styledtext.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

/*******************************************************************************
 * 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 java.util.*;

import org.eclipse.swt.*;
import org.eclipse.swt.accessibility.*;
import org.eclipse.swt.dnd.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.printing.*;
import org.eclipse.swt.widgets.*;

/**
 * A StyledText is an editable user interface object that displays lines 
 * of text.  The following style attributes can be defined for the text: 
 * <ul>
 * <li>foreground color 
 * <li>background color
 * <li>font style (bold, regular)
 * </ul>
 * <p>
 * In addition to text style attributes, the background color of a line may 
 * be specified.
 * </p>
 * <p>
 * There are two ways to use this widget when specifying text style information.  
 * You may use the API that is defined for StyledText or you may define your own 
 * LineStyleListener.  If you define your own listener, you will be responsible 
 * for maintaining the text style information for the widget.  IMPORTANT: You may 
 * not define your own listener and use the StyledText API.  The following
 * StyledText API is not supported if you have defined a LineStyleListener:
 * <ul>
 * <li>getStyleRangeAtOffset(int)
 * <li>getStyleRanges()
 * <li>replaceStyleRanges(int,int,StyleRange[])
 * <li>setStyleRange(StyleRange)
 * <li>setStyleRanges(StyleRange[])
 * </ul>
 * </p>
 * <p>
 * There are two ways to use this widget when specifying line background colors.
 * You may use the API that is defined for StyledText or you may define your own 
 * LineBackgroundListener.  If you define your own listener, you will be responsible 
 * for maintaining the line background color information for the widget.  
 * IMPORTANT: You may not define your own listener and use the StyledText API.  
 * The following StyledText API is not supported if you have defined a 
 * LineBackgroundListener:
 * <ul>
 * <li>getLineBackground(int)
 * <li>setLineBackground(int,int,Color)
 * </ul>
 * </p>
 * <p>
 * The content implementation for this widget may also be user-defined.  To do so,
 * you must implement the StyledTextContent interface and use the StyledText API
 * setContent(StyledTextContent) to initialize the widget. 
 * </p>
 * <p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 * <dl>
 * <dt><b>Styles:</b><dd>FULL_SELECTION, MULTI, READ_ONLY, SINGLE, WRAP
 * <dt><b>Events:</b><dd>ExtendedModify, LineGetBackground, LineGetSegments, LineGetStyle, Modify, Selection, Verify, VerifyKey
 * </dl>
 */
public class StyledText extends Canvas {
	static final char TAB = '\t';
	static final String PlatformLineDelimiter = System.getProperty("line.separator");
	static final int BIDI_CARET_WIDTH = 3;
	static final int DEFAULT_WIDTH	= 64;
	static final int DEFAULT_HEIGHT = 64;
	
	static final int ExtendedModify = 3000;
	static final int LineGetBackground = 3001;
	static final int LineGetStyle = 3002;
	static final int TextChanging = 3003;
	static final int TextSet = 3004;
	static final int VerifyKey = 3005;
	static final int TextChanged = 3006;
	static final int LineGetSegments = 3007;
	
	Color selectionBackground;	// selection background color
	Color selectionForeground;	// selection foreground color
	StyledTextContent logicalContent;	// native content (default or user specified)
	StyledTextContent content;			// line wrapping content, same as logicalContent if word wrap is off
	DisplayRenderer renderer;
	Listener listener;
	TextChangeListener textChangeListener;	// listener for TextChanging, TextChanged and TextSet events from StyledTextContent
	DefaultLineStyler defaultLineStyler;// used for setStyles API when no LineStyleListener is registered
	LineCache lineCache;
	boolean userLineStyle = false;		// true=widget is using a user defined line style listener for line styles. false=widget is using the default line styler to store line styles
	boolean userLineBackground = false;	// true=widget is using a user defined line background listener for line backgrounds. false=widget is using the default line styler to store line backgrounds
	int verticalScrollOffset = 0;		// pixel based
	int horizontalScrollOffset = 0;		// pixel based
	int topIndex = 0;					// top visible line
	int lastPaintTopIndex = -1;
	int topOffset = 0;					// offset of first character in top line
	int clientAreaHeight = 0;			// the client area height. Needed to calculate content width for new 
										// visible lines during Resize callback
	int clientAreaWidth = 0;			// the client area width. Needed during Resize callback to determine 
										// if line wrap needs to be recalculated
	int lineHeight;						// line height=font height
	int tabLength = 4;					// number of characters in a tab
	int leftMargin;
	int topMargin;
	int rightMargin;
	int bottomMargin;
	Cursor ibeamCursor;		
	int columnX;							// keep track of the horizontal caret position
										// when changing lines/pages. Fixes bug 5935
	int caretOffset = 0;
	Point selection = new Point(0, 0);	// x and y are start and end caret offsets of selection
	int selectionAnchor;				// position of selection anchor. 0 based offset from beginning of text
	Point doubleClickSelection;			// selection after last mouse double click
	boolean editable = true;
	boolean wordWrap = false;
	boolean doubleClickEnabled = true;	// see getDoubleClickEnabled 
	boolean overwrite = false;			// insert/overwrite edit mode
	int textLimit = -1;					// limits the number of characters the user can type in the widget. Unlimited by default.
	Hashtable keyActionMap = new Hashtable();
	Color background = null;			// workaround for bug 4791
	Color foreground = null;			//
	Clipboard clipboard;
	boolean mouseDoubleClick = false;	// true=a double click ocurred. Don't do mouse swipe selection.
	int autoScrollDirection = SWT.NULL;	// the direction of autoscrolling (up, down, right, left)
	int lastTextChangeStart;			// cache data of the 
	int lastTextChangeNewLineCount;		// last text changing 
	int lastTextChangeNewCharCount;		// event for use in the 
	int lastTextChangeReplaceLineCount;	// text changed handler
	int lastTextChangeReplaceCharCount;	
	boolean isBidi;
	boolean isMirrored;
	boolean bidiColoring = false;		// apply the BIDI algorithm on text segments of the same color
	Image leftCaretBitmap = null;
	Image rightCaretBitmap = null;
	int caretDirection = SWT.NULL;
	boolean advancing = true;
	Caret defaultCaret = null;
	boolean updateCaretDirection = true;

