src/com/android/settings/SettingsPreferenceFragment.java - platform/packages/apps/Settings - Git at Google

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.settings;

 import android.app.Activity;
 import android.app.Dialog;
 import android.app.DialogFragment;
 import android.app.Fragment;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.pm.PackageManager;
 import android.database.DataSetObserver;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.preference.Preference;
 import android.preference.PreferenceActivity;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceGroupAdapter;
 import android.text.TextUtils;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.ListAdapter;
 import android.widget.ListView;

 /**
  * Base class for Settings fragments, with some helper functions and dialog management.
  */
 public class SettingsPreferenceFragment extends PreferenceFragment implements DialogCreatable {

     private static final String TAG = "SettingsPreferenceFragment";

     private static final int MENU_HELP = Menu.FIRST + 100;
     private static final int DELAY_HIGHLIGHT_DURATION_MILLIS = 600;

     private static final String SAVE_HIGHLIGHTED_KEY = "android:preference_highlighted";

     private SettingsDialogFragment mDialogFragment;

     private String mHelpUrl;

     // Cache the content resolver for async callbacks
     private ContentResolver mContentResolver;

     private String mPreferenceKey;
     private boolean mPreferenceHighlighted = false;
     private Drawable mHighlightDrawable;

     private ListAdapter mCurrentRootAdapter;
     private boolean mIsDataSetObserverRegistered = false;
     private DataSetObserver mDataSetObserver = new DataSetObserver() {
         @Override
         public void onChanged() {
             highlightPreferenceIfNeeded();
         }

         @Override
         public void onInvalidated() {
             highlightPreferenceIfNeeded();
         }
     };

     private ViewGroup mPinnedHeaderFrameLayout;

     @Override
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle);

         if (icicle != null) {
             mPreferenceHighlighted = icicle.getBoolean(SAVE_HIGHLIGHTED_KEY);
         }

         // Prepare help url and enable menu if necessary
         int helpResource = getHelpResource();
         if (helpResource != 0) {
             mHelpUrl = getResources().getString(helpResource);
         }
     }

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
         final View root = super.onCreateView(inflater, container, savedInstanceState);
         mPinnedHeaderFrameLayout = (ViewGroup) root.findViewById(R.id.pinned_header);
         return root;
     }

     public void setPinnedHeaderView(View pinnedHeader) {
         mPinnedHeaderFrameLayout.addView(pinnedHeader);
         mPinnedHeaderFrameLayout.setVisibility(View.VISIBLE);
     }

     public void clearPinnedHeaderView() {
         mPinnedHeaderFrameLayout.removeAllViews();
         mPinnedHeaderFrameLayout.setVisibility(View.GONE);
     }

     @Override
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);

         outState.putBoolean(SAVE_HIGHLIGHTED_KEY, mPreferenceHighlighted);
     }

     @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
         if (!TextUtils.isEmpty(mHelpUrl)) {
             setHasOptionsMenu(true);
         }
     }

     @Override
     public void onResume() {
         super.onResume();

         final Bundle args = getArguments();
         if (args != null) {
             mPreferenceKey = args.getString(SettingsActivity.EXTRA_FRAGMENT_ARG_KEY);
             highlightPreferenceIfNeeded();
         }
     }

     @Override
     protected void onBindPreferences() {
         registerObserverIfNeeded();
     }

     @Override
     protected void onUnbindPreferences() {
         unregisterObserverIfNeeded();
     }

     @Override
     public void onStop() {
         super.onStop();

         unregisterObserverIfNeeded();
     }

     public void registerObserverIfNeeded() {
         if (!mIsDataSetObserverRegistered) {
             if (mCurrentRootAdapter != null) {
                 mCurrentRootAdapter.unregisterDataSetObserver(mDataSetObserver);
             }
             mCurrentRootAdapter = getPreferenceScreen().getRootAdapter();
             mCurrentRootAdapter.registerDataSetObserver(mDataSetObserver);
             mIsDataSetObserverRegistered = true;
         }
     }

     public void unregisterObserverIfNeeded() {
         if (mIsDataSetObserverRegistered) {
             if (mCurrentRootAdapter != null) {
                 mCurrentRootAdapter.unregisterDataSetObserver(mDataSetObserver);
                 mCurrentRootAdapter = null;
             }
             mIsDataSetObserverRegistered = false;
         }
     }

     public void highlightPreferenceIfNeeded() {
         if (isAdded() && !mPreferenceHighlighted &&!TextUtils.isEmpty(mPreferenceKey)) {
             highlightPreference(mPreferenceKey);
         }
     }

     private Drawable getHighlightDrawable() {
         if (mHighlightDrawable == null) {
             mHighlightDrawable = getActivity().getDrawable(R.drawable.preference_highlight);
         }
         return mHighlightDrawable;
     }

