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1 /*
2  * Copyright (C) 2022 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.util;
18 
19 import android.util.ArrayMap;
20 import android.util.FloatProperty;
21 import android.util.Log;
22 import android.view.View;
23 
24 import com.android.launcher3.Utilities;
25 
26 /**
27  * Allows to combine multiple values set by several sources.
28  *
29  * The various sources are meant to use [set], providing different `setterIndex` params. When it is
30  * not set, 0 is used. This is meant to cover the case multiple animations are going on at the same
31  * time.
32  *
33  * This class behaves similarly to [MultiValueAlpha], but is meant to be more abstract and reusable.
34  * It sets the multiplication of all values, bounded to the max and the min values.
35  *
36  * @param <T> Type where to apply the property.
37  */
38 public class MultiScalePropertyFactory<T extends View> {
39 
40     private static final boolean DEBUG = false;
41     private static final String TAG = "MultiScaleProperty";
42     private final String mName;
43     private final ArrayMap<Integer, MultiScaleProperty> mProperties = new ArrayMap<>();
44 
45     // This is an optimization for cases when set is called repeatedly with the same setterIndex.
46     private float mMinOfOthers = 0;
47     private float mMaxOfOthers = 0;
48     private float mMultiplicationOfOthers = 0;
49     private Integer mLastIndexSet = -1;
50     private float mLastAggregatedValue = 1.0f;
51 
MultiScalePropertyFactory(String name)52     public MultiScalePropertyFactory(String name) {
53         mName = name;
54     }
55 
56     /** Returns the [MultiFloatProperty] associated with [inx], creating it if not present. */
get(Integer index)57     public FloatProperty<T> get(Integer index) {
58         return mProperties.computeIfAbsent(index,
59                 (k) -> new MultiScaleProperty(index, mName + "_" + index));
60     }
61 
62     /**
63      * Each [setValue] will be aggregated with the other properties values created by the
64      * corresponding factory.
65      */
66     class MultiScaleProperty extends FloatProperty<T> {
67         private final int mInx;
68         private float mValue = 1.0f;
69 
MultiScaleProperty(int inx, String name)70         MultiScaleProperty(int inx, String name) {
71             super(name);
72             mInx = inx;
73         }
74 
75         @Override
setValue(T obj, float newValue)76         public void setValue(T obj, float newValue) {
77             if (mLastIndexSet != mInx) {
78                 mMinOfOthers = Float.MAX_VALUE;
79                 mMaxOfOthers = Float.MIN_VALUE;
80                 mMultiplicationOfOthers = 1.0f;
81                 mProperties.forEach((key, property) -> {
82                     if (key != mInx) {
83                         mMinOfOthers = Math.min(mMinOfOthers, property.mValue);
84                         mMaxOfOthers = Math.max(mMaxOfOthers, property.mValue);
85                         mMultiplicationOfOthers *= property.mValue;
86                     }
87                 });
88                 mLastIndexSet = mInx;
89             }
90             float minValue = Math.min(mMinOfOthers, newValue);
91             float maxValue = Math.max(mMaxOfOthers, newValue);
92             float multValue = mMultiplicationOfOthers * newValue;
93             mLastAggregatedValue = Utilities.boundToRange(multValue, minValue, maxValue);
94             mValue = newValue;
95             apply(obj, mLastAggregatedValue);
96 
97             if (DEBUG) {
98                 Log.d(TAG, "name=" + mName
99                         + " newValue=" + newValue + " mInx=" + mInx
100                         + " aggregated=" + mLastAggregatedValue + " others= " + mProperties);
101             }
102         }
103 
104         @Override
get(T view)105         public Float get(T view) {
106             // The scale of the view should match mLastAggregatedValue. Still, if it has been
107             // changed without using this property, it can differ. As this get method is usually
108             // used to set the starting point on an animation, this would result in some jumps
109             // when the view scale is different than the last aggregated value. To stay on the
110             // safe side, let's return the real view scale.
111             return view.getScaleX();
112         }
113 
114         @Override
toString()115         public String toString() {
116             return String.valueOf(mValue);
117         }
118     }
119 
apply(View view, float value)120     protected void apply(View view, float value) {
121         view.setScaleX(value);
122         view.setScaleY(value);
123     }
124 }
125