1 files changed, 40 insertions, 0 deletions
diff --git a/dom/canvas/nsICanvasRenderingContextInternal.cpp b/dom/canvas/nsICanvasRenderingContextInternal.cpp
new file mode 100644
index 0000000000..8442ed326b
--- /dev/null
+++ b/dom/canvas/nsICanvasRenderingContextInternal.cpp
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsICanvasRenderingContextInternal.h"
+
+#include "mozilla/dom/Document.h"
+#include "mozilla/PresShell.h"
+#include "nsRefreshDriver.h"
+
+nsICanvasRenderingContextInternal::nsICanvasRenderingContextInternal()
+    : mSharedPtrPtr(
+          std::make_shared<nsICanvasRenderingContextInternal*>(this)) {}
+
+nsICanvasRenderingContextInternal::~nsICanvasRenderingContextInternal() =
+    default;
+
+mozilla::PresShell* nsICanvasRenderingContextInternal::GetPresShell() {
+  if (mCanvasElement) {
+    return mCanvasElement->OwnerDoc()->GetPresShell();
+  }
+  return nullptr;
+}
+
+void nsICanvasRenderingContextInternal::RemovePostRefreshObserver() {
+  if (mRefreshDriver) {
+    mRefreshDriver->RemovePostRefreshObserver(this);
+    mRefreshDriver = nullptr;
+  }
+}
+
+void nsICanvasRenderingContextInternal::AddPostRefreshObserverIfNecessary() {
+  if (!GetPresShell() || !GetPresShell()->GetPresContext() ||
+      !GetPresShell()->GetPresContext()->RefreshDriver()) {
+    return;
+  }
+  mRefreshDriver = GetPresShell()->GetPresContext()->RefreshDriver();
+  mRefreshDriver->AddPostRefreshObserver(this);
+}