1 /* 2 * Copyright 2018 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 17 package androidx.leanback.preference.internal; 18 19 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP; 20 21 import android.content.Context; 22 import android.graphics.Outline; 23 import android.util.AttributeSet; 24 import android.view.View; 25 import android.view.ViewOutlineProvider; 26 import android.widget.FrameLayout; 27 28 import androidx.annotation.RequiresApi; 29 import androidx.annotation.RestrictTo; 30 31 /** 32 * {@link FrameLayout} subclass that provides an outline only when it has children, so that it does 33 * not cast a shadow when empty. 34 * 35 * @hide 36 */ 37 @RequiresApi(21) 38 @RestrictTo(LIBRARY_GROUP) 39 public class OutlineOnlyWithChildrenFrameLayout extends FrameLayout { 40 41 private ViewOutlineProvider mMagicalOutlineProvider; 42 private ViewOutlineProvider mInnerOutlineProvider; 43 OutlineOnlyWithChildrenFrameLayout(Context context)44 public OutlineOnlyWithChildrenFrameLayout(Context context) { 45 super(context); 46 } 47 OutlineOnlyWithChildrenFrameLayout(Context context, AttributeSet attrs)48 public OutlineOnlyWithChildrenFrameLayout(Context context, AttributeSet attrs) { 49 super(context, attrs); 50 } 51 OutlineOnlyWithChildrenFrameLayout(Context context, AttributeSet attrs, int defStyleAttr)52 public OutlineOnlyWithChildrenFrameLayout(Context context, AttributeSet attrs, 53 int defStyleAttr) { 54 super(context, attrs, defStyleAttr); 55 } 56 OutlineOnlyWithChildrenFrameLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)57 public OutlineOnlyWithChildrenFrameLayout(Context context, AttributeSet attrs, 58 int defStyleAttr, int defStyleRes) { 59 super(context, attrs, defStyleAttr, defStyleRes); 60 } 61 62 @Override onLayout(boolean changed, int left, int top, int right, int bottom)63 protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 64 super.onLayout(changed, left, top, right, bottom); 65 invalidateOutline(); 66 } 67 68 @Override setOutlineProvider(ViewOutlineProvider provider)69 public void setOutlineProvider(ViewOutlineProvider provider) { 70 mInnerOutlineProvider = provider; 71 if (mMagicalOutlineProvider == null) { 72 // Can't initialize this directly because this method is called from the superclass's 73 // constructor. 74 mMagicalOutlineProvider = new ViewOutlineProvider() { 75 @Override 76 public void getOutline(View view, Outline outline) { 77 if (getChildCount() > 0) { 78 mInnerOutlineProvider.getOutline(view, outline); 79 } else { 80 ViewOutlineProvider.BACKGROUND.getOutline(view, outline); 81 } 82 } 83 }; 84 } 85 super.setOutlineProvider(mMagicalOutlineProvider); 86 } 87 } 88