/*
* Copyright 2019 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.preference;
import android.content.Context;
import android.text.TextUtils;
import java.util.ArrayList;
import java.util.List;
/**
* A {@link Preference} that visually wraps preferences collapsed in a {@link PreferenceGroup},
* and expands those preferences into the group when tapped.
*
* @hide
*/
final class ExpandButton extends Preference {
private long mId;
ExpandButton(Context context, List<Preference> collapsedPreferences, long parentId) {
super(context);
initLayout();
setSummary(collapsedPreferences);
// Since IDs are unique, using the parentId as a reference ensures that this expand
// button will have a unique ID and hence transitions will be correctly animated by
// RecyclerView when there are multiple expand buttons.
mId = parentId + 1000000;
}
private void initLayout() {
setLayoutResource(R.layout.expand_button);
setIcon(R.drawable.ic_arrow_down_24dp);
setTitle(R.string.expand_button_title);
// Sets a high order so that the expand button will be placed at the bottom of the group
setOrder(999);
}
/*
* Sets the summary of the expand button to a list containing the titles of the collapsed
* preferences. If there are any nested groups with titles, only add the group's title
* and not the titles of the group's children.
*/
private void setSummary(List<Preference> collapsedPreferences) {
CharSequence summary = null;
final List<PreferenceGroup> parents = new ArrayList<>();
for (Preference preference : collapsedPreferences) {
final CharSequence title = preference.getTitle();
if (preference instanceof PreferenceGroup && !TextUtils.isEmpty(title)) {
parents.add((PreferenceGroup) preference);
}
if (parents.contains(preference.getParent())) {
if (preference instanceof PreferenceGroup) {
parents.add((PreferenceGroup) preference);
}
continue;
}
if (!TextUtils.isEmpty(title)) {
if (summary == null) {
summary = title;
} else {
summary = getContext().getString(
R.string.summary_collapsed_preference_list, summary, title);
}
}
}
setSummary(summary);
}
@Override
public void onBindViewHolder(PreferenceViewHolder holder) {
super.onBindViewHolder(holder);
holder.setDividerAllowedAbove(false);
}
@Override
long getId() {
return mId;
}
}