1 /*
2  * Copyright (C) 2014 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.example.android.apis.graphics;
18 
19 import android.animation.Animator;
20 import android.animation.AnimatorSet;
21 import android.animation.ObjectAnimator;
22 import android.app.Activity;
23 import android.os.Bundle;
24 import android.view.ViewGroup;
25 import android.widget.TextView;
26 
27 import com.example.android.apis.R;
28 
29 import java.util.ArrayList;
30 
31 public class ShadowCardStack extends Activity {
32 
33     private static final float X_SHIFT_DP = 1000;
34     private static final float Y_SHIFT_DP = 50;
35     private static final float Z_LIFT_DP = 8;
36     private static final float ROTATE_DEGREES = 15;
37 
createSet(ArrayList<Animator> items, long startDelay)38     public AnimatorSet createSet(ArrayList<Animator> items, long startDelay) {
39         AnimatorSet set = new AnimatorSet();
40         set.playTogether(items);
41         set.setStartDelay(startDelay);
42         return set;
43     }
44 
45     @Override
onCreate(Bundle savedInstanceState)46     protected void onCreate(Bundle savedInstanceState) {
47         super.onCreate(savedInstanceState);
48         setContentView(R.layout.shadow_card_stack);
49 
50         float density = getResources().getDisplayMetrics().density;
51 
52         final ViewGroup cardParent = (ViewGroup) findViewById(R.id.card_parent);
53 
54         final float X = X_SHIFT_DP * density;
55         final float Y = Y_SHIFT_DP * density;
56         final float Z = Z_LIFT_DP * density;
57 
58         ArrayList<Animator> towardAnimators = new ArrayList<Animator>();
59         ArrayList<Animator> expandAnimators = new ArrayList<Animator>();
60         ArrayList<Animator> moveAwayAnimators = new ArrayList<Animator>();
61         ArrayList<Animator> moveBackAnimators = new ArrayList<Animator>();
62         ArrayList<Animator> awayAnimators = new ArrayList<Animator>();
63         ArrayList<Animator> collapseAnimators = new ArrayList<Animator>();
64 
65         final int max = cardParent.getChildCount();
66         for (int i = 0; i < max; i++) {
67             TextView card = (TextView) cardParent.getChildAt(i);
68             card.setText("Card number " + i);
69 
70             float targetY = (i - (max-1) / 2.0f) * Y;
71             Animator expand = ObjectAnimator.ofFloat(card, "translationY", targetY);
72             expandAnimators.add(expand);
73 
74             Animator toward = ObjectAnimator.ofFloat(card, "translationZ", i * Z);
75             toward.setStartDelay(200 * ((max) - i));
76             towardAnimators.add(toward);
77 
78             card.setPivotX(X_SHIFT_DP);
79             Animator rotateAway = ObjectAnimator.ofFloat(card, "rotationY",
80                     i == 0 ? 0 : ROTATE_DEGREES);
81             rotateAway.setStartDelay(200 * ((max) - i));
82             rotateAway.setDuration(100);
83             moveAwayAnimators.add(rotateAway);
84             Animator slideAway = ObjectAnimator.ofFloat(card, "translationX",
85                     i == 0 ? 0 : X);
86             slideAway.setStartDelay(200 * ((max) - i));
87             slideAway.setDuration(100);
88             moveAwayAnimators.add(slideAway);
89 
90             Animator rotateBack = ObjectAnimator.ofFloat(card, "rotationY", 0);
91             rotateBack.setStartDelay(200 * i);
92             moveBackAnimators.add(rotateBack);
93             Animator slideBack = ObjectAnimator.ofFloat(card, "translationX", 0);
94             slideBack.setStartDelay(200 * i);
95             moveBackAnimators.add(slideBack);
96 
97             Animator away = ObjectAnimator.ofFloat(card, "translationZ", 0);
98             away.setStartDelay(200 * i);
99             awayAnimators.add(away);
100 
101             Animator collapse = ObjectAnimator.ofFloat(card, "translationY", 0);
102             collapseAnimators.add(collapse);
103         }
104 
105         AnimatorSet totalSet = new AnimatorSet();
106         totalSet.playSequentially(
107                 createSet(expandAnimators, 250),
108                 createSet(towardAnimators, 0),
109 
110                 createSet(moveAwayAnimators, 250),
111                 createSet(moveBackAnimators, 0),
112 
113                 createSet(awayAnimators, 250),
114                 createSet(collapseAnimators, 0));
115         totalSet.start();
116         totalSet.addListener(new RepeatListener(totalSet));
117     }
118 
119     public static class RepeatListener implements Animator.AnimatorListener {
120         final Animator mRepeatAnimator;
RepeatListener(Animator repeatAnimator)121         public RepeatListener(Animator repeatAnimator) {
122             mRepeatAnimator = repeatAnimator;
123         }
124 
125         @Override
onAnimationStart(Animator animation)126         public void onAnimationStart(Animator animation) {}
127 
128         @Override
onAnimationEnd(Animator animation)129         public void onAnimationEnd(Animator animation) {
130             if (animation == mRepeatAnimator) {
131                 mRepeatAnimator.start();
132             }
133         }
134 
135         @Override
onAnimationCancel(Animator animation)136         public void onAnimationCancel(Animator animation) {}
137 
138         @Override
onAnimationRepeat(Animator animation)139         public void onAnimationRepeat(Animator animation) {}
140     }
141 }
142