/*
* Copyright (C) 2015 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.support.v7.preference;
import android.content.Context;
import android.util.AttributeSet;
/**
* Represents a top-level {@link Preference} that
* is the root of a Preference hierarchy. A {@link PreferenceFragmentCompat}
* points to an instance of this class to show the preferences. To instantiate
* this class, use {@link PreferenceManager#createPreferenceScreen(android.content.Context)}.
* <ul>
* This class can appear in two places:
* <li> When a {@link PreferenceFragmentCompat} points to this, it is used as the root
* and is not shown (only the contained preferences are shown).
* <li> When it appears inside another preference hierarchy, it is shown and
* serves as the gateway to another screen of preferences (either by showing
* another screen of preferences as a {@link android.app.Dialog} or via a
* {@link android.content.Context#startActivity(android.content.Intent)} from the
* {@link Preference#getIntent()}). The children of this {@link PreferenceScreen}
* are NOT shown in the screen that this {@link PreferenceScreen} is shown in.
* Instead, a separate screen will be shown when this preference is clicked.
* </ul>
* <p>Here's an example XML layout of a PreferenceScreen:</p>
* <pre>
<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> </pre>
* <p>
* In this example, the "first_preferencescreen" will be used as the root of the
* hierarchy and given to a {@link android.support.v14.preference.PreferenceFragment}
* or {@link PreferenceFragmentCompat}.
* 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).
*
* <div class="special reference">
* <h3>Developer Guides</h3>
* <p>For information about building a settings UI with Preferences,
* read the <a href="{@docRoot}guide/topics/ui/settings.html">Settings</a>
* guide.</p>
* </div>
*
* @see PreferenceCategory
*/
public final class PreferenceScreen extends PreferenceGroup {
/**
* Do NOT use this constructor, use {@link PreferenceManager#createPreferenceScreen(Context)}.
* @hide-
*/
public PreferenceScreen(Context context, AttributeSet attrs) {
super(context, attrs, R.attr.preferenceScreenStyle);
}
@Override
protected void onClick() {
if (getIntent() != null || getFragment() != null || getPreferenceCount() == 0) {
return;
}
final PreferenceManager.OnNavigateToScreenListener listener =
getPreferenceManager().getOnNavigateToScreenListener();
if (listener != null) {
listener.onNavigateToScreen(this);
}
}
@Override
protected boolean isOnSameScreenAsChildren() {
return false;
}
}