bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/graphics/TextLayout.java

/*******************************************************************************
 * 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.graphics;

import org.eclipse.swt.internal.cocoa.*;
import org.eclipse.swt.*;

/**
 * <code>TextLayout</code> is a graphic object that represents
 * styled text.
 * <p>
 * Instances of this class provide support for drawing, cursor
 * navigation, hit testing, text wrapping, alignment, tab expansion
 * line breaking, etc.  These are aspects required for rendering internationalized text.
 * </p><p>
 * Application code must explicitly invoke the <code>TextLayout#dispose()</code> 
 * method to release the operating system resources managed by each instance
 * when those instances are no longer required.
 * </p>
 * 
 *  @since 3.0
 */
public final class TextLayout extends Resource {
	
	NSTextStorage textStorage;
	NSLayoutManager layoutManager;
	NSTextContainer textContainer;
	Font font;
	String text;
	StyleItem[] styles;
	int spacing, ascent, descent, indent;
	boolean justify;
	int alignment;
	int[] tabs;
	int[] segments;
	int wrapWidth;
	int orientation;
	
	int[] lineOffsets;
	NSRect[] lineBounds;

	static class StyleItem {
		TextStyle style;
		int start;

		public String toString () {
			return "StyleItem {" + start + ", " + style + "}";
		}
	}

//	static final int TAB_COUNT = 32;
//	static final char ZWS = '\u200B';
//	
//	static final int UNDERLINE_IME_INPUT = 1 << 16;
//	static final int UNDERLINE_IME_TARGET_CONVERTED = 2 << 16;
//	static final int UNDERLINE_IME_CONVERTED = 3 << 16;
	
/**	 
 * Constructs a new instance of this class on the given device.
 * <p>
 * You must dispose the text layout when it is no longer required. 
 * </p>
 * 
 * @param device the device on which to allocate the text layout
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 * </ul>
 * 
 * @see #dispose()
 */
public TextLayout (Device device) {
	super(device);
	wrapWidth = ascent = descent = -1;
	alignment = SWT.LEFT;
	orientation = SWT.LEFT_TO_RIGHT;
	text = "";
	styles = new StyleItem[2];
	styles[0] = new StyleItem();
	styles[1] = new StyleItem();
	init();
}

void checkLayout() {
	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
}

void computeRuns() {
	if (textStorage != null) return;
	NSString str = NSString.stringWith(text);
	textStorage = ((NSTextStorage)new NSTextStorage().alloc());
	textStorage.initWithString_(str);
	layoutManager = (NSLayoutManager)new NSLayoutManager().alloc().init();
	textContainer = (NSTextContainer)new NSTextContainer().alloc();
	NSSize size = new NSSize();
	size.width = wrapWidth != -1 ? wrapWidth : Float.MAX_VALUE;
	size.height = Float.MAX_VALUE;
	textContainer.initWithContainerSize(size);
	textStorage.addLayoutManager(layoutManager);
	layoutManager.addTextContainer(textContainer);
	
	textStorage.beginEditing();
	Font defaultFont = font != null ? font : device.systemFont;
	NSRange range = new NSRange();
	range.length = str.length();
	textStorage.addAttribute(OS.NSFontAttributeName(), defaultFont.handle, range);
	
	NSMutableParagraphStyle paragraph = (NSMutableParagraphStyle)new NSMutableParagraphStyle().alloc().init();
	int align = OS.NSLeftTextAlignment;
	if (justify) {
		align = OS.NSJustifiedTextAlignment;
	} else {
		switch (alignment) {
			case SWT.CENTER:
				align = OS.NSCenterTextAlignment;
				break;
			case SWT.RIGHT:
				align = OS.NSRightTextAlignment;
		}
	}
	paragraph.setAlignment(align);
	paragraph.setLineSpacing(spacing);
	paragraph.setFirstLineHeadIndent(indent);
	
	//TODO tabs ascend descent wrap
	
	textStorage.addAttribute(OS.NSParagraphStyleAttributeName(), paragraph, range);
	paragraph.release();
	
