.XtGetValues (handle, argList, argList.length / 2);
 	if (argList [1] == 0) gc.setForeground (disabledColor);
 	layout.draw (gc, 0, 0, selStart, selEnd, null, null);
 	if (hasFocus () && focusIndex != -1) {
 		Rectangle [] rects = getRectangles (focusIndex);
 		for (int i = 0; i < rects.length; i++) {
 			Rectangle rect = rects [i];
 			gc.drawFocus (rect.x, rect.y, rect.width, rect.height);
 		}
 	}
 	gc.dispose ();
 	OS.XDestroyRegion (damageRgn);
 	return super.XExposure (w, client_data, call_data, continue_to_dispatch);
 }
 int XFocusChange (int w, int client_data, int call_data, int continue_to_dispatch) {
 	int result = super.XFocusChange (w, client_data, call_data, continue_to_dispatch);
 	redraw ();
 	return result;
 }
 int XKeyPress (int w, int client_data, int call_data, int continue_to_dispatch) {
 	int result = super.XKeyPress (w, client_data, call_data, continue_to_dispatch);
 	if (result != 0) return result;
 	if (focusIndex == -1) return result;
 	XKeyEvent xEvent = new XKeyEvent ();
 	OS.memmove (xEvent, call_data, XKeyEvent.sizeof);
 	int [] keysym = new int [1];
 	OS.XLookupString (xEvent, null, 0, keysym, null);
 	keysym [0] &= 0xFFFF;
 	switch (keysym [0]) {
 		case OS.XK_space:
 		case OS.XK_Return:
 		case OS.XK_KP_Enter:
 			Event event = new Event ();
 			event.text = ids [focusIndex];
 			sendEvent (SWT.Selection, event);
 			break;
 		case OS.XK_Tab:
 			if (focusIndex < offsets.length - 1) {
 				focusIndex++;
 				redraw ();
 				OS.memmove (continue_to_dispatch, new int [1], 4);
 				return 1;
 			}
 			break;
 		case OS.XK_ISO_Left_Tab:
 			if (focusIndex > 0) {
 				focusIndex--;
 				redraw ();
 				OS.memmove (continue_to_dispatch, new int [1], 4);
 				return 1;
 			}
 			break;
 	}
 	return result;
 }
 int XPointerMotion (int w, int client_data, int call_data, int continue_to_dispatch) {
 	int result = super.XPointerMotion (w, client_data, call_data, continue_to_dispatch);
 	if (result != 0) return result;
 	XMotionEvent xEvent = new XMotionEvent ();
 	OS.memmove (xEvent, call_data, XMotionEvent.sizeof);
 	if ((xEvent.state & OS.Button1Mask) != 0) {
 		int oldSelection = selection.y;
 		selection.y = layout.getOffset (xEvent.x, xEvent.y, null);
 		if (selection.y != oldSelection) {
 			int newSelection = selection.y;
 			if (oldSelection > newSelection) {
 				int temp = oldSelection;
 				oldSelection = newSelection;
 				newSelection = temp;
 			}
 			Rectangle rect = layout.getBounds (oldSelection, newSelection);
 			redraw (rect.x, rect.y, rect.width, rect.height, false);
 		}
 		return result;
 	}
 	for (int j = 0; j < offsets.length; j++) {
 		Rectangle [] rects = getRectangles (j);
 		for (int i = 0; i < rects.length; i++) {
 			Rectangle rect = rects [i];
 			if (rect.contains (xEvent.x, xEvent.y)) {
 				setCursor (display.getSystemCursor (SWT.CURSOR_HAND));
 				return result;
 			}
 		}
 	}
 	setCursor (null);
 	return result;
 }
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2009 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.internal.motif.*;
	import org.eclipse.swt.*;
	import org.eclipse.swt.graphics.*;
	import org.eclipse.swt.events.*;

	/**
	* Instances of this class represent a selectable
	* user interface object that displays a text with
	* links.
