Add support to display thumbnail or mime icon in the document inspector.

Displays the thumbnail or mime icon in the header.

Bug: 62862758
Test: --
Change-Id: I8cc5807a002cba19f544fc404181e8c212384381

4 files changed, 193 insertions, 98 deletions

diff --git a/res/layout/inspector_header.xml b/res/layout/inspector_header.xml
index cfbc29f98..bb6acb4da 100644
--- a/res/layout/inspector_header.xml
+++ b/res/layout/inspector_header.xml
@@ -17,11 +17,22 @@
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
+
+    <ImageView
+        android:id="@+id/inspector_mime"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:scaleType="fitCenter"
+        android:background="@android:color/black" />
+
     <ImageView
         android:id="@+id/inspector_thumbnail"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
+        android:alpha="0.0"
+        android:scaleType="centerCrop"
         android:background="@android:color/black" />
+
     <TextView
         android:id="@+id/inspector_file_title"
         android:layout_width="wrap_content"
diff --git a/src/com/android/documentsui/ThumbnailLoader.java b/src/com/android/documentsui/ThumbnailLoader.java
new file mode 100644
index 000000000..bb1e5d5a4
--- /dev/null
+++ b/src/com/android/documentsui/ThumbnailLoader.java
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2017 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.android.documentsui;
+
+import static com.android.documentsui.base.Shared.VERBOSE;
+
+import android.content.ContentProviderClient;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Point;
+import android.net.Uri;
+import android.os.AsyncTask;
+import android.os.CancellationSignal;
+import android.os.OperationCanceledException;
+import android.provider.DocumentsContract;
+import android.util.Log;
+import android.view.View;
+import android.widget.ImageView;
+import com.android.documentsui.ProviderExecutor.Preemptable;
+import java.util.function.BiConsumer;
+
+/**
+ *  Loads a Thumbnails asynchronously then animates from the mime icon to the thumbnail
+ */
+public final class ThumbnailLoader extends AsyncTask<Uri, Void, Bitmap> implements Preemptable {
+
+    private static final String TAG = ThumbnailLoader.class.getCanonicalName();
+
+    /**
+     * Two animations applied to image views. The first is used to switch mime icon and thumbnail.
+     * The second is used when we need to update thumbnail.
+     */
+    public static final BiConsumer<View, View> ANIM_FADE_IN = (mime, thumb) -> {
+        float alpha = mime.getAlpha();
+        mime.animate().alpha(0f).start();
+        thumb.setAlpha(0f);
+        thumb.animate().alpha(alpha).start();
+    };
+    public static final BiConsumer<View, View> ANIM_NO_OP = (mime, thumb) -> {};
+
+    private final ImageView mIconThumb;
+    private final Point mThumbSize;
+    // A callback to apply animation to image views after the thumbnail is loaded.
+    private final BiConsumer<View, View> mImageAnimator;
+    private final Uri mUri;
+    private final ImageView mIconMime;
+    private final long mLastModified;
+    private final boolean mAddToCache;
+    private final CancellationSignal mSignal;
+
+    /**
+     * @param uri - to a thumbnail.
+     * @param iconMime - ImageView for displaying a mime type.
+     * @param iconThumb - ImageView to display the thumbnail.
+     * @param thumbSize - size of the thumbnail.
+     * @param lastModified - used for updating thumbnail caches.
+     * @param animator - used to animate from the mime icon to the thumbnail.
+     * @param addToCache - flag that determines if the loader saves the thumbnail to the cache.
+     */
+    public ThumbnailLoader(Uri uri, ImageView iconMime, ImageView iconThumb,
+        Point thumbSize, long lastModified, BiConsumer<View, View> animator, boolean addToCache) {
+        mUri = uri;
+        mIconMime = iconMime;
+        mIconThumb = iconThumb;
+        mThumbSize = thumbSize;
+        mImageAnimator = animator;
+        mLastModified = lastModified;
+        mAddToCache = addToCache;
+        mSignal = new CancellationSignal();
+        mIconThumb.setTag(this);
+        if (VERBOSE) Log.v(TAG, "Starting icon loader task for " + mUri);
+    }
+
+    @Override
+    public void preempt() {
+        if (VERBOSE) Log.v(TAG, "Icon loader task for " + mUri + " was cancelled.");
+        cancel(false);
+        mSignal.cancel();
+    }
+
+    @Override
+    protected Bitmap doInBackground(Uri... params) {
+        if (isCancelled()) {
+            return null;
+        }
+
+        final Context context = mIconThumb.getContext();
+        final ContentResolver resolver = context.getContentResolver();
+
+        ContentProviderClient client = null;
+        Bitmap result = null;
+        try {
+            client = DocumentsApplication.acquireUnstableProviderOrThrow(
+                resolver, mUri.getAuthority());
+            result = DocumentsContract.getDocumentThumbnail(client, mUri, mThumbSize, mSignal);
+            if (result != null && mAddToCache) {
+                final ThumbnailCache cache = DocumentsApplication.getThumbnailCache(context);
+                cache.putThumbnail(mUri, mThumbSize, result, mLastModified);
+            }
+        } catch (Exception e) {
+            if (!(e instanceof OperationCanceledException)) {
+                Log.w(TAG, "Failed to load thumbnail for " + mUri + ": " + e);
+            }
+        } finally {
+            ContentProviderClient.releaseQuietly(client);
+        }
+        return result;
+    }
+
+    @Override
+    protected void onPostExecute(Bitmap result) {
+        if (VERBOSE) Log.v(TAG, "Loader task for " + mUri + " completed");
+
+            if (mIconThumb.getTag() == this && result != null) {
+                mIconThumb.setTag(null);
+                mIconThumb.setImageBitmap(result);
+                mImageAnimator.accept(mIconMime, mIconThumb);
+            }
+    }
+}
diff --git a/src/com/android/documentsui/dirlist/IconHelper.java b/src/com/android/documentsui/dirlist/IconHelper.java
index 77a646695..d9eabae25 100644
--- a/src/com/android/documentsui/dirlist/IconHelper.java
+++ b/src/com/android/documentsui/dirlist/IconHelper.java
@@ -20,16 +20,11 @@ import static com.android.documentsui.base.Shared.VERBOSE;
 import static com.android.documentsui.base.State.MODE_GRID;
 import static com.android.documentsui.base.State.MODE_LIST;
 