	final static boolean IS_CARBON;
	final static boolean DOUBLE_BUFFERED;	
	static {
		String platform = SWT.getPlatform();
		IS_CARBON = "carbon".equals(platform);
		DOUBLE_BUFFERED = !("carbon".equals(platform) || "gtk".equals(platform));
	}

	/**
	 * The Printing class implements printing of a range of text.
	 * An instance of <class>Printing </class> is returned in the 
	 * StyledText#print(Printer) API. The run() method may be 
	 * invoked from any thread.
	 */
	static class Printing implements Runnable {
		final static int LEFT = 0;						// left aligned header/footer segment
		final static int CENTER = 1;					// centered header/footer segment
		final static int RIGHT = 2;						// right aligned header/footer segment

		StyledText parent;
		Printer printer;
		PrintRenderer renderer;
		StyledTextPrintOptions printOptions;
		StyledTextContent printerContent;				// copy of the widget content
		Rectangle clientArea;							// client area to print on
		Font printerFont;
		FontData displayFontData;
		Hashtable printerColors;						// printer color cache for line backgrounds and style
		Hashtable lineBackgrounds = new Hashtable();	// cached line backgrounds
		Hashtable lineStyles = new Hashtable();			// cached line styles
		Hashtable bidiSegments = new Hashtable();		// cached bidi segments when running on a bidi platform
		GC gc;											// printer GC
		int pageWidth;									// width of a printer page in pixels
		int startPage;									// first page to print
		int endPage;									// last page to print
		int pageSize;									// number of lines on a page
		int startLine;									// first (wrapped) line to print
		int endLine;									// last (wrapped) line to print
		boolean singleLine;								// widget single line mode
		Point selection = null;					// selected text

	/**
	 * Creates an instance of <class>Printing</class>.
	 * Copies the widget content and rendering data that needs 
	 * to be requested from listeners.
	 * </p>
	 * @param parent StyledText widget to print.
	 * @param printer printer device to print on.
	 * @param printOptions print options
	 */		
	Printing(StyledText parent, Printer printer, StyledTextPrintOptions printOptions) {
		PrinterData data = printer.getPrinterData();

		this.parent = parent;
		this.printer = printer;
		this.printOptions = printOptions;
		singleLine = parent.isSingleLine();
		startPage = 1;
		endPage = Integer.MAX_VALUE;
		if (data.scope == PrinterData.PAGE_RANGE) {
			startPage = data.startPage;
			endPage = data.endPage;
			if (endPage < startPage) {
				int temp = endPage;
				endPage = startPage;
				startPage = temp;
			}			
		} 
		else 
		if (data.scope == PrinterData.SELECTION) {
			selection = parent.getSelectionRange();
		}

		displayFontData = parent.getFont().getFontData()[0];
		copyContent(parent.getContent());
		cacheLineData(printerContent);
	}
	/**
	 * Caches the bidi segments of the given line.
	 * </p>
	 * @param lineOffset offset of the line to cache bidi segments for. 
	 * 	Relative to the start of the document.
	 * @param line line to cache bidi segments for. 
	 */
	void cacheBidiSegments(int lineOffset, String line) {
		int[] segments = parent.getBidiSegments(lineOffset, line);
		
