June 11th, 2010

Immovable. Unshaken.

Bear with me for a moment. There’s this guy sitting in a bar. He doesn’t have any money to pay for the drinks, and nobody wants to invite him to join their table. Thinking about what he can do, he sees a bunch of guys from Mongolia sitting around a table full of food and alcohol. Strolling over, he asks them: “Do you want to hear a story about a fight between a russian warrior and a mongol warrior”? Half ignoring him, they say “whatever, go ahead”.

“And so the story goes that a russian warrior and a mongol warrior met for a fight. The mongol struck the russian, and the russian sunk into the ground up to his ankles”. The mongols are starting to pay some interest, and give the guy a small drink. After finishing the drink the guy continues. “The mongol strikes the russian one more time, and the russian sinks into the ground up to his knees”. The mongols give him some food and more to drink. “He strikes him the third time, and the russian sinks into the ground up to his chest”.

Now the mongols are really happy, giving him some steak to eat and more to drink. The guy starts getting drunk and relaxed, and continues the story. “Now it’s time for the russian. He strikes him once, but the mongol stands. Immovable, unshaken”. The mongols keep on giving him more food and alcohol. “The russian strikes once more, but the mongol stands. Immovable, unshaken”. They give him all their food, captivated by the story. The guy keeps on drinking. “The russian strikes the third time, but the mongol stands. Immovable, unshaken”. The mongols are ecstatic, unable to contain their joy. The guy is done with eating and drinking, and leans back to rest. The mongols are urging him to continue the story and keep on asking him what’s next. The guy says: “What’s next? The mongol stands. Immovable, unshaken. With only his ears above the ground”. (*)

Which brings me to Swing. The last 18 months have seen little change in the direction of the core Swing library – maintenance and bug fixing. With every passing milestone of JDK 7, more and more Swing features have been removed from the feature list. Swing application framework, SwingX painters and new components all fell to the side. And while there have been a number of bug fixes in the last few months, the only public API enhancements in core Swing are shaped / translucent windows (an API that has been promoted from 6u10+ to be public) and JLayer (an almost direct port of JXLayer).

In the meantime, we’re not going to see any of:

  • Components such as date picker, month view, task panes, split buttons.
  • A modern (HTML 5 / CSS 3) browser component.
  • Form / grid oriented layout managers.
  • Binding.
  • Video playback / recording.
  • Docking / windowing.
  • API enhancements to the table component.

Given how much is going on with JavaFX, this is not really surprising. This just confirms what i said before. Core Swing is in feature freeze, immovable, unshaken. It is a solid foundation, and lends itself quite easily to external third-party enhancements. But as far as the core feature set – it’s not going anywhere. A couple of random observations.

Since Oracle acquisition, the bug fixing pace has definitely picked up. There’s a bunch of bugs being fixed in both Swing and Java2D. On the other hand, JavaFX has Prism, a new rendering pipeline for mobile, desktop and TV stacks. While Swing / Java2D has been the foundation of JavaFX desktop profile before, and we enjoyed incidental performance improvements and bug fixes as the result, it’s not going to last for very long. New composites, hardware acceleration, new graphic primitives are unlikely to be ported and maintained in two different pipelines. And i would imagine that internally Prism also has quite a few different backends, each one optimized for the specific graphics hardware – meaning more work in the foreseeable future outside the existing Java2D backends.

NetBeans is an interesting beast. A solid foundation for writing modular boring business applications, it has not seen any of its features ported to core Swing. We’re talking about docking, windowing, sliding palettes, layouts, application framework and more. If the crossover has not happened until now, how likely is it that it will happen in the future? Speculating widely, recently rumored cuts in european / asian offices may jeopardize the future of NetBeans – which, to the best of my knowledge, is mainly developed in Prague. And don’t forget that Oracle has its own JDeveloper IDE. The only hope for NetBeans would be if they position themselves as the platform for JavaFX development. Given Eclipse’s dominance presence outside the internal bubble, how long will it be before the internal investment in NetBeans is reconsidered in this profit-oriented environment?

And what’s up with an embeddable browser component? Seriously, everybody is doing it. WebKit must be exposed in a gazillion other UI toolkits by now. Big companies are doing it. Small companies are doing it. It’s been what? Two, three years? If this is still going on internally, and you’re thinking to somehow monetize your investment, you can forget about it. Open source it now, and let people help you. You’re not really thinking that this port is going to be so unique that companies will be lining up to pay top dollar to license it.

(*) Russian readers not familiar with the joke can find the original here (number 48). This is not really politically correct, but i’m sure that every folklore has its own version.

