Removing unwanted preference pages from eclipse

To remove unwanted preferences from your eclipse rcp app, we can do the following.

As part of your App MyRCPWorkbenchAdvisor#postStartup() method, you need to invoke the following code with the preference page id.

private void removeUnwantedPreferences()

{

PreferenceManager pm = PlatformUI.getWorkbench().getPreferenceManager();

IPreferenceNode root = getRoot(pm);

if (root != null)

{

removePrefsPage(root, "com.windows.preference.mypage.id"); 

}

}

//Identify preference node

private IPreferenceNode getRoot(PreferenceManager pm)

{

try

{

Method m = PreferenceManager.class.getDeclaredMethod("getRoot", (Class[]) null); 

m.setAccessible(true);

return (IPreferenceNode) m.invoke(pm);

}

catch (Exception e)

{

IdeLog.logWarning(TitaniumCorePlugin.getDefault(), e);

}

return null;

}

//remove preference id from the preference node

private void removePrefsPage(IPreferenceNode root, String id)

{

for (IPreferenceNode node : root.getSubNodes())

{

if (node.getId().equals(id))

{

root.remove(node);

}

else

{

removePrefsPage(node, id);

}

}

}

This seems to be work without any issues.

However, I could see other direct approach but that doesn't seem to work well in all scenarios.

PreferenceManager pm = PlatformUI.getWorkbench().getPreferenceManager();

pm.remove("com.windows.preference.mypage.id");

Preferences sharing across all workspaces - Handling programatically

To share preferences across all workspaces in eclipse, you need to save preferences via ConfigurationScope.

What is configuration scope ?

Preferences stored in this scope are shared by all workspaces that are launched using a particular configuration of Eclipse plug-ins. On a single-user installation, this serves to capture preferences that are common to all workspaces launched by that user. On a multi-user installation, these preferences are shared by all users of the configuration.

How to save ?

IEclipsePreferences store = ConfigurationScope.INSTANCE.getNode(MyUIPlugin.PLUGIN_ID);

if (store != null)

{

store.putBoolean(MyFLAG_PREF, true);

try

{

store.flush();

}

catch (BackingStoreException e)

{

//Log exception

}

}

How to retrieve the saved preference value?

boolean isSet = Platform.getPreferencesService().getBoolean(MyUIPlugin.PLUGIN_ID,

MyFLAG_PREF, false, new IScopeContext[] { ConfigurationScope.INSTANCE });

Understand more about preference scopes:

https://wiki.eclipse.org/FAQ_What_is_a_preference_scope%3F

Registering a listener for changes in network connections and proxy from eclipse preferences

import org.eclipse.core.net.proxy.IProxyChangeEvent;

import org.eclipse.core.net.proxy.IProxyChangeListener;

import org.eclipse.core.net.proxy.IProxyService;

import org.osgi.util.tracker.ServiceTracker;

public class ProxyHelper

{

public void registerListener()

{

ServiceTracker tracker = new ServiceTracker(MyPlugin.getDefault().getBundle().getBundleContext(),

IProxyService.class.getName(), null);

tracker.open();

IProxyService proxyService = (IProxyService) tracker.getService();

proxyService.addProxyChangeListener(new IProxyChangeListener()

{

@Override

public void proxyInfoChanged(IProxyChangeEvent event)

{

// TODO: your action for proxy changed

}

});

}

}

Where can I find eclipse preferences stored files ?

Eclipse stores all the preferences in the preference configuration files. This you can find in the below eclipse workspace location.

<eclipseworkspace>\.metadata\.plugins\org.eclipse.core.runtime\.settings\

Say for example, jre configuration will be stored in the "org.eclipse.jdt.launching.prefs" file.