		if (segments != null) {
			bidiSegments.put(new Integer(lineOffset), segments);
		}
	}
	/**
	 * Caches the line background color of the given line.
	 * </p>
	 * @param lineOffset offset of the line to cache the background 
	 * 	color for. Relative to the start of the document.
	 * @param line line to cache the background color for
	 */
	void cacheLineBackground(int lineOffset, String line) {
		StyledTextEvent event = parent.getLineBackgroundData(lineOffset, line);
		
		if (event != null) {
			lineBackgrounds.put(new Integer(lineOffset), event);
		}
	}
	/**
	 * Caches all line data that needs to be requested from a listener.
	 * </p>
	 * @param printerContent <class>StyledTextContent</class> to request 
	 * 	line data for.
	 */
	void cacheLineData(StyledTextContent printerContent) {	
		for (int i = 0; i < printerContent.getLineCount(); i++) {
			int lineOffset = printerContent.getOffsetAtLine(i);
			String line = printerContent.getLine(i);
	
			if (printOptions.printLineBackground) {
				cacheLineBackground(lineOffset, line);
			}
			if (printOptions.printTextBackground ||
				printOptions.printTextForeground ||
				printOptions.printTextFontStyle) {
				cacheLineStyle(lineOffset, line);
			}
			if (parent.isBidi()) {
				cacheBidiSegments(lineOffset, line);
			}
		}
	}
	/**
	 * Caches all line styles of the given line.
	 * </p>
	 * @param lineOffset offset of the line to cache the styles for.
	 * 	Relative to the start of the document.
	 * @param line line to cache the styles for.
	 */
	void cacheLineStyle(int lineOffset, String line) {
		StyledTextEvent event = parent.getLineStyleData(lineOffset, line);
		
		if (event != null) {
			StyleRange[] styles = event.styles;
			for (int i = 0; i < styles.length; i++) {
				StyleRange styleCopy = null;
				if (printOptions.printTextBackground == false && styles[i].background != null) {
					styleCopy = (StyleRange) styles[i].clone();
					styleCopy.background = null;
				}
				if (printOptions.printTextForeground == false && styles[i].foreground != null) {
					if (styleCopy == null) {
						styleCopy = (StyleRange) styles[i].clone();
					}
					styleCopy.foreground = null;
				}
				if (printOptions.printTextFontStyle == false && styles[i].fontStyle != SWT.NORMAL) {
					if (styleCopy == null) {
						styleCopy = (StyleRange) styles[i].clone();
					}
					styleCopy.fontStyle = SWT.NORMAL;
				}
				if (styleCopy != null) {
					styles[i] = styleCopy;
				}
			}	
			lineStyles.put(new Integer(lineOffset), event);
		}
	}
	/**
	 * Copies the text of the specified <class>StyledTextContent</class>.
	 * </p>
	 * @param original the <class>StyledTextContent</class> to copy.
	 */
	void copyContent(StyledTextContent original) {
		int insertOffset = 0;
		
		printerContent = new DefaultContent();
		for (int i = 0; i < original.getLineCount(); i++) {
			int insertEndOffset;
			if (i < original.getLineCount() - 1) {
				insertEndOffset = original.getOffsetAtLine(i + 1);
			}
			else {
				insertEndOffset = original.getCharCount();
			}
			printerContent.replaceTextRange(insertOffset, 0, original.getTextRange(insertOffset, insertEndOffset - insertOffset));
			insertOffset = insertEndOffset;
		}
	}
	/**
	 * Replaces all display colors in the cached line backgrounds and 
	 * line styles with printer colors.
	 */
	void createPrinterColors() {
		Enumeration values = lineBackgrounds.elements();
		printerColors = new Hashtable();
		while (values.hasMoreElements()) {
			StyledTextEvent event = (StyledTextEvent) values.nextElement();
			event.lineBackground = getPrinterColor(event.lineBackground);
		}
		
		values = lineStyles.elements();
		while (values.hasMoreElements()) {
			StyledTextEvent event = (StyledTextEvent) values.nextElement();
			for (int i = 0; i < event.styles.length; i++) {
				StyleRange style = event.styles[i];
				Color printerBackground = getPrinterColor(style.background);
				Color printerForeground = getPrinterColor(style.foreground);
				
				if (printerBackground != style.background || 
					printerForeground != style.foreground) {
					style = (StyleRange) style.clone();
					style.background = printerBackground;
					style.foreground = printerForeground;
					event.styles[i] = style;
				}
			}
		}		
	}
	/**
	 * Disposes of the resources and the <class>PrintRenderer</class>.
	 */
	void dispose() {
		if (printerColors != null) {
			Enumeration colors = printerColors.elements();
			
			while (colors.hasMoreElements()) {
				Color color = (Color) colors.nextElement();
				color.dispose();
			}
			printerColors = null;
		}
		if (gc != null) {
			gc.dispose();
			gc = null;
		}
		if (printerFont != null) {
			printerFont.dispose();
			printerFont = null;
		}
		if (renderer != null) {