Create a Plug-in for Eclipse Tutorial

The Eclipse IDE is highly extendable and can be customized through the creation of plug-ins. With all of its features, one thing it doesn’t have is a simple and quick way to change the font size in the editor without going through a complex preferences screen. This functionality is particularly useful when reviewing your code with others during a code review. Follow these tutorial steps, and you will be able to build such a plug-in allowing you to share your code with people sitting anywhere in the room.

Tutorial Steps

The following steps can be followed in order to build this feature into a plug-in that you can use in your projects.

• Create a new plug-in project
• Run the new plugin project
• Update the icon to a new 16 x 16 pixel image
• Update the plug-in tooltip and name
• Add a variable in the Action class
• Edit the plugin.xml to add the preference dependencies (org.eclipse.core.runtime)
• Integrate font change size methods (for org.eclipse.jface.textfont & org.eclipse.jdt.ui.editors.textfont)
• Export the completed plug-in as a jar

Additional Features to Add

• Change the icon when pressed to reflect the font size state
• Change the wrapping from 120 to 80 characters per line

public void run(IAction action) {
    IPreferencesService srv = Platform.getPreferencesService();
    String value = srv.getString("org.eclipse.ui.workbench","org.eclipse.jdt.ui.editors.textfont", null, null);
		
    Preferences preference = srv.getRootNode().node("/instance/org.eclipse.ui.workbench");
    preference.put("org.eclipse.jdt.ui.editors.textfont",getFontDataOfSize(value,size).toString());
		
    try {
	preference.flush();
    }catch(BackingStoreException e){ /* Do nothing */ }
}
        
private int getFontSize(String info,int fontSize) {
    return PreferenceConverter.basicGetFontData(info)[0].getHeight();
}
	
private FontData getFontDataOfSize(String info, int size){
    FontData fd = PreferenceConverter.basicGetFontData(info)[0];
    fd.setHeight(size);
    return fd;
}

Troubleshooting

When running a new instance of Eclipse to test your plug-in from Eclipse, you may receive an MaxPermGen exception. This can be fixed by adding the following arguments to your run configuration.

    vm args: -XX:MaxPermSize=512M
    program args: --launcher.XXMaxPermSize=512m