	int textLength = str.length();
	for (int i = 0; i < styles.length - 1; i++) {
		StyleItem run = styles[i];
		if (run.style == null) continue;
		TextStyle style = run.style;		
		range.location = textLength != 0 ? translateOffset(run.start) : 0;
		range.length = translateOffset(styles[i + 1].start) - range.location;
		Font font = style.font;
		if (font != null) {
			textStorage.addAttribute(OS.NSFontAttributeName(), font.handle, range);
		}
		Color foreground = style.foreground;
		if (foreground != null) {
			NSColor color = NSColor.colorWithDeviceRed(foreground.handle[0], foreground.handle[1], foreground.handle[2], 1);
			textStorage.addAttribute(OS.NSForegroundColorAttributeName(), color, range);
		}
		Color background = style.background;
		if (background != null) {
			NSColor color = NSColor.colorWithDeviceRed(background.handle[0], background.handle[1], background.handle[2], 1);
			textStorage.addAttribute(OS.NSBackgroundColorAttributeName(), color, range);
		}
		if (style.strikeout) {
			textStorage.addAttribute(OS.NSStrikethroughStyleAttributeName(), NSNumber.numberWithInt(OS.NSUnderlineStyleSingle), range);
			Color strikeColor = style.strikeoutColor;
			if (strikeColor != null) {
				NSColor color = NSColor.colorWithDeviceRed(strikeColor.handle[0], strikeColor.handle[1], strikeColor.handle[2], 1);
				textStorage.addAttribute(OS.NSStrikethroughColorAttributeName(), color, range);
			}
		}
		if (style.underline) {
			//TODO - IME - thick
			int underlineStyle = 0;
			switch (style.underlineStyle) {
				case SWT.UNDERLINE_SINGLE:
					underlineStyle = OS.NSUnderlineStyleSingle;
					break;
				case SWT.UNDERLINE_DOUBLE:
					underlineStyle = OS.NSUnderlineStyleDouble;
					break;
			}
			if (underlineStyle != 0) {
				textStorage.addAttribute(OS.NSUnderlineStyleAttributeName(), NSNumber.numberWithInt(underlineStyle), range);
				Color underlineColor = style.underlineColor;
				if (underlineColor != null) {
					NSColor color = NSColor.colorWithDeviceRed(underlineColor.handle[0], underlineColor.handle[1], underlineColor.handle[2], 1);
					textStorage.addAttribute(OS.NSUnderlineColorAttributeName(), color, range);
				}
			}
		}
		if (style.rise != 0) {
			textStorage.addAttribute(OS.NSBaselineOffsetAttributeName(), NSNumber.numberWithInt(style.rise), range);
		}
		if (style.metrics != null) {
			//TODO
		}
	}
	textStorage.endEditing();
	
	textContainer.setLineFragmentPadding(0);	
	layoutManager.glyphRangeForTextContainer(textContainer);
	
	int numberOfLines, index, numberOfGlyphs = layoutManager.numberOfGlyphs();
	int rangePtr = OS.malloc(NSRange.sizeof);
	NSRange lineRange = new NSRange();
	for (numberOfLines = 0, index = 0; index < numberOfGlyphs; numberOfLines++){
	    layoutManager.lineFragmentUsedRectForGlyphAtIndex_effectiveRange_withoutAdditionalLayout_(index, rangePtr, true);
	    OS.memmove(lineRange, rangePtr, NSRange.sizeof);
	    index = lineRange.location + lineRange.length;
	}
	if (numberOfLines == 0) numberOfLines++;
	int[] offsets = new int[numberOfLines + 1];
	NSRect[] bounds = new NSRect[numberOfLines];
	for (numberOfLines = 0, index = 0; index < numberOfGlyphs; numberOfLines++){
		bounds[numberOfLines] = layoutManager.lineFragmentUsedRectForGlyphAtIndex_effectiveRange_withoutAdditionalLayout_(index, rangePtr, true);
	    OS.memmove(lineRange, rangePtr, NSRange.sizeof);
	    offsets[numberOfLines] = lineRange.location;
	    index = lineRange.location + lineRange.length;
	}
	if (numberOfLines == 0) {
		Font font = this.font != null ? this.font : device.systemFont;
		NSFont nsFont = font.handle;
		bounds[0] = new NSRect();
		bounds[0].height = Math.max(layoutManager.defaultLineHeightForFont(nsFont), ascent + descent);
	}
	OS.free(rangePtr);
	offsets[numberOfLines] = textStorage.length();
	this.lineOffsets = offsets;
	this.lineBounds = bounds;
}

void destroy() {
	freeRuns();
	font = null;
	text = null;
	styles = null;
}

/**
 * Draws the receiver's text using the specified GC at the specified
 * point.
 * 
 * @param gc the GC to draw
 * @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
 * </ul>
 */
public void draw(GC gc, int x, int y) {
	draw(gc, x, y, -1, -1, null, null);
}

/**
 * Draws the receiver's text using the specified GC at the specified
 * point.
 * 
 * @param gc the GC to draw
 * @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param selectionStart the offset where the selections starts, or -1 indicating no selection
 * @param selectionEnd the offset where the selections ends, or -1 indicating no selection
 * @param selectionForeground selection foreground, or NULL to use the system default color
 * @param selectionBackground selection background, or NULL to use the system default color
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
 * </ul>
 */
public void draw(GC gc, int x, int y, int selectionStart, int selectionEnd, Color selectionForeground, Color selectionBackground) {
	draw(gc, x, y, selectionStart, selectionEnd, selectionForeground, selectionBackground, 0);
}

