Docs: Sync browseable samples for lmp-docs

Synced to developers/samples/android commit
bc036ecdf44cd03163c206096172299f3940b057.

Change-Id: Ib68230d79ca300e7db906aff2ebfc2cb6c6968f7

3 files changed, 105 insertions, 153 deletions

diff --git a/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/DetailActivity.java b/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/DetailActivity.java
index 958900890..17d1b2a7b 100644
--- a/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/DetailActivity.java
+++ b/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/DetailActivity.java
@@ -16,13 +16,14 @@
 
 package com.example.android.activityscenetransitionbasic;
 
-import com.android.volley.toolbox.ImageLoader;
-import com.android.volley.toolbox.NetworkImageView;
-import com.android.volley.toolbox.Volley;
+import com.squareup.picasso.Picasso;
 
 import android.app.Activity;
-import android.graphics.Bitmap;
+import android.os.Build;
 import android.os.Bundle;
+import android.support.v4.view.ViewCompat;
+import android.transition.Transition;
+import android.widget.ImageView;
 import android.widget.TextView;
 
 /**
@@ -40,23 +41,20 @@ public class DetailActivity extends Activity {
     // View name of the header title. Used for activity scene transitions
     public static final String VIEW_NAME_HEADER_TITLE = "detail:header:title";
 
-    private NetworkImageView mHeaderImageView;
+    private ImageView mHeaderImageView;
     private TextView mHeaderTitle;
 
-    private ImageLoader mImageLoader;
+    private Item mItem;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.details);
 
-        // Construct an ImageLoader instance so that we can load images from the network
-        mImageLoader = new ImageLoader(Volley.newRequestQueue(this), ImageMemoryCache.INSTANCE);
-
         // Retrieve the correct Item instance, using the ID provided in the Intent
-        Item item = Item.getItem(getIntent().getIntExtra(EXTRA_PARAM_ID, 0));
+        mItem = Item.getItem(getIntent().getIntExtra(EXTRA_PARAM_ID, 0));
 
-        mHeaderImageView = (NetworkImageView) findViewById(R.id.imageview_header);
+        mHeaderImageView = (ImageView) findViewById(R.id.imageview_header);
         mHeaderTitle = (TextView) findViewById(R.id.textview_title);
 
         // BEGIN_INCLUDE(detail_set_view_name)
@@ -65,31 +63,97 @@ public class DetailActivity extends Activity {
          * This could be done in the layout XML, but exposing it via static variables allows easy
          * querying from other Activities
          */
-        mHeaderImageView.setTransitionName(VIEW_NAME_HEADER_IMAGE);
-        mHeaderTitle.setTransitionName(VIEW_NAME_HEADER_TITLE);
+        ViewCompat.setTransitionName(mHeaderImageView, VIEW_NAME_HEADER_IMAGE);
+        ViewCompat.setTransitionName(mHeaderTitle, VIEW_NAME_HEADER_TITLE);
         // END_INCLUDE(detail_set_view_name)
 
-        loadItem(item);
+        loadItem();
     }
 
-    private void loadItem(Item item) {
+    private void loadItem() {
         // Set the title TextView to the item's name and author
-        mHeaderTitle.setText(getString(R.string.image_header, item.getName(), item.getAuthor()));
+        mHeaderTitle.setText(getString(R.string.image_header, mItem.getName(), mItem.getAuthor()));
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && addTransitionListener()) {
+            // If we're running on Lollipop and we have added a listener to the shared element
+            // transition, load the thumbnail. The listener will load the full-size image when
+            // the transition is complete.
+            loadThumbnail();
+        } else {
+            // If all other cases we should just load the full-size image now
+            loadFullSizeImage();
+        }
+    }
 
-        final ImageMemoryCache cache = ImageMemoryCache.INSTANCE;
-        Bitmap thumbnailImage = cache.getBitmapFromUrl(item.getThumbnailUrl());
+    /**
+     * Load the item's thumbnail image into our {@link ImageView}.
+     */
+    private void loadThumbnail() {
+        Picasso.with(mHeaderImageView.getContext())
+                .load(mItem.getThumbnailUrl())
+                .noFade()
+                .into(mHeaderImageView);
+    }
+
+    /**
+     * Load the item's full-size image into our {@link ImageView}.
+     */
+    private void loadFullSizeImage() {
+        Picasso.with(mHeaderImageView.getContext())
+                .load(mItem.getPhotoUrl())
+                .noFade()
+                .noPlaceholder()
+                .into(mHeaderImageView);
+    }
 
