Improving SwingRepaintTimeline

[Rob Eden <rob@starlight-systems.com>]

Hi Krill -

First off, I'm just getting into Trident and it's a really nice library. Thanks for putting it together!

I've been playing with a setup similar to the one used in the Snake demo app in which there's a master repaint timeline. The thing I'm not crazy about is that it constantly does repaints whether it needs to or not.

So, I created a class to manage only repainting when necessary and I figured I'd see if you'd be interested in it or something similar.

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public class CheckedSwingRepaintTimeline extends Timeline {

public CheckedSwingRepaintTimeline(Component mainTimelineComp,

AtomicBoolean needRepaintFlag) {

this(mainTimelineComp, null, needRepaintFlag);

}

public CheckedSwingRepaintTimeline(Component mainTimelineComp, Rectangle toRepaint,

AtomicBoolean needRepaintFlag) {

super(mainTimelineComp);

this.addCallback(new CheckedSwingRepaintCallback(mainTimelineComp, toRepaint,

needRepaintFlag));

}

// The rest is unchanged from SwingRepaintTimeline...

}

public class CheckedSwingRepaintCallback extends TimelineCallbackAdapter {

private Component comp;

private Rectangle rect;

private final AtomicBoolean needRepaintFlag;

public CheckedSwingRepaintCallback(Component comp, AtomicBoolean needRepaintFlag) {

this(comp, null, needRepaintFlag);

}

public CheckedSwingRepaintCallback(Component comp, Rectangle rect,

AtomicBoolean needRepaintFlag) {

if (comp == null) {

throw new NullPointerException("Component must be non-null");

}

this.comp = comp;

this.rect = rect;

this.needRepaintFlag = needRepaintFlag;

}

@Override

public void onTimelinePulse(float durationFraction, float timelinePosition) {

if ( !needRepaintFlag.compareAndSet( true, false ) ) return;

if (this.rect == null)

this.comp.repaint();

else

this.comp.repaint(this.rect.x, this.rect.y, this.rect.width,

this.rect.height);

}

@Override

public void onTimelineStateChanged( Timeline.TimelineState oldState,

Timeline.TimelineState newState, float durationFraction,

float timelinePosition) {

onTimelinePulse( durationFraction, timelinePosition );

}

}

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Snake is then patched as follows:

-----------------------------------------------------------

@@ -3,6 +3,7 @@

 import java.awt.*;

 import java.awt.event.MouseEvent;

 import java.awt.event.MouseMotionAdapter;

+import java.util.concurrent.atomic.AtomicBoolean;

 

 import javax.swing.*;

 

@@ -11,6 +12,8 @@

 import org.pushingpixels.trident.swing.SwingRepaintTimeline;

 

 public class Snake {

+ private static final AtomicBoolean needRepaintFlag = new AtomicBoolean(false);

+

  public static class SnakePanelRectangle {

  private Color backgroundColor;

 

@@ -39,6 +42,7 @@

 

  public void setBackgroundColor(Color backgroundColor) {

  this.backgroundColor = backgroundColor;

+ needRepaintFlag.set(true);

  }

 

  public Color getBackgroundColor() {

@@ -66,7 +70,7 @@

  this.setPreferredSize(new Dimension(COLUMNS * (DIM + 1), ROWS

  * (DIM + 1)));

 

- Timeline repaint = new SwingRepaintTimeline(this);

+ Timeline repaint = new CheckedSwingRepaintTimeline(this, needRepaintFlag);

  repaint.playLoop(RepeatBehavior.LOOP);

 

  this.addMouseMotionListener(new MouseMotionAdapter() {

-----------------------------------------------------------

Thanks!

Rob