/*******************************************************************************
* Copyright (c) 2006, 2018 Wind River Systems, Inc., IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* 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
* John Hendrikx - [painting] Performance improvement of space character rendering - https://bugs.eclipse.org/bugs/show_bug.cgi?id=434194
*******************************************************************************/
package org.eclipse.jface.text;
import org.eclipse.swt.SWT;
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.swt.graphics.Rectangle;
/**
* 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= '\u00b6';
private static final String SPACE_SIGN_STRING= String.valueOf(SPACE_SIGN);
private static final String IDEOGRAPHIC_SPACE_SIGN_STRING= String.valueOf(IDEOGRAPHIC_SPACE_SIGN);
/** 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;
/**
* Tells whether the text widget was created with the full selection style bit or not.
* @since 3.7
*/
private final boolean fIsFullSelectionStyle;
/** @since 3.7 */
private boolean fShowLeadingSpaces= true;
/** @since 3.7 */
private boolean fShowEnclosedSpace= true;
/** @since 3.7 */
private boolean fShowTrailingSpaces= true;
/** @since 3.7 */
private boolean fShowLeadingIdeographicSpaces= true;
/** @since 3.7 */
private boolean fShowEnclosedIdeographicSpaces= true;
/** @since 3.7 */
private boolean fShowTrailingIdeographicSpaces= true;
/** @since 3.7 */
private boolean fShowLeadingTabs= true;
/** @since 3.7 */
private boolean fShowEnclosedTabs= true;
/** @since 3.7 */
private boolean fShowTrailingTabs= true;
/** @since 3.7 */
private boolean fShowCarriageReturn= true;
/** @since 3.7 */
private boolean fShowLineFeed= true;
/** @since 3.7 */
private int fAlpha= 80;
/**
* 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();
fIsFullSelectionStyle= (fTextWidget.getStyle() & SWT.FULL_SELECTION) != SWT.NONE;
}
/**
* Creates a new painter for the given text viewer and the painter options.
*
* @param viewer the text viewer the painter should be attached to
* @param showLeadingSpaces if <code>true</code>, show leading Spaces
* @param showEnclosedSpaces if <code>true</code>, show enclosed Spaces
* @param showTrailingSpaces if <code>true</code>, show trailing Spaces
* @param showLeadingIdeographicSpaces if <code>true</code>, show leading Ideographic Spaces
* @param showEnclosedIdeographicSpaces if <code>true</code>, show enclosed Ideographic Spaces
* @param showTrailingIdeographicSpace if <code>true</code>, show trailing Ideographic Spaces
* @param showLeadingTabs if <code>true</code>, show leading Tabs
* @param showEnclosedTabs if <code>true</code>, show enclosed Tabs
* @param showTrailingTabs if <code>true</code>, show trailing Tabs
* @param showCarriageReturn if <code>true</code>, show Carriage Returns
* @param showLineFeed if <code>true</code>, show Line Feeds
* @param alpha the alpha value
* @since 3.7
*/
public WhitespaceCharacterPainter(ITextViewer viewer, boolean showLeadingSpaces, boolean showEnclosedSpaces, boolean showTrailingSpaces, boolean showLeadingIdeographicSpaces,
boolean showEnclosedIdeographicSpaces, boolean showTrailingIdeographicSpace, boolean showLeadingTabs,
boolean showEnclosedTabs, boolean showTrailingTabs, boolean showCarriageReturn, boolean showLineFeed, int alpha) {
this(viewer);
fShowLeadingSpaces= showLeadingSpaces;
fShowEnclosedSpace= showEnclosedSpaces;
fShowTrailingSpaces= showTrailingSpaces;
fShowLeadingIdeographicSpaces= showLeadingIdeographicSpaces;
fShowEnclosedIdeographicSpaces= showEnclosedIdeographicSpaces;
fShowTrailingIdeographicSpaces= showTrailingIdeographicSpace;
fShowLeadingTabs= showLeadingTabs;
fShowEnclosedTabs= showEnclosedTabs;
fShowTrailingTabs= showTrailingTabs;
fShowCarriageReturn= showCarriageReturn;
fShowLineFeed= showLineFeed;
fAlpha= alpha;
}
@Override
public void dispose() {
fTextViewer= null;
fTextWidget= null;
}
@Override
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();
}
}
@Override
public void deactivate(boolean redraw) {
if (fIsActive) {
fIsActive= false;
fTextWidget.removePaintListener(this);
if (redraw) {
redrawAll();
}
}
}
@Override
public void setPositionManager(IPaintPositionManager manager) {
// no need for a position manager
}
@Override
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()) {
// avoid painting into the margins:
Rectangle clipping= gc.getClipping();
Rectangle clientArea= fTextWidget.getClientArea();
int leftMargin= fTextWidget.getLeftMargin();
int rightMargin= fTextWidget.getRightMargin();
clientArea.x+= leftMargin;
clientArea.width-= leftMargin + rightMargin;
clipping.intersect(clientArea);
gc.setClipping(clientArea);
if (fIsAdvancedGraphicsPresent) {
int alpha= gc.getAlpha();
gc.setAlpha(fAlpha);
drawLineRange(gc, startLine, endLine, x, w);
gc.setAlpha(alpha);
} else {
drawLineRange(gc, startLine, endLine, x, w);
}
gc.setClipping(clipping);
}
}
/**
* 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;
int spaceCharWidth= gc.stringExtent(" ").x; //$NON-NLS-1$
boolean spaceCharsAreSameWidth= spaceCharWidth == gc.stringExtent(SPACE_SIGN_STRING).x &&
spaceCharWidth == gc.stringExtent(IDEOGRAPHIC_SPACE_SIGN_STRING).x;
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 = fTextWidget.getOffsetAtPoint(new Point(x, y)) - 1;
if (startOffset == -1) {
startOffset= lineOffset;
} else if (startOffset - 2 <= lineOffset) {
startOffset= lineOffset;
}
// compute last visible char offset
int endOffset;
if (x + w >= endOfLine.x) {
// line end is visible
endOffset= lineEndOffset;
} else {
endOffset= fTextWidget.getOffsetAtPoint(new Point(x + w - 1, y)) + 1;
if (endOffset == -1) {
endOffset= lineEndOffset;
} else if (endOffset + 2 >= lineEndOffset) {
endOffset= lineEndOffset;
}
}
// draw character range
if (endOffset > startOffset) {
drawCharRange(gc, startOffset, endOffset, lineOffset, lineEndOffset, spaceCharsAreSameWidth);
}
}
}
private boolean isWhitespaceCharacter(char c) {
return c == ' ' || c == '\u3000' || c == '\t' || c == '\r' || c == '\n';
}
/**
* Draw characters of content range.
