/usr/share/doc/libicu-devel/samples/layout
Edit: /usr/share/doc/libicu-devel/samples/layout/paragraph.cpp (7765B)
/*
*******************************************************************************
*
* © 2016 and later: Unicode, Inc. and others.
* License & terms of use: http://www.unicode.org/copyright.html#License
*
*******************************************************************************
*******************************************************************************
*
* Copyright (C) 1999-2015, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: Paragraph.cpp
*
* created on: 09/06/2000
* created by: Eric R. Mader
*/
#include "unicode/utypes.h"
#include "unicode/uchar.h"
#include "unicode/ubidi.h"
#include "unicode/ustring.h"
#include "layout/ParagraphLayout.h"
#include "RenderingSurface.h"
#include "paragraph.h"
#include "UnicodeReader.h"
#define MARGIN 10
#define LINE_GROW 32
#define PARA_GROW 8
#define CH_LF 0x000A
#define CH_CR 0x000D
#define CH_LSEP 0x2028
#define CH_PSEP 0x2029
static LEUnicode *skipLineEnd(LEUnicode *ptr)
{
if (ptr[0] == CH_CR && ptr[1] == CH_LF) {
ptr += 1;
}
return ptr + 1;
}
static le_int32 findRun(const RunArray *runArray, le_int32 offset)
{
le_int32 runCount = runArray->getCount();
for (le_int32 run = 0; run < runCount; run += 1) {
if (runArray->getLimit(run) > offset) {
return run;
}
}
return -1;
}
static void subsetFontRuns(const FontRuns *fontRuns, le_int32 start, le_int32 limit, FontRuns *sub)
{
le_int32 startRun = findRun(fontRuns, start);
le_int32 endRun = findRun(fontRuns, limit - 1);
sub->reset();
for (le_int32 run = startRun; run <= endRun; run += 1) {
const LEFontInstance *runFont = fontRuns->getFont(run);
le_int32 runLimit = fontRuns->getLimit(run) - start;
if (run == endRun) {
runLimit = limit - start;
}
sub->add(runFont, runLimit);
}
}
Paragraph::Paragraph(const LEUnicode chars[], int32_t charCount, const FontRuns *fontRuns, LEErrorCode &status)
: fParagraphLayout(NULL), fParagraphCount(0), fParagraphMax(PARA_GROW), fParagraphGrow(PARA_GROW),
fLineCount(0), fLinesMax(LINE_GROW), fLinesGrow(LINE_GROW), fLines(NULL), fChars(NULL),
fLineHeight(-1), fAscent(-1), fWidth(-1), fHeight(-1), fParagraphLevel(UBIDI_DEFAULT_LTR)
{
static const LEUnicode separators[] = {CH_LF, CH_CR, CH_LSEP, CH_PSEP, 0x0000};
if (LE_FAILURE(status)) {
return;
}
le_int32 ascent = 0;
le_int32 descent = 0;
le_int32 leading = 0;
LocaleRuns *locales = NULL;
FontRuns fr(0);
fLines = LE_NEW_ARRAY(const ParagraphLayout::Line *, fLinesMax);
fParagraphLayout = LE_NEW_ARRAY(ParagraphLayout *, fParagraphMax);
fChars = LE_NEW_ARRAY(LEUnicode, charCount + 1);
LE_ARRAY_COPY(fChars, chars, charCount);
fChars[charCount] = 0;
LEUnicode *pStart = &fChars[0];
while (*pStart != 0) {
LEUnicode *pEnd = u_strpbrk(pStart, separators);
le_int32 pAscent, pDescent, pLeading;
ParagraphLayout *paragraphLayout = NULL;
if (pEnd == NULL) {
pEnd = &fChars[charCount];
}
if (pEnd != pStart) {
subsetFontRuns(fontRuns, pStart - fChars, pEnd - fChars, &fr);
paragraphLayout = new ParagraphLayout(pStart, pEnd - pStart, &fr, NULL, NULL, locales, fParagraphLevel, FALSE, status);
if (LE_FAILURE(status)) {
delete paragraphLayout;
break; // return? something else?
