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
17package com.example.android.activityscenetransitionbasic;
18
19import com.squareup.picasso.Picasso;
20
21import android.app.Activity;
22import android.os.Build;
23import android.os.Bundle;
24import android.support.v4.view.ViewCompat;
25import android.transition.Transition;
26import android.widget.ImageView;
27import android.widget.TextView;
28
29/**
30 * Our secondary Activity which is launched from {@link MainActivity}. Has a simple detail UI
31 * which has a large banner image, title and body text.
32 */
33public class DetailActivity extends Activity {
34
35    // Extra name for the ID parameter
36    public static final String EXTRA_PARAM_ID = "detail:_id";
37
38    // View name of the header image. Used for activity scene transitions
39    public static final String VIEW_NAME_HEADER_IMAGE = "detail:header:image";
40
41    // View name of the header title. Used for activity scene transitions
42    public static final String VIEW_NAME_HEADER_TITLE = "detail:header:title";
43
44    private ImageView mHeaderImageView;
45    private TextView mHeaderTitle;
46
47    private Item mItem;
48
49    @Override
50    protected void onCreate(Bundle savedInstanceState) {
51        super.onCreate(savedInstanceState);
52        setContentView(R.layout.details);
53
54        // Retrieve the correct Item instance, using the ID provided in the Intent
55        mItem = Item.getItem(getIntent().getIntExtra(EXTRA_PARAM_ID, 0));
56
57        mHeaderImageView = (ImageView) findViewById(R.id.imageview_header);
58        mHeaderTitle = (TextView) findViewById(R.id.textview_title);
59
60        // BEGIN_INCLUDE(detail_set_view_name)
61        /**
62         * Set the name of the view's which will be transition to, using the static values above.
63         * This could be done in the layout XML, but exposing it via static variables allows easy
64         * querying from other Activities
65         */
66        ViewCompat.setTransitionName(mHeaderImageView, VIEW_NAME_HEADER_IMAGE);
67        ViewCompat.setTransitionName(mHeaderTitle, VIEW_NAME_HEADER_TITLE);
68        // END_INCLUDE(detail_set_view_name)
69
70        loadItem();
71    }
72
73    private void loadItem() {
74        // Set the title TextView to the item's name and author
75        mHeaderTitle.setText(getString(R.string.image_header, mItem.getName(), mItem.getAuthor()));
76
77        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && addTransitionListener()) {
78            // If we're running on Lollipop and we have added a listener to the shared element
79            // transition, load the thumbnail. The listener will load the full-size image when
80            // the transition is complete.
81            loadThumbnail();
82        } else {
83            // If all other cases we should just load the full-size image now
84            loadFullSizeImage();
85        }
86    }
87
88    /**
89     * Load the item's thumbnail image into our {@link ImageView}.
90     */
91    private void loadThumbnail() {
92        Picasso.with(mHeaderImageView.getContext())
93                .load(mItem.getThumbnailUrl())
94                .noFade()
95                .into(mHeaderImageView);
96    }
97
98    /**
99     * Load the item's full-size image into our {@link ImageView}.
100     */
101    private void loadFullSizeImage() {
102        Picasso.with(mHeaderImageView.getContext())
103                .load(mItem.getPhotoUrl())
104                .noFade()
105                .noPlaceholder()
106                .into(mHeaderImageView);
107    }
108
109    /**
110     * Try and add a {@link Transition.TransitionListener} to the entering shared element
111     * {@link Transition}. We do this so that we can load the full-size image after the transition
112     * has completed.
113     *
114     * @return true if we were successful in adding a listener to the enter transition
115     */
116    private boolean addTransitionListener() {
117        final Transition transition = getWindow().getSharedElementEnterTransition();
118
119        if (transition != null) {
120            // There is an entering shared element transition so add a listener to it
121            transition.addListener(new Transition.TransitionListener() {
122                @Override
123                public void onTransitionEnd(Transition transition) {
124                    // As the transition has ended, we can now load the full-size image
125                    loadFullSizeImage();
126
127                    // Make sure we remove ourselves as a listener
128                    transition.removeListener(this);
129                }
130
131                @Override
132                public void onTransitionStart(Transition transition) {
133                    // No-op
134                }
135
136                @Override
137                public void onTransitionCancel(Transition transition) {
138                    // Make sure we remove ourselves as a listener
139                    transition.removeListener(this);
140                }
141
142                @Override
143                public void onTransitionPause(Transition transition) {
144                    // No-op
145                }
146
147                @Override
148                public void onTransitionResume(Transition transition) {
149                    // No-op
150                }
151            });
152            return true;
153        }
154
155        // If we reach here then we have not added a listener
156        return false;
157    }
158
159}
160