/*
* Breaker.java
* Copyright (c) 2004, 2005 Torbjoern Gannholm,
* Copyright (c) 2005 Wisconsin Court System
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
package org.xhtmlrenderer.layout;
import java.text.BreakIterator;
import org.xhtmlrenderer.css.constants.IdentValue;
import org.xhtmlrenderer.css.style.CalculatedStyle;
import org.xhtmlrenderer.render.FSFont;
/**
* A utility class that scans the text of a single inline box, looking for the
* next break point.
* @author Torbjoern Gannholm
*/
public class Breaker {
public static void breakFirstLetter(LayoutContext c, LineBreakContext context,
int avail, CalculatedStyle style) {
FSFont font = style.getFSFont(c);
context.setEnd(getFirstLetterEnd(context.getMaster(), context.getStart()));
context.setWidth(c.getTextRenderer().getWidth(
c.getFontContext(), font, context.getCalculatedSubstring()));
if (context.getWidth() > avail) {
context.setNeedsNewLine(true);
context.setUnbreakable(true);
}
}
private static int getFirstLetterEnd(String text, int start) {
boolean letterFound = false;
int end = text.length();
char currentChar;
for ( int i = start; i < end; i++ ) {
currentChar = text.charAt(i);
if (!TextUtil.isFirstLetterSeparatorChar(currentChar)) {
if (letterFound) {
return i;
} else {
letterFound = true;
}
}
}
return end;
}
public static void breakText(LayoutContext c,
LineBreakContext context, int avail, CalculatedStyle style) {
FSFont font = style.getFSFont(c);
IdentValue whitespace = style.getWhitespace();
// ====== handle nowrap
if (whitespace == IdentValue.NOWRAP) {
context.setEnd(context.getLast());
context.setWidth(c.getTextRenderer().getWidth(
c.getFontContext(), font, context.getCalculatedSubstring()));
return;
}
//check if we should break on the next newline
if (whitespace == IdentValue.PRE ||
whitespace == IdentValue.PRE_WRAP ||
whitespace == IdentValue.PRE_LINE) {
int n = context.getStartSubstring().indexOf(WhitespaceStripper.EOL);
if (n > -1) {
context.setEnd(context.getStart() + n + 1);
context.setWidth(c.getTextRenderer().getWidth(
c.getFontContext(), font, context.getCalculatedSubstring()));
context.setNeedsNewLine(true);
context.setEndsOnNL(true);
} else if (whitespace == IdentValue.PRE) {
context.setEnd(context.getLast());
context.setWidth(c.getTextRenderer().getWidth(
c.getFontContext(), font, context.getCalculatedSubstring()));
}
}
//check if we may wrap
if (whitespace == IdentValue.PRE ||
(context.isNeedsNewLine() && context.getWidth() <= avail)) {
return;
}
context.setEndsOnNL(false);
doBreakText(c, context, avail, style, false);
}
private static void doBreakText(LayoutContext c,
LineBreakContext context, int avail, CalculatedStyle style,
boolean tryToBreakAnywhere) {
FSFont font = style.getFSFont(c);
String currentString = context.getStartSubstring();
BreakIterator iterator = getWordStream(currentString);
int left = 0;
int right = tryToBreakAnywhere ? 1 : iterator.next();
int lastWrap = 0;
int graphicsLength = 0;
int lastGraphicsLength = 0;
while (right > 0 && graphicsLength <= avail) {
lastGraphicsLength = graphicsLength;
graphicsLength += c.getTextRenderer().getWidth(
c.getFontContext(), font, currentString.substring(left, right));
lastWrap = left;
left = right;
if ( tryToBreakAnywhere ) {
right = ( right + 1 ) % currentString.length();
}
else { // break relies on BreakIterator
right = iterator.next();
}
}
if (graphicsLength <= avail) {
//try for the last bit too!
lastWrap = left;
lastGraphicsLength = graphicsLength;
graphicsLength += c.getTextRenderer().getWidth(
c.getFontContext(), font, currentString.substring(left));
}
if (graphicsLength <= avail) {
context.setWidth(graphicsLength);
context.setEnd(context.getMaster().length());
//It fit!
return;
}
context.setNeedsNewLine(true);
if ( lastWrap == 0 && style.getWordWrap() == IdentValue.BREAK_WORD ) {
if ( ! tryToBreakAnywhere ) {
doBreakText(c, context, avail, style, true);
return;
}
}
if (lastWrap != 0) {//found a place to wrap
context.setEnd(context.getStart() + lastWrap);
context.setWidth(lastGraphicsLength);
} else {//unbreakable string
if (left == 0) {
left = currentString.length();
}
context.setEnd(context.getStart() + left);
context.setUnbreakable(true);
if (left == currentString.length()) {
context.setWidth(c.getTextRenderer().getWidth(
c.getFontContext(), font, context.getCalculatedSubstring()));
} else {
context.setWidth(graphicsLength);
}
}
return;
}
public static BreakIterator getWordStream(String s) {
BreakIterator i = BreakIterator.getWordInstance();
i.setText(s);
return i;
}
}