*
* @param gc the GC
* @param startOffset inclusive start index of the drawing range
* @param endOffset exclusive end index of the drawing range
* @param lineOffset inclusive start index of the line
* @param lineEndOffset exclusive end index of the line
* @param spaceCharsAreSameWidth whether or not all space chars are same width, if <code>true</code>
* rendering can be optimized
*/
private void drawCharRange(GC gc, int startOffset, int endOffset, int lineOffset, int lineEndOffset, boolean spaceCharsAreSameWidth) {
StyledTextContent content= fTextWidget.getContent();
String lineText= content.getTextRange(lineOffset, lineEndOffset - lineOffset);
int startOffsetInLine= startOffset - lineOffset;
int endOffsetInLine= endOffset - lineOffset;
int textBegin= -1;
for (int i= 0; i < lineText.length(); ++i) {
if (!isWhitespaceCharacter(lineText.charAt(i))) {
textBegin= i;
break;
}
}
boolean isEmptyLine= textBegin == -1;
int textEnd= lineText.length() - 1;
if (!isEmptyLine) {
for (int i= lineText.length() - 1; i >= 0; --i) {
if (!isWhitespaceCharacter(lineText.charAt(i))) {
textEnd= i;
break;
}
}
}
StyleRange styleRange= null;
Color fg= null;
StringBuilder visibleChar= new StringBuilder(10);
int delta= 0;
for (int textOffset= startOffsetInLine; textOffset <= endOffsetInLine; ++textOffset) {
boolean eol= false;
delta++;
if (textOffset < endOffsetInLine) {
char c= lineText.charAt(textOffset);
switch (c) {
case ' ':
if (isEmptyLine) {
if (fShowLeadingSpaces || fShowEnclosedSpace || fShowTrailingSpaces) {
visibleChar.append(SPACE_SIGN);
}
} else if (textOffset < textBegin) {
if (fShowLeadingSpaces) {
visibleChar.append(SPACE_SIGN);
}
} else if (textOffset < textEnd) {
if (fShowEnclosedSpace) {
visibleChar.append(SPACE_SIGN);
}
} else {
if (fShowTrailingSpaces) {
visibleChar.append(SPACE_SIGN);
}
}
// 'continue' improves performance but may produce drawing errors
// for long runs of space if width of space and dot differ, therefore
// it can be used only for monospace fonts
if (spaceCharsAreSameWidth) {
continue;
}
break;
case '\u3000': // ideographic whitespace
if (isEmptyLine) {
if (fShowLeadingIdeographicSpaces || fShowEnclosedIdeographicSpaces || fShowTrailingIdeographicSpaces) {
visibleChar.append(IDEOGRAPHIC_SPACE_SIGN);
}
} else if (textOffset < textBegin) {
if (fShowLeadingIdeographicSpaces) {
visibleChar.append(IDEOGRAPHIC_SPACE_SIGN);
}
} else if (textOffset < textEnd) {
if (fShowEnclosedIdeographicSpaces) {
visibleChar.append(IDEOGRAPHIC_SPACE_SIGN);
}
} else {
if (fShowTrailingIdeographicSpaces) {
visibleChar.append(IDEOGRAPHIC_SPACE_SIGN);
}
}
// 'continue' improves performance but may produce drawing errors
// for long runs of space if width of space and dot differ, therefore
// it can be used only for monospace fonts
if (spaceCharsAreSameWidth) {
continue;
}
break;
case '\t':
if (isEmptyLine) {
if (fShowLeadingTabs || fShowEnclosedTabs || fShowTrailingTabs) {
visibleChar.append(TAB_SIGN);
}
} else if (textOffset < textBegin) {
if (fShowLeadingTabs) {
visibleChar.append(TAB_SIGN);
}
} else if (textOffset < textEnd) {
if (fShowEnclosedTabs) {
visibleChar.append(TAB_SIGN);
}
} else {
if (fShowTrailingTabs) {
visibleChar.append(TAB_SIGN);
}
}
break;
case '\r':
if (fShowCarriageReturn) {
visibleChar.append(CARRIAGE_RETURN_SIGN);
}
if (textOffset >= endOffsetInLine - 1 || lineText.charAt(textOffset + 1) != '\n') {
eol= true;
break;
}
continue;
case '\n':
if (fShowLineFeed) {
visibleChar.append(LINE_FEED_SIGN);
}
eol= true;
break;
default:
break;
}
}
if (visibleChar.length() > 0) {
int widgetOffset= startOffset + textOffset - startOffsetInLine - delta + 1;
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() && fIsFullSelectionStyle && 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());
}
delta= 0;
}
}
/**
* 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);
}
}
