1 /* 2 * Copyright (C) 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 com.android.launcher3.graphics; 18 19 import android.graphics.Canvas; 20 import android.util.Property; 21 import android.view.View; 22 import android.view.ViewParent; 23 24 import com.android.launcher3.R; 25 26 /** 27 * A utility class that can be used to draw a scrim behind a view 28 */ 29 public abstract class ViewScrim<T extends View> { 30 31 public static Property<ViewScrim, Float> PROGRESS = 32 new Property<ViewScrim, Float>(Float.TYPE, "progress") { 33 @Override 34 public Float get(ViewScrim viewScrim) { 35 return viewScrim.mProgress; 36 } 37 38 @Override 39 public void set(ViewScrim object, Float value) { 40 object.setProgress(value); 41 } 42 }; 43 44 protected final T mView; 45 protected float mProgress = 0; 46 ViewScrim(T view)47 public ViewScrim(T view) { 48 mView = view; 49 } 50 attach()51 public void attach() { 52 mView.setTag(R.id.view_scrim, this); 53 } 54 setProgress(float progress)55 public void setProgress(float progress) { 56 if (mProgress != progress) { 57 mProgress = progress; 58 onProgressChanged(); 59 invalidate(); 60 } 61 } 62 draw(Canvas canvas, int width, int height)63 public abstract void draw(Canvas canvas, int width, int height); 64 onProgressChanged()65 protected void onProgressChanged() { } 66 invalidate()67 public void invalidate() { 68 ViewParent parent = mView.getParent(); 69 if (parent != null) { 70 ((View) parent).invalidate(); 71 } 72 } 73 get(View view)74 public static ViewScrim get(View view) { 75 return (ViewScrim) view.getTag(R.id.view_scrim); 76 } 77 } 78