	* <p>
	* <dl>
	* <dt><b>Styles:</b></dt>
	* <dd>(none)</dd>
	* <dt><b>Events:</b></dt>
	* <dd>Selection</dd>
	* </dl>
	* <p>
	* IMPORTANT: This class is <em>not</em> intended to be subclassed.
	* </p>
	*
	* @see <a href="http://www.eclipse.org/swt/snippets/#link">Link snippets</a>
	* @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
	* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
	*
	* @since 3.1
	* @noextend This class is not intended to be subclassed by clients.
	*/
	public class Link extends Control {
	String text;
	TextLayout layout;
	Color linkColor, disabledColor;
	Point [] offsets;
	Point selection;
	String [] ids;
	int [] mnemonics;
	int focusIndex;

	static final RGB LINK_FOREGROUND = new RGB (0, 51, 153);
	static final RGB LINK_DISABLED_FOREGROUND = new RGB (172, 168, 153);

	/**
	* 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 Widget#checkSubclass
	* @see Widget#getStyle
	*/
	public Link (Composite parent, int style) {
	super (parent, style);
	}
	/**
	* Adds the listener to the collection of listeners who will
	* be notified when the control is selected by the user, by sending
	* it one of the messages defined in the <code>SelectionListener</code>
	* interface.
	* <p>
	* <code>widgetSelected</code> is called when the control is selected by the user.
	* <code>widgetDefaultSelected</code> is not called.
	* </p>
	*
	* @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 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);
	}
	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;
	int width, height;
	int layoutWidth = layout.getWidth ();
	//TEMPORARY CODE
	if (wHint == 0) {
	layout.setWidth (1);
	Rectangle rect = layout.getBounds ();
	width = 0;
	height = rect.height;
	} else {
	layout.setWidth (wHint);
	Rectangle rect = layout.getBounds ();
	width = rect.width;
	height = rect.height;
	}
	layout.setWidth (layoutWidth);
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	int border = getBorderWidth ();
	width += border * 2;
	height += border * 2;
	return new Point (width, height);
	}
	void createHandle (int index) {
	state \|= THEME_BACKGROUND;
	int [] argList = {
	OS.XmNancestorSensitive, 1,
	OS.XmNborderWidth, (style & SWT.BORDER) != 0 ? 1 : 0,
	OS.XmNmarginWidth, 0,
	OS.XmNmarginHeight, 0,
	OS.XmNresizePolicy, OS.XmRESIZE_NONE,
	OS.XmNtraversalOn, 0,
	};
	handle = OS.XmCreateDrawingArea (parent.handle, null, argList, argList.length / 2);
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
	layout = new TextLayout (display);
	linkColor = new Color (display, LINK_FOREGROUND);
	disabledColor = new Color (display, LINK_DISABLED_FOREGROUND);
	offsets = new Point [0];
	ids = new String [0];
	mnemonics = new int [0];
	selection = new Point (-1, -1);
	focusIndex = -1;
	}
	void createWidget (int index) {
	super.createWidget (index);
	text = "";
	//TODO - accessibility
	}
	void enableWidget (boolean enabled) {
	super.enableWidget (enabled);
	TextStyle linkStyle = new TextStyle (null, enabled ? linkColor : disabledColor, null);
	linkStyle.underline = true;
	for (int i = 0; i < offsets.length; i++) {
	Point point = offsets [i];
	layout.setStyle (linkStyle, point.x, point.y);
	}
	redraw ();
	}
	String getNameText () {
	return getText ();
	}
	Rectangle [] getRectangles (int linkIndex) {
	int lineCount = layout.getLineCount ();
	Rectangle [] rects = new Rectangle [lineCount];
	int [] lineOffsets = layout.getLineOffsets ();
	Point point = offsets [linkIndex];
	int lineStart = 1;
	while (point.x > lineOffsets [lineStart]) lineStart++;
	int lineEnd = 1;
	while (point.y > lineOffsets [lineEnd]) lineEnd++;
	int index = 0;
	if (lineStart == lineEnd) {
	rects [index++] = layout.getBounds (point.x, point.y);
	} else {
	rects [index++] = layout.getBounds (point.x, lineOffsets [lineStart]-1);
	rects [index++] = layout.getBounds (lineOffsets [lineEnd-1], point.y);
	if (lineEnd - lineStart > 1) {
	for (int i = lineStart; i < lineEnd - 1; i++) {
	rects [index++] = layout.getLineBounds (i);
	}
	}
	}
	if (rects.length != index) {
	Rectangle [] tmp = new Rectangle [index];
	System.arraycopy (rects, 0, tmp, 0, index);
	rects = tmp;
	}
	return rects;
	}
	/**
	* Returns the receiver's text, which will be an empty
	* string if it has never been set.
