BaseLeanbackPreferenceFragmentCompat.java
/*
* Copyright 2018 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 androidx.leanback.preference;
import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP_PREFIX;
import android.content.Context;
import android.os.Bundle;
import android.util.TypedValue;
import android.view.ContextThemeWrapper;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import androidx.fragment.app.Fragment;
import androidx.leanback.widget.VerticalGridView;
import androidx.preference.PreferenceFragmentCompat;
import androidx.preference.PreferenceRecyclerViewAccessibilityDelegate;
import androidx.recyclerview.widget.RecyclerView;
/**
* This fragment provides a preference fragment with leanback-style behavior, suitable for
* embedding into broader UI elements.
*/
public abstract class BaseLeanbackPreferenceFragmentCompat extends PreferenceFragmentCompat {
private Context mThemedContext;
@Nullable
@Override
public Context getContext() {
if (mThemedContext == null && getActivity() != null) {
final TypedValue tv = new TypedValue();
getActivity().getTheme().resolveAttribute(
androidx.preference.R.attr.preferenceTheme, tv, true);
int theme = tv.resourceId;
if (theme == 0) {
// Fallback to default theme.
theme = R.style.PreferenceThemeOverlayLeanback;
}
// aosp/821989 has forced PreferenceFragment to use the theme of activity and only
// override theme attribute value when it's not defined in activity theme.
// However, a side panel preference fragment can use different values than main content.
// So a ContextThemeWrapper is required, overrides getContext() before
// super.onCreate() call to use the ContextThemeWrapper in creating PreferenceManager
// and onCreateView().
// super.onCreate() will apply() the theme to activity in non-force way, which shouldn't
// affect activity as the theme attributes of PreferenceThemeOverlayLeanback is already
// in the activity's theme (in framework)
mThemedContext = new ContextThemeWrapper(super.getContext(), theme);
}
return mThemedContext;
}
@Override
public RecyclerView onCreateRecyclerView(LayoutInflater inflater, ViewGroup parent,
Bundle savedInstanceState) {
VerticalGridView verticalGridView = (VerticalGridView) inflater
.inflate(R.layout.leanback_preferences_list, parent, false);
verticalGridView.setWindowAlignment(VerticalGridView.WINDOW_ALIGN_BOTH_EDGE);
verticalGridView.setFocusScrollStrategy(VerticalGridView.FOCUS_SCROLL_ALIGNED);
verticalGridView.setAccessibilityDelegateCompat(
new PreferenceRecyclerViewAccessibilityDelegate(verticalGridView));
return verticalGridView;
}
/**
* @hide
*/
@RestrictTo(LIBRARY_GROUP_PREFIX)
@Override
public Fragment getCallbackFragment() {
return getParentFragment();
}
}