The Tor Browser: mobile/android/base/ThumbnailHelper.java@fc2d59ddac77 (annotated)

mobile/android/base/ThumbnailHelper.java@fc2d59ddac77 (annotated)

mobile/android/base/ThumbnailHelper.java

Wed, 31 Dec 2014 07:22:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:22:50 +0100
branch: TOR_BUG_3246
changeset 4: fc2d59ddac77
permissions: -rw-r--r--

Correct previous dual key logic pending first delivery installment.

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko;
 import org.mozilla.gecko.db.BrowserDB;
 import org.mozilla.gecko.gfx.BitmapUtils;
 import org.mozilla.gecko.gfx.IntSize;
 import org.mozilla.gecko.mozglue.DirectBufferAllocator;
 import org.mozilla.gecko.mozglue.generatorannotations.WrapElementForJNI;
 import android.graphics.Bitmap;
 import android.util.Log;
 import android.content.res.Resources;
 import java.nio.ByteBuffer;
 import java.util.LinkedList;
 import java.util.concurrent.atomic.AtomicInteger;
 /**
  * Helper class to generate thumbnails for tabs.
  * Internally, a queue of pending thumbnails is maintained in mPendingThumbnails.
  * The head of the queue is the thumbnail that is currently being processed; upon
  * completion of the current thumbnail the next one is automatically processed.
  * Changes to the thumbnail width are stashed in mPendingWidth and the change is
  * applied between thumbnail processing. This allows a single thumbnail buffer to
  * be used for all thumbnails.
  */
 public final class ThumbnailHelper {
     private static final String LOGTAG = "GeckoThumbnailHelper";
     public static final float THUMBNAIL_ASPECT_RATIO = 0.571f;  // this is a 4:7 ratio (as per UX decision)
     // static singleton stuff
     private static ThumbnailHelper sInstance;
     public static synchronized ThumbnailHelper getInstance() {
         if (sInstance == null) {
             sInstance = new ThumbnailHelper();
         }
         return sInstance;
     }
     // instance stuff
     private final LinkedList<Tab> mPendingThumbnails;    // synchronized access only
     private AtomicInteger mPendingWidth;
     private int mWidth;
     private int mHeight;
     private ByteBuffer mBuffer;
     private ThumbnailHelper() {
         mPendingThumbnails = new LinkedList<Tab>();
         try {
             mPendingWidth = new AtomicInteger((int)GeckoAppShell.getContext().getResources().getDimension(R.dimen.tab_thumbnail_width));
         } catch (Resources.NotFoundException nfe) { mPendingWidth = new AtomicInteger(0); }
         mWidth = -1;
         mHeight = -1;
     }
     public void getAndProcessThumbnailFor(Tab tab) {
         if (AboutPages.isAboutHome(tab.getURL())) {
             tab.updateThumbnail(null);
             return;
         }
         if (tab.getState() == Tab.STATE_DELAYED) {
             String url = tab.getURL();
             if (url != null) {
                 byte[] thumbnail = BrowserDB.getThumbnailForUrl(GeckoAppShell.getContext().getContentResolver(), url);
                 if (thumbnail != null) {
                     setTabThumbnail(tab, null, thumbnail);
                 }
             }
             return;
         }
         synchronized (mPendingThumbnails) {
             if (mPendingThumbnails.lastIndexOf(tab) > 0) {
                 // This tab is already in the queue, so don't add it again.
                 // Note that if this tab is only at the *head* of the queue,
                 // (i.e. mPendingThumbnails.lastIndexOf(tab) == 0) then we do
                 // add it again because it may have already been thumbnailed
                 // and now we need to do it again.
                 return;
             }
             mPendingThumbnails.add(tab);
             if (mPendingThumbnails.size() > 1) {
                 // Some thumbnail was already being processed, so wait
                 // for that to be done.
                 return;
             }
         }
         requestThumbnailFor(tab);
     }
     public void setThumbnailWidth(int width) {
         // Check inverted for safety: Bug 803299 Comment 34.
         if (GeckoAppShell.getScreenDepth() == 24) {
             mPendingWidth.set(width);
         } else {
             // Bug 776906: on 16-bit screens we need to ensure an even width.
             mPendingWidth.set((width & 1) == 0 ? width : width + 1);
         }
     }
     private void updateThumbnailSize() {
         // Apply any pending width updates.
         mWidth = mPendingWidth.get();
         mHeight = Math.round(mWidth * THUMBNAIL_ASPECT_RATIO);
