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1 /*
2  *******************************************************************************
3  *
4  *   Copyright (C) 1999-2007, International Business Machines
5  *   Corporation and others.  All Rights Reserved.
6  *
7  *******************************************************************************
8  *   file name:  Paragraph.cpp
9  *
10  *   created on: 09/06/2000
11  *   created by: Eric R. Mader
12  */
13 
14 #include "unicode/utypes.h"
15 #include "unicode/uchar.h"
16 #include "unicode/ubidi.h"
17 #include "unicode/ustring.h"
18 
19 #include "layout/ParagraphLayout.h"
20 
21 #include "RenderingSurface.h"
22 
23 #include "paragraph.h"
24 #include "UnicodeReader.h"
25 
26 #define MARGIN 10
27 #define LINE_GROW 32
28 #define PARA_GROW 8
29 
30 #define CH_LF 0x000A
31 #define CH_CR 0x000D
32 #define CH_LSEP 0x2028
33 #define CH_PSEP 0x2029
34 
skipLineEnd(LEUnicode * ptr)35 static LEUnicode *skipLineEnd(LEUnicode *ptr)
36 {
37     if (ptr[0] == CH_CR && ptr[1] == CH_LF) {
38         ptr += 1;
39     }
40 
41     return ptr + 1;
42 }
43 
findRun(const RunArray * runArray,le_int32 offset)44 static le_int32 findRun(const RunArray *runArray, le_int32 offset)
45 {
46     le_int32 runCount = runArray->getCount();
47 
48     for (le_int32 run = 0; run < runCount; run += 1) {
49         if (runArray->getLimit(run) > offset) {
50             return run;
51         }
52     }
53 
54     return -1;
55 }
56 
subsetFontRuns(const FontRuns * fontRuns,le_int32 start,le_int32 limit,FontRuns * sub)57 static void subsetFontRuns(const FontRuns *fontRuns, le_int32 start, le_int32 limit, FontRuns *sub)
58 {
59     le_int32 startRun = findRun(fontRuns, start);
60     le_int32 endRun   = findRun(fontRuns, limit - 1);
61 
62     sub->reset();
63 
64     for (le_int32 run = startRun; run <= endRun; run += 1) {
65         const LEFontInstance *runFont = fontRuns->getFont(run);
66         le_int32 runLimit = fontRuns->getLimit(run) - start;
67 
68         if (run == endRun) {
69             runLimit = limit - start;
70         }
71 
72         sub->add(runFont, runLimit);
73     }
74 }
75 
Paragraph(const LEUnicode chars[],int32_t charCount,const FontRuns * fontRuns,LEErrorCode & status)76 Paragraph::Paragraph(const LEUnicode chars[], int32_t charCount, const FontRuns *fontRuns, LEErrorCode &status)
77   : fParagraphLayout(NULL), fParagraphCount(0), fParagraphMax(PARA_GROW), fParagraphGrow(PARA_GROW),
78     fLineCount(0), fLinesMax(LINE_GROW), fLinesGrow(LINE_GROW), fLines(NULL), fChars(NULL),
79     fLineHeight(-1), fAscent(-1), fWidth(-1), fHeight(-1), fParagraphLevel(UBIDI_DEFAULT_LTR)
80 {
81     static const LEUnicode separators[] = {CH_LF, CH_CR, CH_LSEP, CH_PSEP, 0x0000};
82 
83 	if (LE_FAILURE(status)) {
84 		return;
85 	}
86 
87     le_int32 ascent  = 0;
88     le_int32 descent = 0;
89     le_int32 leading = 0;
90 
91 	LocaleRuns *locales = NULL;
92     FontRuns fr(0);
93 
94     fLines = LE_NEW_ARRAY(const ParagraphLayout::Line *, fLinesMax);
95     fParagraphLayout = LE_NEW_ARRAY(ParagraphLayout *, fParagraphMax);
96 
97     fChars = LE_NEW_ARRAY(LEUnicode, charCount + 1);
98     LE_ARRAY_COPY(fChars, chars, charCount);
99     fChars[charCount] = 0;
100 
101     LEUnicode *pStart = &fChars[0];
102 
103     while (*pStart != 0) {
104         LEUnicode *pEnd = u_strpbrk(pStart, separators);
105         le_int32 pAscent, pDescent, pLeading;
106         ParagraphLayout *paragraphLayout = NULL;
107 
108         if (pEnd == NULL) {
109             pEnd = &fChars[charCount];
110         }
111 
112         if (pEnd != pStart) {
113             subsetFontRuns(fontRuns, pStart - fChars, pEnd - fChars, &fr);
114 
115             paragraphLayout = new ParagraphLayout(pStart, pEnd - pStart, &fr, NULL, NULL, locales, fParagraphLevel, FALSE, status);
116 
117             if (LE_FAILURE(status)) {
118                 break; // return? something else?