     /**
      * Return a valid ListView position or -1 if none is found
      */
     private int canUseListViewForHighLighting(String key) {
         if (!hasListView()) {
             return -1;
         }

         ListView listView = getListView();
         ListAdapter adapter = listView.getAdapter();

         if (adapter != null && adapter instanceof PreferenceGroupAdapter) {
             return findListPositionFromKey(adapter, key);
         }

         return -1;
     }

     private void highlightPreference(String key) {
         final Drawable highlight = getHighlightDrawable();

         final int position = canUseListViewForHighLighting(key);
         if (position >= 0) {
             mPreferenceHighlighted = true;

             final ListView listView = getListView();
             final ListAdapter adapter = listView.getAdapter();

             ((PreferenceGroupAdapter) adapter).setHighlightedDrawable(highlight);
             ((PreferenceGroupAdapter) adapter).setHighlighted(position);

             listView.post(new Runnable() {
                 @Override
                 public void run() {
                     listView.setSelection(position);
                     listView.postDelayed(new Runnable() {
                         @Override
                         public void run() {
                             final int index = position - listView.getFirstVisiblePosition();
                             if (index >= 0 && index < listView.getChildCount()) {
                                 final View v = listView.getChildAt(index);
                                 final int centerX = v.getWidth() / 2;
                                 final int centerY = v.getHeight() / 2;
                                 highlight.setHotspot(centerX, centerY);
                                 v.setPressed(true);
                                 v.setPressed(false);
                             }
                         }
                     }, DELAY_HIGHLIGHT_DURATION_MILLIS);
                 }
             });
         }
     }

     private int findListPositionFromKey(ListAdapter adapter, String key) {
         final int count = adapter.getCount();
         for (int n = 0; n < count; n++) {
             final Object item = adapter.getItem(n);
             if (item instanceof Preference) {
                 Preference preference = (Preference) item;
                 final String preferenceKey = preference.getKey();
                 if (preferenceKey != null && preferenceKey.equals(key)) {
                     return n;
                 }
             }
         }
         return -1;
     }

     protected void removePreference(String key) {
         Preference pref = findPreference(key);
         if (pref != null) {
             getPreferenceScreen().removePreference(pref);
         }
     }

     /**
      * Override this if you want to show a help item in the menu, by returning the resource id.
      * @return the resource id for the help url
      */
     protected int getHelpResource() {
         return 0;
     }

     @Override
     public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
         if (mHelpUrl != null && getActivity() != null) {
             MenuItem helpItem = menu.add(0, MENU_HELP, 0, R.string.help_label);
             HelpUtils.prepareHelpMenuItem(getActivity(), helpItem, mHelpUrl);
         }
     }

     /*
      * The name is intentionally made different from Activity#finish(), so that
      * users won't misunderstand its meaning.
      */
     public final void finishFragment() {
         getActivity().onBackPressed();
     }

     // Some helpers for functions used by the settings fragments when they were activities

     /**
      * Returns the ContentResolver from the owning Activity.
      */
     protected ContentResolver getContentResolver() {
         Context context = getActivity();
         if (context != null) {
             mContentResolver = context.getContentResolver();
         }
         return mContentResolver;
     }

     /**
      * Returns the specified system service from the owning Activity.
      */
     protected Object getSystemService(final String name) {
         return getActivity().getSystemService(name);
     }

     /**
      * Returns the PackageManager from the owning Activity.
      */
     protected PackageManager getPackageManager() {
         return getActivity().getPackageManager();
     }

     @Override
     public void onDetach() {
         if (isRemoving()) {
             if (mDialogFragment != null) {
                 mDialogFragment.dismiss();
                 mDialogFragment = null;
             }
         }
         super.onDetach();
     }