/**
 * Draws the receiver's text using the specified GC at the specified
 * point.
 * <p>
 * The parameter <code>flags</code> can include one of <code>SWT.DELIMITER_SELECTION</code>
 * or <code>SWT.FULL_SELECTION</code> to specify the selection behavior on all lines except
 * for the last line, and can also include <code>SWT.LAST_LINE_SELECTION</code> to extend
 * the specified selection behavior to the last line.
 * </p>
 * @param gc the GC to draw
 * @param x the x coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param y the y coordinate of the top left corner of the rectangular area where the text is to be drawn
 * @param selectionStart the offset where the selections starts, or -1 indicating no selection
 * @param selectionEnd the offset where the selections ends, or -1 indicating no selection
 * @param selectionForeground selection foreground, or NULL to use the system default color
 * @param selectionBackground selection background, or NULL to use the system default color
 * @param flags drawing options
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
 * </ul>
 * 
 * @since 3.3
 */
public void draw(GC gc, int x, int y, int selectionStart, int selectionEnd, Color selectionForeground, Color selectionBackground, int flags) {
	checkLayout ();
	computeRuns();
	if (gc == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (gc.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (selectionForeground != null && selectionForeground.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (selectionBackground != null && selectionBackground.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	gc.checkGC(GC.CLIPPING | GC.TRANSFORM | GC.FOREGROUND);
//	float[] foreground = gc.data.foreground;
//	NSColor color = NSColor.colorWithDeviceRed(foreground[0], foreground[1], foreground[2], foreground[3]);
//	textStorage.setForegroundColor(color);
	NSPoint pt = new NSPoint();
	pt.x = x;
	pt.y = y;
	NSRange range = new NSRange();
	range.length = layoutManager.numberOfGlyphs();
	boolean hasSelection = selectionStart <= selectionEnd && selectionStart != -1 && selectionEnd != -1;
	NSRange selectionRange = null;
	if (hasSelection) {
		selectionRange = new NSRange();
		selectionRange.location = selectionStart;
		selectionRange.length = selectionEnd - selectionStart + 1;
		if (selectionBackground == null) selectionBackground = device.getSystemColor(SWT.COLOR_LIST_SELECTION);
		NSColor selectionColor = NSColor.colorWithDeviceRed(selectionBackground.handle[0], selectionBackground.handle[1], selectionBackground.handle[2], selectionBackground.handle[3]);
		layoutManager.addTemporaryAttribute(OS.NSBackgroundColorAttributeName, selectionColor, selectionRange);
	}
	//TODO draw selection for flags (LAST_LINE_SELECTION and FULL_SELECTION)
	if (range.length > 0) {
		layoutManager.drawBackgroundForGlyphRange(range, pt);
		layoutManager.drawGlyphsForGlyphRange(range, pt);
	}
	if (selectionRange != null) {
		layoutManager.removeTemporaryAttribute(OS.NSBackgroundColorAttributeName, selectionRange);
	}
}

void freeRuns() {
	if (textStorage == null) return;
	if (textStorage != null) {
		textStorage.release();
	}
	if (layoutManager != null) {
		layoutManager.release();
	}
	if (textContainer != null) {
		textContainer.release();
	}
	textStorage = null;
	layoutManager = null;
	textContainer = null;
}

/** 
 * Returns the receiver's horizontal text alignment, which will be one
 * of <code>SWT.LEFT</code>, <code>SWT.CENTER</code> or
 * <code>SWT.RIGHT</code>.
 *
 * @return the alignment used to positioned text horizontally
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getAlignment() {
	checkLayout();
	return alignment;
}

/**
 * Returns the ascent of the receiver.
 *
 * @return the ascent
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getDescent()
 * @see #setDescent(int)
 * @see #setAscent(int)
 * @see #getLineMetrics(int)
 */
public int getAscent () {
	checkLayout();	
	return ascent;
}

/**
 * Returns the bounds of the receiver.
 * 
 * @return the bounds of the receiver
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Rectangle getBounds() {
	checkLayout();
	computeRuns();
	NSRect rect = layoutManager.usedRectForTextContainer(textContainer);
	if (wrapWidth != -1) rect.width = wrapWidth;
	if (text.length() == 0) {
		Font font = this.font != null ? this.font : device.systemFont;
		NSFont nsFont = font.handle;
		rect.height = Math.max(rect.height, layoutManager.defaultLineHeightForFont(nsFont));
	}
	rect.height = Math.max(rect.height, ascent + descent);
	return new Rectangle(0, 0, (int)rect.width, (int)rect.height);
}

