Bug 926091 - Make Gamepad.buttons into an array of GamepadButton objects. r=smaug

dom/gamepad/Gamepad.cpp

@@ -19,7 +19,7 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Gamepad)
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_1(Gamepad, mParent)
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_2(Gamepad, mParent, mButtonsVariant)
 
 Gamepad::Gamepad(nsISupports* aParent,
                  const nsAString& aID, uint32_t aIndex,
@@ -29,10 +29,14 @@ Gamepad::Gamepad(nsISupports* aParent,
     mID(aID),
     mIndex(aIndex),
     mMapping(aMapping),
-    mConnected(true)
+    mConnected(true),
+    mButtons(aNumButtons),
+    mAxes(aNumAxes)
 {
   SetIsDOMBinding();
-  mButtons.InsertElementsAt(0, aNumButtons);
+  for (unsigned i = 0; i < aNumButtons; i++) {
+    mButtons.InsertElementAt(i, new GamepadButton(mParent));
+  }
   mAxes.InsertElementsAt(0, aNumAxes, 0.0f);
 }
 
@@ -52,8 +56,8 @@ void
 Gamepad::SetButton(uint32_t aButton, bool aPressed, double aValue)
 {
   MOZ_ASSERT(aButton < mButtons.Length());
-  mButtons[aButton].pressed = aPressed;
-  mButtons[aButton].value = aValue;
+  mButtons[aButton]->SetPressed(aPressed);
+  mButtons[aButton]->SetValue(aValue);
 }
 
 void
@@ -66,6 +70,11 @@ Gamepad::SetAxis(uint32_t aAxis, double aValue)
 nsresult
 Gamepad::GetButtons(nsIVariant** aButtons)
 {
+  if (mButtonsVariant) {
+    NS_ADDREF(*aButtons = mButtonsVariant);
+    return NS_OK;
+  }
+
   nsRefPtr<nsVariant> out = new nsVariant();
   NS_ENSURE_STATE(out);
 
@@ -74,15 +83,15 @@ Gamepad::GetButtons(nsIVariant** aButtons)
     NS_ENSURE_SUCCESS(rv, rv);
   } else {
     // Note: The resulting nsIVariant dupes both the array and its elements.
-    double* array = reinterpret_cast<double*>
-                      (NS_Alloc(mButtons.Length() * sizeof(double)));
+    GamepadButton** array = reinterpret_cast<GamepadButton**>
+                      (NS_Alloc(mButtons.Length() * sizeof(GamepadButton*)));
     NS_ENSURE_TRUE(array, NS_ERROR_OUT_OF_MEMORY);
 
     for (uint32_t i = 0; i < mButtons.Length(); ++i) {
-      array[i] = mButtons[i].value;
+      array[i] = mButtons[i].get();
     }
 
-    nsresult rv = out->SetAsArray(nsIDataType::VTYPE_DOUBLE,
+    nsresult rv = out->SetAsArray(nsIDataType::VTYPE_INTERFACE,
                                   nullptr,
                                   mButtons.Length(),
                                   reinterpret_cast<void*>(array));
@@ -90,6 +99,7 @@ Gamepad::GetButtons(nsIVariant** aButtons)
     NS_ENSURE_SUCCESS(rv, rv);
   }
 
+  mButtonsVariant = out;
   *aButtons = out.forget().get();
   return NS_OK;
 }
@@ -135,7 +145,8 @@ Gamepad::SyncState(Gamepad* aOther)
 
   mConnected = aOther->mConnected;
   for (uint32_t i = 0; i < mButtons.Length(); ++i) {
-    mButtons[i] = aOther->mButtons[i];
+    mButtons[i]->SetPressed(aOther->mButtons[i]->Pressed());
+    mButtons[i]->SetValue(aOther->mButtons[i]->Value());
   }
   for (uint32_t i = 0; i < mAxes.Length(); ++i) {
     mAxes[i] = aOther->mAxes[i];

dom/gamepad/Gamepad.h

@@ -6,6 +6,7 @@
 #define mozilla_dom_gamepad_Gamepad_h
 
 #include "mozilla/ErrorResult.h"
+#include "mozilla/dom/GamepadButton.h"
 #include <stdint.h>
 #include "nsCOMPtr.h"
 #include "nsIVariant.h"
@@ -22,16 +23,6 @@ enum GamepadMappingType
   StandardMapping = 1
 };
 
-// TODO: fix the spec to expose both pressed and value:
-// https://www.w3.org/Bugs/Public/show_bug.cgi?id=21388
-struct GamepadButton
-{
-  bool pressed;
-  double value;
-
-  GamepadButton(): pressed(false), value(0.0) {}
-};
-
 class Gamepad : public nsISupports,
                 public nsWrapperCache
 {
@@ -119,8 +110,11 @@ protected:
   bool mConnected;
 
   // Current state of buttons, axes.
-  nsTArray<GamepadButton> mButtons;
+  nsTArray<nsRefPtr<GamepadButton>> mButtons;
   nsTArray<double> mAxes;
+
+  // Cached variant array.
+  nsCOMPtr<nsIVariant> mButtonsVariant;
 };
 