         int pixelSize = (GeckoAppShell.getScreenDepth() == 24) ? 4 : 2;
         int capacity = mWidth * mHeight * pixelSize;
         Log.d(LOGTAG, "Using new thumbnail size: " + capacity + " (width " + mWidth + ")");
         if (mBuffer == null || mBuffer.capacity() != capacity) {
             if (mBuffer != null) {
                 mBuffer = DirectBufferAllocator.free(mBuffer);
             }
             try {
                 mBuffer = DirectBufferAllocator.allocate(capacity);
             } catch (IllegalArgumentException iae) {
                 Log.w(LOGTAG, iae.toString());
             } catch (OutOfMemoryError oom) {
                 Log.w(LOGTAG, "Unable to allocate thumbnail buffer of capacity " + capacity);
             }
             // If we hit an error above, mBuffer will be pointing to null, so we are in a sane state.
         }
     }
     private void requestThumbnailFor(Tab tab) {
         updateThumbnailSize();
         if (mBuffer == null) {
             // Buffer allocation may have failed. In this case we can't send the
             // event requesting the screenshot which means we won't get back a response
             // and so our queue will grow unboundedly. Handle this scenario by clearing
             // the queue (no point trying more thumbnailing right now since we're likely
             // low on memory). We will try again normally on the next call to
             // getAndProcessThumbnailFor which will hopefully be when we have more free memory.
             synchronized (mPendingThumbnails) {
                 mPendingThumbnails.clear();
             }
             return;
         }
         Log.d(LOGTAG, "Sending thumbnail event: " + mWidth + ", " + mHeight);
         GeckoEvent e = GeckoEvent.createThumbnailEvent(tab.getId(), mWidth, mHeight, mBuffer);
         GeckoAppShell.sendEventToGecko(e);
     }
     /* This method is invoked by JNI once the thumbnail data is ready. */
     @WrapElementForJNI(stubName = "SendThumbnail")
     public static void notifyThumbnail(ByteBuffer data, int tabId, boolean success) {
         Tab tab = Tabs.getInstance().getTab(tabId);
         ThumbnailHelper helper = ThumbnailHelper.getInstance();
         if (success && tab != null) {
             helper.handleThumbnailData(tab, data);
         }
         helper.processNextThumbnail(tab);
     }
     private void processNextThumbnail(Tab tab) {
         Tab nextTab = null;
         synchronized (mPendingThumbnails) {
             if (tab != null && tab != mPendingThumbnails.peek()) {
                 Log.e(LOGTAG, "handleThumbnailData called with unexpected tab's data!");
                 // This should never happen, but recover gracefully by processing the
                 // unexpected tab that we found in the queue
             } else {
                 mPendingThumbnails.remove();
             }
             nextTab = mPendingThumbnails.peek();
         }
         if (nextTab != null) {
             requestThumbnailFor(nextTab);
         }
     }
     private void handleThumbnailData(Tab tab, ByteBuffer data) {
         Log.d(LOGTAG, "handleThumbnailData: " + data.capacity());
         if (data != mBuffer) {
             // This should never happen, but log it and recover gracefully
             Log.e(LOGTAG, "handleThumbnailData called with an unexpected ByteBuffer!");
         }
         if (shouldUpdateThumbnail(tab)) {
             processThumbnailData(tab, data);
         }
     }
     private void processThumbnailData(Tab tab, ByteBuffer data) {
         Bitmap b = tab.getThumbnailBitmap(mWidth, mHeight);
         data.position(0);
         b.copyPixelsFromBuffer(data);
         setTabThumbnail(tab, b, null);
     }
     private void setTabThumbnail(Tab tab, Bitmap bitmap, byte[] compressed) {
         if (bitmap == null) {
             if (compressed == null) {
                 Log.w(LOGTAG, "setTabThumbnail: one of bitmap or compressed must be non-null!");
                 return;
             }
             bitmap = BitmapUtils.decodeByteArray(compressed);
         }
         tab.updateThumbnail(bitmap);
     }
     private boolean shouldUpdateThumbnail(Tab tab) {
         return (Tabs.getInstance().isSelectedTab(tab) || (GeckoAppShell.getGeckoInterface() != null && GeckoAppShell.getGeckoInterface().areTabsShown()));
     }
 }

The Tor Browser / annotate

mobile/android/base/ThumbnailHelper.java@fc2d59ddac77 (annotated)

mobile/android/base/ThumbnailHelper.java