styledtext.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 * 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 widget which will be the parent of the new instance (cannot be null)
 * @param style the style of widget 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>
 * </ul>
 *
 * @see SWT#FULL_SELECTION
 * @see SWT#MULTI
 * @see SWT#READ_ONLY
 * @see SWT#SINGLE
 * @see SWT#WRAP
 * @see #getStyle
 */
public StyledText(Composite parent, int style) {
	super(parent, checkStyle(style | SWT.NO_REDRAW_RESIZE | SWT.NO_BACKGROUND));
	// set the bg/fg in the OS to ensure that these are the same as StyledText, necessary
	// for ensuring that the bg/fg the IME box uses is the same as what StyledText uses
	super.setForeground(getForeground());
	super.setBackground(getBackground());
	Display display = getDisplay();
	isMirrored = (super.getStyle() & SWT.MIRRORED) != 0;
	isBidi = BidiUtil.isBidiPlatform() || isMirrored;
	if ((style & SWT.READ_ONLY) != 0) {
		setEditable(false);
	}
	leftMargin = rightMargin = isBidi() ? BIDI_CARET_WIDTH - 1: 0;
	if ((style & SWT.SINGLE) != 0 && (style & SWT.BORDER) != 0) {
		leftMargin = topMargin = rightMargin = bottomMargin = 2;
	}
	clipboard = new Clipboard(display);
	installDefaultContent();
	initializeRenderer();
	if ((style & SWT.WRAP) != 0) {
		setWordWrap(true);
	}
	else {
	    lineCache = new ContentWidthCache(this, content);
	}	
	defaultCaret = new Caret(this, SWT.NULL);
	if (isBidi) {
		createCaretBitmaps();
		Runnable runnable = new Runnable() {
			public void run() {
				int direction = BidiUtil.getKeyboardLanguage() == BidiUtil.KEYBOARD_BIDI ? SWT.RIGHT : SWT.LEFT;
				if (direction == caretDirection) return;
				if (getCaret() != defaultCaret) return;
				int lineIndex = getCaretLine();
				String line = content.getLine(lineIndex);
				int lineOffset = content.getOffsetAtLine(lineIndex);
				int offsetInLine = caretOffset - lineOffset;
				int newCaretX = getXAtOffset(line, lineIndex, offsetInLine);
				setCaretLocation(newCaretX, getCaretLine(), direction);
			}
		};
		BidiUtil.addLanguageListener(handle, runnable);
	}
	setCaret(defaultCaret);	
	calculateScrollBars();
	createKeyBindings();
	ibeamCursor = new Cursor(display, SWT.CURSOR_IBEAM);
	setCursor(ibeamCursor);
	installListeners();
	installDefaultLineStyler();
	initializeAccessible();
}
/**	 
 * Adds an extended modify listener. An ExtendedModify event is sent by the 
 * widget when the widget text has changed.
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addExtendedModifyListener(ExtendedModifyListener extendedModifyListener) {
	checkWidget();
	if (extendedModifyListener == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	StyledTextListener typedListener = new StyledTextListener(extendedModifyListener);
	addListener(ExtendedModify, typedListener);
}
/** 
 * Maps a key to an action.
 * One action can be associated with N keys. However, each key can only 
 * have one action (key:action is N:1 relation).
 * <p>
 *
 * @param key a key code defined in SWT.java or a character. 
 * 	Optionally ORd with a state mask.  Preferred state masks are one or more of
 *  SWT.MOD1, SWT.MOD2, SWT.MOD3, since these masks account for modifier platform 
 *  differences.  However, there may be cases where using the specific state masks
 *  (i.e., SWT.CTRL, SWT.SHIFT, SWT.ALT, SWT.COMMAND) makes sense.
 * @param action one of the predefined actions defined in ST.java. 
 * 	Use SWT.NULL to remove a key binding.
 * @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 setKeyBinding(int key, int action) {
	checkWidget(); 
	
	int keyValue = key & SWT.KEY_MASK;
	int modifierValue = key & SWT.MODIFIER_MASK;
	char keyChar = (char)keyValue;

	if (Compatibility.isLetter(keyChar)) {
		// make the keybinding case insensitive by adding it
		// in its upper and lower case form
		char ch = Character.toUpperCase(keyChar);
		int newKey = ch | modifierValue;
		if (action == SWT.NULL) {
			keyActionMap.remove(new Integer(newKey));
		}
		else {
		 	keyActionMap.put(new Integer(newKey), new Integer(action));
		}
		ch = Character.toLowerCase(keyChar);
		newKey = ch | modifierValue;
		if (action == SWT.NULL) {
			keyActionMap.remove(new Integer(newKey));
		}
		else {
		 	keyActionMap.put(new Integer(newKey), new Integer(action));
		}
	} else {
		if (action == SWT.NULL) {
			keyActionMap.remove(new Integer(key));
		}
		else {
		 	keyActionMap.put(new Integer(key), new Integer(action));
		}
	}
		