 } // namespace dom

dom/gamepad/GamepadButton.cpp

@@ -0,0 +1,28 @@
+/* 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 "mozilla/dom/GamepadButton.h"
+#include "mozilla/dom/GamepadBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(GamepadButton)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(GamepadButton)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GamepadButton)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_1(GamepadButton, mParent)
+
+/* virtual */ JSObject*
+GamepadButton::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
+{
+  return GamepadButtonBinding::Wrap(aCx, aScope, this);
+}
+
+} // namespace dom
+} // namespace mozilla

dom/gamepad/GamepadButton.h

@@ -0,0 +1,69 @@
+/* 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_gamepad_GamepadButton_h
+#define mozilla_dom_gamepad_GamepadButton_h
+
+#include <stdint.h>
+#include "nsCOMPtr.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla {
+namespace dom {
+
+class GamepadButton : public nsISupports,
+                      public nsWrapperCache
+{
+public:
+  GamepadButton(nsISupports* aParent) : mParent(aParent),
+                                        mPressed(false),
+                                        mValue(0)
+  {
+    SetIsDOMBinding();
+  }
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(GamepadButton)
+
+  nsISupports* GetParentObject() const
+  {
+    return mParent;
+  }
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+			       JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
+
+  void SetPressed(bool aPressed)
+  {
+    mPressed = aPressed;
+  }
+
+  void SetValue(double aValue)
+  {
+    mValue = aValue;
+  }
+
+  bool Pressed() const
+  {
+    return mPressed;
+  }
+
+  double Value() const
+  {
+    return mValue;
+  }
+
+private:
+  virtual ~GamepadButton() {}
+
+protected:
+  nsCOMPtr<nsISupports> mParent;
+  bool mPressed;
+  double mValue;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_gamepad_GamepadButton_h

dom/gamepad/moz.build

@@ -6,11 +6,13 @@
 
 EXPORTS.mozilla.dom += [
     'Gamepad.h',
+    'GamepadButton.h',
     'GamepadService.h',
     ]
 
 CPP_SOURCES = [
     'Gamepad.cpp',
+    'GamepadButton.cpp',
     'GamepadService.cpp',
     ]
 

dom/tests/mochitest/gamepad/test_gamepad_frame_state_sync.html

@@ -47,8 +47,8 @@ var tests = [
 
 function check_button_pressed() {
   // At this point the both frames should see the button as pressed.
-  is(f1.contentWindow.gamepad.buttons[0], 1, "frame 1 sees button pressed");
-  is(f2.contentWindow.gamepad.buttons[0], 1, "frame 2 sees button pressed");
+  ok(f1.contentWindow.gamepad.buttons[0].pressed, "frame 1 sees button pressed");
+  ok(f2.contentWindow.gamepad.buttons[0].pressed, "frame 2 sees button pressed");
 
   // Now release the button, then hide the second frame.
   GamepadService.newButtonEvent(index, 0, false);
@@ -64,15 +64,15 @@ function check_second_frame_no_button_press () {
    * At this point the first frame should see the button as pressed,
    * but the second frame should not, since it's hidden.
    */
-  is(f1.contentWindow.gamepad.buttons[0], 1, "frame 1 sees button pressed");
-  is(f2.contentWindow.gamepad.buttons[0], 0, "frame 2 should not see button pressed");
+  ok(f1.contentWindow.gamepad.buttons[0].pressed, "frame 1 sees button pressed");
+  ok(!f2.contentWindow.gamepad.buttons[0].pressed, "frame 2 should not see button pressed");
 
   // Now unhide the second frame.
   setFrameVisible(f2, true);
   SpecialPowers.executeSoon(function() {
     // Now that the frame is visible again, it should see the button
     // that was pressed.
-    is(f2.contentWindow.gamepad.buttons[0], 1, "frame 2 sees button pressed");
+    ok(f2.contentWindow.gamepad.buttons[0].pressed, "frame 2 sees button pressed");
     // cleanup
     GamepadService.removeGamepad(index);
     SimpleTest.finish();

dom/tests/mochitest/general/test_interfaces.html

@@ -202,6 +202,7 @@ var interfaceNamesInGlobalScope =
     {name: "Gamepad", desktop: true},
     {name: "GamepadAxisMoveEvent", desktop: true},
     {name: "GamepadButtonEvent", desktop: true},
+    {name: "GamepadButton", desktop: true},
     {name: "GamepadEvent", desktop: true},
     "HashChangeEvent",
     "History",

dom/webidl/Gamepad.webidl

@@ -5,6 +5,12 @@
 
 interface nsIVariant;
 
+[Pref="dom.gamepad.enabled"]
+interface GamepadButton {
+  readonly    attribute boolean pressed;
+  readonly    attribute double  value;
+};
+
 [Pref="dom.gamepad.enabled"]
 interface Gamepad {
   /**
@@ -31,7 +37,7 @@ interface Gamepad {
 
   /**
    * The current state of all buttons on the device, an
-   * array of doubles.
+   * array of GamepadButton.
    */
   [Throws]
   readonly attribute nsIVariant buttons;