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 */ 16 package androidx.leanback.widget; 17 18 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP; 19 20 import android.graphics.drawable.Drawable; 21 import android.os.Build; 22 import android.view.View; 23 24 import androidx.annotation.RestrictTo; 25 26 /** 27 * Helper for view backgrounds. 28 * @hide 29 */ 30 @RestrictTo(LIBRARY_GROUP) 31 public 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
