1 files changed, 116 insertions, 0 deletions
diff --git a/dom/ipc/CoalescedMouseData.cpp b/dom/ipc/CoalescedMouseData.cpp
new file mode 100644
index 0000000000..5e3083c85b
--- /dev/null
+++ b/dom/ipc/CoalescedMouseData.cpp
@@ -0,0 +1,116 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+#include "base/basictypes.h"
+
+#include "CoalescedMouseData.h"
+#include "BrowserChild.h"
+
+#include "mozilla/PresShell.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "nsRefreshDriver.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+void CoalescedMouseData::Coalesce(const WidgetMouseEvent& aEvent,
+                                  const ScrollableLayerGuid& aGuid,
+                                  const uint64_t& aInputBlockId) {
+  if (IsEmpty()) {
+    mCoalescedInputEvent = MakeUnique<WidgetMouseEvent>(aEvent);
+    mGuid = aGuid;
+    mInputBlockId = aInputBlockId;
+    MOZ_ASSERT(!mCoalescedInputEvent->mCoalescedWidgetEvents);
+  } else {
+    MOZ_ASSERT(mGuid == aGuid);
+    MOZ_ASSERT(mInputBlockId == aInputBlockId);
+    MOZ_ASSERT(mCoalescedInputEvent->mModifiers == aEvent.mModifiers);
+    MOZ_ASSERT(mCoalescedInputEvent->mReason == aEvent.mReason);
+    MOZ_ASSERT(mCoalescedInputEvent->mInputSource == aEvent.mInputSource);
+    MOZ_ASSERT(mCoalescedInputEvent->mButton == aEvent.mButton);
+    MOZ_ASSERT(mCoalescedInputEvent->mButtons == aEvent.mButtons);
+    mCoalescedInputEvent->mTimeStamp = aEvent.mTimeStamp;
+    mCoalescedInputEvent->mRefPoint = aEvent.mRefPoint;
+    mCoalescedInputEvent->mPressure = aEvent.mPressure;
+    mCoalescedInputEvent->AssignPointerHelperData(aEvent);
+  }
+
+  if (aEvent.mMessage == eMouseMove &&
+      StaticPrefs::dom_w3c_pointer_events_enabled()) {
+    // PointerEvent::getCoalescedEvents is only applied to pointermove events.
+    if (!mCoalescedInputEvent->mCoalescedWidgetEvents) {
+      mCoalescedInputEvent->mCoalescedWidgetEvents =
+          new WidgetPointerEventHolder();
+    }
+    // Append current event in mCoalescedWidgetEvents. We use them to generate
+    // DOM events when content calls PointerEvent::getCoalescedEvents.
+    WidgetPointerEvent* event =
+        mCoalescedInputEvent->mCoalescedWidgetEvents->mEvents.AppendElement(
+            aEvent);
+
+    event->mFlags.mBubbles = false;
+    event->mFlags.mCancelable = false;
+  }
+}
+
+bool CoalescedMouseData::CanCoalesce(const WidgetMouseEvent& aEvent,
+                                     const ScrollableLayerGuid& aGuid,
+                                     const uint64_t& aInputBlockId) {
+  MOZ_ASSERT(aEvent.mMessage == eMouseMove);
+  return !mCoalescedInputEvent ||
+         (!mCoalescedInputEvent->mFlags.mIsSynthesizedForTests &&
+          !aEvent.mFlags.mIsSynthesizedForTests &&
+          mCoalescedInputEvent->mModifiers == aEvent.mModifiers &&
+          mCoalescedInputEvent->mInputSource == aEvent.mInputSource &&
+          mCoalescedInputEvent->pointerId == aEvent.pointerId &&
+          mCoalescedInputEvent->mButton == aEvent.mButton &&
+          mCoalescedInputEvent->mButtons == aEvent.mButtons && mGuid == aGuid &&
+          mInputBlockId == aInputBlockId);
+}
+
+void CoalescedMouseMoveFlusher::WillRefresh(mozilla::TimeStamp aTime) {
+  MOZ_ASSERT(mRefreshDriver);
+  mBrowserChild->FlushAllCoalescedMouseData();
+  mBrowserChild->ProcessPendingCoalescedMouseDataAndDispatchEvents();
+}
+
+void CoalescedMouseMoveFlusher::StartObserver() {
+  nsRefreshDriver* refreshDriver = GetRefreshDriver();
+  if (mRefreshDriver && mRefreshDriver == refreshDriver) {
+    // Nothing to do if we already added an observer and it's same refresh
+    // driver.
+    return;
+  }
+  RemoveObserver();
+  if (refreshDriver) {
+    mRefreshDriver = refreshDriver;
+    mRefreshDriver->AddRefreshObserver(this, FlushType::Event,
+                                       "Coalesced mouse move flusher");
+  }
+}
+
+void CoalescedMouseMoveFlusher::RemoveObserver() {
+  if (mRefreshDriver) {
+    mRefreshDriver->RemoveRefreshObserver(this, FlushType::Event);
+    mRefreshDriver = nullptr;
+  }
+}
+
+CoalescedMouseMoveFlusher::CoalescedMouseMoveFlusher(
+    BrowserChild* aBrowserChild)
+    : mBrowserChild(aBrowserChild) {
+  MOZ_ASSERT(mBrowserChild);
+}
+
+CoalescedMouseMoveFlusher::~CoalescedMouseMoveFlusher() { RemoveObserver(); }
+
+nsRefreshDriver* CoalescedMouseMoveFlusher::GetRefreshDriver() {
+  PresShell* presShell = mBrowserChild->GetTopLevelPresShell();
+  if (!presShell || !presShell->GetPresContext() ||
+      !presShell->GetPresContext()->RefreshDriver()) {
+    return nullptr;
+  }
+  return presShell->GetPresContext()->RefreshDriver();
+}