org.eclipse.jface.text.CursorLinePainter Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.jface.text Show documentation
Show all versions of org.eclipse.jface.text Show documentation
This is org.eclipse.jface.text jar used by Scout SDK
The newest version!
/*******************************************************************************
* Copyright (c) 2000, 2015 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:
* IBM Corporation - initial API and implementation
* Tom Eicher (Avaloq Evolution AG) - block selection mode
* Holger Voormann - Word Wrap - https://bugs.eclipse.org/bugs/show_bug.cgi?id=35779
* Florian Weßling - Word Wrap - https://bugs.eclipse.org/bugs/show_bug.cgi?id=35779
*******************************************************************************/
package org.eclipse.jface.text;
import org.eclipse.swt.custom.LineBackgroundEvent;
import org.eclipse.swt.custom.LineBackgroundListener;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Point;
/**
* A painter the draws the background of the caret line in a configured color.
*
* Clients usually instantiate and configure object of this class.
*
* This class is not intended to be subclassed.
*
* @since 2.1
* @noextend This class is not intended to be subclassed by clients.
*/
public class CursorLinePainter implements IPainter, LineBackgroundListener {
/** The viewer the painter works on */
private final ITextViewer fViewer;
/** The cursor line back ground color */
private Color fHighlightColor;
/** The paint position manager for managing the line coordinates */
private IPaintPositionManager fPositionManager;
/** Keeps track of the line to be painted */
private Position fCurrentLine= new Position(0, 0);
/** Keeps track of the line to be cleared */
private Position fLastLine= new Position(0, 0);
/** Keeps track of the line number of the last painted line */
private int fLastLineNumber= -1;
/** Indicates whether this painter is active */
private boolean fIsActive;
/**
* Creates a new painter for the given source viewer.
*
* @param textViewer the source viewer for which to create a painter
*/
public CursorLinePainter(ITextViewer textViewer) {
fViewer= textViewer;
}
/**
* Sets the color in which to draw the background of the cursor line.
*
* @param highlightColor the color in which to draw the background of the cursor line
*/
public void setHighlightColor(Color highlightColor) {
fHighlightColor= highlightColor;
}
@Override
public void lineGetBackground(LineBackgroundEvent event) {
// don't use cached line information because of asynchronous painting
StyledText textWidget= fViewer.getTextWidget();
if (textWidget != null) {
int caret= textWidget.getCaretOffset();
int length= event.lineText.length();
if (event.lineOffset <= caret && caret <= event.lineOffset + length && !hasMultiLineSelection(textWidget))
event.lineBackground= fHighlightColor;
}
}
/**
* Updates all the cached information about the lines to be painted and to be cleared. Returns true
* if the line number of the cursor line has changed.
*
* @return true if cursor line changed
*/
private boolean updateHighlightLine() {
try {
IDocument document= fViewer.getDocument();
int modelCaret= getModelCaret();
int lineNumber= document.getLineOfOffset(modelCaret);
// redraw if the current line number is different from the last line number we painted
// initially fLastLineNumber is -1
if (lineNumber != fLastLineNumber || !fCurrentLine.overlapsWith(modelCaret, 0)) {
fLastLine.offset= fCurrentLine.offset;
fLastLine.length= fCurrentLine.length;
fLastLine.isDeleted= fCurrentLine.isDeleted;
if (fCurrentLine.isDeleted) {
fCurrentLine.isDeleted= false;
fPositionManager.managePosition(fCurrentLine);
}
fCurrentLine.offset= document.getLineOffset(lineNumber);
if (lineNumber == document.getNumberOfLines() - 1)
fCurrentLine.length= document.getLength() - fCurrentLine.offset;
else
fCurrentLine.length= document.getLineOffset(lineNumber + 1) - fCurrentLine.offset;
fLastLineNumber= lineNumber;
return true;
}
} catch (BadLocationException e) {
}
return false;
}
/**
* Returns the location of the caret as offset in the source viewer's
* input document.
