Bug 1409664 - P2. Add ScreenLuminance objects and friends to Screen. r=bz

Summary:
As per https://wicg.github.io/media-capabilities/#idl-index

Depends on D1613

Tags: #secure-revision

Bug #: 1409664

Differential Revision: https://phabricator.services.mozilla.com/D1614

dom/base/ScreenLuminance.cpp

@@ -0,0 +1,24 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 et tw=78: */
+/* 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 "ScreenLuminance.h"
+#include "nsScreen.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(ScreenLuminance, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(ScreenLuminance, Release)
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(ScreenLuminance, mScreen)
+
+JSObject*
+ScreenLuminance::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return ScreenLuminance_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+} // namespace dom
+} // namespace mozilla

dom/base/ScreenLuminance.h

@@ -0,0 +1,58 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 et tw=78: */
+/* 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/. */
+
+#ifndef mozilla_dom_ScreenLuminance_h
+#define mozilla_dom_ScreenLuminance_h
+
+#include "nsCycleCollectionParticipant.h"
+#include "nsISupportsImpl.h"
+
+class nsScreen;
+
+namespace mozilla {
+namespace dom {
+
+class ScreenLuminance final : public nsWrapperCache
+{
+public:
+  // Ref counting and cycle collection
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(ScreenLuminance)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(ScreenLuminance)
+
+  // WebIDL methods
+  double Min() const { return mMin; }
+  double Max() const { return mMax; }
+  double MaxAverage() const { return mMaxAverage; }
+  // End WebIDL methods
+
+  ScreenLuminance(nsScreen* aScreen,
+                  double aMin,
+                  double aMax,
+                  double aMaxAverage)
+    : mScreen(aScreen)
+    , mMin(aMin)
+    , mMax(aMax)
+    , mMaxAverage(aMaxAverage)
+  {
+  }
+
+  nsScreen* GetParentObject() const { return mScreen; }
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override;
+
+private:
+  virtual ~ScreenLuminance() {}
+
+  RefPtr<nsScreen> mScreen;
+  double mMin;
+  double mMax;
+  double mMaxAverage;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_ScreenLuminance_h

dom/base/moz.build

@@ -210,6 +210,7 @@ EXPORTS.mozilla.dom += [
     'ProcessMessageManager.h',
     'ResponsiveImageSelector.h',
     'SameProcessMessageQueue.h',
+    'ScreenLuminance.h',
     'ScreenOrientation.h',
     'Selection.h',
     'ShadowRoot.h',
@@ -359,6 +360,7 @@ UNIFIED_SOURCES += [
     'ProcessMessageManager.cpp',
     'ResponsiveImageSelector.cpp',
     'SameProcessMessageQueue.cpp',
+    'ScreenLuminance.cpp',
     'ScreenOrientation.cpp',
     'Selection.cpp',
     'SelectionChangeListener.cpp',

dom/base/nsScreen.cpp

@@ -4,7 +4,6 @@
  * 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 "mozilla/dom/ScreenBinding.h"
 #include "nsContentUtils.h"
 #include "nsScreen.h"
 #include "nsIDocument.h"

dom/base/nsScreen.h

@@ -7,6 +7,8 @@
 #define nsScreen_h___
 
 #include "mozilla/Attributes.h"
+#include "mozilla/dom/ScreenBinding.h"
+#include "mozilla/dom/ScreenLuminance.h"
 #include "mozilla/dom/ScreenOrientation.h"
 #include "mozilla/DOMEventTargetHelper.h"
 #include "mozilla/ErrorResult.h"
@@ -110,6 +112,19 @@ public:
     return rect.Height();
   }
 
+  // Media Capabilities extension
+  mozilla::dom::ScreenColorGamut ColorGamut() const
+  {
+    return mozilla::dom::ScreenColorGamut::Srgb;
+  }
+
+  already_AddRefed<mozilla::dom::ScreenLuminance> GetLuminance() const
+  {
+    return nullptr;
+  }
+
+  IMPL_EVENT_HANDLER(change);
+
   // Deprecated
   void GetMozOrientation(nsString& aOrientation,
                          mozilla::dom::CallerType aCallerType) const;

dom/webidl/Screen.webidl

@@ -59,3 +59,27 @@ interface Screen : EventTarget {
 partial interface Screen {
   readonly attribute ScreenOrientation orientation;
 };
+
+// https://wicg.github.io/media-capabilities/#idl-index
+enum ScreenColorGamut {
+  "srgb",
+  "p3",
+  "rec2020",
+};
+
+[Func="mozilla::dom::MediaCapabilities::Enabled"]
+interface ScreenLuminance {
+  readonly attribute double min;
+  readonly attribute double max;
+  readonly attribute double maxAverage;
+};
+
+partial interface Screen {
+  [Func="mozilla::dom::MediaCapabilities::Enabled"]
+  readonly attribute ScreenColorGamut colorGamut;
+  [Func="mozilla::dom::MediaCapabilities::Enabled"]
+  readonly attribute ScreenLuminance? luminance;
+
+  [Func="mozilla::dom::MediaCapabilities::Enabled"]
+  attribute EventHandler onchange;
+};