Native text rendering in Swing applications – ready, steady, go!

January 2nd, 2008

The subject of native text rendering in Swing applications has been introduced on this blog about six weeks ago, and I already described some of the implementation details. The devil is, of course, in details (unless you’re working on whizzy demoes), and i’ve spent the last month working on all the issues mentioned in the original post. This post addresses the functionality that has been missing, talks about the unsupported cases and links to a WebStart demo (at the end).

Easier deployment and support for WebStart environment

With migration to release 3.3.0 of SWT and valuable help from the SWT dev mailing list (thanks, Dave), it is now much easier to configure Bramble and SWT. Browse to the SWT main page, download the relevant distribution (Bramble distribution bundles the Windows version) and add the swt.jar to your classpath. That’s it – no more need to muck with the java.library.path VM flag and no need to extract the native libraries from the SWT jar (like was the case in 3.2.1).

To use the native text rendering in your WebStart application, take the latest substance-bramble.jar and the matching swt.jar, sign them and you’re ready to go. Note that if you’re using the jar from Eclipse itself, it’s already signed. Although it’s possible to use jars signed by different parties, I had security access exceptions on using the SWT jar from Eclipse. If you use the jar from the SWT main page, it works flawlessly (see the WebStart link at the end of this entry). If you need your application targeting multiple platforms, you’ll need to bundle the matching SWT jars and use the resources JNLP tag accordingly.

Support for all core Swing components

The latest binary and source drops of Bramble plugin provide support for all core Swing components with the following exclusions:

  • Non-plain text components, including text panes and editor panes.
  • HTML text.
  • Titled borders.

The text on all these components (including HTML) is painted with the default core AWT text font rasterizer. The latest plugin version also provides support for painting rotated (vertical) texts which are used on vertical progress bars and sliders (with labels). Interestingly enough, the rotation transformations in AWT and SWT are different (rotation angles have opposite values, and hence the translation offsets are different as well).

Support for SwingX components

This will be done in the next Substance release. As a proof of concept, the latest SwingX plugin provides native text painting for the status bar components. As in the case above, all other SwingX components use the core AWT text font rasterizer.

Support for additional operating systems

While the primary target of Bramble plugin is Windows Vista (and the inadequate AWT rasterizing of the default “Segoe UI” font), this plugin is not Windows-specific. It has been successfully tested under Windows Vista, Windows XP, Windows 2003 and Ubuntu 7.10. If you encounter bugs (visual or exceptions) under other platforms (KDE, Mac and others which are supported by SWT), I would be very interested in hearing about it.

Incidentally, using the native text renderer can not only make the applications look better. The core AWT font rasterizer has its own bugs (as all software does). This bug report opened on Substance (under Ubuntu / Gnome) is caused by a bug in the default font rasterizer that fails on a specific non-Latin character (see the bug report for more details). Since this happens under the core GTK look-and-feel and Substance provides the platform-specific font policy lookup that is aligned with the GTK LAF font lookup, this bug is seen under Substance as well. While the visual quality of the AWT font rasterizer on “DejaVu Sans” is very close to the native text renderer and there isn’t much reason to bundle SWT and Bramble, at least in this case doing so makes the application run with no exceptions and look like it belongs to the specific desktop.

Under Windows Vista, the Bramble plugin will also instruct Substance to use “Segoe UI” font under JDK 5.0 as well. Unlike the AWT font rasterizer that did even worse job under JDK 5.0, the native text renderer doesn’t care. So, you don’t have to upgrade to JDK 6.0 to have your applications look good on Vista.


Clicking on the button below will launch the full Substance test application that uses Bramble plugin to render all the texts with the native renderer. Note that while the application itself is cross-platform, this specific JNLP file only uses Windows version of SWT (no need to leave comments that this specific JNLP doesn’t work on Ubuntu or Mac). It is signed since one of the tabs shows the file system tree. As you’ll see, the texts on the task panes (left hand side) do not have proper background – as mentioned earlier, full support for SwingX components will be added in the next release. So, click around and let me know if you see something fishy :)

You’re more than welcome to leave comments with your thoughts, suggestions and bug reports (but first make sure that you’ve read this entry in its entirety). The plugin is distributed under the Eclipse Public License (EPL). The release candidate is scheduled for January 21st, with the release scheduled for February 4th.