PreferenceCategory.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.preference;
import android.content.Context;
import android.os.Build;
import android.os.Build.VERSION_CODES;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.content.ContextCompat;
import androidx.core.content.res.TypedArrayUtils;
/**
* A container that is used to group similar {@link Preference}s. A PreferenceCategory displays a
* category title and visually separates groups of Preferences.
*
* <div class="special reference">
* <h3>Developer Guides</h3>
* <p>For information about building a settings screen using the AndroidX Preference library, see
* <a href="{@docRoot}guide/topics/ui/settings.html">Settings</a>.</p>
* </div>
*/
public class PreferenceCategory extends PreferenceGroup {
public PreferenceCategory(
@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr,
int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
public PreferenceCategory(@NonNull Context context, @Nullable AttributeSet attrs,
int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
public PreferenceCategory(@NonNull Context context, @Nullable AttributeSet attrs) {
this(context, attrs, TypedArrayUtils.getAttr(context, R.attr.preferenceCategoryStyle,
android.R.attr.preferenceCategoryStyle));
}
public PreferenceCategory(@NonNull Context context) {
this(context, null);
}
@Override
public boolean isEnabled() {
return false;
}
@Override
public boolean shouldDisableDependents() {
return !super.isEnabled();
}
@Override
public void onBindViewHolder(@NonNull PreferenceViewHolder holder) {
super.onBindViewHolder(holder);
if (Build.VERSION.SDK_INT >= VERSION_CODES.P) {
holder.itemView.setAccessibilityHeading(true);
} else if (Build.VERSION.SDK_INT < VERSION_CODES.LOLLIPOP) {
// We can't safely look for colorAccent in the category layout XML below Lollipop, as it
// only exists within AppCompat, and will crash if using a platform theme. We should
// still try and parse the attribute here in case we are running inside
// PreferenceFragmentCompat with an AppCompat theme, and to set the category title
// accordingly.
final TypedValue value = new TypedValue();
if (!getContext().getTheme().resolveAttribute(
androidx.appcompat.R.attr.colorAccent, value, true)) {
// Return if the attribute could not be resolved
return;
}
final TextView titleView = (TextView) holder.findViewById(android.R.id.title);
if (titleView == null) {
return;
}
final int fallbackColor = ContextCompat.getColor(getContext(),
R.color.preference_fallback_accent_color);
// If the current color is not the fallback color we hardcode in the layout XML,
// then this has already been handled by developers and we shouldn't override the
// color.
if (titleView.getCurrentTextColor() != fallbackColor) {
return;
}
titleView.setTextColor(value.data);
}
}
}