	*
	* @return the receiver's 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 getText () {
	checkWidget ();
	return text;
	}
	void releaseWidget () {
	super.releaseWidget ();
	if (layout != null) layout.dispose ();
	layout = null;
	if (linkColor != null) linkColor.dispose ();
	linkColor = null;
	if (disabledColor != null) disabledColor.dispose ();
	disabledColor = null;
	offsets = null;
	ids = null;
	mnemonics = null;
	text = null;
	}
	/**
	* Removes the listener from the collection of listeners who will
	* be notified when the control is selected by the user.
	*
	* @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);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection, listener);
	}
	String parse (String string) {
	int length = string.length ();
	offsets = new Point [length / 4];
	ids = new String [length / 4];
	mnemonics = new int [length / 4 + 1];
	StringBuffer result = new StringBuffer ();
	char [] buffer = new char [length];
	string.getChars (0, string.length (), buffer, 0);
	int index = 0, state = 0, linkIndex = 0;
	int start = 0, tagStart = 0, linkStart = 0, endtagStart = 0, refStart = 0;
	while (index < length) {
	char c = Character.toLowerCase (buffer [index]);
	switch (state) {
	case 0:
	if (c == '<') {
	tagStart = index;
	state++;
	}
	break;
	case 1:
	if (c == 'a') state++;
	break;
	case 2:
	switch (c) {
	case 'h':
	state = 7;
	break;
	case '>':
	linkStart = index + 1;
	state++;
	break;
	default:
	if (Character.isWhitespace(c)) break;
	else state = 13;
	}
	break;
	case 3:
	if (c == '<') {
	endtagStart = index;
	state++;
	}
	break;
	case 4:
	state = c == '/' ? state + 1 : 3;
	break;
	case 5:
	state = c == 'a' ? state + 1 : 3;
	break;
	case 6:
	if (c == '>') {
	mnemonics [linkIndex] = parseMnemonics (buffer, start, tagStart, result);
	int offset = result.length ();
	parseMnemonics (buffer, linkStart, endtagStart, result);
	offsets [linkIndex] = new Point (offset, result.length () - 1);
	if (ids [linkIndex] == null) {
	ids [linkIndex] = new String (buffer, linkStart, endtagStart - linkStart);
	}
	linkIndex++;
	start = tagStart = linkStart = endtagStart = refStart = index + 1;
	state = 0;
	} else {
	state = 3;
	}
	break;
	case 7:
	state = c == 'r' ? state + 1 : 0;
	break;
	case 8:
	state = c == 'e' ? state + 1 : 0;
	break;
	case 9:
	state = c == 'f' ? state + 1 : 0;
	break;
	case 10:
	state = c == '=' ? state + 1 : 0;
	break;
	case 11:
	if (c == '"') {
	state++;
	refStart = index + 1;
	} else {
	state = 0;
	}
	break;
	case 12:
	if (c == '"') {
	ids[linkIndex] = new String (buffer, refStart, index - refStart);
	state = 2;
	}
	break;
	case 13:
	if (Character.isWhitespace (c)) {
	state = 0;
	} else if (c == '='){
	state++;
	}
	break;
	case 14:
