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.app.Activity;
17import android.os.Handler;
18import android.support.v17.leanback.transition.TransitionHelper;
19import android.support.v17.leanback.transition.TransitionListener;
20import android.support.v17.leanback.widget.FullWidthDetailsOverviewRowPresenter.ViewHolder;
21import android.support.v4.app.ActivityCompat;
22import android.support.v4.view.ViewCompat;
23import android.text.TextUtils;
24import android.util.Log;
25
26import java.lang.ref.WeakReference;
27
28/**
29 * Helper class to assist delayed shared element activity transition for view created by
30 * {@link FullWidthDetailsOverviewRowPresenter}. User must call
31 * {@link #setSharedElementEnterTransition(Activity, String, long)} during activity onCreate() and
32 * call {@link FullWidthDetailsOverviewRowPresenter#setListener(FullWidthDetailsOverviewRowPresenter.Listener)}.
33 * The helper implements {@link FullWidthDetailsOverviewRowPresenter.Listener} and starts delayed
34 * activity transition once {@link FullWidthDetailsOverviewRowPresenter.Listener#onBindLogo(ViewHolder)}
35 * is called.
36 */
37public class FullWidthDetailsOverviewSharedElementHelper extends
38        FullWidthDetailsOverviewRowPresenter.Listener {
39
40    static final String TAG = "DetailsTransitionHelper";
41    static final boolean DEBUG = false;
42
43    private static final long DEFAULT_TIMEOUT = 5000;
44
45    static class TransitionTimeOutRunnable implements Runnable {
46        WeakReference<FullWidthDetailsOverviewSharedElementHelper> mHelperRef;
47
48        TransitionTimeOutRunnable(FullWidthDetailsOverviewSharedElementHelper helper) {
49            mHelperRef = new WeakReference<FullWidthDetailsOverviewSharedElementHelper>(helper);
50        }
51
52        @Override
53        public void run() {
54            FullWidthDetailsOverviewSharedElementHelper helper = mHelperRef.get();
55            if (helper == null) {
56                return;
57            }
58            if (DEBUG) {
59                Log.d(TAG, "timeout " + helper.mActivityToRunTransition);
60            }
61            helper.startPostponedEnterTransition();
62        }
63    }
64
65    ViewHolder mViewHolder;
66    Activity mActivityToRunTransition;
67    private boolean mStartedPostpone;
68    String mSharedElementName;
69    private boolean mAutoStartSharedElementTransition = true;
70
71    public void setSharedElementEnterTransition(Activity activity, String sharedElementName) {
72        setSharedElementEnterTransition(activity, sharedElementName, DEFAULT_TIMEOUT);
73    }
74
75    public void setSharedElementEnterTransition(Activity activity, String sharedElementName,
76            long timeoutMs) {
77        if ((activity == null && !TextUtils.isEmpty(sharedElementName))
78                || (activity != null && TextUtils.isEmpty(sharedElementName))) {
79            throw new IllegalArgumentException();
80        }
81        if (activity == mActivityToRunTransition
82                && TextUtils.equals(sharedElementName, mSharedElementName)) {
83            return;
84        }
85        mActivityToRunTransition = activity;
86        mSharedElementName = sharedElementName;
87        if (DEBUG) {
88            Log.d(TAG, "postponeEnterTransition " + mActivityToRunTransition);
89        }
90        Object transition = TransitionHelper.getSharedElementEnterTransition(activity.getWindow());
91        setAutoStartSharedElementTransition(transition != null);
92        ActivityCompat.postponeEnterTransition(mActivityToRunTransition);
93        if (timeoutMs > 0) {
94            new Handler().postDelayed(new TransitionTimeOutRunnable(this), timeoutMs);
95        }
96    }
97
98    /**
99     * Enable or disable auto startPostponedEnterTransition() when bound to logo. When it's
100     * disabled, app must call {@link #startPostponedEnterTransition()} to kick off
101     * windowEnterTransition. By default, it is disabled when there is no
102     * windowEnterSharedElementTransition set on the activity.
103     */
104    public void setAutoStartSharedElementTransition(boolean enabled) {
105        mAutoStartSharedElementTransition = enabled;
106    }
107
108    /**
109     * Returns true if auto startPostponedEnterTransition() when bound to logo. When it's
110     * disabled, app must call {@link #startPostponedEnterTransition()} to kick off
111     * windowEnterTransition. By default, it is disabled when there is no
112     * windowEnterSharedElementTransition set on the activity.
113     */
114    public boolean getAutoStartSharedElementTransition() {
115        return mAutoStartSharedElementTransition;
116    }
117
118    @Override
119    public void onBindLogo(ViewHolder vh) {
120        if (DEBUG) {
121            Log.d(TAG, "onBindLogo, could start transition of " + mActivityToRunTransition);
122        }
123        mViewHolder = vh;
124        if (!mAutoStartSharedElementTransition) {
125            return;
126        }
127        if (mViewHolder != null) {
128            if (DEBUG) {
129                Log.d(TAG, "rebind? clear transitionName on current viewHolder "
130                        + mViewHolder.getOverviewView());
131            }
132            ViewCompat.setTransitionName(mViewHolder.getLogoViewHolder().view, null);
133        }
134        // After we got a image drawable,  we can determine size of right panel.
135        // We want right panel to have fixed size so that the right panel don't change size
136        // when the overview is layout as a small bounds in transition.
137        mViewHolder.getDetailsDescriptionFrame().postOnAnimation(new Runnable() {
138            @Override
139            public void run() {
140                if (DEBUG) {
141                    Log.d(TAG, "setTransitionName "+mViewHolder.getOverviewView());
142                }
143                ViewCompat.setTransitionName(mViewHolder.getLogoViewHolder().view,
144                        mSharedElementName);
145                Object transition = TransitionHelper.getSharedElementEnterTransition(
146                        mActivityToRunTransition.getWindow());
147                if (transition != null) {
148                    TransitionHelper.addTransitionListener(transition, new TransitionListener() {
149                        @Override
150                        public void onTransitionEnd(Object transition) {
151                            if (DEBUG) {
152                                Log.d(TAG, "onTransitionEnd " + mActivityToRunTransition);
153                            }
154                            // after transition if the action row still focused, transfer
155                            // focus to its children
156                            if (mViewHolder.getActionsRow().isFocused()) {
157                                mViewHolder.getActionsRow().requestFocus();
158                            }
159                            TransitionHelper.removeTransitionListener(transition, this);
160                        }
161                    });
162                }
163                startPostponedEnterTransitionInternal();
164            }
165        });
166    }
167
168    /**
169     * Manually start postponed enter transition.
170     */
171    public void startPostponedEnterTransition() {
172        new Handler().post(new Runnable(){
173            @Override
174            public void run() {
175                startPostponedEnterTransitionInternal();
176            }
177        });
178    }
179
180    void startPostponedEnterTransitionInternal() {
181        if (!mStartedPostpone && mViewHolder != null) {
182            if (DEBUG) {
183                Log.d(TAG, "startPostponedEnterTransition " + mActivityToRunTransition);
184            }
185            ActivityCompat.startPostponedEnterTransition(mActivityToRunTransition);
186            mStartedPostpone = true;
187        }
188    }
189}
190