Dropping async task for bonsai in image downloading

app/build.gradle

@@ -66,7 +66,7 @@ dexcount {
 dependencies {
 
     // support libraries
-    def supportLibVersion = '25.3.0'
+    def supportLibVersion = '25.3.1'
     compile "com.android.support:palette-v7:$supportLibVersion"
     compile "com.android.support:appcompat-v7:$supportLibVersion"
     compile "com.android.support:design:$supportLibVersion"

app/src/main/java/acr/browser/lightning/app/AppComponent.java

@@ -7,6 +7,7 @@ import acr.browser.lightning.activity.ReadingActivity;
 import acr.browser.lightning.activity.TabsManager;
 import acr.browser.lightning.activity.ThemableBrowserActivity;
 import acr.browser.lightning.activity.ThemableSettingsActivity;
+import acr.browser.lightning.view.ImageDownloader;
 import acr.browser.lightning.browser.BrowserPresenter;
 import acr.browser.lightning.constant.BookmarkPage;
 import acr.browser.lightning.constant.HistoryPage;
@@ -76,4 +77,6 @@ public interface AppComponent {
 
     void inject(SuggestionsAdapter suggestionsAdapter);
 
+    void inject(ImageDownloader imageDownloader);
+
 }

app/src/main/java/acr/browser/lightning/async/AsyncExecutor.java

@@ -1,53 +0,0 @@
-package acr.browser.lightning.async;
-
-import android.support.annotation.NonNull;
-import android.util.Log;
-
-import java.util.ArrayDeque;
-import java.util.Queue;
-import java.util.concurrent.Executor;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.RejectedExecutionException;
-
-/**
- * Created 9/27/2015 Anthony Restaino
- */
-public class AsyncExecutor implements Executor {
-
-    private static final String TAG = AsyncExecutor.class.getSimpleName();
-    private static final AsyncExecutor INSTANCE = new AsyncExecutor();
-    private final Queue<Runnable> mQueue = new ArrayDeque<>(1);
-    private final ExecutorService mExecutor = Executors.newFixedThreadPool(4);
-
-    private AsyncExecutor() {}
-
-    @NonNull
-    public static AsyncExecutor getInstance() {
-        return INSTANCE;
-    }
-
-    public synchronized void notifyThreadFinish() {
-        if (mQueue.isEmpty()) {
-            return;
-        }
-        Runnable runnable = mQueue.remove();
-        execute(runnable);
-    }
-
-    @Override
-    protected void finalize() throws Throwable {
-        mExecutor.shutdownNow();
-        super.finalize();
-    }
-
-    @Override
-    public void execute(@NonNull Runnable command) {
-        try {
-            mExecutor.execute(command);
-        } catch (RejectedExecutionException ignored) {
-            mQueue.add(command);
-            Log.d(TAG, "Thread was enqueued");
-        }
-    }
-}

app/src/main/java/acr/browser/lightning/fragment/BookmarksFragment.java

@@ -35,6 +35,7 @@ import com.anthonycr.bonsai.SingleSubscriber;
 import com.squareup.otto.Bus;
 import com.squareup.otto.Subscribe;
 
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -44,8 +45,7 @@ import acr.browser.lightning.R;
 import acr.browser.lightning.activity.ReadingActivity;
 import acr.browser.lightning.activity.TabsManager;
 import acr.browser.lightning.app.BrowserApp;
-import acr.browser.lightning.async.AsyncExecutor;
-import acr.browser.lightning.async.ImageDownloadTask;
+import acr.browser.lightning.view.ImageDownloader;
 import acr.browser.lightning.browser.BookmarksView;
 import acr.browser.lightning.bus.BookmarkEvents;
 import acr.browser.lightning.constant.Constants;
@@ -74,6 +74,8 @@ public class BookmarksFragment extends Fragment implements View.OnClickListener,
 
     @Inject PreferenceManager mPreferenceManager;
 
+    private ImageDownloader mImageDownloader;
+
     private TabsManager mTabsManager;
 
     private UIController mUiController;
@@ -124,7 +126,9 @@ public class BookmarksFragment extends Fragment implements View.OnClickListener,
         mWebpageBitmap = ThemeUtils.getThemedBitmap(context, R.drawable.ic_webpage, darkTheme);
         mFolderBitmap = ThemeUtils.getThemedBitmap(context, R.drawable.ic_folder, darkTheme);
         mIconColor = darkTheme ? ThemeUtils.getIconDarkThemeColor(context) :
-            ThemeUtils.getIconLightThemeColor(context);
+                ThemeUtils.getIconLightThemeColor(context);
+
+        mImageDownloader = new ImageDownloader(mWebpageBitmap);
     }
 
