Move notification resource loading from content/child to blink

third_party/WebKit/Source/modules/notifications/NotificationResourcesLoader.cpp

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/notifications/NotificationResourcesLoader.h"
+
+#include "platform/weborigin/KURL.h"
+#include "public/platform/modules/notifications/WebNotificationData.h"
+#include "public/platform/modules/notifications/WebNotificationResources.h"
+#include "skia/ext/image_operations.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+
+namespace blink {
+
+namespace {
+
+// TODO(mvanouwerkerk): Get icon dimensions from the embedder.
+
+// The maximum reasonable notification icon size, scaled from dip units to
+// pixels using the largest supported scaling factor.
+static const int kMaxIconSizePx = 320; // 80 dip * 4
+
+// The maximum reasonable badge size, scaled from dip units to pixels using the
+// largest supported scaling factor.
+static const int kMaxBadgeSizePx = 96; // 24 dip * 4
+
+// The maximum reasonable action icon size, scaled from dip units to pixels
+// using the largest supported scaling factor.
+static const int kMaxActionIconSizePx = 128; // 32 dip * 4
+
+// Scales down |image| to fit within |maxSizePx| if its width or height is
+// larger than |maxSizePx| and returns the result. Otherwise does nothing and
+// returns |image| unchanged.
+// TODO(mvanouwerkerk): Explore doing the scaling on a background thread.
+SkBitmap scaleDownIfNeeded(const SkBitmap& image, int maxSizePx)
+{
+    if (image.width() > maxSizePx || image.height() > maxSizePx)
+        return skia::ImageOperations::Resize(image, skia::ImageOperations::RESIZE_BEST, std::min(image.width(), maxSizePx), std::min(image.height(), maxSizePx));
+    return image;
+}
+
+} // namespace
+
+NotificationResourcesLoader::NotificationResourcesLoader(PassOwnPtr<CompletionCallback> completionCallback)
+    : m_started(false), m_completionCallback(completionCallback), m_pendingRequestCount(0)
+{
+    ThreadState::current()->registerPreFinalizer(this);
+    DCHECK(m_completionCallback);
+}
+
+NotificationResourcesLoader::~NotificationResourcesLoader()
+{
+}
+
+void NotificationResourcesLoader::start(ExecutionContext* executionContext, const WebNotificationData& notificationData)
+{
+    DCHECK(!m_started);
+    m_started = true;
+
+    size_t numActions = notificationData.actions.size();
+    m_pendingRequestCount = 2 /* icon and badge */ + numActions;
+
+    loadImage(executionContext, notificationData.icon, bind<const SkBitmap&>(&NotificationResourcesLoader::didLoadIcon, WeakPersistentThisPointer<NotificationResourcesLoader>(this)));
+    loadImage(executionContext, notificationData.badge, bind<const SkBitmap&>(&NotificationResourcesLoader::didLoadBadge, WeakPersistentThisPointer<NotificationResourcesLoader>(this)));
+
+    m_actionIcons.resize(numActions);
+    for (size_t i = 0; i < numActions; i++)
+        loadImage(executionContext, notificationData.actions[i].icon, bind<const SkBitmap&>(&NotificationResourcesLoader::didLoadActionIcon, WeakPersistentThisPointer<NotificationResourcesLoader>(this), i));
+}
+
+std::unique_ptr<WebNotificationResources> NotificationResourcesLoader::getResources() const
+{
+    std::unique_ptr<WebNotificationResources> resources(new WebNotificationResources());
+    resources->icon = m_icon;
+    resources->badge = m_badge;
+    resources->actionIcons = m_actionIcons;
+    return resources;
+}
+
+void NotificationResourcesLoader::stop()
+{
+    for (auto imageLoader : m_imageLoaders)
+        imageLoader->stop();

[haraken, 2016/04/19 01:12:52]

Would it be better to clear m_imageLoaders to avoid stop() from getting called
twice?

[Michael van Ouwerkerk, 2016/04/19 09:47:31]

Not sure, as there is already a guard in that stop method, it is safe. Both
NotificationResourcesLoader and NotificationImageLoader are on-heap, so I'd like
to avoid manually clearing pointers, it seems confusing.

+}
+
+DEFINE_TRACE(NotificationResourcesLoader)
+{
+    visitor->trace(m_imageLoaders);
+}
+
+void NotificationResourcesLoader::loadImage(ExecutionContext* executionContext, const KURL& url, PassOwnPtr<NotificationImageLoader::ImageCallback> imageCallback)
+{
+    if (url.isNull() || url.isEmpty() || !url.isValid()) {
+        didFinishRequest();
+        return;
+    }
+
+    NotificationImageLoader* imageLoader = new NotificationImageLoader();
+    m_imageLoaders.append(imageLoader);
+    imageLoader->start(executionContext, url, imageCallback);
+}
+
+void NotificationResourcesLoader::didLoadIcon(const SkBitmap& image)
+{
+    m_icon = scaleDownIfNeeded(image, kMaxIconSizePx);
+    didFinishRequest();
+}
+
+void NotificationResourcesLoader::didLoadBadge(const SkBitmap& image)
+{
+    m_badge = scaleDownIfNeeded(image, kMaxBadgeSizePx);
+    didFinishRequest();
+}
+
+void NotificationResourcesLoader::didLoadActionIcon(size_t actionIndex, const SkBitmap& image)
+{
+    DCHECK_LT(actionIndex, m_actionIcons.size());
+
+    m_actionIcons[actionIndex] = scaleDownIfNeeded(image, kMaxActionIconSizePx);
+    didFinishRequest();
+}
+
+void NotificationResourcesLoader::didFinishRequest()
+{
+    DCHECK_GT(m_pendingRequestCount, 0);
+    m_pendingRequestCount--;
+    if (!m_pendingRequestCount) {
+        stop();
+        (*m_completionCallback)(this);
+        // The |this| pointer may have been deleted now.
+    }
+}
+
+} // namespace blink