     // Dialog management

     protected void showDialog(int dialogId) {
         if (mDialogFragment != null) {
             Log.e(TAG, "Old dialog fragment not null!");
         }
         mDialogFragment = new SettingsDialogFragment(this, dialogId);
         mDialogFragment.show(getChildFragmentManager(), Integer.toString(dialogId));
     }

     public Dialog onCreateDialog(int dialogId) {
         return null;
     }

     protected void removeDialog(int dialogId) {
         // mDialogFragment may not be visible yet in parent fragment's onResume().
         // To be able to dismiss dialog at that time, don't check
         // mDialogFragment.isVisible().
         if (mDialogFragment != null && mDialogFragment.getDialogId() == dialogId) {
             mDialogFragment.dismiss();
         }
         mDialogFragment = null;
     }

     /**
      * Sets the OnCancelListener of the dialog shown. This method can only be
      * called after showDialog(int) and before removeDialog(int). The method
      * does nothing otherwise.
      */
     protected void setOnCancelListener(DialogInterface.OnCancelListener listener) {
         if (mDialogFragment != null) {
             mDialogFragment.mOnCancelListener = listener;
         }
     }

     /**
      * Sets the OnDismissListener of the dialog shown. This method can only be
      * called after showDialog(int) and before removeDialog(int). The method
      * does nothing otherwise.
      */
     protected void setOnDismissListener(DialogInterface.OnDismissListener listener) {
         if (mDialogFragment != null) {
             mDialogFragment.mOnDismissListener = listener;
         }
     }

     public void onDialogShowing() {
         // override in subclass to attach a dismiss listener, for instance
     }

     public static class SettingsDialogFragment extends DialogFragment {
         private static final String KEY_DIALOG_ID = "key_dialog_id";
         private static final String KEY_PARENT_FRAGMENT_ID = "key_parent_fragment_id";

         private int mDialogId;

         private Fragment mParentFragment;

         private DialogInterface.OnCancelListener mOnCancelListener;
         private DialogInterface.OnDismissListener mOnDismissListener;

         public SettingsDialogFragment() {
             /* do nothing */
         }

         public SettingsDialogFragment(DialogCreatable fragment, int dialogId) {
             mDialogId = dialogId;
             if (!(fragment instanceof Fragment)) {
                 throw new IllegalArgumentException("fragment argument must be an instance of "
                         + Fragment.class.getName());
             }
             mParentFragment = (Fragment) fragment;
         }

         @Override
         public void onSaveInstanceState(Bundle outState) {
             super.onSaveInstanceState(outState);
             if (mParentFragment != null) {
                 outState.putInt(KEY_DIALOG_ID, mDialogId);
                 outState.putInt(KEY_PARENT_FRAGMENT_ID, mParentFragment.getId());
             }
         }

         @Override
         public void onStart() {
             super.onStart();

             if (mParentFragment != null && mParentFragment instanceof SettingsPreferenceFragment) {
                 ((SettingsPreferenceFragment) mParentFragment).onDialogShowing();
             }
         }

         @Override
         public Dialog onCreateDialog(Bundle savedInstanceState) {
             if (savedInstanceState != null) {
                 mDialogId = savedInstanceState.getInt(KEY_DIALOG_ID, 0);
                 mParentFragment = getParentFragment();
                 int mParentFragmentId = savedInstanceState.getInt(KEY_PARENT_FRAGMENT_ID, -1);
                 if (mParentFragment == null) {
                     mParentFragment = getFragmentManager().findFragmentById(mParentFragmentId);
                 }
                 if (!(mParentFragment instanceof DialogCreatable)) {
                     throw new IllegalArgumentException(
                             (mParentFragment != null
                                     ? mParentFragment.getClass().getName()
                                     : mParentFragmentId)
                                     + " must implement "
                                     + DialogCreatable.class.getName());
                 }
                 // This dialog fragment could be created from non-SettingsPreferenceFragment
                 if (mParentFragment instanceof SettingsPreferenceFragment) {
                     // restore mDialogFragment in mParentFragment
                     ((SettingsPreferenceFragment) mParentFragment).mDialogFragment = this;
                 }
             }
             return ((DialogCreatable) mParentFragment).onCreateDialog(mDialogId);
         }

         @Override
         public void onCancel(DialogInterface dialog) {
             super.onCancel(dialog);
             if (mOnCancelListener != null) {
                 mOnCancelListener.onCancel(dialog);
             }
         }