/**
 * Returns the bounds for the specified range of characters. The
 * bounds is the smallest rectangle that encompasses all characters
 * in the range. The start and end offsets are inclusive and will be
 * clamped if out of range.
 * 
 * @param start the start offset
 * @param end the end offset
 * @return the bounds of the character range
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Rectangle getBounds(int start, int end) {
	checkLayout();
	computeRuns();
	int length = text.length();
	if (length == 0) return new Rectangle(0, 0, 0, 0);
	if (start > end) return new Rectangle(0, 0, 0, 0);
	start = Math.min(Math.max(0, start), length - 1);
	end = Math.min(Math.max(0, end), length - 1);
	start = translateOffset(start);
	end = translateOffset(end);
	NSRange range = new NSRange();
	range.location = layoutManager.glyphIndexForCharacterAtIndex(start);
	range.length = layoutManager.glyphIndexForCharacterAtIndex(end + 1) - range.location;
	NSRect rect = layoutManager.boundingRectForGlyphRange(range, textContainer);
	return new Rectangle((int)rect.x, (int)rect.y, (int)Math.ceil(rect.width), (int)Math.ceil(rect.height));
}

/**
 * Returns the descent of the receiver.
 *
 * @return the descent
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getAscent()
 * @see #setAscent(int)
 * @see #setDescent(int)
 * @see #getLineMetrics(int)
 */
public int getDescent () {
	checkLayout();	
	return descent;
}

/** 
 * Returns the default font currently being used by the receiver
 * to draw and measure text.
 *
 * @return the receiver's font
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Font getFont () {
	checkLayout();
	return font;
}

/**
* Returns the receiver's indent.
*
* @return the receiver's indent
* 
* @exception SWTException <ul>
*    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
* </ul>
* 
* @since 3.2
*/
public int getIndent () {
	checkLayout();	
	return indent;
}

/**
* Returns the receiver's justification.
*
* @return the receiver's justification
* 
* @exception SWTException <ul>
*    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
* </ul>
* 
* @since 3.2
*/
public boolean getJustify () {
	checkLayout();
	return justify;
}

/**
 * Returns the embedding level for the specified character offset. The
 * embedding level is usually used to determine the directionality of a
 * character in bidirectional text.
 * 
 * @param offset the character offset
 * @return the embedding level
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the character offset is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 */
public int getLevel(int offset) {
	checkLayout();
	computeRuns();
	int length = text.length();
	if (!(0 <= offset && offset <= length)) SWT.error(SWT.ERROR_INVALID_RANGE);
	offset = translateOffset(offset);	
	int level = 0;
	//TODO
	return level;
}

/**
 * Returns the line offsets.  Each value in the array is the
 * offset for the first character in a line except for the last
 * value, which contains the length of the text.
 * 
 * @return the line offsets
 *  
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int[] getLineOffsets() {
	checkLayout ();
	computeRuns();
	int[] offsets = new int[lineOffsets.length];
	for (int i = 0; i < offsets.length; i++) {
		offsets[i] = untranslateOffset(lineOffsets[i]);
	}
	return offsets;
}

/**
 * Returns the index of the line that contains the specified
 * character offset.
 * 
 * @param offset the character offset
 * @return the line index
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the character offset is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getLineIndex(int offset) {
	checkLayout ();
	computeRuns();
	int length = text.length();
	if (!(0 <= offset && offset <= length)) SWT.error(SWT.ERROR_INVALID_RANGE);
	offset = translateOffset(offset);
	for (int line=0; line<lineOffsets.length - 1; line++) {
		if (lineOffsets[line + 1] > offset) {
			return line;
		}
	}
	return lineBounds.length - 1;
}

/**
 * Returns the bounds of the line for the specified line index.
 * 
 * @param lineIndex the line index
 * @return the line bounds 
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the line index is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Rectangle getLineBounds(int lineIndex) {
	checkLayout();
	computeRuns();
	if (!(0 <= lineIndex && lineIndex < lineBounds.length)) SWT.error(SWT.ERROR_INVALID_RANGE);
	NSRect rect = lineBounds[lineIndex];
	return new Rectangle((int)rect.x, (int)rect.y, (int)rect.width, (int)rect.height);
}

/**
 * Returns the receiver's line count. This includes lines caused
 * by wrapping.
 *
 * @return the line count
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getLineCount() {
	checkLayout ();
	computeRuns();	
	return lineOffsets.length - 1;
}

/**
 * Returns the font metrics for the specified line index.
 * 
 * @param lineIndex the line index
 * @return the font metrics 
 * 
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the line index is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public FontMetrics getLineMetrics (int lineIndex) {
	checkLayout ();
	computeRuns();
	int lineCount = getLineCount();
	if (!(0 <= lineIndex && lineIndex < lineCount)) SWT.error(SWT.ERROR_INVALID_RANGE);
	int length = text.length();
	if (length == 0) {
		Font font = this.font != null ? this.font : device.systemFont;
		NSFont nsFont = font.handle;
		int ascent = (int)(0.5f + nsFont.ascender());
		int descent = (int)(0.5f + (-nsFont.descender() + nsFont.leading()));	
		ascent = Math.max(ascent, this.ascent);
		descent = Math.max(descent, this.descent);
		return FontMetrics.cocoa_new(ascent, descent, 0, 0, ascent + descent);
	}
	Rectangle rect = getLineBounds(lineIndex);
	int baseline = (int)layoutManager.typesetter().baselineOffsetInLayoutManager(layoutManager, getLineOffsets()[lineIndex]);
	return FontMetrics.cocoa_new(rect.height - baseline, baseline, 0, 0, rect.height);
}

