Bug 1538805 - Send GamepadAdded events to the later GamepadEventChannels. r=baku

Differential Revision: https://phabricator.services.mozilla.com/D74769

dom/gamepad/GamepadManager.cpp

@@ -416,9 +416,9 @@ bool GamepadManager::MaybeWindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
     // This window hasn't seen this gamepad before, so
     // send a connection event first.
     SetWindowHasSeenGamepad(aWindow, aIndex);
-    return true;
+    return false;
   }
-  return false;
+  return true;
 }
 
 bool GamepadManager::WindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
@@ -531,7 +531,7 @@ bool GamepadManager::SetGamepadByEvent(const GamepadChangeEvent& aEvent,
   const uint32_t index =
       GetGamepadIndexWithServiceType(aEvent.index(), aEvent.service_type());
   if (aWindow) {
-    firstTime = MaybeWindowHasSeenGamepad(aWindow, index);
+    firstTime = !MaybeWindowHasSeenGamepad(aWindow, index);
   }
 
   RefPtr<Gamepad> gamepad =

dom/gamepad/GamepadPlatformService.cpp

@@ -92,6 +92,7 @@ uint32_t GamepadPlatformService::AddGamepad(
                  aHand, 0, aNumButtons, aNumAxes, aHaptics, aNumLightIndicator,
                  aNumTouchEvents);
 
+  mGamepadAdded.emplace(index, a);
   NotifyGamepadChange<GamepadAdded>(index, a);
   return index;
 }
@@ -103,6 +104,7 @@ void GamepadPlatformService::RemoveGamepad(uint32_t aIndex) {
   MOZ_ASSERT(!NS_IsMainThread());
   GamepadRemoved a;
   NotifyGamepadChange<GamepadRemoved>(aIndex, a);
+  mGamepadAdded.erase(aIndex);
 }
 
 void GamepadPlatformService::NewButtonEvent(uint32_t aIndex, uint32_t aButton,
@@ -207,6 +209,17 @@ void GamepadPlatformService::AddChannelParent(
   // We use mutex here to prevent race condition with monitor thread
   MutexAutoLock autoLock(mMutex);
   mChannelParents.AppendElement(aParent);
+
+  // For a new GamepadEventChannel, we have to send the exising GamepadAdded
+  // to it to make it can have the same amount of gamepads with others.
+  if (mChannelParents.Length() > 1) {
+    for (const auto& evt : mGamepadAdded) {
+      GamepadChangeEventBody body(evt.second);
+      GamepadChangeEvent e(evt.first, GamepadServiceType::Standard, body);
+      aParent->DispatchUpdateEvent(e);
+    }
+  }
+
   FlushPendingEvents();
 }
 
@@ -275,6 +288,7 @@ void GamepadPlatformService::MaybeShutdown() {
     if (isChannelParentEmpty) {
       kungFuDeathGrip = gGamepadPlatformServiceSingleton;
       gGamepadPlatformServiceSingleton = nullptr;
+      mGamepadAdded.clear();
     }
   }
 }

dom/gamepad/GamepadPlatformService.h

@@ -9,6 +9,7 @@
 
 #include "mozilla/dom/GamepadBinding.h"
 
+#include <map>
 #include "mozilla/Mutex.h"
 #include "mozilla/StaticPtr.h"
 
@@ -115,6 +116,7 @@ class GamepadPlatformService final {
   // before GamepadEventChannel created, we need to buffer all events
   // until the channel is created if that happens.
   nsTArray<GamepadChangeEvent> mPendingEvents;
+  std::map<uint32_t, GamepadAdded> mGamepadAdded;
 };
 
 }  // namespace dom