}
if (fParagraphLevel == UBIDI_DEFAULT_LTR) {
fParagraphLevel = paragraphLayout->getParagraphLevel();
}
pAscent = paragraphLayout->getAscent();
pDescent = paragraphLayout->getDescent();
pLeading = paragraphLayout->getLeading();
if (pAscent > ascent) {
ascent = pAscent;
}
if (pDescent > descent) {
descent = pDescent;
}
if (pLeading > leading) {
leading = pLeading;
}
}
if (fParagraphCount >= fParagraphMax) {
fParagraphLayout = (ParagraphLayout **) LE_GROW_ARRAY(fParagraphLayout, fParagraphMax + fParagraphGrow);
fParagraphMax += fParagraphGrow;
}
fParagraphLayout[fParagraphCount++] = paragraphLayout;
if (*pEnd == 0) {
break;
}
pStart = skipLineEnd(pEnd);
}
fLineHeight = ascent + descent + leading;
fAscent = ascent;
}
Paragraph::~Paragraph()
{
for (le_int32 line = 0; line < fLineCount; line += 1) {
delete /*(LineInfo *)*/ fLines[line];
}
for (le_int32 paragraph = 0; paragraph < fParagraphCount; paragraph += 1) {
delete fParagraphLayout[paragraph];
}
LE_DELETE_ARRAY(fLines);
LE_DELETE_ARRAY(fParagraphLayout);
LE_DELETE_ARRAY(fChars);
}
void Paragraph::addLine(const ParagraphLayout::Line *line)
{
if (fLineCount >= fLinesMax) {
fLines = (const ParagraphLayout::Line **) LE_GROW_ARRAY(fLines, fLinesMax + fLinesGrow);
fLinesMax += fLinesGrow;
}
fLines[fLineCount++] = line;
}
void Paragraph::breakLines(le_int32 width, le_int32 height)
{
fHeight = height;
// don't re-break if the width hasn't changed
if (fWidth == width) {
return;
}
fWidth = width;
float lineWidth = (float) (width - 2 * MARGIN);
const ParagraphLayout::Line *line;
// Free the old LineInfo's...
for (le_int32 li = 0; li < fLineCount; li += 1) {
delete fLines[li];
}
fLineCount = 0;
for (le_int32 p = 0; p < fParagraphCount; p += 1) {
ParagraphLayout *paragraphLayout = fParagraphLayout[p];
if (paragraphLayout != NULL) {
paragraphLayout->reflow();
while ((line = paragraphLayout->nextLine(lineWidth)) != NULL) {
addLine(line);
}
} else {
addLine(NULL);
}
}
}
void Paragraph::draw(RenderingSurface *surface, le_int32 firstLine, le_int32 lastLine)
{
le_int32 li, x, y;
x = MARGIN;
y = fAscent;
for (li = firstLine; li <= lastLine; li += 1) {
const ParagraphLayout::Line *line = fLines[li];
if (line != NULL) {
le_int32 runCount = line->countRuns();
le_int32 run;
if (fParagraphLevel == UBIDI_RTL) {
le_int32 lastX = line->getWidth();
x = (fWidth - lastX - MARGIN);
}
for (run = 0; run < runCount; run += 1) {
const ParagraphLayout::VisualRun *visualRun = line->getVisualRun(run);
le_int32 glyphCount = visualRun->getGlyphCount();
const LEFontInstance *font = visualRun->getFont();
const LEGlyphID *glyphs = visualRun->getGlyphs();
const float *positions = visualRun->getPositions();
surface->drawGlyphs(font, glyphs, glyphCount, positions, x, y, fWidth, fHeight);
}
}
y += fLineHeight;
}
}
Paragraph *Paragraph::paragraphFactory(const char *fileName, const LEFontInstance *font, GUISupport *guiSupport)
{
LEErrorCode status = LE_NO_ERROR;
le_int32 charCount;
const UChar *text = UnicodeReader::readFile(fileName, guiSupport, charCount);
Paragraph *result = NULL;
if (text == NULL) {
return NULL;
}
FontRuns fontRuns(0);
fontRuns.add(font, charCount);
result = new Paragraph(text, charCount, &fontRuns, status);
if (LE_FAILURE(status)) {
delete result;
result = NULL;
}
LE_DELETE_ARRAY(text);
return result;
}