net.java.balloontip.positioners.BalloonTipPositioner Maven / Gradle / Ivy
/**
* Copyright (c) 2011 Bernhard Pauler, Tim Molderez.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the 3-Clause BSD License
* which accompanies this distribution, and is available at
* http://www.opensource.org/licenses/BSD-3-Clause
*/
package net.java.balloontip.positioners;
import java.awt.Point;
import java.awt.Rectangle;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import net.java.balloontip.BalloonTip;
/**
* A BalloonTipPositioner is used to determine the position of a BalloonTip
* Note: If you change a positioner's settings, the changes may not be visible until the balloon tip is redrawn.
* @author Tim Molderez
*/
public abstract class BalloonTipPositioner {
protected BalloonTip balloonTip = null;
private PropertyChangeListener styleListener = new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent evt) {
onStyleChange();
}
};
/**
* Default constructor
*/
public BalloonTipPositioner() {}
/**
* Retrieve the balloon tip that uses this positioner
* @return The balloon tip that uses this positioner
*/
public final BalloonTip getBalloonTip() {
return balloonTip;
}
/**
* This method is meant only to be used by BalloonTip!
* A BalloonTip must call this method at the end of its construction (or when it's swapping for a new BalloonTipPositioner).
* @param balloonTip the balloon tip
*/
public final void setBalloonTip(final BalloonTip balloonTip) {
this.balloonTip = balloonTip;
this.balloonTip.addPropertyChangeListener("style", styleListener);
onStyleChange();
}
/**
* Find the current location of the balloon's tip, relative to the top-level container
* @return The location of the tip
*/
public abstract Point getTipLocation();
/**
* Determine and set the current location of the balloon tip
* @param attached the balloon tip is attached to this rectangle
*/
public abstract void determineAndSetLocation(Rectangle attached);
/**
* This method is called whenever the balloon tip's style changes.
* The positioner will ensure the new style is set up properly.
*/
protected abstract void onStyleChange();
protected void finalize() throws Throwable {
if (balloonTip!=null) {
balloonTip.removePropertyChangeListener("style", styleListener);
}
super.finalize();
}
}