/**
 * Returns the location for the specified character offset. The
 * <code>trailing</code> argument indicates whether the offset
 * corresponds to the leading or trailing edge of the cluster.
 * 
 * @param offset the character offset
 * @param trailing the trailing flag
 * @return the location of the character offset
 *  
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getOffset(Point, int[])
 * @see #getOffset(int, int, int[])
 */
public Point getLocation(int offset, boolean trailing) {
	checkLayout();
	computeRuns();
	int length = text.length();
	if (!(0 <= offset && offset <= length)) SWT.error(SWT.ERROR_INVALID_RANGE);
	if (length == 0) return new Point(0, 0);
	offset = translateOffset(offset);
	int glyphIndex = layoutManager.glyphIndexForCharacterAtIndex(offset);
	NSRect rect = layoutManager.lineFragmentUsedRectForGlyphAtIndex_effectiveRange_(glyphIndex, 0);
	NSPoint point = layoutManager.locationForGlyphAtIndex(glyphIndex);
	if (trailing) {
		NSRange range = new NSRange();
		range.location = glyphIndex;
		range.length = 1;
		NSRect bounds = layoutManager.boundingRectForGlyphRange(range, textContainer);
		point.x += bounds.width;
	}
	return new Point((int)point.x, (int)rect.y);
}

/**
 * Returns the next offset for the specified offset and movement
 * type.  The movement is one of <code>SWT.MOVEMENT_CHAR</code>, 
 * <code>SWT.MOVEMENT_CLUSTER</code>, <code>SWT.MOVEMENT_WORD</code>,
 * <code>SWT.MOVEMENT_WORD_END</code> or <code>SWT.MOVEMENT_WORD_START</code>.
 * 
 * @param offset the start offset
 * @param movement the movement type 
 * @return the next offset
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the offset is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getPreviousOffset(int, int)
 */
public int getNextOffset (int offset, int movement) {
	return _getOffset(offset, movement, true);
}

int _getOffset (int offset, int movement, boolean forward) {
	checkLayout();
	computeRuns();
	int length = text.length();
	if (!(0 <= offset && offset <= length)) SWT.error(SWT.ERROR_INVALID_RANGE);
	if (length == 0) return 0;
	offset = translateOffset(offset);
	switch (movement) {
		case SWT.MOVEMENT_CLUSTER://TODO cluster
		case SWT.MOVEMENT_CHAR: {
			if (forward) {
				offset++;
			} else {
				offset--;
			}
			return untranslateOffset(offset);
		}
		case SWT.MOVEMENT_WORD: {
			return untranslateOffset(textStorage.nextWordFromIndex(offset, forward));
		}
		case SWT.MOVEMENT_WORD_END: {
			NSRange range = textStorage.doubleClickAtIndex(offset);
			return untranslateOffset(range.location + range.length);
		}
		case SWT.MOVEMENT_WORD_START: {
			NSRange range = textStorage.doubleClickAtIndex(offset);
			return untranslateOffset(range.location);
		}
		default:
			break;
	}
	return -1;
}

/**
 * Returns the character offset for the specified point.  
 * For a typical character, the trailing argument will be filled in to 
 * indicate whether the point is closer to the leading edge (0) or
 * the trailing edge (1).  When the point is over a cluster composed 
 * of multiple characters, the trailing argument will be filled with the 
 * position of the character in the cluster that is closest to
 * the point.
 * 
 * @param point the point
 * @param trailing the trailing buffer
 * @return the character offset
 *  
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the trailing length is less than <code>1</code></li>
 *    <li>ERROR_NULL_ARGUMENT - if the point is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getLocation(int, boolean)
 */
public int getOffset(Point point, int[] trailing) {
	checkLayout();
	computeRuns();
	if (point == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	return getOffset(point.x, point.y, trailing);
}

