/* * Copyright (C) 2007 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 android.preference; import android.app.Dialog; import android.content.Context; import android.content.DialogInterface; import android.os.Bundle; import android.os.Parcel; import android.os.Parcelable; import android.text.TextUtils; import android.util.AttributeSet; import android.view.View; import android.widget.Adapter; import android.widget.AdapterView; import android.widget.ListAdapter; import android.widget.ListView; /** * Represents a top-level {@link Preference} that * is the root of a Preference hierarchy. A {@link PreferenceActivity} * points to an instance of this class to show the preferences. To instantiate * this class, use {@link PreferenceManager#createPreferenceScreen(Context)}. * *

Here's an example XML layout of a PreferenceScreen:

*
<PreferenceScreen
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:key="first_preferencescreen">
    <CheckBoxPreference
            android:key="wifi enabled"
            android:title="WiFi" />
    <PreferenceScreen
            android:key="second_preferencescreen"
            android:title="WiFi settings">
        <CheckBoxPreference
                android:key="prefer wifi"
                android:title="Prefer WiFi" />
        ... other preferences here ...
    </PreferenceScreen>
</PreferenceScreen> 
*

* In this example, the "first_preferencescreen" will be used as the root of the * hierarchy and given to a {@link PreferenceActivity}. The first screen will * show preferences "WiFi" (which can be used to quickly enable/disable WiFi) * and "WiFi settings". The "WiFi settings" is the "second_preferencescreen" and when * clicked will show another screen of preferences such as "Prefer WiFi" (and * the other preferences that are children of the "second_preferencescreen" tag). * * @see PreferenceCategory */ public final class PreferenceScreen extends PreferenceGroup implements AdapterView.OnItemClickListener, DialogInterface.OnDismissListener { private ListAdapter mRootAdapter; private Dialog mDialog; /** * Do NOT use this constructor, use {@link PreferenceManager#createPreferenceScreen(Context)}. * @hide- */ public PreferenceScreen(Context context, AttributeSet attrs) { super(context, attrs, com.android.internal.R.attr.preferenceScreenStyle); } /** * Returns an adapter that can be attached to a {@link PreferenceActivity} * to show the preferences contained in this {@link PreferenceScreen}. *

* This {@link PreferenceScreen} will NOT appear in the returned adapter, instead * it appears in the hierarchy above this {@link PreferenceScreen}. *

* This adapter's {@link Adapter#getItem(int)} should always return a * subclass of {@link Preference}. * * @return An adapter that provides the {@link Preference} contained in this * {@link PreferenceScreen}. */ public ListAdapter getRootAdapter() { if (mRootAdapter == null) { mRootAdapter = onCreateRootAdapter(); } return mRootAdapter; } /** * Creates the root adapter. * * @return An adapter that contains the preferences contained in this {@link PreferenceScreen}. * @see #getRootAdapter() */ protected ListAdapter onCreateRootAdapter() { return new PreferenceGroupAdapter(this); } /** * Binds a {@link ListView} to the preferences contained in this {@link PreferenceScreen} via * {@link #getRootAdapter()}. It also handles passing list item clicks to the corresponding * {@link Preference} contained by this {@link PreferenceScreen}. * * @param listView The list view to attach to. */ public void bind(ListView listView) { listView.setOnItemClickListener(this); listView.setAdapter(getRootAdapter()); onAttachedToActivity(); } @Override protected void onClick() { if (getIntent() != null || getPreferenceCount() == 0) { return; } showDialog(null); } private void showDialog(Bundle state) { Context context = getContext(); ListView listView = new ListView(context); bind(listView); // Set the title bar if title is available, else no title bar final CharSequence title = getTitle(); Dialog dialog = mDialog = new Dialog(context, TextUtils.isEmpty(title) ? com.android.internal.R.style.Theme_NoTitleBar : com.android.internal.R.style.Theme); dialog.setContentView(listView); if (!TextUtils.isEmpty(title)) { dialog.setTitle(title); } dialog.setOnDismissListener(this); if (state != null) { dialog.onRestoreInstanceState(state); } // Add the screen to the list of preferences screens opened as dialogs getPreferenceManager().addPreferencesScreen(dialog); dialog.show(); } public void onDismiss(DialogInterface dialog) { mDialog = null; getPreferenceManager().removePreferencesScreen(dialog); } /** * Used to get a handle to the dialog. * This is useful for cases where we want to manipulate the dialog * as we would with any other activity or view. */ public Dialog getDialog() { return mDialog; } public void onItemClick(AdapterView parent, View view, int position, long id) { Object item = getRootAdapter().getItem(position); if (!(item instanceof Preference)) return; final Preference preference = (Preference) item; preference.performClick(this); } @Override protected boolean isOnSameScreenAsChildren() { return false; } @Override protected Parcelable onSaveInstanceState() { final Parcelable superState = super.onSaveInstanceState(); final Dialog dialog = mDialog; if (dialog == null || !dialog.isShowing()) { return superState; } final SavedState myState = new SavedState(superState); myState.isDialogShowing = true; myState.dialogBundle = dialog.onSaveInstanceState(); return myState; } @Override protected void onRestoreInstanceState(Parcelable state) { if (state == null || !state.getClass().equals(SavedState.class)) { // Didn't save state for us in onSaveInstanceState super.onRestoreInstanceState(state); return; } SavedState myState = (SavedState) state; super.onRestoreInstanceState(myState.getSuperState()); if (myState.isDialogShowing) { showDialog(myState.dialogBundle); } } private static class SavedState extends BaseSavedState { boolean isDialogShowing; Bundle dialogBundle; public SavedState(Parcel source) { super(source); isDialogShowing = source.readInt() == 1; dialogBundle = source.readBundle(); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeInt(isDialogShowing ? 1 : 0); dest.writeBundle(dialogBundle); } public SavedState(Parcelable superState) { super(superState); } public static final Parcelable.Creator CREATOR = new Parcelable.Creator() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; } }