Kai's Blog

The css theming capabilities of the Eclipse 4.0 SDK are improving. Especially the mechanism to implement a dynamic theme switcher is much easier now. If you want to implement a css theme switcher, you just need to contribute to the extension point org.eclipse.e4.ui.css.swt.theme. Here is an example from my e4 contacts demo for declaring two themes:

<extension
 point="org.eclipse.e4.ui.css.swt.theme">
 <theme
    basestylesheeturi="css/dark-gradient.css"
    id="org.eclipse.e4.demo.contacts.themes.darkgradient"
    label="Dark Gradient Theme">
 </theme>
 <theme
    basestylesheeturi="css/bright-gradient.css"
    id="org.eclipse.e4.demo.contacts.themes.brightgradient"
    label="Bright Gradient Theme">
 </theme>
</extension>

Then you need to specify a handler that does the actual theme switching. Here is the whole handler code for switching to the dark gradient theme:

public class DarkThemeHandler {

   @Execute
   public void execute(IThemeEngine engine) {
      engine.setTheme("org.eclipse.e4.demo.contacts.themes.darkgradient");
   }
}

Use the workbench model to bind this handler to a menu or tool bar item — that’s it. The two screenshots show the results when dynamically switching between the dark and the bright theme.

Kai
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