/**
 * Returns the character offset for the specified point.  
 * For a typical character, the trailing argument will be filled in to 
 * indicate whether the point is closer to the leading edge (0) or
 * the trailing edge (1).  When the point is over a cluster composed 
 * of multiple characters, the trailing argument will be filled with the 
 * position of the character in the cluster that is closest to
 * the point.
 * 
 * @param x the x coordinate of the point
 * @param y the y coordinate of the point
 * @param trailing the trailing buffer
 * @return the character offset
 *  
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the trailing length is less than <code>1</code></li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getLocation(int, boolean)
 */
public int getOffset(int x, int y, int[] trailing) {
	checkLayout();
	computeRuns();
	if (trailing != null && trailing.length < 1) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	int length = text.length();
	if (length == 0) return 0;
	NSPoint pt = new NSPoint();
	pt.x = x;
	pt.y = y;
	float[] partialFration = new float[1];
	int glyphIndex = layoutManager.glyphIndexForPoint_inTextContainer_fractionOfDistanceThroughGlyph_(pt, textContainer, partialFration);
	int offset = layoutManager.characterIndexForGlyphAtIndex(glyphIndex);
	if (trailing != null) trailing[0] = Math.round(partialFration[0]);
	return Math.min(untranslateOffset(offset), length - 1);
}

/**
 * Returns the orientation of the receiver.
 *
 * @return the orientation style
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getOrientation() {
	checkLayout();
	return orientation;
}

/**
 * Returns the previous offset for the specified offset and movement
 * type.  The movement is one of <code>SWT.MOVEMENT_CHAR</code>, 
 * <code>SWT.MOVEMENT_CLUSTER</code> or <code>SWT.MOVEMENT_WORD</code>,
 * <code>SWT.MOVEMENT_WORD_END</code> or <code>SWT.MOVEMENT_WORD_START</code>.
 * 
 * @param offset the start offset
 * @param movement the movement type 
 * @return the previous offset
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the offset is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getNextOffset(int, int)
 */
public int getPreviousOffset (int index, int movement) {
	return _getOffset(index, movement, false);
}

/**
 * Gets the ranges of text that are associated with a <code>TextStyle</code>.
 *
 * @return the ranges, an array of offsets representing the start and end of each
 * text style. 
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getStyles()
 * 
 * @since 3.2
 */
public int[] getRanges () {
	checkLayout();
	int[] result = new int[styles.length * 2];
	int count = 0;
	for (int i=0; i<styles.length - 1; i++) {
		if (styles[i].style != null) {
			result[count++] = styles[i].start;
			result[count++] = styles[i + 1].start - 1;
		}
	}
	if (count != result.length) {
		int[] newResult = new int[count];
		System.arraycopy(result, 0, newResult, 0, count);
		result = newResult;
	}
	return result;
}

/**
 * Returns the text segments offsets of the receiver.
 *
 * @return the text segments offsets
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int[] getSegments() {
	checkLayout();
	return segments;
}

/**
 * Returns the line spacing of the receiver.
 *
 * @return the line spacing
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getSpacing () {
	checkLayout();	
	return spacing;
}

/**
 * Gets the style of the receiver at the specified character offset.
 *
 * @param offset the text offset
 * @return the style or <code>null</code> if not set
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the character offset is out of range</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public TextStyle getStyle (int offset) {
	checkLayout();
	int length = text.length();
	if (!(0 <= offset && offset < length)) SWT.error(SWT.ERROR_INVALID_RANGE);
	for (int i=1; i<styles.length; i++) {
		StyleItem item = styles[i];
		if (item.start > offset) {
			return styles[i - 1].style;
		}
	}
	return null;
}

/**
 * Gets all styles of the receiver.
 *
 * @return the styles
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #getRanges()
 * 
 * @since 3.2
 */
public TextStyle[] getStyles () {
	checkLayout();
	TextStyle[] result = new TextStyle[styles.length];
	int count = 0;
	for (int i=0; i<styles.length; i++) {
		if (styles[i].style != null) {
			result[count++] = styles[i].style;
		}
	}
	if (count != result.length) {
		TextStyle[] newResult = new TextStyle[count];
		System.arraycopy(result, 0, newResult, 0, count);
		result = newResult;
	}
	return result;
}

/**
 * Returns the tab list of the receiver.
 *
 * @return the tab list
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int[] getTabs() {
	checkLayout();
	return tabs;
}

/**
 * Gets 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_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public String getText () {
	checkLayout ();
	return text;
}

/**
 * Returns the width of the receiver.
 *
 * @return the width
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public int getWidth () {
	checkLayout();
	return wrapWidth;
}

/**
 * Returns <code>true</code> if the text layout has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the text layout.
 * When a text layout has been disposed, it is an error to
 * invoke any other method using the text layout.
 * </p>
 *
 * @return <code>true</code> when the text layout is disposed and <code>false</code> otherwise
 */
public boolean isDisposed () {
	return device == null;
}