-        // Check to see if we already have the thumbnail sized image in the cache. If so, start
-        // loading the full size image and display the thumbnail as a placeholder.
-        if (thumbnailImage != null) {
-            mHeaderImageView.setImageUrl(item.getPhotoUrl(), mImageLoader);
-            mHeaderImageView.setImageBitmap(thumbnailImage);
-            return;
+    /**
+     * Try and add a {@link Transition.TransitionListener} to the entering shared element
+     * {@link Transition}. We do this so that we can load the full-size image after the transition
+     * has completed.
+     *
+     * @return true if we were successful in adding a listener to the enter transition
+     */
+    private boolean addTransitionListener() {
+        final Transition transition = getWindow().getSharedElementEnterTransition();
+
+        if (transition != null) {
+            // There is an entering shared element transition so add a listener to it
+            transition.addListener(new Transition.TransitionListener() {
+                @Override
+                public void onTransitionEnd(Transition transition) {
+                    // As the transition has ended, we can now load the full-size image
+                    loadFullSizeImage();
+
+                    // Make sure we remove ourselves as a listener
+                    transition.removeListener(this);
+                }
+
+                @Override
+                public void onTransitionStart(Transition transition) {
+                    // No-op
+                }
+
+                @Override
+                public void onTransitionCancel(Transition transition) {
+                    // Make sure we remove ourselves as a listener
+                    transition.removeListener(this);
+                }
+
+                @Override
+                public void onTransitionPause(Transition transition) {
+                    // No-op
+                }
+
+                @Override
+                public void onTransitionResume(Transition transition) {
+                    // No-op
+                }
+            });
+            return true;
         }
 
-        // If we get here then we do not have either the full size or the thumbnail in the cache.
-        // Here we just load the full size and make do.
-        mHeaderImageView.setImageUrl(item.getPhotoUrl(), mImageLoader);
+        // If we reach here then we have not added a listener
+        return false;
     }
 
 }
diff --git a/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/ImageMemoryCache.java b/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/ImageMemoryCache.java
deleted file mode 100644
index 53d47bae1..000000000
--- a/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/ImageMemoryCache.java
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.example.android.activityscenetransitionbasic;
-
-import com.android.volley.toolbox.ImageLoader;
-
-import android.graphics.Bitmap;
-import android.util.LruCache;
-
-import java.util.Map;
-
-/**
- * An image memory cache implementation for Volley which allows the retrieval of entires via a URL.
- * Volley internally inserts items with a key which is a combination of a the size of the image,
- * and the url.
- *
- * This class provide the method {@link #getBitmapFromUrl(String)} which allows the retrieval of
- * a bitmap solely on the URL.
- */
-public class ImageMemoryCache extends LruCache<String, Bitmap> implements ImageLoader.ImageCache {
-
-    /**
-     * Singleton instance which has it's maximum size set to be 1/8th of the allowed memory size.
-     */
-    public static final ImageMemoryCache INSTANCE = new ImageMemoryCache(
-            (int) (Runtime.getRuntime().maxMemory() / 8));
-
-    // Cache the last created snapshot
-    private Map<String, Bitmap> mLastSnapshot;
-
-    private ImageMemoryCache(int maxSize) {
-        super(maxSize);
-    }
-
-    public Bitmap getBitmapFromUrl(String url) {
-        // If we do not have a snapshot to use, generate one
-        if (mLastSnapshot == null) {
-            mLastSnapshot = snapshot();
-        }
-
-        // Iterate through the snapshot to find any entries which match our url
-        for (Map.Entry<String, Bitmap> entry : mLastSnapshot.entrySet()) {
-            if (url.equals(extractUrl(entry.getKey()))) {
-                // We've found an entry with the same url, return the bitmap
-                return entry.getValue();
-            }
-        }
-
-        // We didn't find an entry, so return null
-        return null;
-    }
-
-    @Override
-    public Bitmap getBitmap(String key) {
-        return get(key);
-    }
-
-    @Override
-    public void putBitmap(String key, Bitmap bitmap) {
-        put(key, bitmap);
-
-        // An entry has been added, so invalidate the snapshot
-        mLastSnapshot = null;
-    }
-
-    @Override
-    protected void entryRemoved(boolean evicted, String key, Bitmap oldValue, Bitmap newValue) {
-        super.entryRemoved(evicted, key, oldValue, newValue);
-
-        // An entry has been removed, so invalidate the snapshot
-        mLastSnapshot = null;
-    }
-
-    private static String extractUrl(String key) {
-        return key.substring(key.indexOf("http"));
-    }
-
-    @Override
-    protected int sizeOf(String key, Bitmap value) {
-        return value.getAllocationByteCount();
-    }
-}
diff --git a/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/MainActivity.java b/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/MainActivity.java
index 9c51789db..9eed44a3d 100644
--- a/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/MainActivity.java
+++ b/samples/browseable/ActivitySceneTransitionBasic/src/com.example.android.activityscenetransitionbasic/MainActivity.java
@@ -16,20 +16,20 @@
 
 package com.example.android.activityscenetransitionbasic;
 
