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comparison dwtx/jface/text/CursorLinePainter.d @ 129:eb30df5ca28b

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Added JFace Text sources
author Frank Benoit <benoit@tionex.de>
date Sat, 23 Aug 2008 19:10:48 +0200
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children c4fb132a086c
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128:8df1d4193877 129:eb30df5ca28b
1 /*******************************************************************************
2 * Copyright (c) 2000, 2008 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13
14 module dwtx.jface.text.CursorLinePainter;
15
16 import dwt.dwthelper.utils;
17
18
19
20
21 import dwt.custom.LineBackgroundEvent;
22 import dwt.custom.LineBackgroundListener;
23 import dwt.custom.StyledText;
24 import dwt.graphics.Color;
25 import dwt.graphics.Point;
26
27
28 /**
29 * A painter the draws the background of the caret line in a configured color.
30 * <p>
31 * Clients usually instantiate and configure object of this class.</p>
32 * <p>
33 * This class is not intended to be subclassed.</p>
34 *
35 * @since 2.1
36 * @noextend This class is not intended to be subclassed by clients.
37 */
38 public class CursorLinePainter : IPainter, LineBackgroundListener {
39
40 /** The viewer the painter works on */
41 private final ITextViewer fViewer;
42 /** The cursor line back ground color */
43 private Color fHighlightColor;
44 /** The paint position manager for managing the line coordinates */
45 private IPaintPositionManager fPositionManager;
46
47 /** Keeps track of the line to be painted */
48 private Position fCurrentLine= new Position(0, 0);
49 /** Keeps track of the line to be cleared */
50 private Position fLastLine= new Position(0, 0);
51 /** Keeps track of the line number of the last painted line */
52 private int fLastLineNumber= -1;
53 /** Indicates whether this painter is active */
54 private bool fIsActive;
55
56 /**
57 * Creates a new painter for the given source viewer.
58 *
59 * @param textViewer the source viewer for which to create a painter
60 */
61 public CursorLinePainter(ITextViewer textViewer) {
62 fViewer= textViewer;
63 }
64
65 /**
66 * Sets the color in which to draw the background of the cursor line.
67 *
68 * @param highlightColor the color in which to draw the background of the cursor line
69 */
70 public void setHighlightColor(Color highlightColor) {
71 fHighlightColor= highlightColor;
72 }
73
74 /*
75 * @see LineBackgroundListener#lineGetBackground(LineBackgroundEvent)
76 */
77 public void lineGetBackground(LineBackgroundEvent event) {
78 // don't use cached line information because of asynchronous painting
79
80 StyledText textWidget= fViewer.getTextWidget();
81 if (textWidget !is null) {
82
83 int caret= textWidget.getCaretOffset();
84 int length= event.lineText.length();
85
86 if (event.lineOffset <= caret && caret <= event.lineOffset + length)
87 event.lineBackground= fHighlightColor;
88 else
89 event.lineBackground= textWidget.getBackground();
90 }
91 }
92
93 /**
94 * Updates all the cached information about the lines to be painted and to be cleared. Returns <code>true</code>
95 * if the line number of the cursor line has changed.
96 *
97 * @return <code>true</code> if cursor line changed
98 */
99 private bool updateHighlightLine() {
100 try {
101
102 IDocument document= fViewer.getDocument();
103 int modelCaret= getModelCaret();
104 int lineNumber= document.getLineOfOffset(modelCaret);
105
106 // redraw if the current line number is different from the last line number we painted
107 // initially fLastLineNumber is -1
108 if (lineNumber !is fLastLineNumber || !fCurrentLine.overlapsWith(modelCaret, 0)) {
109
110 fLastLine.offset= fCurrentLine.offset;
111 fLastLine.length= fCurrentLine.length;
112 fLastLine.isDeleted= fCurrentLine.isDeleted;
113
114 if (fCurrentLine.isDeleted) {
115 fCurrentLine.isDeleted= false;
116 fPositionManager.managePosition(fCurrentLine);
117 }
118
119 fCurrentLine.offset= document.getLineOffset(lineNumber);
120 if (lineNumber is document.getNumberOfLines() - 1)
121 fCurrentLine.length= document.getLength() - fCurrentLine.offset;
122 else
123 fCurrentLine.length= document.getLineOffset(lineNumber + 1) - fCurrentLine.offset;
124
125 fLastLineNumber= lineNumber;
126 return true;
127
128 }
129
130 } catch (BadLocationException e) {
131 }
132
133 return false;
134 }
135
136 /**
137 * Returns the location of the caret as offset in the source viewer's
138 * input document.
