Preferences in Eclipse RCP

Preferences

Preference pages will be appear Window>Preferences dialog. It can be used to configure different features from once place. Eclipse Preferences is kind of registry of configurations.

e.g.:

As you see here are the various configuration ( preferences ) for Java, Ant, etc.

Sample Preference in Eclipse

org.eclipse.ui.preferencePages extension has to be added to in the plug-in manifest editor for Preference Pages.

Extension point for PreferencePages

Once you add the extension, the following will be the structure:

Extensions post adding PreferencePages

Following is the implementation of SamplePreferencePage.java

SamplePreferencePage.java

package trial.preferences;

​import org.eclipse.jface.preference.BooleanFieldEditor;

import org.eclipse.jface.preference.DirectoryFieldEditor;

import org.eclipse.jface.preference.FieldEditorPreferencePage;

import org.eclipse.jface.preference.RadioGroupFieldEditor;

import org.eclipse.jface.preference.StringFieldEditor;

import org.eclipse.ui.IWorkbench;

import org.eclipse.ui.IWorkbenchPreferencePage;

import org.eclipse.ui.PlatformUI;

​/**

 * This class represents a preference page that

 * is contributed to the Preferences dialog. By 

 * subclassing <samp>FieldEditorPreferencePage</samp>, we

 * can use the field support built into JFace that allows

 * us to create a page that is small and knows how to 

 * save, restore and apply itself.

 * <p>

 * This page is used to modify preferences only. They

 * are stored in the preference store that belongs to

 * the main plug-in class. That way, preferences can

 * be accessed directly via the preference store.

 */

public class SamplePreferencePage

 extends FieldEditorPreferencePage

 implements IWorkbenchPreferencePage {

 public SamplePreferencePage() {

  super(GRID);

  setPreferenceStore(PlatformUI.getPreferenceStore());

  setDescription("A demonstration of a preference page implementation");

 }

 /**

  * Creates the field editors. Field editors are abstractions of

  * the common GUI blocks needed to manipulate various types

  * of preferences. Each field editor knows how to save and

  * restore itself.

  */

public void createFieldEditors() {

 addField(new DirectoryFieldEditor(PreferenceConstants.P_PATH, 

  "&Directory preference:", getFieldEditorParent()));

  addField(

   new BooleanFieldEditor(

    PreferenceConstants.P_BOOLEAN,

    "&An example of a boolean preference",

    getFieldEditorParent()));

  addField(new RadioGroupFieldEditor(

    PreferenceConstants.P_CHOICE,

   "An example of a multiple-choice preference",

   1,

   new String[][] { { "&Choice 1", "choice1" }, {

    "C&hoice 2", "choice2" }

  }, getFieldEditorParent()));

  addField(

   new StringFieldEditor(PreferenceConstants.P_STRING, "A &text preference:", getFieldEditorParent()));

 }



 /* (non-Javadoc)

  * @see org.eclipse.ui.IWorkbenchPreferencePage#init(org.eclipse.ui.IWorkbench)

  */

 public void init(IWorkbench workbench) {

 }

}

Following is the code for PreferenceConstants.java

PreferenceConstants.java

package trial.preferences;

/**

* Constant definitions for plug-in preferences

 */

public class PreferenceConstants {

 public static final String P_PATH = "pathPreference";

 public static final String P_BOOLEAN = "booleanPreference";

 public static final String P_CHOICE = "choicePreference";

​ public static final String P_STRING = "stringPreference";

 

}​

Code for PreferenceInitializer.java

PreferenceInitializer.java

package trial.preferences;

​

import org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer;

import org.eclipse.jface.preference.IPreferenceStore;

import org.eclipse.ui.PlatformUI;

/**

 * Class used to initialize default preference values.

 */

public class PreferenceInitializer extends AbstractPreferenceInitializer {

​ /*

  * (non-Javadoc)

  * 

  * @see org.eclipse.core.runtime.preferences.AbstractPreferenceInitializer#initializeDefaultPreferences()

  */

 public void initializeDefaultPreferences() {

  IPreferenceStore store = PlatformUI.getPreferenceStore();

  store.setDefault(PreferenceConstants.P_BOOLEAN, true);

  store.setDefault(PreferenceConstants.P_CHOICE, "choice2");

  store.setDefault(PreferenceConstants.P_STRING,

    "Default value");

 }

​}​

Once you run the Application as Eclipse Application post the above configuration, following will be the preference page:

Demo of "Sample Preferences"

Getting and Setting Preferences

Preferences for a plug-in are stored in an org.eclipse.jface.preference.IPreferenceStore object. You can access a plug-ins preference through the Activator