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Point;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
-import android.os.AsyncTask;
-import android.os.CancellationSignal;
-import android.os.OperationCanceledException;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
 import android.support.annotation.Nullable;
@@ -40,10 +35,10 @@ import android.widget.ImageView;
 import com.android.documentsui.DocumentsApplication;
 import com.android.documentsui.IconUtils;
 import com.android.documentsui.ProviderExecutor;
-import com.android.documentsui.ProviderExecutor.Preemptable;
 import com.android.documentsui.R;
 import com.android.documentsui.ThumbnailCache;
 import com.android.documentsui.ThumbnailCache.Result;
+import com.android.documentsui.ThumbnailLoader;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.MimeTypes;
 import com.android.documentsui.base.State;
@@ -58,16 +53,6 @@ import java.util.function.BiConsumer;
 public class IconHelper {
     private static final String TAG = "IconHelper";
 
-    // Two animations applied to image views. The first is used to switch mime icon and thumbnail.
-    // The second is used when we need to update thumbnail.
-    private static final BiConsumer<View, View> ANIM_FADE_IN = (mime, thumb) -> {
-        float alpha = mime.getAlpha();
-        mime.animate().alpha(0f).start();
-        thumb.setAlpha(0f);
-        thumb.animate().alpha(alpha).start();
-    };
-    private static final BiConsumer<View, View> ANIM_NO_OP = (mime, thumb) -> {};
-
     private final Context mContext;
     private final ThumbnailCache mThumbnailCache;
 
@@ -129,89 +114,13 @@ public class IconHelper {
      * @param icon
      */
     public void stopLoading(ImageView icon) {
-        final LoaderTask oldTask = (LoaderTask) icon.getTag();
+        final ThumbnailLoader oldTask = (ThumbnailLoader) icon.getTag();
         if (oldTask != null) {
             oldTask.preempt();
             icon.setTag(null);
         }
     }
 
-    /** Internal task for loading thumbnails asynchronously. */
-    private static class LoaderTask
-            extends AsyncTask<Uri, Void, Bitmap>
-            implements Preemptable {
-        private final Uri mUri;
-        private final ImageView mIconMime;
-        private final ImageView mIconThumb;
-        private final Point mThumbSize;
-        private final long mLastModified;
-
-        // A callback to apply animation to image views after the thumbnail is loaded.
-        private final BiConsumer<View, View> mImageAnimator;
-
-        private final CancellationSignal mSignal;
-
-        public LoaderTask(Uri uri, ImageView iconMime, ImageView iconThumb,
-                Point thumbSize, long lastModified, BiConsumer<View, View> animator) {
-            mUri = uri;
-            mIconMime = iconMime;
-            mIconThumb = iconThumb;
-            mThumbSize = thumbSize;
-            mImageAnimator = animator;
-            mLastModified = lastModified;
-            mSignal = new CancellationSignal();
-            if (VERBOSE) Log.v(TAG, "Starting icon loader task for " + mUri);
-        }
-
-        @Override
-        public void preempt() {
-            if (VERBOSE) Log.v(TAG, "Icon loader task for " + mUri + " was cancelled.");
-            cancel(false);
-            mSignal.cancel();
-        }
-
-        @Override
-        protected Bitmap doInBackground(Uri... params) {
-            if (isCancelled()) {
-                return null;
-            }
-
-            final Context context = mIconThumb.getContext();
-            final ContentResolver resolver = context.getContentResolver();
-
-            ContentProviderClient client = null;
-            Bitmap result = null;
-            try {
-                client = DocumentsApplication.acquireUnstableProviderOrThrow(
-                        resolver, mUri.getAuthority());
-                result = DocumentsContract.getDocumentThumbnail(client, mUri, mThumbSize, mSignal);
-                if (result != null) {
-                    final ThumbnailCache cache = DocumentsApplication.getThumbnailCache(context);
-                    cache.putThumbnail(mUri, mThumbSize, result, mLastModified);
-                }
-            } catch (Exception e) {
-                if (!(e instanceof OperationCanceledException)) {
-                    Log.w(TAG, "Failed to load thumbnail for " + mUri + ": " + e);
-                }
-            } finally {
-                ContentProviderClient.releaseQuietly(client);
-            }
-            return result;
-        }
-
-        @Override
-        protected void onPostExecute(Bitmap result) {
-            if (VERBOSE) Log.v(TAG, "Loader task for " + mUri + " completed");
-
-            if (mIconThumb.getTag() == this && result != null) {
-                mIconThumb.setTag(null);
-                mIconThumb.setImageBitmap(result);
-
-                mImageAnimator.accept(mIconMime, mIconThumb);
-            }
-        }
-    }
-
     /**
      * Load thumbnails for a directory list item.
      *
@@ -287,11 +196,11 @@ public class IconHelper {
                             uri.toString(), result.getStatus(), stale));
             if (!result.isExactHit() || stale) {
                 final BiConsumer<View, View> animator =
-                        (cachedThumbnail == null ? ANIM_FADE_IN : ANIM_NO_OP);
-                final LoaderTask task = new LoaderTask(uri, iconMime, iconThumb, mCurrentSize,
-                        docLastModified, animator);
+                        (cachedThumbnail == null ? ThumbnailLoader.ANIM_FADE_IN :
+                                ThumbnailLoader.ANIM_NO_OP);
 
