DetailsOverviewSharedElementHelper.java revision 4121f22713bbed467a977ec0d867ef53989ff374 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14package android.support.v17.leanback.widget;
15
16import android.support.v4.app.ActivityCompat;
17import android.support.v4.app.SharedElementListener;
18import android.support.v4.view.ViewCompat;
19import android.support.v17.leanback.widget.DetailsOverviewRowPresenter.ViewHolder;
20
21import android.app.Activity;
22import android.text.TextUtils;
23import android.view.View;
24import android.view.View.MeasureSpec;
25
26import java.util.List;
27
28final class DetailsOverviewSharedElementHelper extends SharedElementListener {
29
30    private ViewHolder mViewHolder;
31    private Activity mActivityToRunTransition;
32    private String mSharedElementName;
33    private int mRightPanelWidth;
34    private int mRightPanelHeight;
35
36    @Override
37    public void setSharedElementStart(List<String> sharedElementNames,
38            List<View> sharedElements, List<View> sharedElementSnapshots) {
39        if (sharedElements.size() < 1) {
40            return;
41        }
42        View overviewView = sharedElements.get(0);
43        if (mViewHolder == null || mViewHolder.mOverviewView != overviewView) {
44            return;
45        }
46        View imageView = mViewHolder.mImageView;
47        final int width = overviewView.getWidth();
48        final int height = overviewView.getHeight();
49        imageView.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
50                MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
51        imageView.layout(0, 0, width, height);
52        View rightPanel = mViewHolder.mRightPanel;
53        if (mRightPanelWidth != 0 && mRightPanelHeight != 0) {
54            rightPanel.measure(MeasureSpec.makeMeasureSpec(mRightPanelWidth, MeasureSpec.EXACTLY),
55                    MeasureSpec.makeMeasureSpec(mRightPanelHeight, MeasureSpec.EXACTLY));
56            rightPanel.layout(width, rightPanel.getTop(), width + mRightPanelWidth,
57                    rightPanel.getTop() + mRightPanelHeight);
58        } else {
59            rightPanel.offsetLeftAndRight(width - rightPanel.getLeft());
60        }
61    }
62
63    void setSharedElementEnterTransition(Activity activity, String sharedElementName) {
64        if (activity == null && !TextUtils.isEmpty(sharedElementName) ||
65                activity != null && TextUtils.isEmpty(sharedElementName)) {
66            throw new IllegalArgumentException();
67        }
68        if (activity == mActivityToRunTransition &&
69                TextUtils.equals(sharedElementName, mSharedElementName)) {
70            return;
71        }
72        if (mActivityToRunTransition != null) {
73            ActivityCompat.setEnterSharedElementListener(mActivityToRunTransition, null);
74        }
75        mActivityToRunTransition = activity;
76        mSharedElementName = sharedElementName;
77        if (mActivityToRunTransition != null) {
78            ActivityCompat.setEnterSharedElementListener(mActivityToRunTransition, this);
79            ActivityCompat.postponeEnterTransition(mActivityToRunTransition);
80        }
81    }
82
83    void onBindToDrawable(ViewHolder vh) {
84        // After we got a image drawable,  we can determine size of right panel.
85        // We want right panel to have fixed size so that the right panel don't change size
86        // when the overview is layout as a small bounds in transition.
87        mViewHolder = vh;
88        mViewHolder.mRightPanel.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
89            @Override
90            public void onLayoutChange(View v, int left, int top, int right, int bottom,
91                    int oldLeft, int oldTop, int oldRight, int oldBottom) {
92                mViewHolder.mRightPanel.removeOnLayoutChangeListener(this);
93                mRightPanelWidth = mViewHolder.mRightPanel.getWidth();
94                mRightPanelHeight = mViewHolder.mRightPanel.getHeight();
95            }
96        });
97        if (mActivityToRunTransition != null) {
98            mViewHolder.mRightPanel.postOnAnimation(new Runnable() {
99                @Override
100                public void run() {
101                    ViewCompat.setTransitionName(mViewHolder.mOverviewView, mSharedElementName);
102                    ActivityCompat.startPostponedEnterTransition(mActivityToRunTransition);
103                    mActivityToRunTransition = null;
104                    mSharedElementName = null;
105                }
106            });
107        }
108    }
109}
110