PreferenceFragment.java

package org.holoeverywhere.preference;

import org.holoeverywhere.LayoutInflater;
import org.holoeverywhere.app.Fragment;
import org.holoeverywhere.widget.ListView;

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnKeyListener;
import android.view.ViewGroup;

public abstract class PreferenceFragment extends Fragment implements
        PreferenceManager.OnPreferenceTreeClickListener {
    public interface OnPreferenceStartFragmentCallback {
        boolean onPreferenceStartFragment(PreferenceFragment caller,
                Preference pref);
    }

    private static final int FIRST_REQUEST_CODE = 100;

    private static final int MSG_BIND_PREFERENCES = 1;
    private static final String PREFERENCES_TAG = "android:preferences";
    static {
        PreferenceInit.init();
    }
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {

                case MSG_BIND_PREFERENCES:
                    bindPreferences();
                    break;
            }
        }
    };

    private boolean mHavePrefs, mInitDone;
    private ListView mList;
    private OnKeyListener mListOnKeyListener = new OnKeyListener() {

        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            Object selectedItem = mList.getSelectedItem();
            if (selectedItem instanceof Preference) {
                View selectedView = mList.getSelectedView();
                return ((Preference) selectedItem).onKey(selectedView, keyCode,
                        event);
            }
            return false;
        }

    };

    private PreferenceManager mPreferenceManager;

    final private Runnable mRequestFocus = new Runnable() {
        @Override
        public void run() {
            mList.focusableViewAvailable(mList);
        }
    };

    public void addPreferencesFromIntent(Intent intent) {
        requirePreferenceManager();

        setPreferenceScreen(mPreferenceManager.inflateFromIntent(intent,
                getPreferenceScreen()));
    }

    public void addPreferencesFromResource(int preferencesResId) {
        requirePreferenceManager();

        setPreferenceScreen(mPreferenceManager.inflateFromResource(
                getActivity(), preferencesResId, getPreferenceScreen()));
    }

    private void bindPreferences() {
        final PreferenceScreen preferenceScreen = getPreferenceScreen();
        if (preferenceScreen != null) {
            preferenceScreen.bind(getListView());
        }
    }

    private void ensureList() {
        if (mList != null) {
            return;
        }
        View root = getView();
        if (root == null) {
            throw new IllegalStateException("Content view not yet created");
        }
        View rawListView = root.findViewById(android.R.id.list);
        if (!(rawListView instanceof ListView)) {
            throw new RuntimeException(
                    "Content has view with id attribute 'android.R.id.list' "
                            + "that is not a ListView class");
        }
        mList = (ListView) rawListView;
        if (mList == null) {
            throw new RuntimeException(
                    "Your content must have a ListView whose id attribute is "
                            + "'android.R.id.list'");
        }
        mList.setOnKeyListener(mListOnKeyListener);
        mHandler.post(mRequestFocus);
    }

    public Preference findPreference(CharSequence key) {
        if (mPreferenceManager == null) {
            return null;
        }
        return mPreferenceManager.findPreference(key);
    }

    public Preference findPreference(int id) {
        if (mPreferenceManager == null) {
            return null;
        }
        return mPreferenceManager.findPreference(id);
    }

    public ListView getListView() {
        ensureList();
        return mList;
    }

    public PreferenceManager getPreferenceManager() {
        return mPreferenceManager;
    }

    public PreferenceScreen getPreferenceScreen() {
        return mPreferenceManager.getPreferenceScreen();
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        if (mHavePrefs) {
            bindPreferences();
        }
        mInitDone = true;
        if (savedInstanceState != null) {
            Bundle container = savedInstanceState
                    .getBundle(PreferenceFragment.PREFERENCES_TAG);
            if (container != null) {
                final PreferenceScreen preferenceScreen = getPreferenceScreen();
                if (preferenceScreen != null) {
                    preferenceScreen.restoreHierarchyState(container);
                }
            }
        }
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        mPreferenceManager
                .dispatchActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mPreferenceManager = new PreferenceManager(getSupportActivity(),
                PreferenceFragment.FIRST_REQUEST_CODE);
        mPreferenceManager.setFragment(this);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        return inflater.inflate(R.layout.preference_list_fragment, container,
                false);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mPreferenceManager.dispatchActivityDestroy();
    }

    @Override
    public void onDestroyView() {
        mList = null;
        mHandler.removeCallbacks(mRequestFocus);
        mHandler.removeMessages(PreferenceFragment.MSG_BIND_PREFERENCES);
        super.onDestroyView();
    }

    @Override
    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen,
            Preference preference) {
        if (preference.getFragment() != null
                && getActivity() instanceof OnPreferenceStartFragmentCallback) {
            return ((OnPreferenceStartFragmentCallback) getActivity())
                    .onPreferenceStartFragment(this, preference);
        }
        return false;
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        final PreferenceScreen preferenceScreen = getPreferenceScreen();
        if (preferenceScreen != null) {
            Bundle container = new Bundle();
            preferenceScreen.saveHierarchyState(container);
            outState.putBundle(PreferenceFragment.PREFERENCES_TAG, container);
        }
    }

    @Override
    public void onStart() {
        super.onStart();
        mPreferenceManager.setOnPreferenceTreeClickListener(this);
    }

    @Override
    public void onStop() {
        super.onStop();
        mPreferenceManager.dispatchActivityStop();
        mPreferenceManager.setOnPreferenceTreeClickListener(null);
    }

    private void postBindPreferences() {
        if (mHandler.hasMessages(PreferenceFragment.MSG_BIND_PREFERENCES)) {
            return;
        }
        mHandler.obtainMessage(PreferenceFragment.MSG_BIND_PREFERENCES)
                .sendToTarget();
    }

    private void requirePreferenceManager() {
        if (mPreferenceManager == null) {
            throw new RuntimeException(
                    "This should be called after super.onCreate.");
        }
    }

    public void setPreferenceScreen(PreferenceScreen preferenceScreen) {
        if (mPreferenceManager.setPreferences(preferenceScreen)
                && preferenceScreen != null) {
            mHavePrefs = true;
            if (mInitDone) {
                postBindPreferences();
            }
        }
    }
}