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1
11
12 package org.eclipse.pde.internal.ui.util;
13
14 import java.io.BufferedReader  ;
15 import java.io.IOException ;
16 import java.io.Reader ;
17
18 import com.ibm.icu.text.BreakIterator;
19 import org.eclipse.swt.graphics.GC;
20
21
25 public class LineBreakingReader {
26
27 private BufferedReader fReader;
28
29 private GC fGC;
30
31 private int fMaxWidth;
32
33 private String fLine;
34
35 private int fOffset;
36
37 private BreakIterator fLineBreakIterator;
38
39 private boolean fBreakWords;
40
41
51 public LineBreakingReader(Reader reader, GC gc, int maxLineWidth) {
52 fReader = new BufferedReader (reader);
53 fGC = gc;
54 fMaxWidth = maxLineWidth;
55 fOffset = 0;
56 fLine = null;
57 fLineBreakIterator = BreakIterator.getLineInstance();
58 fBreakWords = true;
59 }
60
61 public boolean isFormattedLine() {
62 return fLine != null;
63 }
64
65
72 public String readLine() throws IOException {
73 if (fLine == null) {
74 String line = fReader.readLine();
75 if (line == null)
76 return null;
77
78 int lineLen = fGC.textExtent(line).x;
79 if (lineLen < fMaxWidth) {
80 return line;
81 }
82 fLine = line;
83 fLineBreakIterator.setText(line);
84 fOffset = 0;
85 }
86 int breakOffset = findNextBreakOffset(fOffset);
87 String res;
88 if (breakOffset != BreakIterator.DONE) {
89 res = fLine.substring(fOffset, breakOffset);
90 fOffset = findWordBegin(breakOffset);
91 if (fOffset == fLine.length()) {
92 fLine = null;
93 }
94 } else {
95 res = fLine.substring(fOffset);
96 fLine = null;
97 }
98 return res;
99 }
100
101 private int findNextBreakOffset(int currOffset) {
102 int currWidth = 0;
103 int nextOffset = fLineBreakIterator.following(currOffset);
104 while (nextOffset != BreakIterator.DONE) {
105 String word = fLine.substring(currOffset, nextOffset);
106 int wordWidth = fGC.textExtent(word).x;
107 int nextWidth = wordWidth + currWidth;
108 if (nextWidth > fMaxWidth) {
109 if (currWidth > 0)
110 return currOffset;
111
112 if (!fBreakWords)
113 return nextOffset;
114
115 int length = word.length();
117 while (length >= 0) {
118 length--;
119 word = word.substring(0, length);
120 wordWidth = fGC.textExtent(word).x;
121 if (wordWidth + currWidth < fMaxWidth)
122 return currOffset + length;
123 }
124 return nextOffset;
125 }
126 currWidth = nextWidth;
127 currOffset = nextOffset;
128 nextOffset = fLineBreakIterator.next();
129 }
130 return nextOffset;
131 }
132
133 private int findWordBegin(int idx) {
134 while (idx < fLine.length()
135 && Character.isWhitespace(fLine.charAt(idx))) {
136 idx++;
137 }
138 return idx;
139 }
140 }
141 |
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