119             }
120 
121             if (fParagraphLevel == UBIDI_DEFAULT_LTR) {
122                 fParagraphLevel = paragraphLayout->getParagraphLevel();
123             }
124 
125             pAscent  = paragraphLayout->getAscent();
126             pDescent = paragraphLayout->getDescent();
127             pLeading = paragraphLayout->getLeading();
128 
129             if (pAscent > ascent) {
130                 ascent = pAscent;
131             }
132 
133             if (pDescent > descent) {
134                 descent = pDescent;
135             }
136 
137             if (pLeading > leading) {
138                 leading = pLeading;
139             }
140         }
141 
142         if (fParagraphCount >= fParagraphMax) {
143             fParagraphLayout = (ParagraphLayout **) LE_GROW_ARRAY(fParagraphLayout, fParagraphMax + fParagraphGrow);
144             fParagraphMax += fParagraphGrow;
145         }
146 
147         fParagraphLayout[fParagraphCount++] = paragraphLayout;
148 
149         if (*pEnd == 0) {
150             break;
151         }
152 
153         pStart = skipLineEnd(pEnd);
154     }
155 
156     fLineHeight = ascent + descent + leading;
157     fAscent     = ascent;
158 }
159 
~Paragraph()160 Paragraph::~Paragraph()
161 {
162     for (le_int32 line = 0; line < fLineCount; line += 1) {
163         delete /*(LineInfo *)*/ fLines[line];
164     }
165 
166     LE_DELETE_ARRAY(fLines);
167     delete fParagraphLayout;
168     LE_DELETE_ARRAY(fChars);
169 }
170 
addLine(const ParagraphLayout::Line * line)171 void Paragraph::addLine(const ParagraphLayout::Line *line)
172 {
173     if (fLineCount >= fLinesMax) {
174         fLines = (const ParagraphLayout::Line **) LE_GROW_ARRAY(fLines, fLinesMax + fLinesGrow);
175         fLinesMax += fLinesGrow;
176     }
177 
178     fLines[fLineCount++] = line;
179 }
180 
breakLines(le_int32 width,le_int32 height)181 void Paragraph::breakLines(le_int32 width, le_int32 height)
182 {
183     fHeight = height;
184 
185     // don't re-break if the width hasn't changed
186     if (fWidth == width) {
187         return;
188     }
189 
190     fWidth  = width;
191 
192     float lineWidth = (float) (width - 2 * MARGIN);
193     const ParagraphLayout::Line *line;
194 
195     // Free the old LineInfo's...
196     for (le_int32 li = 0; li < fLineCount; li += 1) {
197         delete fLines[li];
198     }
199 
200     fLineCount = 0;
201 
202     for (le_int32 p = 0; p < fParagraphCount; p += 1) {
203         ParagraphLayout *paragraphLayout = fParagraphLayout[p];
204 
205         if (paragraphLayout != NULL) {
206             paragraphLayout->reflow();
207             while ((line = paragraphLayout->nextLine(lineWidth)) != NULL) {
208                 addLine(line);
209             }
210         } else {
211             addLine(NULL);
212         }
213     }
214 }
215 
draw(RenderingSurface * surface,le_int32 firstLine,le_int32 lastLine)216 void Paragraph::draw(RenderingSurface *surface, le_int32 firstLine, le_int32 lastLine)
217 {
218     le_int32 li, x, y;
219 
220     x = MARGIN;
221     y = fAscent;
222 
223     for (li = firstLine; li <= lastLine; li += 1) {
224         const ParagraphLayout::Line *line = fLines[li];
225 
226         if (line != NULL) {
227             le_int32 runCount = line->countRuns();
228             le_int32 run;
229 
230 		    if (fParagraphLevel == UBIDI_RTL) {
231 			    le_int32 lastX = line->getWidth();
232 
233 			    x = (fWidth - lastX - MARGIN);
234 		    }
235 
236 
237             for (run = 0; run < runCount; run += 1) {
238                 const ParagraphLayout::VisualRun *visualRun = line->getVisualRun(run);
239                 le_int32 glyphCount = visualRun->getGlyphCount();
240                 const LEFontInstance *font = visualRun->getFont();
241                 const LEGlyphID *glyphs = visualRun->getGlyphs();
242                 const float *positions = visualRun->getPositions();
243 
244                 surface->drawGlyphs(font, glyphs, glyphCount, positions, x, y, fWidth, fHeight);
245             }
246         }
247 
248         y += fLineHeight;
249     }
250 }
251 
paragraphFactory(const char * fileName,const LEFontInstance * font,GUISupport * guiSupport)252 Paragraph *Paragraph::paragraphFactory(const char *fileName, const LEFontInstance *font, GUISupport *guiSupport)
253 {
254     LEErrorCode status  = LE_NO_ERROR;
255     le_int32 charCount;
256     const UChar *text = UnicodeReader::readFile(fileName, guiSupport, charCount);
257     Paragraph *result = NULL;
258 
259     if (text == NULL) {
260         return NULL;
261     }
262 
263     FontRuns  fontRuns(0);
264 
265     fontRuns.add(font, charCount);
266 
267     result = new Paragraph(text, charCount, &fontRuns, status);
268 
269 	if (LE_FAILURE(status)) {
270 		delete result;
271 		result = NULL;
272 	}
273 
274     LE_DELETE_ARRAY(text);
275 
276     return result;
277 }
278 
279