1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License
15 */
16package androidx.leanback.widget;
17
18import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
19
20import android.graphics.drawable.Drawable;
21import android.os.Build;
22import android.view.View;
23
24import androidx.annotation.RestrictTo;
25
26/**
27 * Helper for view backgrounds.
28 * @hide
29 */
30@RestrictTo(LIBRARY_GROUP)
31public final class BackgroundHelper {
32    public static void setBackgroundPreservingAlpha(View view, Drawable drawable) {
33        if (Build.VERSION.SDK_INT >= 19) {
34            if (view.getBackground() != null) {
35                drawable.setAlpha(view.getBackground().getAlpha());
36            }
37            view.setBackground(drawable);
38        } else {
39            // Cannot query drawable alpha
40            view.setBackground(drawable);
41        }
42    }
43
44    private BackgroundHelper() {
45    }
46}
47