	state = c == '"' ? state + 1 : 0;
	break;
	case 15:
	if (c == '"') state = 2;
	break;
	default:
	state = 0;
	break;
	}
	index++;
	}
	if (start < length) {
	int tmp = parseMnemonics (buffer, start, tagStart, result);
	int mnemonic = parseMnemonics (buffer, Math.max (tagStart, linkStart), length, result);
	if (mnemonic == -1) mnemonic = tmp;
	mnemonics [linkIndex] = mnemonic;
	} else {
	mnemonics [linkIndex] = -1;
	}
	if (offsets.length != linkIndex) {
	Point [] newOffsets = new Point [linkIndex];
	System.arraycopy (offsets, 0, newOffsets, 0, linkIndex);
	offsets = newOffsets;
	String [] newIDs = new String [linkIndex];
	System.arraycopy (ids, 0, newIDs, 0, linkIndex);
	ids = newIDs;
	int [] newMnemonics = new int [linkIndex + 1];
	System.arraycopy (mnemonics, 0, newMnemonics, 0, linkIndex + 1);
	mnemonics = newMnemonics;
	}
	return result.toString ();
	}
	int parseMnemonics (char[] buffer, int start, int end, StringBuffer result) {
	int mnemonic = -1, index = start;
	while (index < end) {
	if (buffer [index] == '&') {
	if (index + 1 < end && buffer [index + 1] == '&') {
	result.append (buffer [index]);
	index++;
	} else {
	mnemonic = result.length();
	}
	} else {
	result.append (buffer [index]);
	}
	index++;
	}
	return mnemonic;
	}
	boolean setBounds (int x, int y, int width, int height, boolean move, boolean resize) {
	boolean changed = super.setBounds (x, y, width,height, move, resize);
	if (changed && resize) {
	layout.setWidth (width > 0 ? width : -1);
	redraw ();
	}
	return changed;
	}
	public void setFont (Font font) {
	super.setFont (font);
	layout.setFont (this.font);
	int xDisplay = OS.XtDisplay (handle);
	if (xDisplay == 0) return;
	int xWindow = OS.XtWindow (handle);
	if (xWindow == 0) return;
	OS.XClearArea (xDisplay, xWindow, 0, 0, 0, 0, true);
	}
	void setForegroundPixel (int pixel) {
	super.setForegroundPixel (pixel);
	int xDisplay = OS.XtDisplay (handle);
	if (xDisplay == 0) return;
	int xWindow = OS.XtWindow (handle);
	if (xWindow == 0) return;
	OS.XClearArea (xDisplay, xWindow, 0, 0, 0, 0, true);
	}
	/**
	* Sets the receiver's text.
	* <p>
	* The string can contain both regular text and hyperlinks. A hyperlink
	* is delimited by an anchor tag, <A> and </A>. Within an
	* anchor, a single HREF attribute is supported. When a hyperlink is
	* selected, the text field of the selection event contains either the
	* text of the hyperlink or the value of its HREF, if one was specified.
	* In the rare case of identical hyperlinks within the same string, the
	* HREF attribute can be used to distinguish between them. The string may
	* include the mnemonic character and line delimiters. The only delimiter
	* the HREF attribute supports is the quotation mark (").