}
/**
 * Adds a bidirectional segment listener. A BidiSegmentEvent is sent 
 * whenever a line of text is measured or rendered. The user can 
 * specify text ranges in the line that should be treated as if they 
 * had a different direction than the surrounding text.
 * This may be used when adjacent segments of right-to-left text should
 * not be reordered relative to each other. 
 * E.g., Multiple Java string literals in a right-to-left language
 * should generally remain in logical order to each other, that is, the
 * way they are stored. 
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 * @see BidiSegmentEvent
 * @since 2.0
 */
public void addBidiSegmentListener(BidiSegmentListener listener) {
	checkWidget();
	if (listener == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	StyledTextListener typedListener = new StyledTextListener(listener);
	addListener(LineGetSegments, typedListener);	
}
/**
 * Adds a line background listener. A LineGetBackground event is sent by the 
 * widget to determine the background color for a line.
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addLineBackgroundListener(LineBackgroundListener listener) {
	checkWidget();
	if (listener == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (userLineBackground == false) {
		removeLineBackgroundListener(defaultLineStyler);
		defaultLineStyler.setLineBackground(0, logicalContent.getLineCount(), null);
		userLineBackground = true;
	}	
	StyledTextListener typedListener = new StyledTextListener(listener);
	addListener(LineGetBackground, typedListener);	
}
/**
 * Adds a line style listener. A LineGetStyle event is sent by the widget to 
 * determine the styles for a line.
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addLineStyleListener(LineStyleListener listener) {
	checkWidget();
	if (listener == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	if (userLineStyle == false) {
		removeLineStyleListener(defaultLineStyler);
		defaultLineStyler.setStyleRange(null);
		userLineStyle = true;
	}
	StyledTextListener typedListener = new StyledTextListener(listener);
	addListener(LineGetStyle, typedListener);	
}
/**	 
 * Adds a modify listener. A Modify event is sent by the widget when the widget text 
 * has changed.
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addModifyListener(ModifyListener modifyListener) {
	checkWidget();
	if (modifyListener == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	TypedListener typedListener = new TypedListener(modifyListener);
	addListener(SWT.Modify, typedListener);
}
/**	 
 * Adds a selection listener. A Selection event is sent by the widget when the 
 * selection has changed.
 * <p>
 * When <code>widgetSelected</code> is called, the event x amd y fields contain
 * the start and end caret indices of the selection.
 * <code>widgetDefaultSelected</code> is not called for StyledTexts.
 * </p>
 * 
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addSelectionListener(SelectionListener listener) {
	checkWidget();
	if (listener == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	TypedListener typedListener = new TypedListener(listener);
	addListener(SWT.Selection, typedListener);	
}
/**	 
 * Adds a verify key listener. A VerifyKey event is sent by the widget when a key 
 * is pressed. The widget ignores the key press if the listener sets the doit field 
 * of the event to false. 
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addVerifyKeyListener(VerifyKeyListener listener) {
	checkWidget();
	if (listener == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	StyledTextListener typedListener = new StyledTextListener(listener);
	addListener(VerifyKey, typedListener);	
}
/**	 
 * Adds a verify listener. A Verify event is sent by the widget when the widget text 
 * is about to change. The listener can set the event text and the doit field to 
 * change the text that is set in the widget or to force the widget to ignore the 
 * text change.
 * <p>
 *
 * @param listener the listener
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void addVerifyListener(VerifyListener verifyListener) {
	checkWidget();
	if (verifyListener == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	TypedListener typedListener = new TypedListener(verifyListener);
	addListener(SWT.Verify, typedListener);
}
/** 
 * Appends a string to the text at the end of the widget.
 * <p>
 *
 * @param string the string to be appended
 * @see #replaceTextRange(int,int,String)
 * @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>
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
 * </ul>
 */
public void append(String string) {
	checkWidget();
	if (string == null) {
		SWT.error(SWT.ERROR_NULL_ARGUMENT);
	}
	int lastChar = Math.max(getCharCount(), 0);
	replaceTextRange(lastChar, 0, string);
}
/**
 * Calculates the width of the widest visible line.
 */
void calculateContentWidth() {
    lineCache = getLineCache(content);
	lineCache.calculate(topIndex, getPartialBottomIndex() - topIndex + 1);
}
/**
 * Calculates the scroll bars
 */
void calculateScrollBars() {
	ScrollBar horizontalBar = getHorizontalBar();
	ScrollBar verticalBar = getVerticalBar();
	
	setScrollBars();
	if (verticalBar != null) {
		verticalBar.setIncrement(getVerticalIncrement());
	}	
	if (horizontalBar != null) {
		horizontalBar.setIncrement(getHorizontalIncrement());
	}
}
/**
 * Calculates the top index based on the current vertical scroll offset.
 * The top index is the index of the topmost fully visible line or the
 * topmost partially visible line if no line is fully visible.
 * The top index starts at 0.
 */
void calculateTopIndex() {
	int oldTopIndex = topIndex;
	int verticalIncrement = getVerticalIncrement();
	int clientAreaHeight = getClientArea().height;
	
	if (verticalIncrement == 0) {
		return;
	}
	topIndex = Compatibility.ceil(verticalScrollOffset, verticalIncrement);
	// Set top index to partially visible top line if no line is fully