139 *
140 * @return the caret location
141 */
142 private int getModelCaret() {
143 int widgetCaret= fViewer.getTextWidget().getCaretOffset();
144 if (fViewer instanceof ITextViewerExtension5) {
145 ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
146 return extension.widgetOffset2ModelOffset(widgetCaret);
147 }
148 IRegion visible= fViewer.getVisibleRegion();
149 return widgetCaret + visible.getOffset();
150 }
151
152 /**
153 * Assumes the given position to specify offset and length of a line to be painted.
154 *
155 * @param position the specification of the line to be painted
156 */
157 private void drawHighlightLine(Position position) {
158
159 // if the position that is about to be drawn was deleted then we can't
160 if (position.isDeleted())
161 return;
162
163 int widgetOffset= 0;
164 if (fViewer instanceof ITextViewerExtension5) {
165
166 ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
167 widgetOffset= extension.modelOffset2WidgetOffset(position.getOffset());
168 if (widgetOffset is -1)
169 return;
170
171 } else {
172
173 IRegion visible= fViewer.getVisibleRegion();
174 widgetOffset= position.getOffset() - visible.getOffset();
175 if (widgetOffset < 0 || visible.getLength() < widgetOffset )
176 return;
177 }
178
179 StyledText textWidget= fViewer.getTextWidget();
180 // check for https://bugs.eclipse.org/bugs/show_bug.cgi?id=64898
181 // this is a guard against the symptoms but not the actual solution
182 if (0 <= widgetOffset && widgetOffset <= textWidget.getCharCount()) {
183 Point upperLeft= textWidget.getLocationAtOffset(widgetOffset);
184 int width= textWidget.getClientArea().width + textWidget.getHorizontalPixel();
185 int height= textWidget.getLineHeight(widgetOffset);
186 textWidget.redraw(0, upperLeft.y, width, height, false);
187 }
188 }
189
190 /*
191 * @see IPainter#deactivate(bool)
192 */
193 public void deactivate(bool redraw) {
194 if (fIsActive) {
195 fIsActive= false;
196
197 /* on turning off the feature one has to paint the currently
198 * highlighted line with the standard background color
199 */
200 if (redraw)
201 drawHighlightLine(fCurrentLine);
202
203 fViewer.getTextWidget().removeLineBackgroundListener(this);
204
205 if (fPositionManager !is null)
206 fPositionManager.unmanagePosition(fCurrentLine);
207
208 fLastLineNumber= -1;
209 fCurrentLine.offset= 0;
210 fCurrentLine.length= 0;
211 }
212 }
213
214 /*
215 * @see IPainter#dispose()
216 */
217 public void dispose() {
218 }
219
220 /*
221 * @see IPainter#paint(int)
222 */
223 public void paint(int reason) {
224 if (fViewer.getDocument() is null) {
225 deactivate(false);
226 return;
227 }
228
229 StyledText textWidget= fViewer.getTextWidget();
230
231 // check selection
232 Point selection= textWidget.getSelection();
233 int startLine= textWidget.getLineAtOffset(selection.x);
234 int endLine= textWidget.getLineAtOffset(selection.y);
235 if (startLine !is endLine) {
236 deactivate(true);
237 return;
238 }
239
240 // initialization
241 if (!fIsActive) {
242 textWidget.addLineBackgroundListener(this);
243 fPositionManager.managePosition(fCurrentLine);
244 fIsActive= true;
245 }
246
247 //redraw line highlight only if it hasn't been drawn yet on the respective line
248 if (updateHighlightLine()) {
249 // clear last line
250 drawHighlightLine(fLastLine);
251 // draw new line
252 drawHighlightLine(fCurrentLine);
253 }
254 }
255
256 /*
257 * @see IPainter#setPositionManager(IPaintPositionManager)
258 */
259 public void setPositionManager(IPaintPositionManager manager) {
260 fPositionManager = manager;
261 }
262 }