*
* @return the caret location
*/
private int getModelCaret() {
int widgetCaret= fViewer.getTextWidget().getCaretOffset();
if (fViewer instanceof ITextViewerExtension5) {
ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
return extension.widgetOffset2ModelOffset(widgetCaret);
}
IRegion visible= fViewer.getVisibleRegion();
return widgetCaret + visible.getOffset();
}
/**
* Assumes the given position to specify offset and length of a line to be painted.
*
* @param position the specification of the line to be painted
*/
private void drawHighlightLine(Position position) {
// if the position that is about to be drawn was deleted then we can't
if (position.isDeleted())
return;
int widgetOffset= 0;
if (fViewer instanceof ITextViewerExtension5) {
ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
widgetOffset= extension.modelOffset2WidgetOffset(position.getOffset());
if (widgetOffset == -1)
return;
} else {
IRegion visible= fViewer.getVisibleRegion();
widgetOffset= position.getOffset() - visible.getOffset();
if (widgetOffset < 0 || visible.getLength() < widgetOffset )
return;
}
StyledText textWidget= fViewer.getTextWidget();
// check for https://bugs.eclipse.org/bugs/show_bug.cgi?id=64898
// this is a guard against the symptoms but not the actual solution
int charCount= textWidget.getCharCount();
if (widgetOffset > charCount) {
return;
}
Point upperLeft= textWidget.getLocationAtOffset(widgetOffset);
int width= textWidget.getClientArea().width + textWidget.getHorizontalPixel();
// different height if word wrap is activated and line is not empty
int height;
if (position.length == 0 || !textWidget.getWordWrap()) {
height= textWidget.getLineHeight(widgetOffset);
} else {
int offsetEnd= widgetOffset + position.length - 1;
if (offsetEnd >= charCount) {
offsetEnd= charCount - 1;
}
height= textWidget.getTextBounds(widgetOffset, offsetEnd).height;
}
textWidget.redraw(0, upperLeft.y, width, height, false);
}
@Override
public void deactivate(boolean redraw) {
if (fIsActive) {
fIsActive= false;
/* on turning off the feature one has to paint the currently
* highlighted line with the standard background color
*/
if (redraw)
drawHighlightLine(fCurrentLine);
fViewer.getTextWidget().removeLineBackgroundListener(this);
if (fPositionManager != null)
fPositionManager.unmanagePosition(fCurrentLine);
fLastLineNumber= -1;
fCurrentLine.offset= 0;
fCurrentLine.length= 0;
}
}
@Override
public void dispose() {
}
@Override
public void paint(int reason) {
if (fViewer.getDocument() == null) {
deactivate(false);
return;
}
StyledText textWidget= fViewer.getTextWidget();
// check selection
if (hasMultiLineSelection(textWidget)) {
deactivate(true);
return;
}
// initialization
if (!fIsActive) {
textWidget.addLineBackgroundListener(this);
fPositionManager.managePosition(fCurrentLine);
fIsActive= true;
}
//redraw line highlight only if it hasn't been drawn yet on the respective line
if (updateHighlightLine()) {
// clear last line
drawHighlightLine(fLastLine);
// draw new line
drawHighlightLine(fCurrentLine);
}
}
/**
* Returns true if the widget has a selection spanning multiple lines,
* false otherwise.
*
* @param textWidget the text widget to check
* @return true if textWidget has a multiline selection,
* false otherwise
* @since 3.5
*/
private boolean hasMultiLineSelection(StyledText textWidget) {
Point selection= textWidget.getSelection();
try {
int startLine= textWidget.getLineAtOffset(selection.x);
int endLine= textWidget.getLineAtOffset(selection.y);
return startLine != endLine;
} catch (IllegalArgumentException e) {
// ignore - apparently, the widget has a stale selection
// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=273721
return false;
}
}
@Override
public void setPositionManager(IPaintPositionManager manager) {
fPositionManager = manager;
}
}