1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/ThumbnailHelper.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,217 @@
1.4 +/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +package org.mozilla.gecko;
1.10 +
1.11 +import org.mozilla.gecko.db.BrowserDB;
1.12 +import org.mozilla.gecko.gfx.BitmapUtils;
1.13 +import org.mozilla.gecko.gfx.IntSize;
1.14 +import org.mozilla.gecko.mozglue.DirectBufferAllocator;
1.15 +import org.mozilla.gecko.mozglue.generatorannotations.WrapElementForJNI;
1.16 +
1.17 +import android.graphics.Bitmap;
1.18 +import android.util.Log;
1.19 +import android.content.res.Resources;
1.20 +
1.21 +import java.nio.ByteBuffer;
1.22 +import java.util.LinkedList;
1.23 +import java.util.concurrent.atomic.AtomicInteger;
1.24 +
1.25 +/**
1.26 + * Helper class to generate thumbnails for tabs.
1.27 + * Internally, a queue of pending thumbnails is maintained in mPendingThumbnails.
1.28 + * The head of the queue is the thumbnail that is currently being processed; upon
1.29 + * completion of the current thumbnail the next one is automatically processed.
1.30 + * Changes to the thumbnail width are stashed in mPendingWidth and the change is
1.31 + * applied between thumbnail processing. This allows a single thumbnail buffer to
1.32 + * be used for all thumbnails.
1.33 + */
1.34 +public final class ThumbnailHelper {
1.35 + private static final String LOGTAG = "GeckoThumbnailHelper";
1.36 +
1.37 + public static final float THUMBNAIL_ASPECT_RATIO = 0.571f; // this is a 4:7 ratio (as per UX decision)
1.38 +
1.39 + // static singleton stuff
1.40 +
1.41 + private static ThumbnailHelper sInstance;
1.42 +
1.43 + public static synchronized ThumbnailHelper getInstance() {
1.44 + if (sInstance == null) {
1.45 + sInstance = new ThumbnailHelper();
1.46 + }
1.47 + return sInstance;
1.48 + }
1.49 +
1.50 + // instance stuff
1.51 +
1.52 + private final LinkedList<Tab> mPendingThumbnails; // synchronized access only
1.53 + private AtomicInteger mPendingWidth;
1.54 + private int mWidth;
1.55 + private int mHeight;
1.56 + private ByteBuffer mBuffer;
1.57 +
1.58 + private ThumbnailHelper() {
1.59 + mPendingThumbnails = new LinkedList<Tab>();
1.60 + try {
1.61 + mPendingWidth = new AtomicInteger((int)GeckoAppShell.getContext().getResources().getDimension(R.dimen.tab_thumbnail_width));
1.62 + } catch (Resources.NotFoundException nfe) { mPendingWidth = new AtomicInteger(0); }
1.63 + mWidth = -1;
1.64 + mHeight = -1;
1.65 + }
1.66 +
1.67 + public void getAndProcessThumbnailFor(Tab tab) {
1.68 + if (AboutPages.isAboutHome(tab.getURL())) {
1.69 + tab.updateThumbnail(null);
1.70 + return;
1.71 + }
1.72 +
1.73 + if (tab.getState() == Tab.STATE_DELAYED) {
1.74 + String url = tab.getURL();
1.75 + if (url != null) {
1.76 + byte[] thumbnail = BrowserDB.getThumbnailForUrl(GeckoAppShell.getContext().getContentResolver(), url);
1.77 + if (thumbnail != null) {
1.78 + setTabThumbnail(tab, null, thumbnail);
1.79 + }
1.80 + }
1.81 + return;
1.82 + }
1.83 +
1.84 + synchronized (mPendingThumbnails) {
1.85 + if (mPendingThumbnails.lastIndexOf(tab) > 0) {
1.86 + // This tab is already in the queue, so don't add it again.
1.87 + // Note that if this tab is only at the *head* of the queue,
1.88 + // (i.e. mPendingThumbnails.lastIndexOf(tab) == 0) then we do
1.89 + // add it again because it may have already been thumbnailed
1.90 + // and now we need to do it again.
1.91 + return;
1.92 + }
1.93 +
1.94 + mPendingThumbnails.add(tab);
1.95 + if (mPendingThumbnails.size() > 1) {
1.96 + // Some thumbnail was already being processed, so wait
1.97 + // for that to be done.
1.98 + return;
1.99 + }
1.100 + }
1.101 + requestThumbnailFor(tab);
1.102 + }
1.103 +
1.104 + public void setThumbnailWidth(int width) {
1.105 + // Check inverted for safety: Bug 803299 Comment 34.
1.106 + if (GeckoAppShell.getScreenDepth() == 24) {
1.107 + mPendingWidth.set(width);
1.108 + } else {
1.109 + // Bug 776906: on 16-bit screens we need to ensure an even width.
1.110 + mPendingWidth.set((width & 1) == 0 ? width : width + 1);
1.111 + }
1.112 + }
1.113 +
1.114 + private void updateThumbnailSize() {
1.115 + // Apply any pending width updates.