June 6th, 2010

Repaint timelines in Trident 1.3

Trident aims to be a general-purpose animation library for Java applications. However, most of the time people talk and refer to animations in the context of pixels on the screen, be it for transitions between different states, rollover effects, smooth scrolling of large content and what not. Trident comes with built-in support for Java based UI toolkits. The three UI specific requirements are addressed by the core Trident library:

  • Automatically respecting the threading rules of the UI toolkits
  • Providing property interpolators for classes that represent graphical objects of the UI toolkits
  • Repainting application windows that have continuous animations

Today i’m going to talk about the last point – repainting application windows. Trident has two special timelines – org.pushingpixels.trident.swing.SwingRepaintTimeline and org.pushingpixels.trident.swt.SWTRepaintTimeline. These are simple utility timelines that can be used to continuously repaint the contents of the specific window / component on every timeline pulse. For example, if you have a continuous emulation of fireworks, you can have “worker” timelines updating the model objects that represent the firework volleys, and one repaint timeline that updates the entire screen based on the current state of all firework volley model objects. This allows you to separate the model updates from the view updates.

However, as Rob Eden pointed out to me this week, these two classes repaint the window / component on every timeline pulse. This can result in unnecessary repaints if the model updates are not done on every timeline pulse as well. In the “snake” example, the model is updated only when the mouse is moving. Once the mouse has stopped moving and all rollover timelines are done, there are no changes to the model, and continuously repainting the screen consumes unnecessary CPU resources.

To address this, both SwingRepaintTimeline and SWTRepaintTimeline now have three new APIs:

  1. setAutoRepaintMode(boolean) – by default the auto repaint mode is true. Application that wishes to control the repaint will call this method with false.
  2. forceRepaintAtNextPulse() – will make the repaint() / redraw() call when the next pulse is fired. This will throw an exception if the timeline is in auto-repaint mode.
  3. setRepaintRectangle(Rectangle) – allows to dynamically change the rectangle to be repainted. Can be used if the bounds of the view that represents the specific model can change dynamically (e.g. when the user resizes the application window).

The snake examples for both Swing and SWT have been updated to show the recommended usage of the first two APIs. Click the button below to run the WebStart version of the Swing demo:

If you’re interested in testing this functionality in your application, take the latest 1.3dev drop (code named Diamond In The Sky) for a spin.

May 28th, 2010

Color selector popup in Flamingo 5.0

The latest 5.0dev drop of Flamingo provides a flexible color selector popup that you can associate with the command buttons that control the color selection of elements in your application. Here is how a color selector popup looks like under left-to-right and right-to-left orientation:


To associate a color selector popup with the specific command button (that has a popup area), return an instance of JColorSelectorPopupMenu from the PopupPanelCallback. This class extends the JCommandPopupMenu and allows adding command menu buttons, command toggle menu buttons and separators. The screenshot above shows two command menu buttons in the color selector popup – one at the top and another at the bottom.

In adition, the JColorSelectorPopupMenu provides the following APIs to add color selector sections:

  • addColorSection that gets 10 colors. The “Standard Colors” in the screenshot above is an example.
  • addColorSectionWithDerived that gets 10 primary colors. Each primary color will show a column of 5 derived colors below it. The “Theme Colors” in the screenshot above is an example.
  • addRecentSection. Shows the LRU list of the recently selected colors.

A JColorSelectorPopupMenu is created with an instance of ColorSelectorCallback. This interface has two methods:

  • onColorRollover(Color) – allows your application to show the live preview of the color under the mouse. When called with null, the application needs to unset the live preview.
  • onColorSelected(Color) – called when the user selects one of the colors in the popup.

The selector sections added with the APIs above will be automatically wired to the color selector callback that you pass in the constructor. If your design requires displaying additional menu buttons to select color, these will need to be explicitly wired to the callback and the list of recently selected colors.

The test.common.TestColorSelector application shows sample code on how to do this. The top button selects a default color. It has an ActionListener which calls the same logic as onColorSelected(), and a ChangeListener that tracks changes to the rollover state of the menu button and calls the same logic as onColorRollover(). The bottom button in this sample application launches the core JColorChooser. When a color is selected in that chooser, the custom application code calls the same logic as onColorSelected().

When a color is selected in both custom menu buttons, the list of recently selected colors is updated – so that the user can quickly choose it again in the future. The relevant APIs in the JColorSelectorPopupMenu are:

  • static getRecentlyUsedColors(). The last element in the list is the most recently selected.
  • static addColorToRecentlyUsed() adds the specified color to the list. If the color is already there, it is moved to the end of the list.

This list is guaranteed to contain at most ten colors.

If you want to take the new color selector popup for a spin, you will need the following:

Note that the last two are required if you’re running your application under one of Substance skins.