         @Override
         public void onDismiss(DialogInterface dialog) {
             super.onDismiss(dialog);
             if (mOnDismissListener != null) {
                 mOnDismissListener.onDismiss(dialog);
             }
         }

         public int getDialogId() {
             return mDialogId;
         }

         @Override
         public void onDetach() {
             super.onDetach();

             // This dialog fragment could be created from non-SettingsPreferenceFragment
             if (mParentFragment instanceof SettingsPreferenceFragment) {
                 // in case the dialog is not explicitly removed by removeDialog()
                 if (((SettingsPreferenceFragment) mParentFragment).mDialogFragment == this) {
                     ((SettingsPreferenceFragment) mParentFragment).mDialogFragment = null;
                 }
             }
         }
     }

     protected boolean hasNextButton() {
         return ((ButtonBarHandler)getActivity()).hasNextButton();
     }

     protected Button getNextButton() {
         return ((ButtonBarHandler)getActivity()).getNextButton();
     }

     public void finish() {
         getActivity().onBackPressed();
     }

     public boolean startFragment(Fragment caller, String fragmentClass, int titleRes,
             int requestCode, Bundle extras) {
         final Activity activity = getActivity();
         if (activity instanceof SettingsActivity) {
             SettingsActivity sa = (SettingsActivity) activity;
             sa.startPreferencePanel(fragmentClass, extras, titleRes, null, caller, requestCode);
             return true;
         } else if (activity instanceof PreferenceActivity) {
             PreferenceActivity sa = (PreferenceActivity) activity;
             sa.startPreferencePanel(fragmentClass, extras, titleRes, null, caller, requestCode);
             return true;
         } else {
             Log.w(TAG,
                     "Parent isn't SettingsActivity nor PreferenceActivity, thus there's no way to "
                     + "launch the given Fragment (name: " + fragmentClass
                     + ", requestCode: " + requestCode + ")");
             return false;
         }
     }
 }
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.settings;

	import android.app.Activity;
	import android.app.Dialog;
	import android.app.DialogFragment;
	import android.app.Fragment;
	import android.content.ContentResolver;
	import android.content.Context;
	import android.content.DialogInterface;
	import android.content.pm.PackageManager;
	import android.database.DataSetObserver;
	import android.graphics.drawable.Drawable;
	import android.os.Bundle;
	import android.preference.Preference;
	import android.preference.PreferenceActivity;
	import android.preference.PreferenceFragment;
	import android.preference.PreferenceGroupAdapter;
	import android.text.TextUtils;
	import android.util.Log;
	import android.view.LayoutInflater;
	import android.view.Menu;
	import android.view.MenuInflater;
	import android.view.MenuItem;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.Button;
	import android.widget.ListAdapter;
	import android.widget.ListView;

	/**
	* Base class for Settings fragments, with some helper functions and dialog management.
	*/
	public class SettingsPreferenceFragment extends PreferenceFragment implements DialogCreatable {

	private static final String TAG = "SettingsPreferenceFragment";

	private static final int MENU_HELP = Menu.FIRST + 100;
	private static final int DELAY_HIGHLIGHT_DURATION_MILLIS = 600;

	private static final String SAVE_HIGHLIGHTED_KEY = "android:preference_highlighted";

	private SettingsDialogFragment mDialogFragment;

	private String mHelpUrl;

	// Cache the content resolver for async callbacks
	private ContentResolver mContentResolver;

	private String mPreferenceKey;
	private boolean mPreferenceHighlighted = false;
	private Drawable mHighlightDrawable;

	private ListAdapter mCurrentRootAdapter;
	private boolean mIsDataSetObserverRegistered = false;
	private DataSetObserver mDataSetObserver = new DataSetObserver() {
	@Override
	public void onChanged() {
	highlightPreferenceIfNeeded();
	}

	@Override
	public void onInvalidated() {
	highlightPreferenceIfNeeded();
	}
	};

	private ViewGroup mPinnedHeaderFrameLayout;

	@Override
	public void onCreate(Bundle icicle) {
	super.onCreate(icicle);

	if (icicle != null) {
	mPreferenceHighlighted = icicle.getBoolean(SAVE_HIGHLIGHTED_KEY);
	}