1.116 + mWidth = mPendingWidth.get();
1.117 +
1.118 + mHeight = Math.round(mWidth * THUMBNAIL_ASPECT_RATIO);
1.119 +
1.120 + int pixelSize = (GeckoAppShell.getScreenDepth() == 24) ? 4 : 2;
1.121 + int capacity = mWidth * mHeight * pixelSize;
1.122 + Log.d(LOGTAG, "Using new thumbnail size: " + capacity + " (width " + mWidth + ")");
1.123 + if (mBuffer == null || mBuffer.capacity() != capacity) {
1.124 + if (mBuffer != null) {
1.125 + mBuffer = DirectBufferAllocator.free(mBuffer);
1.126 + }
1.127 + try {
1.128 + mBuffer = DirectBufferAllocator.allocate(capacity);
1.129 + } catch (IllegalArgumentException iae) {
1.130 + Log.w(LOGTAG, iae.toString());
1.131 + } catch (OutOfMemoryError oom) {
1.132 + Log.w(LOGTAG, "Unable to allocate thumbnail buffer of capacity " + capacity);
1.133 + }
1.134 + // If we hit an error above, mBuffer will be pointing to null, so we are in a sane state.
1.135 + }
1.136 + }
1.137 +
1.138 + private void requestThumbnailFor(Tab tab) {
1.139 + updateThumbnailSize();
1.140 +
1.141 + if (mBuffer == null) {
1.142 + // Buffer allocation may have failed. In this case we can't send the
1.143 + // event requesting the screenshot which means we won't get back a response
1.144 + // and so our queue will grow unboundedly. Handle this scenario by clearing
1.145 + // the queue (no point trying more thumbnailing right now since we're likely
1.146 + // low on memory). We will try again normally on the next call to
1.147 + // getAndProcessThumbnailFor which will hopefully be when we have more free memory.
1.148 + synchronized (mPendingThumbnails) {
1.149 + mPendingThumbnails.clear();
1.150 + }
1.151 + return;
1.152 + }
1.153 +
1.154 + Log.d(LOGTAG, "Sending thumbnail event: " + mWidth + ", " + mHeight);
1.155 + GeckoEvent e = GeckoEvent.createThumbnailEvent(tab.getId(), mWidth, mHeight, mBuffer);
1.156 + GeckoAppShell.sendEventToGecko(e);
1.157 + }
1.158 +
1.159 + /* This method is invoked by JNI once the thumbnail data is ready. */
1.160 + @WrapElementForJNI(stubName = "SendThumbnail")
1.161 + public static void notifyThumbnail(ByteBuffer data, int tabId, boolean success) {
1.162 + Tab tab = Tabs.getInstance().getTab(tabId);
1.163 + ThumbnailHelper helper = ThumbnailHelper.getInstance();
1.164 + if (success && tab != null) {
1.165 + helper.handleThumbnailData(tab, data);
1.166 + }
1.167 + helper.processNextThumbnail(tab);
1.168 + }
1.169 +
1.170 + private void processNextThumbnail(Tab tab) {
1.171 + Tab nextTab = null;
1.172 + synchronized (mPendingThumbnails) {
1.173 + if (tab != null && tab != mPendingThumbnails.peek()) {
1.174 + Log.e(LOGTAG, "handleThumbnailData called with unexpected tab's data!");
1.175 + // This should never happen, but recover gracefully by processing the
1.176 + // unexpected tab that we found in the queue
1.177 + } else {
1.178 + mPendingThumbnails.remove();
1.179 + }
1.180 + nextTab = mPendingThumbnails.peek();
1.181 + }
1.182 + if (nextTab != null) {
1.183 + requestThumbnailFor(nextTab);
1.184 + }
1.185 + }
1.186 +
1.187 + private void handleThumbnailData(Tab tab, ByteBuffer data) {
1.188 + Log.d(LOGTAG, "handleThumbnailData: " + data.capacity());
1.189 + if (data != mBuffer) {
1.190 + // This should never happen, but log it and recover gracefully
1.191 + Log.e(LOGTAG, "handleThumbnailData called with an unexpected ByteBuffer!");
1.192 + }
1.193 +
1.194 + if (shouldUpdateThumbnail(tab)) {
1.195 + processThumbnailData(tab, data);
1.196 + }
1.197 + }
1.198 +
1.199 + private void processThumbnailData(Tab tab, ByteBuffer data) {
1.200 + Bitmap b = tab.getThumbnailBitmap(mWidth, mHeight);
1.201 + data.position(0);
1.202 + b.copyPixelsFromBuffer(data);
1.203 + setTabThumbnail(tab, b, null);
1.204 + }
1.205 +
1.206 + private void setTabThumbnail(Tab tab, Bitmap bitmap, byte[] compressed) {
1.207 + if (bitmap == null) {
1.208 + if (compressed == null) {
1.209 + Log.w(LOGTAG, "setTabThumbnail: one of bitmap or compressed must be non-null!");
1.210 + return;
1.211 + }
1.212 + bitmap = BitmapUtils.decodeByteArray(compressed);
1.213 + }
1.214 + tab.updateThumbnail(bitmap);
1.215 + }
1.216 +
1.217 + private boolean shouldUpdateThumbnail(Tab tab) {
1.218 + return (Tabs.getInstance().isSelectedTab(tab) || (GeckoAppShell.getGeckoInterface() != null && GeckoAppShell.getGeckoInterface().areTabsShown()));
1.219 + }
1.220 +}
