gecko/mobile/android/base/ThumbnailHelper.java
Ehsan Akhgari 6c61de1ac0 Backed out 8 changesets (bug 803299) because it makes Tcheckerboard and Tpan so much worse
Backed out changeset f0311781c218 (bug 803299)
Backed out changeset 946467115924 (bug 803299)
Backed out changeset 59af481d8888 (bug 803299)
Backed out changeset 99a03f7ca8a4 (bug 803299)
Backed out changeset 44539f533a92 (bug 803299)
Backed out changeset 3f3963a3ebf6 (bug 803299)
Backed out changeset 5269f0483d1e (bug 803299)
Backed out changeset a9485787fdb1 (bug 803299)
2013-05-29 17:14:27 -04:00

204 lines
7.6 KiB
Java

/* -*- 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 android.graphics.Bitmap;
import android.util.Log;
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 = 0.714f; // this is a 5:7 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>();
mPendingWidth = new AtomicInteger((int)GeckoAppShell.getContext().getResources().getDimension(R.dimen.tab_thumbnail_width));
mWidth = -1;
mHeight = -1;
}
public void getAndProcessThumbnailFor(Tab tab) {
if ("about:home".equals(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) {
mPendingWidth.set(IntSize.nextPowerOfTwo(width));
}
private void updateThumbnailSize() {
// Apply any pending width updates
mWidth = mPendingWidth.get();
mWidth &= ~0x1; // Ensure the width is always an even number (bug 776906)
mHeight = Math.round(mWidth * THUMBNAIL_ASPECT_RATIO);
int capacity = mWidth * mHeight * 2; // Multiply by 2 for 16bpp
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;
}
GeckoEvent e = GeckoEvent.createThumbnailEvent(tab.getId(), mWidth, mHeight, mBuffer);
GeckoAppShell.sendEventToGecko(e);
}
/* This method is invoked by JNI once the thumbnail data is ready. */
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) {
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()));
}
}