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 */
16package android.transition;
17
18import com.android.internal.R;
19
20import android.animation.Animator;
21import android.animation.AnimatorListenerAdapter;
22import android.animation.ObjectAnimator;
23import android.animation.TimeInterpolator;
24import android.graphics.Path;
25import android.view.View;
26
27/**
28 * This class is used by Slide and Explode to create an animator that goes from the start
29 * position to the end position. It takes into account the canceled position so that it
30 * will not blink out or shift suddenly when the transition is interrupted.
31 */
32class TranslationAnimationCreator {
33
34    /**
35     * Creates an animator that can be used for x and/or y translations. When interrupted,
36     * it sets a tag to keep track of the position so that it may be continued from position.
37     *
38     * @param view The view being moved. This may be in the overlay for onDisappear.
39     * @param values The values containing the view in the view hierarchy.
40     * @param viewPosX The x screen coordinate of view
41     * @param viewPosY The y screen coordinate of view
42     * @param startX The start translation x of view
43     * @param startY The start translation y of view
44     * @param endX The end translation x of view
45     * @param endY The end translation y of view
46     * @param interpolator The interpolator to use with this animator.
47     * @return An animator that moves from (startX, startY) to (endX, endY) unless there was
48     * a previous interruption, in which case it moves from the current position to (endX, endY).
49     */
50    static Animator createAnimation(View view, TransitionValues values, int viewPosX, int viewPosY,
51            float startX, float startY, float endX, float endY, TimeInterpolator interpolator) {
52        float terminalX = view.getTranslationX();
53        float terminalY = view.getTranslationY();
54        int[] startPosition = (int[]) values.view.getTag(R.id.transitionPosition);
55        if (startPosition != null) {
56            startX = startPosition[0] - viewPosX + terminalX;
57            startY = startPosition[1] - viewPosY + terminalY;
58        }
59        // Initial position is at translation startX, startY, so position is offset by that amount
60        int startPosX = viewPosX + Math.round(startX - terminalX);
61        int startPosY = viewPosY + Math.round(startY - terminalY);
62
63        view.setTranslationX(startX);
64        view.setTranslationY(startY);
65        if (startX == endX && startY == endY) {
66            return null;
67        }
68        Path path = new Path();
69        path.moveTo(startX, startY);
70        path.lineTo(endX, endY);
71        ObjectAnimator anim = ObjectAnimator.ofFloat(view, View.TRANSLATION_X, View.TRANSLATION_Y,
72                path);
73
74        TransitionPositionListener listener = new TransitionPositionListener(view, values.view,
75                startPosX, startPosY, terminalX, terminalY);
76        anim.addListener(listener);
77        anim.addPauseListener(listener);
78        anim.setInterpolator(interpolator);
79        return anim;
80    }
81
82    private static class TransitionPositionListener extends AnimatorListenerAdapter {
83
84        private final View mViewInHierarchy;
85        private final View mMovingView;
86        private final int mStartX;
87        private final int mStartY;
88        private int[] mTransitionPosition;
89        private float mPausedX;
90        private float mPausedY;
91        private final float mTerminalX;
92        private final float mTerminalY;
93
94        private TransitionPositionListener(View movingView, View viewInHierarchy,
95                int startX, int startY, float terminalX, float terminalY) {
96            mMovingView = movingView;
97            mViewInHierarchy = viewInHierarchy;
98            mStartX = startX - Math.round(mMovingView.getTranslationX());
99            mStartY = startY - Math.round(mMovingView.getTranslationY());
100            mTerminalX = terminalX;
101            mTerminalY = terminalY;
102            mTransitionPosition = (int[]) mViewInHierarchy.getTag(R.id.transitionPosition);
103            if (mTransitionPosition != null) {
104                mViewInHierarchy.setTagInternal(R.id.transitionPosition, null);
105            }
106        }
107
108        @Override
109        public void onAnimationCancel(Animator animation) {
110            if (mTransitionPosition == null) {
111                mTransitionPosition = new int[2];
112            }
113            mTransitionPosition[0] = Math.round(mStartX + mMovingView.getTranslationX());
114            mTransitionPosition[1] = Math.round(mStartY + mMovingView.getTranslationY());
115            mViewInHierarchy.setTagInternal(R.id.transitionPosition, mTransitionPosition);
116        }
117
118        @Override
119        public void onAnimationEnd(Animator animator) {
120            mMovingView.setTranslationX(mTerminalX);
121            mMovingView.setTranslationY(mTerminalY);
122        }
123
124        @Override
125        public void onAnimationPause(Animator animator) {
126            mPausedX = mMovingView.getTranslationX();
127            mPausedY = mMovingView.getTranslationY();
128            mMovingView.setTranslationX(mTerminalX);
129            mMovingView.setTranslationY(mTerminalY);
130        }
131
132        @Override
133        public void onAnimationResume(Animator animator) {
134            mMovingView.setTranslationX(mPausedX);
135            mMovingView.setTranslationY(mPausedY);
136        }
137    }
138
139}
140