/**
 * Sets the text alignment for the receiver. The alignment controls
 * how a line of text is positioned horizontally. The argument should
 * be one of <code>SWT.LEFT</code>, <code>SWT.RIGHT</code> or <code>SWT.CENTER</code>.
 * <p>
 * The default alignment is <code>SWT.LEFT</code>.  Note that the receiver's
 * width must be set in order to use <code>SWT.RIGHT</code> or <code>SWT.CENTER</code>
 * alignment.
 * </p>
 *
 * @param alignment the new alignment 
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #setWidth(int)
 */
public void setAlignment (int alignment) {
	checkLayout();
	int mask = SWT.LEFT | SWT.CENTER | SWT.RIGHT;
	alignment &= mask;
	if (alignment == 0) return;
	if ((alignment & SWT.LEFT) != 0) alignment = SWT.LEFT;
	if ((alignment & SWT.RIGHT) != 0) alignment = SWT.RIGHT;
	if (this.alignment == alignment) return;
	freeRuns();
	this.alignment = alignment;
}

/**
 * Sets the ascent of the receiver. The ascent is distance in pixels
 * from the baseline to the top of the line and it is applied to all
 * lines. The default value is <code>-1</code> which means that the
 * ascent is calculated from the line fonts.
 *
 * @param ascent the new ascent
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the ascent is less than <code>-1</code></li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #setDescent(int)
 * @see #getLineMetrics(int)
 */
public void setAscent (int ascent) {
	checkLayout ();
	if (ascent < -1) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (this.ascent == ascent) return;
	freeRuns();
	this.ascent = ascent;
}

/**
 * Sets the descent of the receiver. The descent is distance in pixels
 * from the baseline to the bottom of the line and it is applied to all
 * lines. The default value is <code>-1</code> which means that the
 * descent is calculated from the line fonts.
 *
 * @param descent the new descent
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the descent is less than <code>-1</code></li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #setAscent(int)
 * @see #getLineMetrics(int)
 */
public void setDescent (int descent) {
	checkLayout ();
	if (descent < -1) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (this.descent == descent) return;
	freeRuns();
	this.descent = descent;
}

/** 
 * Sets the default font which will be used by the receiver
 * to draw and measure text. If the
 * argument is null, then a default font appropriate
 * for the platform will be used instead. Note that a text
 * style can override the default font.
 *
 * @param font the new font for the receiver, or null to indicate a default font
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the font has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setFont (Font font) {
	checkLayout ();
	if (font != null && font.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	Font oldFont = this.font;
	if (oldFont == font) return;
	this.font = font;
	if (oldFont != null && oldFont.equals(font)) return;
	freeRuns();
}

/**
 * Sets the indent of the receiver. This indent it applied of the first line of 
 * each paragraph.  
 *
 * @param indent new indent
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.2
 */
public void setIndent (int indent) {
	checkLayout ();
	if (indent < 0) return;
	if (this.indent == indent) return;
	freeRuns();
	this.indent = indent;
}

/**
 * Sets the justification of the receiver. Note that the receiver's
 * width must be set in order to use justification. 
 *
 * @param justify new justify
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @since 3.2
 */
public void setJustify (boolean justify) {
	checkLayout ();
	if (justify == this.justify) return;
	freeRuns();
	this.justify = justify;
}

/**
 * Sets the orientation of the receiver, which must be one
 * of <code>SWT.LEFT_TO_RIGHT</code> or <code>SWT.RIGHT_TO_LEFT</code>.
 *
 * @param orientation new orientation style
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setOrientation(int orientation) {
	checkLayout();
	int mask = SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
	orientation &= mask;
	if (orientation == 0) return;
	if ((orientation & SWT.LEFT_TO_RIGHT) != 0) orientation = SWT.LEFT_TO_RIGHT;
	if (this.orientation == orientation) return;
	this.orientation = orientation;
	freeRuns();
}

/**
 * Sets the offsets of the receiver's text segments. Text segments are used to
 * override the default behaviour of the bidirectional algorithm.
 * Bidirectional reordering can happen within a text segment but not 
 * between two adjacent segments.
 * <p>
 * Each text segment is determined by two consecutive offsets in the 
 * <code>segments</code> arrays. The first element of the array should 
 * always be zero and the last one should always be equals to length of
 * the text.
 * </p>
 * 
 * @param segments the text segments offset
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setSegments(int[] segments) {
	checkLayout();
	if (this.segments == null && segments == null) return;
	if (this.segments != null && segments !=null) {
		if (this.segments.length == segments.length) {
			int i;
			for (i = 0; i <segments.length; i++) {
				if (this.segments[i] != segments[i]) break;
			}
			if (i == segments.length) return;
		}
	}
	freeRuns();
	this.segments = segments;
}

/**
 * Sets the line spacing of the receiver.  The line spacing
 * is the space left between lines.
 *
 * @param spacing the new line spacing 
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the spacing is negative</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setSpacing (int spacing) {
	checkLayout();
	if (spacing < 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (this.spacing == spacing) return;
	freeRuns();
	this.spacing = spacing;
}