	* </p>
	*
	* @param string the new text
	*
	* @exception IllegalArgumentException <ul>
	* <li>ERROR_NULL_ARGUMENT - if the text 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 void setText (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (string.equals (text)) return;
	text = string;
	layout.setText (parse (string));
	focusIndex = offsets.length > 0 ? 0 : -1;
	selection.x = selection.y = -1;
	int [] argList = new int [] {OS.XmNtraversalOn, offsets.length > 0 ? 1 : 0};
	OS.XtSetValues (handle, argList, argList.length / 2);
	int [] argList1 = {OS.XmNsensitive, 0};
	OS.XtGetValues (handle, argList1, argList1.length / 2);
	boolean enabled = argList1 [1] != 0;
	TextStyle linkStyle = new TextStyle (null, enabled ? linkColor : disabledColor, null);
	linkStyle.underline = true;
	for (int i = 0; i < offsets.length; i++) {
	Point point = offsets [i];
	layout.setStyle (linkStyle, point.x, point.y);
	}
	TextStyle mnemonicStyle = new TextStyle (null, null, null);
	mnemonicStyle.underline = true;
	for (int i = 0; i < mnemonics.length; i++) {
	int mnemonic = mnemonics [i];
	if (mnemonic != -1) {
	layout.setStyle (mnemonicStyle, mnemonic, mnemonic);
	}
	}
	redraw ();
	}
	int traversalCode (int key, XKeyEvent event) {
	if (offsets.length == 0) return 0;
	int bits = super.traversalCode (key, event);
	if (event != null && key == OS.XK_Tab) {
	boolean next = (event.state & OS.ShiftMask) == 0;
	if (next && focusIndex < offsets.length - 1) {
	return bits & ~SWT.TRAVERSE_TAB_NEXT;
	}
	if (!next && focusIndex > 0) {
	return bits & ~SWT.TRAVERSE_TAB_PREVIOUS;
	}
	}
	return bits;
	}
	int XButtonPress (int w, int client_data, int call_data, int continue_to_dispatch) {
	int result = super.XButtonPress (w, client_data, call_data, continue_to_dispatch);
	if (result != 0) return result;
	XButtonEvent xEvent = new XButtonEvent ();
	OS.memmove (xEvent, call_data, XButtonEvent.sizeof);
	if (xEvent.button == 1) {
	int offset = layout.getOffset (xEvent.x, xEvent.y, null);
	int oldSelectionX = selection.x;
	int oldSelectionY = selection.y;
	selection.x = offset;
	selection.y = -1;
	if (oldSelectionX != -1 && oldSelectionY != -1) {
	if (oldSelectionX > oldSelectionY) {
	int temp = oldSelectionX;
	oldSelectionX = oldSelectionY;
	oldSelectionY = temp;
	}
	Rectangle rect = layout.getBounds (oldSelectionX, oldSelectionY);
	redraw (rect.x, rect.y, rect.width, rect.height, false);
	}
	for (int j = 0; j < offsets.length; j++) {
	Rectangle [] rects = getRectangles (j);
	for (int i = 0; i < rects.length; i++) {
	Rectangle rect = rects [i];
	if (rect.contains (xEvent.x, xEvent.y)) {
	focusIndex = j;
	redraw ();
	return result;
	}
	}
	}
	}
	return result;
	}
	int XButtonRelease (int w, int client_data, int call_data, int continue_to_dispatch) {
	int result = super.XButtonRelease (w, client_data, call_data, continue_to_dispatch);
	if (result != 0) return result;
	if (focusIndex == -1) return result;
	XButtonEvent xEvent = new XButtonEvent ();
	OS.memmove (xEvent, call_data, XButtonEvent.sizeof);
	if (xEvent.button == 1) {
	Rectangle [] rects = getRectangles (focusIndex);
	for (int i = 0; i < rects.length; i++) {
	Rectangle rect = rects [i];
	if (rect.contains (xEvent.x, xEvent.y)) {
	Event event = new Event ();
	event.text = ids [focusIndex];
	notifyListeners (SWT.Selection, event);
	return result;
	}
	}
	}
	return result;
	}
	int XExposure (int w, int client_data, int call_data, int continue_to_dispatch) {
