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 package com.android.launcher3.settings;
17 
18 import static com.android.launcher3.icons.GraphicsUtils.setColorAlphaBound;
19 
20 import android.animation.Animator;
21 import android.animation.AnimatorListenerAdapter;
22 import android.animation.ObjectAnimator;
23 import android.animation.ValueAnimator;
24 import android.graphics.Canvas;
25 import android.graphics.Color;
26 import android.graphics.Paint;
27 import android.util.Property;
28 import android.view.View;
29 
30 import com.android.launcher3.util.Themes;
31 
32 import androidx.recyclerview.widget.RecyclerView;
33 import androidx.recyclerview.widget.RecyclerView.ItemDecoration;
34 import androidx.recyclerview.widget.RecyclerView.State;
35 import androidx.recyclerview.widget.RecyclerView.ViewHolder;
36 
37 /**
38  * Utility class for highlighting a preference
39  */
40 public class PreferenceHighlighter extends ItemDecoration implements Runnable {
41 
42     private static final Property<PreferenceHighlighter, Integer> HIGHLIGHT_COLOR =
43             new Property<PreferenceHighlighter, Integer>(Integer.TYPE, "highlightColor") {
44 
45                 @Override
46                 public Integer get(PreferenceHighlighter highlighter) {
47                     return highlighter.mHighlightColor;
48                 }
49 
50                 @Override
51                 public void set(PreferenceHighlighter highlighter, Integer value) {
52                     highlighter.mHighlightColor = value;
53                     highlighter.mRv.invalidateItemDecorations();
54                 }
55             };
56 
57     private static final long HIGHLIGHT_DURATION = 15000L;
58     private static final long HIGHLIGHT_FADE_OUT_DURATION = 500L;
59     private static final long HIGHLIGHT_FADE_IN_DURATION = 200L;
60     private static final int END_COLOR = setColorAlphaBound(Color.WHITE, 0);
61 
62     private final Paint mPaint = new Paint();
63     private final RecyclerView mRv;
64     private final int mIndex;
65 
66     private boolean mHighLightStarted = false;
67     private int mHighlightColor = END_COLOR;
68 
69 
PreferenceHighlighter(RecyclerView rv, int index)70     public PreferenceHighlighter(RecyclerView rv, int index) {
71         mRv = rv;
72         mIndex = index;
73     }
74 
75     @Override
run()76     public void run() {
77         mRv.addItemDecoration(this);
78         mRv.smoothScrollToPosition(mIndex);
79     }
80 
81     @Override
onDraw(Canvas c, RecyclerView parent, State state)82     public void onDraw(Canvas c, RecyclerView parent, State state) {
83         ViewHolder holder = parent.findViewHolderForAdapterPosition(mIndex);
84         if (holder == null) {
85             return;
86         }
87         if (!mHighLightStarted && state.getRemainingScrollVertical() != 0) {
88             // Wait until scrolling stopped
89             return;
90         }
91 
92         if (!mHighLightStarted) {
93             // Start highlight
94             int colorTo = setColorAlphaBound(Themes.getColorAccent(mRv.getContext()), 66);
95             ObjectAnimator anim = ObjectAnimator.ofArgb(this, HIGHLIGHT_COLOR, END_COLOR, colorTo);
96             anim.setDuration(HIGHLIGHT_FADE_IN_DURATION);
97             anim.setRepeatMode(ValueAnimator.REVERSE);
98             anim.setRepeatCount(4);
99             anim.addListener(new AnimatorListenerAdapter() {
100                 @Override
101                 public void onAnimationEnd(Animator animation) {
102                     removeHighlight();
103                 }
104             });
105             anim.start();
106             mHighLightStarted = true;
107         }
108 
109         View view = holder.itemView;
110         mPaint.setColor(mHighlightColor);
111         c.drawRect(0, view.getY(), parent.getWidth(), view.getY() + view.getHeight(), mPaint);
112     }
113 
removeHighlight()114     private void removeHighlight() {
115         ObjectAnimator anim = ObjectAnimator.ofArgb(
116                 this, HIGHLIGHT_COLOR, mHighlightColor, END_COLOR);
117         anim.setDuration(HIGHLIGHT_FADE_OUT_DURATION);
118         anim.setStartDelay(HIGHLIGHT_DURATION);
119         anim.addListener(new AnimatorListenerAdapter() {
120             @Override
121             public void onAnimationEnd(Animator animation) {
122                 mRv.removeItemDecoration(PreferenceHighlighter.this);
123             }
124         });
125         anim.start();
126     }
127 }
128