     private TabsManager getTabsManager() {
@@ -222,7 +226,9 @@ public class BookmarksFragment extends Fragment implements View.OnClickListener,
         mWebpageBitmap = ThemeUtils.getThemedBitmap(activity, R.drawable.ic_webpage, darkTheme);
         mFolderBitmap = ThemeUtils.getThemedBitmap(activity, R.drawable.ic_folder, darkTheme);
         mIconColor = darkTheme ? ThemeUtils.getIconDarkThemeColor(activity) :
-            ThemeUtils.getIconLightThemeColor(activity);
+                ThemeUtils.getIconLightThemeColor(activity);
+
+        mImageDownloader = new ImageDownloader(mWebpageBitmap);
     }
 
     private void updateBookmarkIndicator(final String url) {
@@ -389,14 +395,31 @@ public class BookmarksFragment extends Fragment implements View.OnClickListener,
 
             ViewCompat.jumpDrawablesToCurrentState(row);
 
-            HistoryItem web = mBookmarks.get(position);
+            final HistoryItem web = mBookmarks.get(position);
             holder.txtTitle.setText(web.getTitle());
             if (web.isFolder()) {
                 holder.favicon.setImageBitmap(mFolderBitmap);
             } else if (web.getBitmap() == null) {
                 holder.favicon.setImageBitmap(mWebpageBitmap);
-                new ImageDownloadTask(holder.favicon, web, mWebpageBitmap, BrowserApp.get(context))
-                    .executeOnExecutor(AsyncExecutor.getInstance());
+                holder.favicon.setTag(web.getUrl().hashCode());
+
+                final String url = web.getUrl();
+                final WeakReference<ImageView> imageViewReference = new WeakReference<>(holder.favicon);
+                mImageDownloader.newImageRequest(url)
+                        .subscribeOn(Schedulers.worker())
+                        .observeOn(Schedulers.main())
+                        .subscribe(new SingleOnSubscribe<Bitmap>() {
+                            @Override
+                            public void onItem(@Nullable Bitmap item) {
+                                ImageView imageView = imageViewReference.get();
+                                Object tag = imageView != null ? imageView.getTag() : null;
+                                if (tag != null && tag.equals(url.hashCode())) {
+                                    imageView.setImageBitmap(item);
+                                }
+
+                                web.setBitmap(item);
+                            }
+                        });
             } else {
                 holder.favicon.setImageBitmap(web.getBitmap());
             }

app/src/main/java/acr/browser/lightning/view/ImageDownloader.java

@@ -1,69 +1,91 @@
-package acr.browser.lightning.async;
+package acr.browser.lightning.view;
 
 import android.app.Application;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.Uri;
-import android.os.AsyncTask;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.Log;
-import android.widget.ImageView;
 
-import com.anthonycr.bonsai.Schedulers;
+import com.anthonycr.bonsai.Single;
+import com.anthonycr.bonsai.SingleAction;
+import com.anthonycr.bonsai.SingleSubscriber;
 
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.InputStream;
-import java.lang.ref.WeakReference;
 import java.net.HttpURLConnection;
 import java.net.URL;
 
+import javax.inject.Inject;
+
+import acr.browser.lightning.app.BrowserApp;
 import acr.browser.lightning.constant.Constants;
-import acr.browser.lightning.database.HistoryItem;
 import acr.browser.lightning.utils.Utils;
 
-public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
-
-    private static final String TAG = ImageDownloadTask.class.getSimpleName();
-    @NonNull private final WeakReference<ImageView> mFaviconImage;
-    @NonNull private final Application mContext;
-    @NonNull private final HistoryItem mWeb;
-    private final String mUrl;
-    @NonNull private final Bitmap mDefaultBitmap;
-
-    public ImageDownloadTask(@NonNull ImageView bmImage,
-                             @NonNull HistoryItem web,
-                             @NonNull Bitmap defaultBitmap,
-                             @NonNull Application context) {
-        // Set a tag on the ImageView so we know if the view
-        // has gone out of scope and should not be used
-        bmImage.setTag(web.getUrl().hashCode());
-        this.mFaviconImage = new WeakReference<>(bmImage);
-        this.mWeb = web;
-        this.mUrl = web.getUrl();
-        this.mDefaultBitmap = defaultBitmap;
-        this.mContext = context;
+/**
+ * An ImageDownloader that creates image
+ * loading requests on demand.
+ */
+public class ImageDownloader {
+
+    private static final String TAG = "ImageDownloader";
+
+    @Inject Application mApp;
+
+    @NonNull private Bitmap mDefaultBitmap;
+
+    public ImageDownloader(@NonNull Bitmap defaultBitmap) {
+        mDefaultBitmap = defaultBitmap;
+        BrowserApp.getAppComponent().inject(this);
+    }
+
+    /**
+     * Creates a new image request for the given url.
+     * Emits the bitmap associated with that url, or
+     * the default bitmap if none was found.
+     *
+     * @param url the url for which to retrieve the bitmap.
+     * @return a single that emits the bitmap that was found.
+     */
+    @NonNull
+    public Single<Bitmap> newImageRequest(@Nullable final String url) {
+        return Single.create(new SingleAction<Bitmap>() {
+            @Override
+            public void onSubscribe(@NonNull SingleSubscriber<Bitmap> subscriber) {
+                Bitmap favicon = retrieveBitmap(mApp, mDefaultBitmap, url);
+
+                Bitmap paddedFavicon = Utils.padFavicon(favicon);
+
+                subscriber.onItem(paddedFavicon);
+                subscriber.onComplete();
+            }
+        });
     }
 