	XExposeEvent xEvent = new XExposeEvent ();
	OS.memmove (xEvent, call_data, XExposeEvent.sizeof);
	int xDisplay = OS.XtDisplay (handle);
	if (xDisplay == 0) return 0;
	int damageRgn = OS.XCreateRegion ();
	OS.XtAddExposureToRegion (call_data, damageRgn);
	GCData data = new GCData ();
	data.damageRgn = damageRgn;
	GC gc = GC.motif_new (this, data);
	OS.XSetRegion (xDisplay, gc.handle, damageRgn);
	int selStart = selection.x;
	int selEnd = selection.y;
	if (selStart > selEnd) {
	selStart = selection.y;
	selEnd = selection.x;
	}
	// temporary code to disable text selection
	selStart = selEnd = -1;
	int [] argList = {OS.XmNsensitive, 0};
	OS.XtGetValues (handle, argList, argList.length / 2);
	if (argList [1] == 0) gc.setForeground (disabledColor);
	layout.draw (gc, 0, 0, selStart, selEnd, null, null);
	if (hasFocus () && focusIndex != -1) {
	Rectangle [] rects = getRectangles (focusIndex);
	for (int i = 0; i < rects.length; i++) {
	Rectangle rect = rects [i];
	gc.drawFocus (rect.x, rect.y, rect.width, rect.height);
	}
	}
	gc.dispose ();
	OS.XDestroyRegion (damageRgn);
	return super.XExposure (w, client_data, call_data, continue_to_dispatch);
	}
	int XFocusChange (int w, int client_data, int call_data, int continue_to_dispatch) {
	int result = super.XFocusChange (w, client_data, call_data, continue_to_dispatch);
	redraw ();
	return result;
	}
	int XKeyPress (int w, int client_data, int call_data, int continue_to_dispatch) {
	int result = super.XKeyPress (w, client_data, call_data, continue_to_dispatch);
	if (result != 0) return result;
	if (focusIndex == -1) return result;
	XKeyEvent xEvent = new XKeyEvent ();
	OS.memmove (xEvent, call_data, XKeyEvent.sizeof);
	int [] keysym = new int [1];
	OS.XLookupString (xEvent, null, 0, keysym, null);
	keysym [0] &= 0xFFFF;
	switch (keysym [0]) {
	case OS.XK_space:
	case OS.XK_Return:
	case OS.XK_KP_Enter:
	Event event = new Event ();
	event.text = ids [focusIndex];
	sendEvent (SWT.Selection, event);
	break;
	case OS.XK_Tab:
	if (focusIndex < offsets.length - 1) {
	focusIndex++;
	redraw ();
	OS.memmove (continue_to_dispatch, new int [1], 4);
	return 1;
	}
	break;
	case OS.XK_ISO_Left_Tab:
	if (focusIndex > 0) {
	focusIndex--;
	redraw ();
	OS.memmove (continue_to_dispatch, new int [1], 4);
	return 1;
	}
	break;
	}
	return result;
	}
	int XPointerMotion (int w, int client_data, int call_data, int continue_to_dispatch) {
	int result = super.XPointerMotion (w, client_data, call_data, continue_to_dispatch);
	if (result != 0) return result;
	XMotionEvent xEvent = new XMotionEvent ();
	OS.memmove (xEvent, call_data, XMotionEvent.sizeof);
	if ((xEvent.state & OS.Button1Mask) != 0) {
	int oldSelection = selection.y;
	selection.y = layout.getOffset (xEvent.x, xEvent.y, null);
	if (selection.y != oldSelection) {
	int newSelection = selection.y;
	if (oldSelection > newSelection) {
	int temp = oldSelection;
	oldSelection = newSelection;
	newSelection = temp;
	}
	Rectangle rect = layout.getBounds (oldSelection, newSelection);
	redraw (rect.x, rect.y, rect.width, rect.height, false);
	}
	return result;
	}
	for (int j = 0; j < offsets.length; j++) {
	Rectangle [] rects = getRectangles (j);
	for (int i = 0; i < rects.length; i++) {
	Rectangle rect = rects [i];
	if (rect.contains (xEvent.x, xEvent.y)) {
	setCursor (display.getSystemCursor (SWT.CURSOR_HAND));
	return result;
	}
	}
	}
	setCursor (null);
	return result;
	}
	}