May 22nd, 2010

Onyx reloaded

Exactly a year ago I’ve introduced project Onyx – animation blueprints for Swing using the Trident animation library. Onyx is a small application that loads album information for the specific artist from the Internet and displays it as a scrollable gallery. Here is how Onyx looked a year ago:

And here is how Onyx looks now:

Along with running on Java 6 (with Java 7 weekly binaries for Mac nowhere in sight), Onyx also has received a slight visual facelift for the main window. First, let’s see the code for disposing a window by fading it out:

public static void fadeOutAndDispose(final Window window,
      int fadeOutDuration) {
   Timeline dispose = new Timeline(window);

   try {
      Class clazz = Class.forName("com.sun.awt.AWTUtilities");
      final Method opacityMethod = clazz.getDeclaredMethod(
            "setWindowOpacity", Window.class, float.class);

      dispose.addPropertyToInterpolate(Timeline. property(
            new PropertySetter() {
               public void set(Object obj, String fieldName,
                     Float value) {
                  try {
                     opacityMethod.invoke(null, obj, value);
                  } catch (Exception exc) {
      dispose.addCallback(new UIThreadTimelineCallbackAdapter() {
         public void onTimelineStateChanged(TimelineState oldState,
               TimelineState newState, float durationFraction,
               float timelinePosition) {
            if (newState == TimelineState.DONE) {
   } catch (Exception exc) {

With Java 7, you can simply do this:

dispose.addPropertyToInterpolate("opacity", 1.0f, 0.0f);

and let Trident call Window.setOpacity method at every timeline pulse. In Java 6 (starting with 6u10), the AWTUtilities.setWindowOpacity needs to be called on every pulse explicitly.

And here is the code for painting the main content window. First, we store the current clip and enable anti-aliasing:

protected void paintComponent(Graphics g) {
   Graphics2D g2d = (Graphics2D) g.create();
   Shape clip = g2d.getClip();

   g2d.setStroke(new BasicStroke(1.0f));

Next, we compute the outer and inner contours of the panel (the inner contour will be painted with slightly brighter colors as shown in the screenshot above):

   int radius = 16;

   Shape contour = new RoundRectangle2D.Double(0, 0, getWidth() - 1,
         getHeight() - 1, radius, radius);
   Shape innerContour = new RoundRectangle2D.Double(1, 1, getWidth() - 3,
         getHeight() - 3, radius - 1, radius - 1);

When the main window is first shown and disposed, a special timeline is played to make the window appear and disappear smoothly. The timeline interpolates the alpha field between 0.0 and 0.9. The main panel has two parts – the bright blue header and the black content. While the content is painted based on the current value of alpha, the header uses less translucency:

   g2d.setComposite(AlphaComposite.SrcOver.derive(1.0f - (float) Math.pow(
         1.0f - alpha, 3.0)));

To paint the header, we first update the current clip to make sure that the painting is only done in the header section. Next, we fill the contour, draw the inner contour and draw the outer contour – all based on the specific colors required by the target design:

   // top part
   g2d.clipRect(0, 0, getWidth(), TITLE_HEIGHT);
   g2d.setPaint(new LinearGradientPaint(0, 0, 0, TITLE_HEIGHT,
         new float[] { 0.0f, 0.49999f, 0.5f, 1.0f }, new Color[] {
               new Color(119, 152, 251), new Color(80, 127, 250),
               new Color(48, 109, 250), new Color(10, 97, 250) }));
   g2d.setPaint(new GradientPaint(0, 0, new Color(151, 179, 253), 0,
         TITLE_HEIGHT, new Color(19, 92, 233)));
   g2d.setColor(new Color(11, 61, 200));

Now we restore the clip:


If we have an artist name to display, we position it in the middle of the title area (using font ascent for proper baseline alignment) and paint the string twice to create a lighting effect:

   if (this.searchString != null) {
      int fa = g2d.getFontMetrics().getAscent();
      int x = (getWidth() - g2d.getFontMetrics().stringWidth(
            this.searchString)) / 2;
      int y = (TITLE_HEIGHT + fa) / 2;
      g2d.setColor(new Color(31, 60, 114));
      g2d.drawString(this.searchString, x, y + 1);
      g2d.setColor(new Color(255, 255, 255));
      g2d.drawString(this.searchString, x, y);

The main content area is painted in the same way as the header. We update the clip, fill the contour, draw the inner contour and draw the outer contour:

   // bottom part
   g2d.clipRect(0, TITLE_HEIGHT, getWidth(), getHeight() - TITLE_HEIGHT
         + 1);

   g2d.setColor(new Color(0, 0, 0));
   g2d.setPaint(new GradientPaint(0, TITLE_HEIGHT, new Color(57, 56, 57),
         0, getHeight() - TITLE_HEIGHT, new Color(50, 48, 50)));
   g2d.setPaint(new GradientPaint(0, TITLE_HEIGHT, new Color(13, 11, 15),
         0, getHeight() - TITLE_HEIGHT, new Color(15, 8, 13)));

Finally, we draw a single line separator between the title and main content areas:

   // separator
   g2d.setColor(new Color(12, 11, 12));
   g2d.drawLine(1, TITLE_HEIGHT, getWidth() - 2, TITLE_HEIGHT);


To see the latest Onyx in action, click on the button below to launch the WebStart demo. Use the mouse wheel to scroll between the albums. Click a specific album to show a larger cover and the track list.

If you cannot run the demo, here is a short video of Onyx in action: