How to change Eclipse Preferences programmatically

Question

What approach should be to change Eclipse Preferences?

They are stored in <workspace>/.metadata/.plugin/org.eclipse.core.runtime/.settings

But I hope to find Java API and a way to discover any preference ID.

Answer 1

Somewhat confusingly there are several APIs a plugin can use for preferences.

If your plugin activator extends AbstractUIPlugin then you can call

IPreferenceStore prefStore = getPreferenceStore();

in the activator to get the preference store for your plugin.

You can also use

IEclipsePreferences prefs = InstanceScope.INSTANCE.getNode("node id");

to get a slightly different interface to the preferences.

There is also the org.eclipse.equinox.preferences.preferences extension point which lets you define an 'initializer' to set the default values for preferences.