/******************************************************************************* * Copyright (c) 2000, 2004 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.custom;import org.eclipse.swt.SWT;import org.eclipse.swt.graphics.*;/** * A DisplayRenderer renders the content of a StyledText widget on  * a display device. */class DisplayRenderer extends StyledTextRenderer {	private StyledText parent;			// used to get content and styles during rendering	private int topIndex = -1;	private TextLayout[] layouts;	/** * Creates an instance of <class>DisplayRenderer</class>. * </p> * @param device Device to render on * @param regularFont Font to use for regular (non-bold) text * @param isBidi true=bidi platform, false=no bidi platform * @param leftMargin margin to the left of the text * @param parent <class>StyledText</class> widget to render * @param tabLength length in characters of a tab character */DisplayRenderer(Device device, Font regularFont, StyledText parent, int tabLength) {	super(device, regularFont);	this.parent = parent;	calculateLineHeight();	setTabLength(tabLength);}void dispose() {	super.dispose();	if (layouts != null) {		for (int i = 0; i < layouts.length; i++) {			TextLayout layout = layouts[i];			if (layout != null) super.disposeTextLayout(layout);		}		topIndex = -1;		layouts = null;	}}/** * Dispose the specified GC. * </p> * @param gc GC to dispose. */protected void disposeGC(GC gc) {	gc.dispose();}/**  * Draws the line delimiter selection if the selection extends beyond the given line. * </p> * * @param line the line to draw * @param lineOffset offset of the first character in the line. * 	Relative to the start of the document. * @param styles line styles * @param paintY y location to draw at * @param gc GC to draw on */protected void drawLineBreakSelection(String line, int lineOffset, int paintX, int paintY, GC gc) {	Point selection = parent.internalGetSelection();	int lineLength = line.length();	int selectionStart = Math.max(0, selection.x - lineOffset);	int selectionEnd = selection.y - lineOffset;	int lineEndSpaceWidth = getLineEndSpaceWidth();	int lineHeight = getLineHeight();		if (selectionEnd == selectionStart || selectionEnd < 0 || selectionStart > lineLength || selectionEnd <= lineLength) {		return;	}		gc.setBackground(parent.getSelectionBackground());	gc.setForeground(parent.getSelectionForeground());	if ((parent.getStyle() & SWT.FULL_SELECTION) != 0) {		Rectangle rect = getClientArea();		gc.fillRectangle(paintX, paintY, rect.width - paintX, lineHeight);	} else {		boolean isWrappedLine = false;		if (parent.internalGetWordWrap()) {			StyledTextContent content = getContent();			int lineEnd = lineOffset + lineLength;			int lineIndex = content.getLineAtOffset(lineEnd);			// is the start offset of the next line the same as the end 			// offset of this line?			if (lineIndex < content.getLineCount() - 1 &&				content.getOffsetAtLine(lineIndex + 1) == lineEnd) {				isWrappedLine = true;			}		}		if (isWrappedLine == false) {			// render the line break selection			gc.fillRectangle(paintX, paintY, lineEndSpaceWidth, lineHeight);		}	}	}/** * Returns the text segments that should be treated as if they  * had a different direction than the surrounding text. * </p> * * @param lineOffset offset of the first character in the line.  * 	0 based from the beginning of the document. * @param line text of the line to specify bidi segments for * @return text segments that should be treated as if they had a * 	different direction than the surrounding text. Only the start  * 	index of a segment is specified, relative to the start of the  * 	line. Always starts with 0 and ends with the line length.  * @exception IllegalArgumentException <ul> *    <li>ERROR_INVALID_ARGUMENT - if the segment indices returned  * 		by the listener do not start with 0, are not in ascending order, * 		exceed the line length or have duplicates</li> * </ul> */protected int[] getBidiSegments(int lineOffset, String lineText) {	if (!parent.isBidi()) return null;	return parent.getBidiSegments(lineOffset, lineText);}/** * Returns the visible client area that can be used for rendering. * </p> * @return the visible client area that can be used for rendering. */protected Rectangle getClientArea() {	return parent.getClientArea();}/** * Returns the <class>StyledTextContent</class> to use for line offset * calculations. * </p> * @return the <class>StyledTextContent</class> to use for line offset * calculations. */protected StyledTextContent getContent() {	return parent.internalGetContent();}/** * Returns a new GC to use for rendering and measuring. * When the GC is no longer used it needs to be disposed by  * calling disposeGC. * </p> * @return the GC to use for rendering and measuring. * @see disposeGC */protected GC getGC() {	return new GC(parent);}/** * Returns the horizontal scroll position. * </p> * @return the horizontal scroll position. */protected int getHorizontalPixel() {	return parent.internalGetHorizontalPixel();}protected int getLeftMargin() {	return parent.leftMargin;}/** * @see StyledTextRenderer#getLineBackgroundData */protected StyledTextEvent getLineBackgroundData(int lineOffset, String line) {	return parent.getLineBackgroundData(lineOffset, line);}/** * @see StyledTextRenderer#getLineStyleData */protected StyledTextEvent getLineStyleData(int lineOffset, String line) {	StyledTextEvent logicalLineEvent = parent.getLineStyleData(lineOffset, line);	if (logicalLineEvent != null) {		logicalLineEvent = getLineStyleData(logicalLineEvent, lineOffset, line);	}	return logicalLineEvent;}protected  int getOrientation () {	return parent.getOrientation();}protected int getRightMargin() {	return parent.rightMargin;}protected Color getSelectionBackground() {	return parent.getSelectionBackground();}protected Color getSelectionForeground() {	return parent.getSelectionForeground();}/** * @see StyledTextRenderer#getSelection */protected Point getSelection() {	return parent.internalGetSelection();}/** * @see StyledTextRenderer#getWordWrap */protected boolean getWordWrap() {	return parent.getWordWrap();}/** * @see StyledTextRenderer#isFullLineSelection */protected boolean isFullLineSelection() {	return (parent.getStyle() & SWT.FULL_SELECTION) != 0;}TextLayout createTextLayout(int lineOffset) {	if (!parent.internalGetWordWrap()) {		int lineIndex = getContent().getLineAtOffset(lineOffset);		updateTopIndex();		if (layouts != null) {			int layoutIndex = lineIndex - topIndex;			if (0 <= layoutIndex && layoutIndex < layouts.length) {				TextLayout layout = layouts[layoutIndex];				if (layout != null) return layout;				return layouts[layoutIndex] = super.createTextLayout(lineIndex); 			}		}	}	return super.createTextLayout(lineOffset);}void disposeTextLayout (TextLayout layout) {	if (layouts != null) {		for (int i=0; i<layouts.length; i++) {			if (layouts[i] == layout) return;		}	}	super.disposeTextLayout(layout);}void updateTopIndex() {	int verticalIncrement = parent.getVerticalIncrement();	int topIndex = verticalIncrement == 0 ? 0 : parent.verticalScrollOffset / verticalIncrement;	int newLength = Math.max(1 , parent.getPartialBottomIndex() - topIndex + 1);	if (layouts == null || topIndex != this.topIndex || newLength != layouts.length) {		TextLayout[] newLayouts = new TextLayout[newLength];		if (layouts != null) {			for(int i=0; i<layouts.length; i++) {				TextLayout layout = layouts[i];				if (layout != null) {					int layoutIndex = (i + this.topIndex) - topIndex;					if (0 <= layoutIndex && layoutIndex < newLayouts.length) {						newLayouts[layoutIndex] = layout;					} else {						super.disposeTextLayout(layout);					}				}			}		}		this.topIndex = topIndex;		layouts = newLayouts;	}}}