icuSources/samples/layout/paragraph.cpp

   1 /*
   2  *******************************************************************************
   3  *
   4  *   Copyright (C) 1999-2003, 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
  18 #include "layout/ParagraphLayout.h"
  19
  20 #include "RenderingSurface.h"
  21 #include "ScriptCompositeFontInstance.h"
  22
  23 #include "paragraph.h"
  24 #include "UnicodeReader.h"
  25 #include "FontMap.h"
  26
  27 #define MARGIN 10
  28 #define LINE_GROW 32
  29
  30 Paragraph::Paragraph(const LEUnicode chars[], int32_t charCount, const FontRuns *fontRuns, LEErrorCode &status)
  31   : fParagraphLayout(NULL), fLineCount(0), fLinesMax(0), fLinesGrow(LINE_GROW), fLines(NULL), fChars(NULL),
  32     fLineHeight(-1), fAscent(-1), fWidth(-1), fHeight(-1)
  33 {
  34         if (LE_FAILURE(status)) {
  35                 return;
  36         }
  37
  38         LocaleRuns *locales = NULL;
  39
  40     fChars = LE_NEW_ARRAY(LEUnicode, charCount);
  41     LE_ARRAY_COPY(fChars, chars, charCount);
  42
  43     fParagraphLayout = new ParagraphLayout(fChars, charCount, fontRuns, NULL, NULL, locales, UBIDI_DEFAULT_LTR, FALSE, status);
  44
  45         if (LE_FAILURE(status)) {
  46                 return;
  47         }
  48
  49     le_int32 ascent  = fParagraphLayout->getAscent();
  50     le_int32 descent = fParagraphLayout->getDescent();
  51     le_int32 leading = fParagraphLayout->getLeading();
  52
  53     fLineHeight = ascent + descent + leading;
  54     fAscent     = ascent;
  55 }
  56
  57 Paragraph::~Paragraph()
  58 {
  59     for (le_int32 line = 0; line < fLineCount; line += 1) {
  60         delete /*(LineInfo *)*/ fLines[line];
  61     }
  62
  63     LE_DELETE_ARRAY(fLines);
  64     delete fParagraphLayout;
  65     LE_DELETE_ARRAY(fChars);
  66 }
  67
  68 void Paragraph::breakLines(le_int32 width, le_int32 height)
  69 {
  70     fHeight = height;
  71
  72     // don't re-break if the width hasn't changed
  73     if (fWidth == width) {
  74         return;
  75     }
  76
  77     fWidth  = width;
  78
  79     float lineWidth = (float) (width - 2 * MARGIN);
  80     const ParagraphLayout::Line *line;
  81     le_int32 li;
  82
  83     // Free the old LineInfo's...
  84     for (li = 0; li < fLineCount; li += 1) {
  85         delete fLines[li];
  86     }
  87
  88     li = 0;
  89     fParagraphLayout->reflow();
  90     while ((line = fParagraphLayout->nextLine(lineWidth)) != NULL) {
  91         // grow the line array, if we need to.
  92         if (li >= fLinesMax) {
  93             fLines = (const ParagraphLayout::Line **) LE_GROW_ARRAY(fLines, fLinesMax + fLinesGrow);
  94             fLinesMax += fLinesGrow;
  95         }
  96
  97         fLines[li++] = line;
  98     }
  99
 100     fLineCount = li;
 101 }
 102
 103 void Paragraph::draw(RenderingSurface *surface, le_int32 firstLine, le_int32 lastLine)
 104 {
 105     le_int32 li, x, y;
 106
 107     x = MARGIN;
 108     y = fAscent;
 109
 110     for (li = firstLine; li <= lastLine; li += 1) {
 111         const ParagraphLayout::Line *line = fLines[li];
 112         le_int32 runCount = line->countRuns();
 113         le_int32 run;
 114
 115                 if (fParagraphLayout->getParagraphLevel() == UBIDI_RTL) {
 116                         le_int32 lastX = line->getWidth();
 117
 118                         x = (fWidth - lastX - MARGIN);
 119                 }
 120
 121
 122         for (run = 0; run < runCount; run += 1) {
 123             const ParagraphLayout::VisualRun *visualRun = line->getVisualRun(run);
 124             le_int32 glyphCount = visualRun->getGlyphCount();
 125             const LEFontInstance *font = visualRun->getFont();
 126             const LEGlyphID *glyphs = visualRun->getGlyphs();
 127             const float *positions = visualRun->getPositions();
 128
 129             surface->drawGlyphs(font, glyphs, glyphCount, positions, x, y, fWidth, fHeight);
 130         }
 131
 132         y += fLineHeight;
 133     }
 134 }
 135
 136 Paragraph *Paragraph::paragraphFactory(const char *fileName, const LEFontInstance *font, GUISupport *guiSupport)
 137 {
 138     LEErrorCode status  = LE_NO_ERROR;
 139     le_int32 charCount;
 140     const UChar *text = UnicodeReader::readFile(fileName, guiSupport, charCount);
 141     Paragraph *result = NULL;
 142
 143     if (text == NULL) {
 144         return NULL;
 145     }
 146
 147     FontRuns  fontRuns(0);
 148
 149     fontRuns.add(font, charCount);
 150
 151     result = new Paragraph(text, charCount, &fontRuns, status);
 152
 153         if (LE_FAILURE(status)) {
 154                 delete result;
 155                 result = NULL;
 156         }
 157
 158     LE_DELETE_ARRAY(text);
 159
 160     return result;
 161 }
 162