linphone-android/src/org/linphone/ui/PreferencesListFragment.java

package org.linphone.ui;
/*
PreferencesListFragment.java
Copyright (C) 2012  Belledonne Communications, Grenoble, France

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

import org.linphone.R;
import org.linphone.mediastream.Log;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ListFragment;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.preference.Preference;
import android.preference.PreferenceGroup;
import android.preference.PreferenceManager;
import android.preference.PreferenceScreen;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.widget.ListView;
import android.widget.RelativeLayout;

@SuppressLint("ValidFragment")
public class PreferencesListFragment extends ListFragment {
    private PreferenceManager mPreferenceManager;
    
    /**
     * The starting request code given out to preference framework.
     */
    private static final int FIRST_REQUEST_CODE = 100;
    private static final int MSG_BIND_PREFERENCES = 0;
    
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case MSG_BIND_PREFERENCES:
                bindPreferences();
                break;
            }
        }
    };
    private ListView preferencesList;
    private int xmlResID;
    
    public PreferencesListFragment(int xmlId) {
        this.xmlResID = xmlId;
    }
    
    // Must be provided
    public PreferencesListFragment() {
        
    }
    
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle b) {
    	// Hack to correctly display preferences
    	View view = inflater.inflate(R.layout.settings, null);
    	
    	ViewParent p = preferencesList.getParent();
        if (p != null) {
            ((ViewGroup)p).removeView(preferencesList);
        }
    	
    	RelativeLayout layout = (RelativeLayout) view.findViewById(R.id.topLayout);
    	layout.addView(preferencesList);
    	
        postBindPreferences();
        return view;
    }
    
    @Override
    public void onDestroyView(){
        super.onDestroyView();
        ViewParent p = preferencesList.getParent();
        if (p != null) {
            ((ViewGroup)p).removeView(preferencesList);
        }
    }

    @Override
    public void onCreate(Bundle bundle) {
        super.onCreate(bundle);
        
        if (bundle != null) {
            xmlResID = bundle.getInt("xml");
        }
        
        mPreferenceManager = onCreatePreferenceManager();
        preferencesList = (ListView) LayoutInflater.from(getActivity()).inflate(R.layout.preference_list_content, null);
        preferencesList.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
        addPreferencesFromResource(xmlResID);
        postBindPreferences();
    }

    @Override
    public void onStop(){
        super.onStop();
        try {
            Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityStop");
            m.setAccessible(true);
            m.invoke(mPreferenceManager);
        } catch(Exception e) {
            Log.e("[PreferencesListFragment] onStop " + e);
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        preferencesList = null;
        try {
	        Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityDestroy");
	        m.setAccessible(true);
	        m.invoke(mPreferenceManager);
        } catch(Exception e) {
        	Log.e("[PreferencesListFragment] onDestroy " + e);
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        outState.putInt("xml", xmlResID);
        super.onSaveInstanceState(outState);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        try {
            Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityResult", int.class, int.class, Intent.class);
            m.setAccessible(true);
            m.invoke(mPreferenceManager, requestCode, resultCode, data);
        } catch(Exception e) {
            Log.e("[PreferencesListFragment] onActivityResult " + e);
        }
    }

    /**
     * Posts a message to bind the preferences to the list view.
     * <p>
     * Binding late is preferred as any custom preference types created in
     * {@link #onCreate(Bundle)} are able to have their views recycled.
     */
	private void postBindPreferences() {
        if (mHandler.hasMessages(MSG_BIND_PREFERENCES)) return;
        mHandler.obtainMessage(MSG_BIND_PREFERENCES).sendToTarget();
    }
    
    private void bindPreferences() {
        final PreferenceScreen preferenceScreen = getPreferenceScreen();
        if (preferenceScreen != null && preferencesList != null) {
            preferenceScreen.bind(preferencesList);
        }
    }
    
    /**
     * Creates the {@link PreferenceManager}.
     * 
     * @return The {@link PreferenceManager} used by this activity.
     */
    private PreferenceManager onCreatePreferenceManager() {
        try {
            Constructor<PreferenceManager> c = PreferenceManager.class.getDeclaredConstructor(Activity.class, int.class);
            c.setAccessible(true);
            PreferenceManager preferenceManager = c.newInstance(this.getActivity(), FIRST_REQUEST_CODE);
            return preferenceManager;
        } catch(Exception e) {
            Log.e("[PreferencesListFragment] onCreatePreferenceManager " + e);
            return null;
        }
    }
    
    /**
     * Returns the {@link PreferenceManager} used by this activity.
     * @return The {@link PreferenceManager}.
     */
    public PreferenceManager getPreferenceManager() {
        return mPreferenceManager;
    }

    /**
     * Sets the root of the preference hierarchy that this activity is showing.
     * 
     * @param preferenceScreen The root {@link PreferenceScreen} of the preference hierarchy.
     */
    public void setPreferenceScreen(PreferenceScreen preferenceScreen) {
        try {
            Method m = PreferenceManager.class.getDeclaredMethod("setPreferences", PreferenceScreen.class);
            m.setAccessible(true);
            boolean result = (Boolean) m.invoke(mPreferenceManager, preferenceScreen);
            if (result && preferenceScreen != null) {
                postBindPreferences();
            }
        }catch(Exception e){
            Log.e("[PreferencesListFragment] setPreferenceScreen " + e);
        }
    }
    
    /**
     * Gets the root of the preference hierarchy that this activity is showing.
     * 
     * @return The {@link PreferenceScreen} that is the root of the preference
     *         hierarchy.
     */
    public PreferenceScreen getPreferenceScreen() {
        try {
            Method m = PreferenceManager.class.getDeclaredMethod("getPreferenceScreen");
            m.setAccessible(true);
            return (PreferenceScreen) m.invoke(mPreferenceManager);
        } catch(Exception e) {
            Log.e("[PreferencesListFragment] getPreferenceScreen " + e);
        }
        
        return null;
    }
    
    /**
     * Inflates the given XML resource and adds the preference hierarchy to the current
     * preference hierarchy.
     * 
     * @param preferencesResId The XML resource ID to inflate.
     */
    public void addPreferencesFromResource(int preferencesResId) {   
        try {
            Method m = PreferenceManager.class.getDeclaredMethod("inflateFromResource", Context.class, int.class, PreferenceScreen.class);
            m.setAccessible(true);
            PreferenceScreen prefScreen = (PreferenceScreen) m.invoke(mPreferenceManager, getActivity(), preferencesResId, getPreferenceScreen());
            setPreferenceScreen(prefScreen);
        } catch(Exception e) {
            Log.e("[PreferencesListFragment] addPreferencesFromResource " + e);
        }
    }
    
    /**
     * Finds a {@link Preference} based on its key.
     * 
     * @param key The key of the preference to retrieve.
     * @return The {@link Preference} with the key, or null.
     * @see PreferenceGroup#findPreference(CharSequence)
     */
    public Preference findPreference(CharSequence key) {
        if (mPreferenceManager == null) {
        	Log.e("[PreferencesListFragment] PreferenceManager is null !");
            return null;
        }
        return mPreferenceManager.findPreference(key);
    }
}