Gamepad API: add support for gamepadconnected and gamepaddisconnected events

Source/modules/gamepad/NavigatorGamepad.cpp

Index: Source/modules/gamepad/NavigatorGamepad.cpp
diff --git a/Source/modules/gamepad/NavigatorGamepad.cpp b/Source/modules/gamepad/NavigatorGamepad.cpp
index 27c1e53322ceece8349fc24a3b5d8f530ab8e7e2..161dd0629734ab2dac6b5f51ed3623f6193b2c0e 100644
--- a/Source/modules/gamepad/NavigatorGamepad.cpp
+++ b/Source/modules/gamepad/NavigatorGamepad.cpp
@@ -26,7 +26,10 @@
 #include "config.h"
 #include "modules/gamepad/NavigatorGamepad.h"
 
+#include "core/frame/DOMWindow.h"
+#include "core/frame/LocalFrame.h"
 #include "core/frame/Navigator.h"
+#include "modules/gamepad/GamepadEvent.h"
 #include "modules/gamepad/GamepadList.h"
 #include "modules/gamepad/WebKitGamepadList.h"
 #include "public/platform/Platform.h"
@@ -67,12 +70,15 @@ static void sampleGamepads(ListType* into)
     }
 }
 
-NavigatorGamepad::NavigatorGamepad()
+NavigatorGamepad::NavigatorGamepad(LocalFrame* frame)
+    : DOMWindowProperty(frame)
+    , DOMWindowLifecycleObserver(frame ? frame->domWindow() : 0)
 {
 }
 
 NavigatorGamepad::~NavigatorGamepad()
 {
+    blink::Platform::current()->setGamepadListener(0);

[abarth-chromium, 2014/03/17 18:23:46]

This line sets a static field in the embedder.  How can this work given that
there can be many instances of NavigatorGamepad, one for each iframe?

[kbalazs, 2014/03/17 23:49:27]

Added a singleton mediator that implements WebGamepadListener and forwards the
virtual calls to each NavigatorGamepad that wants to listen. We really just need
to set a listener for the renderer once so I think this is sufficient.

 }
 
 const char* NavigatorGamepad::supplementName()
@@ -84,7 +90,7 @@ NavigatorGamepad& NavigatorGamepad::from(Navigator& navigator)
 {
     NavigatorGamepad* supplement = static_cast<NavigatorGamepad*>(Supplement<Navigator>::from(navigator, supplementName()));
     if (!supplement) {
-        supplement = new NavigatorGamepad();
+        supplement = new NavigatorGamepad(navigator.frame());
         provideTo(navigator, supplementName(), adoptPtr(supplement));
     }
     return *supplement;
@@ -116,4 +122,52 @@ GamepadList* NavigatorGamepad::gamepads()
     return m_gamepads.get();
 }
 
+void NavigatorGamepad::onGamepadConnected(unsigned index, const blink::WebGamepad& webGamepad)
+{
+    if (index >= blink::WebGamepads::itemsLengthCap || !webGamepad.connected)
+        return;
+
+    if (!m_gamepads)
+        m_gamepads = GamepadList::create();
+
+    RefPtrWillBeRawPtr<Gamepad> gamepad = m_gamepads->item(index);
+    if (!gamepad)
+        gamepad = Gamepad::create();
+    sampleGamepad(index, *gamepad, webGamepad);
+    m_gamepads->set(index, gamepad);
+
+    if (frame() && frame()->domWindow()) {
+        RefPtr<GamepadEvent> event = GamepadEvent::create(EventTypeNames::gamepadconnected, false, true, gamepad.get());
+        frame()->domWindow()->dispatchEvent(event);
+    }
+}
+
+void NavigatorGamepad::onGamepadDisconnected(unsigned index, const blink::WebGamepad& webGamepad)
+{
+    if (index >= blink::WebGamepads::itemsLengthCap)
+        return;
+
+    if (!m_gamepads)
+        m_gamepads = GamepadList::create();
+
+    RefPtrWillBeRawPtr<Gamepad> gamepad = m_gamepads->item(index);
+    if (!gamepad)
+        gamepad = Gamepad::create();
+    sampleGamepad(index, *gamepad, webGamepad);
+
+    if (frame() && frame()->domWindow()) {
+        RefPtr<GamepadEvent> event = GamepadEvent::create(EventTypeNames::gamepaddisconnected, false, true, gamepad);
+        frame()->domWindow()->dispatchEvent(event);
+    }
+}
+
+void NavigatorGamepad::didAddEventListener(DOMWindow*, const AtomicString& eventType)
+{
+    // If an event listener is added for gamepad events set ourself as listener and sample the gamepads once to start monitoring gamepad state.
+    if (eventType == EventTypeNames::gamepadconnected || eventType == EventTypeNames::gamepaddisconnected) {
+        blink::Platform::current()->setGamepadListener(this);

[abarth-chromium, 2014/03/17 18:23:46]

Again, this sets a static field, which doesn't seem like it can work.

[kbalazs, 2014/03/17 23:49:27]

Done.

+        gamepads();
+    }
+}
+
 } // namespace WebCore