/*******************************************************************************
* Copyright (c) 2006 Sybase, Inc. and others.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Sybase, Inc. - initial API and implementation
*******************************************************************************/
package org.eclipse.jst.pagedesigner.css2.layout;
import java.util.List;
import org.eclipse.draw2d.Figure;
/**
* A layout for FlowFigures with children.
* <P>
* WARNING: This class is not intended to be subclassed by clients.
*
* @author mengbo
* @since 2.1
*/
public abstract class FlowContainerLayout extends FlowFigureLayout implements
FlowContext {
// private static Logger _log = PDPlugin.getLogger(FlowContainerLayout.class);
/**
* the current line
*/
protected LineBox _currentLine;
private boolean _calculatingMaxWidth;
/**
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowFigureLayout#FlowFigureLayout(FlowFigure)
*/
protected FlowContainerLayout(FlowFigure flowFigure) {
super(flowFigure);
}
/**
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowContext#addToCurrentLine(FlowBox)
*/
public void addToCurrentLine(FlowBox block) {
getCurrentLine().add(block);
}
/**
* Used by getCurrentLine().
*/
protected abstract void createNewLine();
/**
* Used by getCurrentLine(int topmargin)
*
* @param topMargin
*/
protected void createNewLine(int topMargin) {
createNewLine();
}
/**
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowContext#getCurrentLine()
*/
public LineBox getCurrentLine() {
if (_currentLine == null)
createNewLine();
return _currentLine;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowContext#getCurrentLine(int)
*/
public LineBox getCurrentLine(int topMargin) {
if (_currentLine == null) {
createNewLine(topMargin);
}
// if the current line only contains an empty string, reset the current
// line using the given margin.
else if (_currentLine.isEmptyStringLine()) {
List list = _currentLine.getFragments();
createNewLine(topMargin);
_currentLine._fragments.addAll(list);
}
return _currentLine;
}
/**
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowContext#isCurrentLineOccupied
*/
public boolean isCurrentLineOccupied() {
return _currentLine != null && _currentLine.isOccupied();
}
/**
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowFigureLayout#layout()
*/
protected void layout() {
preLayout();
layoutChildren();
flush();
cleanup();
}
/**
* Layout all children.
*/
protected void layoutChildren() {
List children = getFlowFigure().getChildren();
for (int i = 0; i < children.size(); i++) {
Figure f = (Figure) children.get(i);
f.invalidate();
f.validate();
}
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowContext#getLastMarginRight()
*/
public int getLastMarginRight() {
if (_currentLine == null || !_currentLine.isOccupied()) {
return 0;
}
FlowBox box = (FlowBox) _currentLine.getFragments().get(
_currentLine.getFragments().size() - 1);
if (box != null) {
return box.getMarginInsets().right;
}
return 0;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jst.pagedesigner.css2.layout.FlowContext#isCalculatingMaxWidth()
*/
public boolean isCalculatingMaxWidth() {
if (_calculatingMaxWidth) {
return true;
} else if (this.getFlowContext() == null) {
return false;
} else {
return this.getFlowContext().isCalculatingMaxWidth();
}
}
/**
* Called before layoutChildren() to setup any necessary state.
*/
protected abstract void preLayout();
/**
* Called after {@link #layoutChildren()}when all children have been laid
* out. This method exists to flush the last line.
*/
protected abstract void flush();
/**
* Flush anything pending and free all temporary data used during layout.
*/
protected abstract void cleanup();
}