/*******************************************************************************
* Copyright (c) 2005 IBM Corporation 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.draw2d;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.eclipse.draw2d.geometry.Rectangle;
/**
* Animates the layout of a figure's children. The animator will capture the effects of a
* layout manager, and then play back the placement of children using linear interpolation
* for each child's start and end locations.
* <P>
* To use an animator, hook it as a layout listener for the figure whose layout is to
* be animated, by calling {@link IFigure#addLayoutListener(LayoutListener)}. It is not
* necessary to have an animator for every figure in a composition that is undergoing
* animation. For example, if a figure without an animator moves during the animation, it
* will continue to move and layout its children normally during each step of the
* animation.
* <P>
* Animator must be used in conjunction with layouts. If figures are placed manually using
* <code>setBounds()</code>, the animator may not be able to track and playback the
* changes that occur.
*
* @since 3.2
*/
public class LayoutAnimator extends Animator implements LayoutListener {
static final LayoutAnimator INSTANCE = new LayoutAnimator();
/**
* Constructs a new Animator. The default instance ({@link #getDefault()}) can be used on
* all figures being animated.
*
* @since 3.2
*/
protected LayoutAnimator() { }
/**
* Returns an object encapsulating the placement of children in a container. This method
* is called to capture both the initial and final states.
* @param container the container figure
* @return the current state
* @since 3.2
*/
protected Object getCurrentState(IFigure container) {
Map locations = new HashMap();
List children = container.getChildren();
IFigure child;
for (int i = 0; i < children.size(); i++) {
child = (IFigure)children.get(i);
locations.put(child, child.getBounds().getCopy());
}
return locations;
}
/**
* Returns the default instance.
* @return the default instance
* @since 3.2
*/
public static LayoutAnimator getDefault() {
return INSTANCE;
}
/**
* Hooks invalidation in case animation is in progress.
* @see LayoutListener#invalidate(IFigure)
*/
public final void invalidate(IFigure container) {
if (Animation.isInitialRecording())
Animation.hookAnimator(container, this);
}
/**
* Hooks layout in case animation is in progress.
* @see org.eclipse.draw2d.LayoutListener#layout(org.eclipse.draw2d.IFigure)
*/
public final boolean layout(IFigure container) {
if (Animation.isAnimating())
return Animation.hookPlayback(container, this);
return false;
}
/**
* Plays back the animated layout.
* @see Animator#playback(IFigure)
*/
protected boolean playback(IFigure container) {
Map initial = (Map) Animation.getInitialState(this, container);
Map ending = (Map) Animation.getFinalState(this, container);
if (initial == null)
return false;
List children = container.getChildren();
float progress = Animation.getProgress();
float ssergorp = 1 - progress;
Rectangle rect1, rect2;
for (int i = 0; i < children.size(); i++) {
IFigure child = (IFigure) children.get(i);
rect1 = (Rectangle)initial.get(child);
rect2 = (Rectangle)ending.get(child);
//TODO need to change this to hide the figure until the end.
if (rect1 == null)
continue;
child.setBounds(new Rectangle(
Math.round(progress * rect2.x + ssergorp * rect1.x),
Math.round(progress * rect2.y + ssergorp * rect1.y),
Math.round(progress * rect2.width + ssergorp * rect1.width),
Math.round(progress * rect2.height + ssergorp * rect1.height)
));
}
return true;
}
/**
* Hooks post layout in case animation is in progress.
* @see LayoutListener#postLayout(IFigure)
*/
public final void postLayout(IFigure container) {
if (Animation.isFinalRecording())
Animation.hookNeedsCapture(container, this);
}
/**
* This callback is unused. Reserved for possible future use.
* @see LayoutListener#remove(IFigure)
*/
public final void remove(IFigure child) { }
/**
* This callback is unused. Reserved for possible future use.
* @see LayoutListener#setConstraint(IFigure, Object)
*/
public final void setConstraint(IFigure child, Object constraint) { }
}