-                iconThumb.setTag(task);
+                final ThumbnailLoader task = new ThumbnailLoader(uri, iconMime, iconThumb,
+                    mCurrentSize, docLastModified, animator, true);
 
                 ProviderExecutor.forAuthority(docAuthority).execute(task);
             }
diff --git a/src/com/android/documentsui/inspector/HeaderView.java b/src/com/android/documentsui/inspector/HeaderView.java
index a9f36f285..c9c6b3ec3 100644
--- a/src/com/android/documentsui/inspector/HeaderView.java
+++ b/src/com/android/documentsui/inspector/HeaderView.java
@@ -15,13 +15,20 @@
  */
 package com.android.documentsui.inspector;
 
+import android.app.Activity;
 import android.content.Context;
+import android.graphics.Point;
+import android.graphics.drawable.Drawable;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
+import android.widget.ImageView;
 import android.widget.RelativeLayout;
 import android.widget.TextView;
 
+import com.android.documentsui.ProviderExecutor;
+import com.android.documentsui.ThumbnailLoader;
+import com.android.documentsui.base.Display;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.R;
 import java.util.function.Consumer;
@@ -31,8 +38,14 @@ import java.util.function.Consumer;
  */
 public final class HeaderView extends RelativeLayout implements Consumer<DocumentInfo> {
 
+    private static final String TAG = HeaderView.class.getCanonicalName();
+
+    private final Context mContext;
     private final View mHeader;
+    private ImageView mMime;
+    private ImageView mThumbnail;
     private final TextView mTitle;
+    private Point mImageDimensions;
 
     public HeaderView(Context context) {
         this(context, null);
@@ -46,8 +59,15 @@ public final class HeaderView extends RelativeLayout implements Consumer<Documen
         super(context, attrs, defStyleAttr);
         LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(
                 Context.LAYOUT_INFLATER_SERVICE);
+        mContext = context;
         mHeader = inflater.inflate(R.layout.inspector_header, null);
+        mMime = (ImageView) mHeader.findViewById(R.id.inspector_mime);
+        mThumbnail = (ImageView) mHeader.findViewById(R.id.inspector_thumbnail);
         mTitle = (TextView) mHeader.findViewById(R.id.inspector_file_title);
+
+        int width = (int) Display.screenWidth((Activity)context);
+        int height = mContext.getResources().getDimensionPixelSize(R.dimen.inspector_header_height);
+        mImageDimensions = new Point(width, height);
     }
 
     @Override
@@ -55,6 +75,10 @@ public final class HeaderView extends RelativeLayout implements Consumer<Documen
         if (!hasHeader()) {
             addView(mHeader);
         }
+
+        if(!hasHeaderImage()) {
+            loadHeaderImage(info);
+        }
         mTitle.setText(info.displayName);
     }
 
@@ -66,4 +90,21 @@ public final class HeaderView extends RelativeLayout implements Consumer<Documen
         }
         return false;
     }
-}
+
+    private void loadHeaderImage(DocumentInfo info) {
+
+        // load the mime icon.
+        Drawable d = mContext.getContentResolver().getTypeDrawable(info.mimeType);
+        mMime.setImageDrawable(d);
+
+        // load the thumbnail async.
+        final ThumbnailLoader task = new ThumbnailLoader(info.derivedUri, mMime, mThumbnail,
+            mImageDimensions, info.lastModified, ThumbnailLoader.ANIM_FADE_IN, false);
+        task.executeOnExecutor(ProviderExecutor.forAuthority(info.derivedUri.getAuthority()),
+            info.derivedUri);
+    }
+
+    private boolean hasHeaderImage() {
+        return mThumbnail.getAlpha() == 1.0f;
+    }
+}
\ No newline at end of file