	// Prepare help url and enable menu if necessary
	int helpResource = getHelpResource();
	if (helpResource != 0) {
	mHelpUrl = getResources().getString(helpResource);
	}
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
	Bundle savedInstanceState) {
	final View root = super.onCreateView(inflater, container, savedInstanceState);
	mPinnedHeaderFrameLayout = (ViewGroup) root.findViewById(R.id.pinned_header);
	return root;
	}

	public void setPinnedHeaderView(View pinnedHeader) {
	mPinnedHeaderFrameLayout.addView(pinnedHeader);
	mPinnedHeaderFrameLayout.setVisibility(View.VISIBLE);
	}

	public void clearPinnedHeaderView() {
	mPinnedHeaderFrameLayout.removeAllViews();
	mPinnedHeaderFrameLayout.setVisibility(View.GONE);
	}

	@Override
	public void onSaveInstanceState(Bundle outState) {
	super.onSaveInstanceState(outState);

	outState.putBoolean(SAVE_HIGHLIGHTED_KEY, mPreferenceHighlighted);
	}

	@Override
	public void onActivityCreated(Bundle savedInstanceState) {
	super.onActivityCreated(savedInstanceState);
	if (!TextUtils.isEmpty(mHelpUrl)) {
	setHasOptionsMenu(true);
	}
	}

	@Override
	public void onResume() {
	super.onResume();

	final Bundle args = getArguments();
	if (args != null) {
	mPreferenceKey = args.getString(SettingsActivity.EXTRA_FRAGMENT_ARG_KEY);
	highlightPreferenceIfNeeded();
	}
	}

	@Override
	protected void onBindPreferences() {
	registerObserverIfNeeded();
	}

	@Override
	protected void onUnbindPreferences() {
	unregisterObserverIfNeeded();
	}

	@Override
	public void onStop() {
	super.onStop();

	unregisterObserverIfNeeded();
	}

	public void registerObserverIfNeeded() {
	if (!mIsDataSetObserverRegistered) {
	if (mCurrentRootAdapter != null) {
	mCurrentRootAdapter.unregisterDataSetObserver(mDataSetObserver);
	}
	mCurrentRootAdapter = getPreferenceScreen().getRootAdapter();
	mCurrentRootAdapter.registerDataSetObserver(mDataSetObserver);
	mIsDataSetObserverRegistered = true;
	}
	}

	public void unregisterObserverIfNeeded() {
	if (mIsDataSetObserverRegistered) {
	if (mCurrentRootAdapter != null) {
	mCurrentRootAdapter.unregisterDataSetObserver(mDataSetObserver);
	mCurrentRootAdapter = null;
	}
	mIsDataSetObserverRegistered = false;
	}
	}

	public void highlightPreferenceIfNeeded() {
	if (isAdded() && !mPreferenceHighlighted &&!TextUtils.isEmpty(mPreferenceKey)) {
	highlightPreference(mPreferenceKey);
	}
	}

	private Drawable getHighlightDrawable() {
	if (mHighlightDrawable == null) {
	mHighlightDrawable = getActivity().getDrawable(R.drawable.preference_highlight);
	}
	return mHighlightDrawable;
	}

	/**
	* Return a valid ListView position or -1 if none is found
	*/
	private int canUseListViewForHighLighting(String key) {
	if (!hasListView()) {
	return -1;
	}

	ListView listView = getListView();
	ListAdapter adapter = listView.getAdapter();

	if (adapter != null && adapter instanceof PreferenceGroupAdapter) {
	return findListPositionFromKey(adapter, key);
	}

	return -1;
	}

	private void highlightPreference(String key) {
	final Drawable highlight = getHighlightDrawable();

	final int position = canUseListViewForHighLighting(key);
	if (position >= 0) {
	mPreferenceHighlighted = true;

	final ListView listView = getListView();
	final ListAdapter adapter = listView.getAdapter();

