1 files changed, 52 insertions, 0 deletions
diff --git a/dom/base/WindowOrientationObserver.cpp b/dom/base/WindowOrientationObserver.cpp
new file mode 100644
index 0000000000..04c8589562
--- /dev/null
+++ b/dom/base/WindowOrientationObserver.cpp
@@ -0,0 +1,52 @@
+/* -*- 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 "WindowOrientationObserver.h"
+
+#include "nsGlobalWindow.h"
+#include "mozilla/Hal.h"
+
+using namespace mozilla::dom;
+
+/**
+ * This class is used by nsGlobalWindowInner to implement window.orientation
+ * and window.onorientationchange. This class is defined in its own file
+ * because Hal.h pulls in windows.h and can't be included from
+ * nsGlobalWindow.cpp
+ */
+WindowOrientationObserver::WindowOrientationObserver(
+    nsGlobalWindowInner* aGlobalWindow)
+    : mWindow(aGlobalWindow) {
+  MOZ_ASSERT(aGlobalWindow);
+  hal::RegisterScreenConfigurationObserver(this);
+
+  hal::ScreenConfiguration config;
+  hal::GetCurrentScreenConfiguration(&config);
+  mAngle = config.angle();
+}
+
+WindowOrientationObserver::~WindowOrientationObserver() {
+  hal::UnregisterScreenConfigurationObserver(this);
+}
+
+void WindowOrientationObserver::Notify(
+    const mozilla::hal::ScreenConfiguration& aConfiguration) {
+  uint16_t currentAngle = aConfiguration.angle();
+  if (mAngle != currentAngle && mWindow->IsCurrentInnerWindow()) {
+    mAngle = currentAngle;
+    mWindow->GetOuterWindow()->DispatchCustomEvent(u"orientationchange"_ns);
+  }
+}
+
+/* static */
+int16_t WindowOrientationObserver::OrientationAngle() {
+  hal::ScreenConfiguration config;
+  hal::GetCurrentScreenConfiguration(&config);
+  int16_t angle = static_cast<int16_t>(config.angle());
+  // config.angle() returns 0, 90, 180 or 270.
+  // window.orientation returns -90, 0, 90 or 180.
+  return angle <= 180 ? angle : angle - 360;
+}