-import com.android.volley.toolbox.ImageLoader;
-import com.android.volley.toolbox.NetworkImageView;
-import com.android.volley.toolbox.Volley;
+import com.squareup.picasso.Picasso;
 
 import android.app.Activity;
-import android.app.ActivityOptions;
 import android.content.Intent;
 import android.os.Bundle;
-import android.util.Pair;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.app.ActivityOptionsCompat;
+import android.support.v4.util.Pair;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
 import android.widget.BaseAdapter;
 import android.widget.GridView;
+import android.widget.ImageView;
 import android.widget.TextView;
 
 /**
@@ -42,16 +42,11 @@ public class MainActivity extends Activity implements AdapterView.OnItemClickLis
     private GridView mGridView;
     private GridAdapter mAdapter;
 
-    private ImageLoader mImageLoader;
-
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.grid);
 
-        // Retrieve the ImageLoader we are going to use for NetworkImageView
-        mImageLoader = new ImageLoader(Volley.newRequestQueue(this), ImageMemoryCache.INSTANCE);
-
         // Setup the GridView and set the adapter
         mGridView = (GridView) findViewById(R.id.grid);
         mGridView.setOnItemClickListener(this);
@@ -74,23 +69,21 @@ public class MainActivity extends Activity implements AdapterView.OnItemClickLis
         // BEGIN_INCLUDE(start_activity)
         /**
          * Now create an {@link android.app.ActivityOptions} instance using the
-         * {@link android.app.ActivityOptions#makeSceneTransitionAnimation(android.app.Activity, android.util.Pair[])} factory method.
+         * {@link ActivityOptionsCompat#makeSceneTransitionAnimation(Activity, Pair[])} factory
+         * method.
          */
-        ActivityOptions activityOptions = ActivityOptions.makeSceneTransitionAnimation(
+        ActivityOptionsCompat activityOptions = ActivityOptionsCompat.makeSceneTransitionAnimation(
                 this,
 
                 // Now we provide a list of Pair items which contain the view we can transitioning
                 // from, and the name of the view it is transitioning to, in the launched activity
-                new Pair<View, String>(
-                        view.findViewById(R.id.imageview_item),
+                new Pair<View, String>(view.findViewById(R.id.imageview_item),
                         DetailActivity.VIEW_NAME_HEADER_IMAGE),
-                new Pair<View, String>(
-                        view.findViewById(R.id.textview_name),
-                        DetailActivity.VIEW_NAME_HEADER_TITLE)
-        );
+                new Pair<View, String>(view.findViewById(R.id.textview_name),
+                        DetailActivity.VIEW_NAME_HEADER_TITLE));
 
         // Now we can start the Activity, providing the activity options as a bundle
-        startActivity(intent, activityOptions.toBundle());
+        ActivityCompat.startActivity(this, intent, activityOptions.toBundle());
         // END_INCLUDE(start_activity)
     }
 
@@ -123,22 +116,13 @@ public class MainActivity extends Activity implements AdapterView.OnItemClickLis
             final Item item = getItem(position);
 
             // Load the thumbnail image
-            NetworkImageView image = (NetworkImageView) view.findViewById(R.id.imageview_item);
-            image.setImageUrl(item.getThumbnailUrl(), mImageLoader);
+            ImageView image = (ImageView) view.findViewById(R.id.imageview_item);
+            Picasso.with(image.getContext()).load(item.getThumbnailUrl()).into(image);
 
             // Set the TextView's contents
             TextView name = (TextView) view.findViewById(R.id.textview_name);
             name.setText(item.getName());
 
-            // BEGIN_INCLUDE(grid_set_view_name)
-            /**
-             * As we're in an adapter we need to set each view's name dynamically, using the
-             * item's ID so that the names are unique.
-             */
-            image.setTransitionName("grid:image:" + item.getId());
-            name.setTransitionName("grid:name:" + item.getId());
-            // END_INCLUDE(grid_set_view_name)
-
             return view;
         }
     }