	((PreferenceGroupAdapter) adapter).setHighlightedDrawable(highlight);
	((PreferenceGroupAdapter) adapter).setHighlighted(position);

	listView.post(new Runnable() {
	@Override
	public void run() {
	listView.setSelection(position);
	listView.postDelayed(new Runnable() {
	@Override
	public void run() {
	final int index = position - listView.getFirstVisiblePosition();
	if (index >= 0 && index < listView.getChildCount()) {
	final View v = listView.getChildAt(index);
	final int centerX = v.getWidth() / 2;
	final int centerY = v.getHeight() / 2;
	highlight.setHotspot(centerX, centerY);
	v.setPressed(true);
	v.setPressed(false);
	}
	}
	}, DELAY_HIGHLIGHT_DURATION_MILLIS);
	}
	});
	}
	}

	private int findListPositionFromKey(ListAdapter adapter, String key) {
	final int count = adapter.getCount();
	for (int n = 0; n < count; n++) {
	final Object item = adapter.getItem(n);
	if (item instanceof Preference) {
	Preference preference = (Preference) item;
	final String preferenceKey = preference.getKey();
	if (preferenceKey != null && preferenceKey.equals(key)) {
	return n;
	}
	}
	}
	return -1;
	}

	protected void removePreference(String key) {
	Preference pref = findPreference(key);
	if (pref != null) {
	getPreferenceScreen().removePreference(pref);
	}
	}

	/**
	* Override this if you want to show a help item in the menu, by returning the resource id.
	* @return the resource id for the help url
	*/
	protected int getHelpResource() {
	return 0;
	}

	@Override
	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
	if (mHelpUrl != null && getActivity() != null) {
	MenuItem helpItem = menu.add(0, MENU_HELP, 0, R.string.help_label);
	HelpUtils.prepareHelpMenuItem(getActivity(), helpItem, mHelpUrl);
	}
	}

	/*
	* The name is intentionally made different from Activity#finish(), so that
	* users won't misunderstand its meaning.
	*/
	public final void finishFragment() {
	getActivity().onBackPressed();
	}

	// Some helpers for functions used by the settings fragments when they were activities

	/**
	* Returns the ContentResolver from the owning Activity.
	*/
	protected ContentResolver getContentResolver() {
	Context context = getActivity();
	if (context != null) {
	mContentResolver = context.getContentResolver();
	}
	return mContentResolver;
	}

	/**
	* Returns the specified system service from the owning Activity.
	*/
	protected Object getSystemService(final String name) {
	return getActivity().getSystemService(name);
	}

	/**
	* Returns the PackageManager from the owning Activity.
	*/
	protected PackageManager getPackageManager() {
	return getActivity().getPackageManager();
	}

	@Override
	public void onDetach() {
	if (isRemoving()) {
	if (mDialogFragment != null) {
	mDialogFragment.dismiss();
	mDialogFragment = null;
	}
	}
	super.onDetach();
	}

	// Dialog management

	protected void showDialog(int dialogId) {
	if (mDialogFragment != null) {
	Log.e(TAG, "Old dialog fragment not null!");
	}
	mDialogFragment = new SettingsDialogFragment(this, dialogId);
	mDialogFragment.show(getChildFragmentManager(), Integer.toString(dialogId));
	}

	public Dialog onCreateDialog(int dialogId) {
	return null;
	}

	protected void removeDialog(int dialogId) {
	// mDialogFragment may not be visible yet in parent fragment's onResume().
	// To be able to dismiss dialog at that time, don't check
	// mDialogFragment.isVisible().
	if (mDialogFragment != null && mDialogFragment.getDialogId() == dialogId) {
	mDialogFragment.dismiss();
	}
	mDialogFragment = null;
	}

	/**
	* Sets the OnCancelListener of the dialog shown. This method can only be
	* called after showDialog(int) and before removeDialog(int). The method
	* does nothing otherwise.
	*/
	protected void setOnCancelListener(DialogInterface.OnCancelListener listener) {
	if (mDialogFragment != null) {
	mDialogFragment.mOnCancelListener = listener;
	}
	}

	/**
	* Sets the OnDismissListener of the dialog shown. This method can only be
	* called after showDialog(int) and before removeDialog(int). The method
	* does nothing otherwise.
	*/
	protected void setOnDismissListener(DialogInterface.OnDismissListener listener) {
	if (mDialogFragment != null) {
	mDialogFragment.mOnDismissListener = listener;
	}
	}

	public void onDialogShowing() {
	// override in subclass to attach a dismiss listener, for instance
	}

	public static class SettingsDialogFragment extends DialogFragment {
	private static final String KEY_DIALOG_ID = "key_dialog_id";
	private static final String KEY_PARENT_FRAGMENT_ID = "key_parent_fragment_id";

	private int mDialogId;

	private Fragment mParentFragment;

	private DialogInterface.OnCancelListener mOnCancelListener;
	private DialogInterface.OnDismissListener mOnDismissListener;

	public SettingsDialogFragment() {
	/* do nothing */
	}

	public SettingsDialogFragment(DialogCreatable fragment, int dialogId) {
	mDialogId = dialogId;
	if (!(fragment instanceof Fragment)) {
	throw new IllegalArgumentException("fragment argument must be an instance of "
	+ Fragment.class.getName());
	}
	mParentFragment = (Fragment) fragment;
	}

