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Open HTML to PDF is a CSS 2.1 renderer written in Java. This artifact contains the core rendering and layout code.
/*
* {{{ header & license
* 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 com.openhtmltopdf.layout;
import com.openhtmltopdf.layout.Breaker.BreakTextResult;
/**
* A bean which serves as a way for the layout code to pass information to the
* line breaking code and for the line breaking code to pass instructions back
* to the layout code.
*/
public class LineBreakContext {
public enum LineBreakResult {
CHAR_BREAKING_NEED_NEW_LINE,
WORD_BREAKING_NEED_NEW_LINE,
CHAR_BREAKING_UNBREAKABLE,
WORD_BREAKING_UNBREAKABLE,
CHAR_BREAKING_FOUND_WORD_BREAK,
CHAR_BREAKING_FINISHED,
WORD_BREAKING_FINISHED;
}
private String _master;
private int _start;
private int _end;
private int _savedEnd;
private boolean _unbreakable;
private boolean _needsNewLine;
private int _width;
private boolean _endsOnNL;
private boolean _endsOnSoftHyphen;
private int _nextWidth;
private boolean _endsOnWordBreak;
private boolean _finishedInCharBreakingMode;
private boolean _isFirstChar;
// These keep track of our attempts to move to a newline
// before outputting the same content.
// Due to several infinite loop bugs, we only allow
// a defined number of attempts before forcing the output of
// text (with a log message).
private int _lastNewLineStartPosition;
private int _newlineAttemptsForLastStartPosition;
public void reset() {
_width = 0;
_unbreakable = false;
_needsNewLine = false;
_endsOnNL = false;
_endsOnSoftHyphen = false;
_nextWidth = 0;
_endsOnWordBreak = false;
_finishedInCharBreakingMode = false;
_isFirstChar = false;
}
/**
* Record a newline attempt. This should be called
* at each newline and then possibleEndlessLoop method can
* be called to check if excessive attempts have been made to
* output the same character on newlines.
*/
public void newLine() {
if (this.getStart() == _lastNewLineStartPosition) {
_newlineAttemptsForLastStartPosition++;
} else {
_lastNewLineStartPosition = this.getStart();
_newlineAttemptsForLastStartPosition = 1;
}
}
/**
* @see {@link #newLine()}
*/
public boolean possibleEndlessLoop() {
return _newlineAttemptsForLastStartPosition > 5;
}
public int getLast() {
return _master.length();
}
public int getEnd() {
return _end;
}
public void setEnd(int end) {
_end = end;
}
public String getMaster() {
return _master;
}
public void setMaster(String master) {
_master = master;
}
public int getStart() {
return _start;
}
public void setStart(int start) {
_start = start;
}
public String getStartSubstring() {
return _master.substring(_start);
}
public String getCalculatedSubstring() {
// mimic the calculation in InlineText.setSubstring to strip newlines for our width calculations
// the original text width calculation in InlineBox.calcMaxWidthFromLineLength() excludes the newline character
// so if we include them here we get spurious newlines
// apparently newlines do take up some width in most fonts
if (_end > 0 && _master.charAt(_end-1) == WhitespaceStripper.EOLC) {
return _master.substring(_start, _end-1);
}
return _master.substring(_start, _end);
}
public boolean isUnbreakable() {
return _unbreakable;
}
public void setUnbreakable(boolean unbreakable) {
_unbreakable = unbreakable;
}
public boolean isNeedsNewLine() {
return _needsNewLine;
}
public void setNeedsNewLine(boolean needsLineBreak) {
_needsNewLine = needsLineBreak;
}
public int getWidth() {
return _width;
}
public void setWidth(int width) {
_width = width;
}
public boolean isFinished() {
return _end == getMaster().length();
}
public void resetEnd() {
_end = _savedEnd;
}
public void saveEnd() {
_savedEnd = _end;
}
public boolean isEndsOnNL() {
return _endsOnNL;
}
public void setEndsOnNL(boolean b) {
_endsOnNL = b;
}
public boolean isEndsOnSoftHyphen() {
return this._endsOnSoftHyphen;
}
public void setEndsOnSoftHyphen(boolean b) {
this._endsOnSoftHyphen = b;
}
/**
* If needs newline, returns the graphics width of the next unbreakable sequence.
* We use this to test if we should actually put in a newline before a long word
* when break-word is on. If getNextWidth would fit on an empty line we put in the
* new line else we split in the long word immediately.
*/
public int getNextWidth() {
return _nextWidth;
}
public void setNextWidth(int nextWidth) {
this._nextWidth = nextWidth;
}
public boolean isEndsOnWordBreak() {
return _endsOnWordBreak;
}
public void setEndsOnWordBreak(boolean _endsOnWordBreak) {
this._endsOnWordBreak = _endsOnWordBreak;
}
public void setFinishedInCharBreakingMode(boolean mode) {
this._finishedInCharBreakingMode = mode;
}
/**
* If this is true, it means we finished in char breaking mode because
* a word was too large. The next line should begin in char breaking mode.
*/
public boolean isFinishedInCharBreakingMode() {
return _finishedInCharBreakingMode;
}
/**
* @return true if this is the first non-trimmed character
* in a line.
*/
public boolean isFirstCharInLine() {
return _isFirstChar;
}
/**
* @param isFirstChar set to true if this is the first non-trimmable
* character in a line.
*/
public void setFirstCharInLine(boolean isFirstChar) {
_isFirstChar = isFirstChar;
}
/**
* Given the result of text breaking, makes some sanity preserving
* asserts to check the state of this object.
*/
public void checkConsistency(
BreakTextResult breakResult) {
switch (breakResult) {
case CONTINUE_CHAR_BREAKING_ON_NL:
assert this.getStart() < this.getEnd();
assert !this.isUnbreakable();
assert this.isNeedsNewLine();
break;
case CONTINUE_WORD_BREAKING_ON_NL:
assert this.getStart() < this.getEnd();
assert !this.isUnbreakable();
assert this.isNeedsNewLine();
break;
case DANGER_RECONSUME_CHAR_ON_NL:
assert this.isUnbreakable();
assert this.getStart() <= this.getEnd();
break;
case DANGER_RECONSUME_WORD_ON_NL:
assert this.isUnbreakable();
assert this.getStart() <= this.getEnd();
break;
case FINISHED:
assert this.isFinished();
assert this.getStart() < this.getEnd();
assert !this.isUnbreakable();
assert !this.isNeedsNewLine();
break;
case WORD_UNBREAKABLE_BUT_CONSUMED:
assert this.isUnbreakable();
assert this.getStart() < this.getEnd();
break;
case CHAR_UNBREAKABLE_BUT_CONSUMED:
assert this.isUnbreakable();
assert this.getStart() < this.getEnd();
break;
}
}
}