     @NonNull
-    @Override
-    protected Bitmap doInBackground(Void... params) {
-        Bitmap mIcon = null;
+    private static Bitmap retrieveBitmap(@NonNull Application app,
+                                         @NonNull Bitmap defaultBitmap,
+                                         @Nullable String url) {
+
         // unique path for each url that is bookmarked.
-        if (mUrl == null) {
-            return mDefaultBitmap;
+        if (url == null) {
+            return defaultBitmap;
         }
-        File cache = mContext.getCacheDir();
-        final Uri uri = Uri.parse(mUrl);
-        if (uri.getHost() == null || uri.getScheme() == null) {
-            return mDefaultBitmap;
+
+        Bitmap icon = null;
+        File cache = app.getCacheDir();
+        final Uri uri = Uri.parse(url);
+
+        if (uri.getHost() == null || uri.getScheme() == null || Constants.FILE.startsWith(uri.getScheme())) {
+            return defaultBitmap;
         }
+
         final String hash = String.valueOf(uri.getHost().hashCode());
         final File image = new File(cache, hash + ".png");
         final String urlDisplay = uri.getScheme() + "://" + uri.getHost() + "/favicon.ico";
-        if (Constants.FILE.startsWith(uri.getScheme())) {
-            return mDefaultBitmap;
-        }
+
         // checks to see if the image exists
         if (!image.exists()) {
             FileOutputStream fos = null;
@@ -79,12 +101,12 @@ public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
                 in = connection.getInputStream();
 
                 if (in != null) {
-                    mIcon = BitmapFactory.decodeStream(in);
+                    icon = BitmapFactory.decodeStream(in);
                 }
                 // ...and cache it
-                if (mIcon != null) {
+                if (icon != null) {
                     fos = new FileOutputStream(image);
-                    mIcon.compress(Bitmap.CompressFormat.PNG, 100, fos);
+                    icon.compress(Bitmap.CompressFormat.PNG, 100, fos);
                     fos.flush();
                     Log.d(Constants.TAG, "Downloaded: " + urlDisplay);
                 }
@@ -97,9 +119,10 @@ public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
             }
         } else {
             // if it exists, retrieve it from the cache
-            mIcon = BitmapFactory.decodeFile(image.getPath());
+            icon = BitmapFactory.decodeFile(image.getPath());
         }
-        if (mIcon == null) {
+
+        if (icon == null) {
             InputStream in = null;
             FileOutputStream fos = null;
             try {
@@ -113,12 +136,12 @@ public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
                 in = connection.getInputStream();
 
                 if (in != null) {
-                    mIcon = BitmapFactory.decodeStream(in);
+                    icon = BitmapFactory.decodeStream(in);
                 }
                 // ...and cache it
-                if (mIcon != null) {
+                if (icon != null) {
                     fos = new FileOutputStream(image);
-                    mIcon.compress(Bitmap.CompressFormat.PNG, 100, fos);
+                    icon.compress(Bitmap.CompressFormat.PNG, 100, fos);
                     fos.flush();
                 }
 
@@ -129,28 +152,11 @@ public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
                 Utils.close(fos);
             }
         }
-        if (mIcon == null) {
-            return mDefaultBitmap;
-        } else {
-            return mIcon;
-        }
-    }
 
-    @Override
-    protected void onPostExecute(Bitmap bitmap) {
-        super.onPostExecute(bitmap);
-        AsyncExecutor.getInstance().notifyThreadFinish();
-        final Bitmap fav = Utils.padFavicon(bitmap);
-        final ImageView view = mFaviconImage.get();
-        if (view != null && view.getTag().equals(mWeb.getUrl().hashCode())) {
-            Schedulers.main().execute(new Runnable() {
-                @Override
-                public void run() {
-                    view.setImageBitmap(fav);
-                }
-            });
+        if (icon == null) {
+            return defaultBitmap;
+        } else {
+            return icon;
         }
-        mWeb.setBitmap(fav);
     }
-
 }