	@Override
	public void onSaveInstanceState(Bundle outState) {
	super.onSaveInstanceState(outState);
	if (mParentFragment != null) {
	outState.putInt(KEY_DIALOG_ID, mDialogId);
	outState.putInt(KEY_PARENT_FRAGMENT_ID, mParentFragment.getId());
	}
	}

	@Override
	public void onStart() {
	super.onStart();

	if (mParentFragment != null && mParentFragment instanceof SettingsPreferenceFragment) {
	((SettingsPreferenceFragment) mParentFragment).onDialogShowing();
	}
	}

	@Override
	public Dialog onCreateDialog(Bundle savedInstanceState) {
	if (savedInstanceState != null) {
	mDialogId = savedInstanceState.getInt(KEY_DIALOG_ID, 0);
	mParentFragment = getParentFragment();
	int mParentFragmentId = savedInstanceState.getInt(KEY_PARENT_FRAGMENT_ID, -1);
	if (mParentFragment == null) {
	mParentFragment = getFragmentManager().findFragmentById(mParentFragmentId);
	}
	if (!(mParentFragment instanceof DialogCreatable)) {
	throw new IllegalArgumentException(
	(mParentFragment != null
	? mParentFragment.getClass().getName()
	: mParentFragmentId)
	+ " must implement "
	+ DialogCreatable.class.getName());
	}
	// This dialog fragment could be created from non-SettingsPreferenceFragment
	if (mParentFragment instanceof SettingsPreferenceFragment) {
	// restore mDialogFragment in mParentFragment
	((SettingsPreferenceFragment) mParentFragment).mDialogFragment = this;
	}
	}
	return ((DialogCreatable) mParentFragment).onCreateDialog(mDialogId);
	}

	@Override
	public void onCancel(DialogInterface dialog) {
	super.onCancel(dialog);
	if (mOnCancelListener != null) {
	mOnCancelListener.onCancel(dialog);
	}
	}

	@Override
	public void onDismiss(DialogInterface dialog) {
	super.onDismiss(dialog);
	if (mOnDismissListener != null) {
	mOnDismissListener.onDismiss(dialog);
	}
	}

	public int getDialogId() {
	return mDialogId;
	}

	@Override
	public void onDetach() {
	super.onDetach();

	// This dialog fragment could be created from non-SettingsPreferenceFragment
	if (mParentFragment instanceof SettingsPreferenceFragment) {
	// in case the dialog is not explicitly removed by removeDialog()
	if (((SettingsPreferenceFragment) mParentFragment).mDialogFragment == this) {
	((SettingsPreferenceFragment) mParentFragment).mDialogFragment = null;
	}
	}
	}
	}

	protected boolean hasNextButton() {
	return ((ButtonBarHandler)getActivity()).hasNextButton();
	}

	protected Button getNextButton() {
	return ((ButtonBarHandler)getActivity()).getNextButton();
	}

	public void finish() {
	getActivity().onBackPressed();
	}

	public boolean startFragment(Fragment caller, String fragmentClass, int titleRes,
	int requestCode, Bundle extras) {
	final Activity activity = getActivity();
	if (activity instanceof SettingsActivity) {
	SettingsActivity sa = (SettingsActivity) activity;
	sa.startPreferencePanel(fragmentClass, extras, titleRes, null, caller, requestCode);
	return true;
	} else if (activity instanceof PreferenceActivity) {
	PreferenceActivity sa = (PreferenceActivity) activity;
	sa.startPreferencePanel(fragmentClass, extras, titleRes, null, caller, requestCode);
	return true;
	} else {
	Log.w(TAG,
	"Parent isn't SettingsActivity nor PreferenceActivity, thus there's no way to "
	+ "launch the given Fragment (name: " + fragmentClass
	+ ", requestCode: " + requestCode + ")");
	return false;
	}
	}
	}