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comparison dwtx/jface/internal/text/link/contentassist/LineBreakingReader.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, 2006 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 module dwtx.jface.internal.text.link.contentassist.LineBreakingReader;
14
15 import dwt.dwthelper.utils;
16
17
18 import java.io.BufferedReader;
19 import java.io.IOException;
20 import java.io.Reader;
21
22 import com.ibm.icu.text.BreakIterator;
23
24 import dwt.graphics.GC;
25
26 /*
27 * Not a real reader. Could change if requested
28 */
29 public class LineBreakingReader {
30
31 private BufferedReader fReader;
32 private GC fGC;
33 private int fMaxWidth;
34
35 private String fLine;
36 private int fOffset;
37
38 private BreakIterator fLineBreakIterator;
39 private bool fBreakWords;
40
41 /**
42 * Creates a reader that breaks an input text to fit in a given width.
43 *
44 * @param reader Reader of the input text
45 * @param gc The graphic context that defines the currently used font sizes
46 * @param maxLineWidth The max width (pixels) where the text has to fit in
47 */
48 public LineBreakingReader(Reader reader, GC gc, int maxLineWidth) {
49 fReader= new BufferedReader(reader);
50 fGC= gc;
51 fMaxWidth= maxLineWidth;
52 fOffset= 0;
53 fLine= null;
54 fLineBreakIterator= BreakIterator.getLineInstance();
55 fBreakWords= true;
56 }
57
58 public bool isFormattedLine() {
59 return fLine !is null;
60 }
61
62 /**
63 * Reads the next line. The lengths of the line will not exceed the given maximum
64 * width.
65 *
66 * @return the next line
67 * @throws IOException
68 */
69 public String readLine() throws IOException {
70 if (fLine is null) {
71 String line= fReader.readLine();
72 if (line is null)
73 return null;
74
75 int lineLen= fGC.textExtent(line).x;
76 if (lineLen < fMaxWidth) {
77 return line;
78 }
79 fLine= line;
80 fLineBreakIterator.setText(line);
81 fOffset= 0;
82 }
83 int breakOffset= findNextBreakOffset(fOffset);
84 String res;
85 if (breakOffset !is BreakIterator.DONE) {
86 res= fLine.substring(fOffset, breakOffset);
87 fOffset= findWordBegin(breakOffset);
88 if (fOffset is fLine.length()) {
89 fLine= null;
90 }
91 } else {
92 res= fLine.substring(fOffset);
93 fLine= null;
94 }
95 return res;
96 }
97
98 private int findNextBreakOffset(int currOffset) {
99 int currWidth= 0;
100 int nextOffset= fLineBreakIterator.following(currOffset);
101 while (nextOffset !is BreakIterator.DONE) {
102 String word= fLine.substring(currOffset, nextOffset);
103 int wordWidth= fGC.textExtent(word).x;
104 int nextWidth= wordWidth + currWidth;
105 if (nextWidth > fMaxWidth) {
106 if (currWidth > 0)
107 return currOffset;
108
109 if (!fBreakWords)
110 return nextOffset;
111
112 // need to fit into fMaxWidth
113 int length= word.length();
114 while (length >= 0) {
115 length--;
116 word= word.substring(0, length);
117 wordWidth= fGC.textExtent(word).x;
118 if (wordWidth + currWidth < fMaxWidth)
119 return currOffset + length;
120 }
121 return nextOffset;
122 }
123 currWidth= nextWidth;
124 currOffset= nextOffset;
125 nextOffset= fLineBreakIterator.next();
126 }
127 return nextOffset;
128 }
129
130 private int findWordBegin(int idx) {
131 while (idx < fLine.length() && Character.isWhitespace(fLine.charAt(idx))) {
132 idx++;
133 }
134 return idx;
135 }
136 }