/**
 * Sets the style of the receiver for the specified range.  Styles previously
 * set for that range will be overwritten.  The start and end offsets are
 * inclusive and will be clamped if out of range.
 * 
 * @param style the style
 * @param start the start offset
 * @param end the end offset
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setStyle (TextStyle style, int start, int end) {
	checkLayout();
	int length = text.length();
	if (length == 0) return;
	if (start > end) return;
	start = Math.min(Math.max(0, start), length - 1);
	end = Math.min(Math.max(0, end), length - 1);
	int low = -1;
	int high = styles.length;
	while (high - low > 1) {
		int index = (high + low) / 2;
		if (styles[index + 1].start > start) {
			high = index;
		} else {
			low = index;
		}
	}
	if (0 <= high && high < styles.length) {
		StyleItem item = styles[high];
		if (item.start == start && styles[high + 1].start - 1 == end) {
			if (style == null) {
				if (item.style == null) return;
			} else {
				if (style.equals(item.style)) return;
			}
		}
	}
	freeRuns();
	int modifyStart = high;
	int modifyEnd = modifyStart;
	while (modifyEnd < styles.length) {
		if (styles[modifyEnd + 1].start > end) break;
		modifyEnd++;
	}
	if (modifyStart == modifyEnd) {
		int styleStart = styles[modifyStart].start; 
		int styleEnd = styles[modifyEnd + 1].start - 1;
		if (styleStart == start && styleEnd == end) {
			styles[modifyStart].style = style;
			return;
		}
		if (styleStart != start && styleEnd != end) {
			StyleItem[] newStyles = new StyleItem[styles.length + 2];
			System.arraycopy(styles, 0, newStyles, 0, modifyStart + 1);
			StyleItem item = new StyleItem();
			item.start = start;
			item.style = style;
			newStyles[modifyStart + 1] = item;	
			item = new StyleItem();
			item.start = end + 1;
			item.style = styles[modifyStart].style;
			newStyles[modifyStart + 2] = item;
			System.arraycopy(styles, modifyEnd + 1, newStyles, modifyEnd + 3, styles.length - modifyEnd - 1);
			styles = newStyles;
			return;
		}
	}
	if (start == styles[modifyStart].start) modifyStart--;
	if (end == styles[modifyEnd + 1].start - 1) modifyEnd++;
	int newLength = styles.length + 1 - (modifyEnd - modifyStart - 1);
	StyleItem[] newStyles = new StyleItem[newLength];
	System.arraycopy(styles, 0, newStyles, 0, modifyStart + 1);	
	StyleItem item = new StyleItem();
	item.start = start;
	item.style = style;
	newStyles[modifyStart + 1] = item;
	styles[modifyEnd].start = end + 1;
	System.arraycopy(styles, modifyEnd, newStyles, modifyStart + 2, styles.length - modifyEnd);
	styles = newStyles;
}

/**
 * Sets the receiver's tab list. Each value in the tab list specifies
 * the space in pixels from the origin of the text layout to the respective
 * tab stop.  The last tab stop width is repeated continuously.
 * 
 * @param tabs the new tab list
 * 
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setTabs(int[] tabs) {
	checkLayout();
	if (this.tabs == null && tabs == null) return;
	if (this.tabs != null && tabs !=null) {
		if (this.tabs.length == tabs.length) {
			int i;
			for (i = 0; i < tabs.length; i++) {
				if (this.tabs[i] != tabs[i]) break;
			}
			if (i == tabs.length) return;
		}
	}
	freeRuns();
	this.tabs = tabs;
}

/**
 * Sets the receiver's text.
 *
 * @param text the new text
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the text is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setText (String text) {
	checkLayout ();
	if (text == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (text.equals(this.text)) return;
	freeRuns();
	this.text = text;
	styles = new StyleItem[2];
	styles[0] = new StyleItem();
	styles[1] = new StyleItem();
	styles[styles.length - 1].start = text.length();
}

/**
 * Sets the line width of the receiver, which determines how
 * text should be wrapped and aligned. The default value is
 * <code>-1</code> which means wrapping is disabled.
 *
 * @param width the new width 
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the width is <code>0</code> or less than <code>-1</code></li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 * 
 * @see #setAlignment(int)
 */
public void setWidth (int width) {
	checkLayout();
	if (width < -1 || width == 0) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (this.wrapWidth == width) return;
	freeRuns();
	this.wrapWidth = width;
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the receiver
 */
public String toString () {
	if (isDisposed()) return "TextLayout {*DISPOSED*}";
	return "TextLayout {" + text + "}";
}

/*
 *  Translate a client offset to an internal offset
 */
int translateOffset (int offset) {
	return offset;
}

/*
 *  Translate an internal offset to a client offset
 */
int untranslateOffset (int offset) {
	return offset;
}

}