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.

It is a great pleasure to announce the availability of the final release or version 1.2 of Trident animation library (code-named Cookie Jar). The major milestone for this release is moving Substance 6.0 to use Trident – along with validating the library performance and flexibility to support a wide variety of UI animations. Trident 1.2 has also added a few new APIs to address a few common application requirements:

• Custom property accessors
• Refined APIs for stopping timelines

You’re more than welcome to take Trident 1.2 for a ride and see what it can do to add animations to your Swing and SWT applications. To see how Trident is used to drive application animation scenarios, see its use in the following projects:

• Substance look-and-feel – transition animations on core and third-party components
• Onyx – animation blueprints for Swing
• Granite – animation blueprints for SWT

I am thrilled today to announce the availability of the final release for version 1.1 of Trident animation library (code-named Bogeyman). Most of the new functionality in this version was driven by the user feedback, and includes the following:

• Reworked fluent APIs to interpolate properties
• Configuration APIs to extend the core functionality of the library
• Specifying custom pulse source to drive timelines
• Working with custom property interpolators
• Extended support for animations in Java UI toolkits

In addition to the bundled sample applications, Trident has two blueprint projects. These projects show how to use Trident to drive complex animation scenarios in Internet-enabled rich applications that show graphic information on music albums. Project Onyx is the Swing implementation (see detailed walkthroughs), and Project Granite is the SWT implementation (see detailed walkthroughs).

If you have Java 7 installed on your machine, click the button below to launch the WebStart version of Project Onyx:

You are more than welcome to take Trident 1.1 for a ride and report any problems in the project mailing lists, forums or issue tracker.

While Trident requires Java 6 for both the compile and runtime, Emmanuel Bourg has shared his tips on what is required to compile and run version 1.1 of the library under Java 5 and Java 1.4 – complete with a patch for the relevant classes and the build script. While these tips are relevant for the current state of the codebase, Trident core may at any point switch to using Java 6 specific APIs if they are found to be beneficial to the development of the library.

Finally, release 1.1 has one known issue that was found a few hours before the final release was built. As the fix may potentially affect the stability of the library, i have decided to postpone it to the next release. The issue is with running looping timelines on Swing components. If a window hosting such a component is disposed, Trident will continue running the timeline. If the timeline results in updating visual properties of this component (directly or indirectly), the main AWT thread will never shut down – as described in the AWT threading documentation – and the VM will never quit. There are two workaround for this issue in version 1.1:

• Use EXIT_ON_CLOSE mode instead of DISPOSE_ON_CLOSE
• Override the Component.removeNotify of the relevant component and cancel / abort the timeline

I am excited today to announce the availability of the release candidate for version 1.1 of Trident animation library (code-named Bogeyman). Most of the new functionality in this version was driven by the user feedback, and includes the following:

• Reworked fluent APIs to interpolate properties
• Configuration APIs to extend the core functionality of the library
• Specifying custom pulse source to drive timelines
• Working with custom property interpolators
• Extended support for animations in Java UI toolkits

In addition to the bundled simple applications, Trident has two blueprint projects. These projects show how to use Trident to drive complex animation scenarios in Internet-enabled rich applications that show graphic information on music albums. Project Onyx is the Swing implementation (see detailed walkthroughs), and Project Granite is the SWT implementation (see detailed walkthroughs).

If you have Java 7 installed on your machine, click the button below to launch the WebStart version of Project Onyx:

You are more than welcome to take Trident 1.1RC for a ride and report any problems in the project mailing lists, forums or issue tracker. The final release is scheduled for October 12. Only bugs will be fixed until that date.