/*******************************************************************************
* Copyright (c) 2006, 2009 Wind River Systems, Inc., 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:
* Anton Leherbauer (Wind River Systems) - initial API and implementation - https://bugs.eclipse.org/bugs/show_bug.cgi?id=22712
* Anton Leherbauer (Wind River Systems) - [painting] Long lines take too long to display when "Show Whitespace Characters" is enabled - https://bugs.eclipse.org/bugs/show_bug.cgi?id=196116
* Anton Leherbauer (Wind River Systems) - [painting] Whitespace characters not drawn when scrolling to right slowly - https://bugs.eclipse.org/bugs/show_bug.cgi?id=206633
* Tom Eicher (Avaloq Evolution AG) - block selection mode
*******************************************************************************/
package com.redcareditor.mate;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.custom.StyledTextContent;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IPainter;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.ITextViewerExtension5;
import org.eclipse.jface.text.IPaintPositionManager;
/**
* A painter for drawing visible characters for (invisible) whitespace
* characters.
*
* @since 3.3
*/
public class WhitespaceCharacterPainter implements IPainter, PaintListener {
private static final char SPACE_SIGN= '\u00b7';
private static final char IDEOGRAPHIC_SPACE_SIGN= '\u00b0';
private static final char TAB_SIGN= '\u00bb';
private static final char CARRIAGE_RETURN_SIGN= '\u00a4';
private static final char LINE_FEED_SIGN= '\u00ac';
/** Indicates whether this painter is active. */
private boolean fIsActive= false;
/** The source viewer this painter is attached to. */
private ITextViewer fTextViewer;
/** The viewer's widget. */
private StyledText fTextWidget;
/** Tells whether the advanced graphics sub system is available. */
private final boolean fIsAdvancedGraphicsPresent;
/**
* Creates a new painter for the given text viewer.
*
* @param textViewer the text viewer the painter should be attached to
*/
public WhitespaceCharacterPainter(ITextViewer textViewer) {
super();
fTextViewer= textViewer;
fTextWidget= textViewer.getTextWidget();
GC gc= new GC(fTextWidget);
gc.setAdvanced(true);
fIsAdvancedGraphicsPresent= gc.getAdvanced();
gc.dispose();
}
/*
* @see org.eclipse.jface.text.IPainter#dispose()
*/
public void dispose() {
fTextViewer= null;
fTextWidget= null;
}
/*
* @see org.eclipse.jface.text.IPainter#paint(int)
*/
public void paint(int reason) {
IDocument document= fTextViewer.getDocument();
if (document == null) {
deactivate(false);
return;
}
if (!fIsActive) {
fIsActive= true;
fTextWidget.addPaintListener(this);
redrawAll();
} else if (reason == CONFIGURATION || reason == INTERNAL) {
redrawAll();
} else if (reason == TEXT_CHANGE) {
// redraw current line only
try {
IRegion lineRegion =
document.getLineInformationOfOffset(getDocumentOffset(fTextWidget.getCaretOffset()));
int widgetOffset= getWidgetOffset(lineRegion.getOffset());
int charCount= fTextWidget.getCharCount();
int redrawLength= Math.min(lineRegion.getLength(), charCount - widgetOffset);
if (widgetOffset >= 0 && redrawLength > 0) {
fTextWidget.redrawRange(widgetOffset, redrawLength, true);
}
} catch (BadLocationException e) {
// ignore
}
}
}
/*
* @see org.eclipse.jface.text.IPainter#deactivate(boolean)
*/
public void deactivate(boolean redraw) {
if (fIsActive) {
fIsActive= false;
fTextWidget.removePaintListener(this);
if (redraw) {
redrawAll();
}
}
}
/*
* @see org.eclipse.jface.text.IPainter#setPositionManager(org.eclipse.jface.text.IPaintPositionManager)
*/
public void setPositionManager(IPaintPositionManager manager) {
// no need for a position manager
}
/*
* @see org.eclipse.swt.events.PaintListener#paintControl(org.eclipse.swt.events.PaintEvent)
*/
public void paintControl(PaintEvent event) {
if (fTextWidget != null) {
handleDrawRequest(event.gc, event.x, event.y, event.width, event.height);
}
}
/*
* Draw characters in view range.
*/
private void handleDrawRequest(GC gc, int x, int y, int w, int h) {
int startLine= fTextWidget.getLineIndex(y);
int endLine= fTextWidget.getLineIndex(y + h - 1);
if (startLine <= endLine && startLine < fTextWidget.getLineCount()) {
if (fIsAdvancedGraphicsPresent) {
int alpha= gc.getAlpha();
gc.setAlpha(100);
drawLineRange(gc, startLine, endLine, x, w);
gc.setAlpha(alpha);
} else
drawLineRange(gc, startLine, endLine, x, w);
}
}
/**
* Draw the given line range.
*
* @param gc the GC
* @param startLine first line number
* @param endLine last line number (inclusive)
* @param x the X-coordinate of the drawing range
* @param w the width of the drawing range
*/
private void drawLineRange(GC gc, int startLine, int endLine, int x, int w) {
final int viewPortWidth= fTextWidget.getClientArea().width;
for (int line= startLine; line <= endLine; line++) {
int lineOffset= fTextWidget.getOffsetAtLine(line);
// line end offset including line delimiter
int lineEndOffset;
if (line < fTextWidget.getLineCount() - 1) {
lineEndOffset= fTextWidget.getOffsetAtLine(line + 1);
} else {
lineEndOffset= fTextWidget.getCharCount();
}
// line length excluding line delimiter
int lineLength= lineEndOffset - lineOffset;
while (lineLength > 0) {
char c= fTextWidget.getTextRange(lineOffset + lineLength - 1, 1).charAt(0);
if (c != '\r' && c != '\n') {
break;
}
--lineLength;
}
// compute coordinates of last character on line
Point endOfLine= fTextWidget.getLocationAtOffset(lineOffset + lineLength);
if (x - endOfLine.x > viewPortWidth) {
// line is not visible
continue;
}
// Y-coordinate of line
int y= fTextWidget.getLinePixel(line);
// compute first visible char offset
int startOffset;
try {
startOffset= fTextWidget.getOffsetAtLocation(new Point(x, y)) - 1;
if (startOffset - 2 <= lineOffset) {
startOffset= lineOffset;
}
} catch (IllegalArgumentException iae) {
startOffset= lineOffset;
}
// compute last visible char offset
int endOffset;
if (x + w >= endOfLine.x) {
// line end is visible
endOffset= lineEndOffset;
} else {
try {
endOffset= fTextWidget.getOffsetAtLocation(new Point(x + w - 1, y)) + 1;
if (endOffset + 2 >= lineEndOffset) {
endOffset= lineEndOffset;
}
} catch (IllegalArgumentException iae) {
endOffset= lineEndOffset;
}
}
// draw character range
if (endOffset > startOffset) {
drawCharRange(gc, startOffset, endOffset);
}
}
}
/**
* Draw characters of content range.
*
* @param gc the GC
* @param startOffset inclusive start index
* @param endOffset exclusive end index
*/
private void drawCharRange(GC gc, int startOffset, int endOffset) {
StyledTextContent content= fTextWidget.getContent();
int length= endOffset - startOffset;
String text= content.getTextRange(startOffset, length);
StyleRange styleRange= null;
Color fg= null;
StringBuffer visibleChar= new StringBuffer(10);
for (int textOffset= 0; textOffset <= length; ++textOffset) {
int delta= 0;
boolean eol= false;
if (textOffset < length) {
delta= 1;
char c= text.charAt(textOffset);
switch (c) {
//case ' ' :
// visibleChar.append(SPACE_SIGN);
// 'continue' would improve performance but may produce drawing errors
// for long runs of space if width of space and dot differ
// break;
case '\u3000' : // ideographic whitespace
visibleChar.append(IDEOGRAPHIC_SPACE_SIGN);
// 'continue' would improve performance but may produce drawing errors
// for long runs of space if width of space and dot differ
break;
case '\t' :
visibleChar.append(TAB_SIGN);
break;
case '\r' :
visibleChar.append(CARRIAGE_RETURN_SIGN);
if (textOffset >= length - 1 || text.charAt(textOffset + 1) != '\n') {
eol= true;
break;
}
continue;
case '\n' :
visibleChar.append(LINE_FEED_SIGN);
eol= true;
break;
default :
delta= 0;
break;
}
}
if (visibleChar.length() > 0) {
int widgetOffset= startOffset + textOffset - visibleChar.length() + delta;
if (!eol || !isFoldedLine(content.getLineAtOffset(widgetOffset))) {
/*
* Block selection is drawn using alpha and no selection-inverting
* takes place, we always draw as 'unselected' in block selection mode.
*/
if (!fTextWidget.getBlockSelection() && isOffsetSelected(fTextWidget, widgetOffset)) {
fg= fTextWidget.getSelectionForeground();
} else if (styleRange == null || styleRange.start + styleRange.length <= widgetOffset) {
styleRange= fTextWidget.getStyleRangeAtOffset(widgetOffset);
if (styleRange == null || styleRange.foreground == null) {
fg= fTextWidget.getForeground();
} else {
fg= styleRange.foreground;
}
}
draw(gc, widgetOffset, visibleChar.toString(), fg);
}
visibleChar.delete(0, visibleChar.length());
}
}
}
/**
* Returns <code>true</code> if <code>offset</code> is selection in <code>widget</code>,
* <code>false</code> otherwise.
*
* @param widget the widget
* @param offset the offset
* @return <code>true</code> if <code>offset</code> is selection, <code>false</code> otherwise
* @since 3.5
*/
private static final boolean isOffsetSelected(StyledText widget, int offset) {
Point selection= widget.getSelection();
return offset >= selection.x && offset < selection.y;
}
/**
* Check if the given widget line is a folded line.
*
* @param widgetLine the widget line number
* @return <code>true</code> if the line is folded
*/
private boolean isFoldedLine(int widgetLine) {
if (fTextViewer instanceof ITextViewerExtension5) {
ITextViewerExtension5 extension= (ITextViewerExtension5)fTextViewer;
int modelLine= extension.widgetLine2ModelLine(widgetLine);
int widgetLine2= extension.modelLine2WidgetLine(modelLine + 1);
return widgetLine2 == -1;
}
return false;
}
/**
* Redraw all of the text widgets visible content.
*/
private void redrawAll() {
fTextWidget.redraw();
}
/**
* Draw string at widget offset.
*
* @param gc the GC
* @param offset the widget offset
* @param s the string to be drawn
* @param fg the foreground color
*/
private void draw(GC gc, int offset, String s, Color fg) {
// Compute baseline delta (see https://bugs.eclipse.org/bugs/show_bug.cgi?id=165640)
int baseline= fTextWidget.getBaseline(offset);
FontMetrics fontMetrics= gc.getFontMetrics();
int fontBaseline= fontMetrics.getAscent() + fontMetrics.getLeading();
int baslineDelta= baseline - fontBaseline;
Point pos= fTextWidget.getLocationAtOffset(offset);
gc.setForeground(fg);
gc.drawString(s, pos.x, pos.y + baslineDelta, true);
}
/**
* Convert a document offset to the corresponding widget offset.
*
* @param documentOffset the document offset
* @return widget offset
*/
private int getWidgetOffset(int documentOffset) {
if (fTextViewer instanceof ITextViewerExtension5) {
ITextViewerExtension5 extension= (ITextViewerExtension5)fTextViewer;
return extension.modelOffset2WidgetOffset(documentOffset);
}
IRegion visible= fTextViewer.getVisibleRegion();
int widgetOffset= documentOffset - visible.getOffset();
if (widgetOffset > visible.getLength()) {
return -1;
}
return widgetOffset;
}
/**
* Convert a widget offset to the corresponding document offset.
*
* @param widgetOffset the widget offset
* @return document offset
*/
private int getDocumentOffset(int widgetOffset) {
if (fTextViewer instanceof ITextViewerExtension5) {
ITextViewerExtension5 extension= (ITextViewerExtension5)fTextViewer;
return extension.widgetOffset2ModelOffset(widgetOffset);
}
IRegion visible= fTextViewer.getVisibleRegion();
if (widgetOffset > visible.getLength()) {
return -1;
}
return widgetOffset + visible.getOffset();
}
}