Change windows messages api to hook instead of emitter

atom/browser/api/atom_api_window.cc

@@ -190,8 +190,10 @@ void Window::OnExecuteWindowsCommand(const std::string& command_name) {
 }
 
 #if defined(OS_WIN)
-void Window::OnWindowMessage(UINT message, LPARAM l_param, WPARAM w_param) {
-  Emit("message", message, l_param, w_param);
+void Window::OnWindowMessage(UINT message, WPARAM w_param, LPARAM l_param) {
+  if (IsWindowMessageHooked(message)) {
+    messages_callback_map_[message].Run(w_param, l_param);
+  }
 }
 #endif
 
@@ -498,6 +500,29 @@ bool Window::IsMenuBarVisible() {
   return window_->IsMenuBarVisible();
 }
 
+#if defined(OS_WIN)
+bool Window::HookWindowMessage(UINT message,
+                               const MessageCallback& callback) {
+  messages_callback_map_[message] = callback;
+  return true;
+}
+
+void Window::UnhookWindowMessage(UINT message) {
+  if (!ContainsKey(messages_callback_map_, message))
+    return;
+
+  messages_callback_map_.erase(message);
+}
+
+bool Window::IsWindowMessageHooked(UINT message) {
+  return ContainsKey(messages_callback_map_, message);
+}
+
+void Window::UnhookAllWindowMessages() {
+  messages_callback_map_.clear();
+}
+#endif
+
 #if defined(OS_MACOSX)
 void Window::ShowDefinitionForSelection() {
   window_->ShowDefinitionForSelection();
@@ -596,6 +621,12 @@ void Window::BuildPrototype(v8::Isolate* isolate,
                  &Window::SetVisibleOnAllWorkspaces)
       .SetMethod("isVisibleOnAllWorkspaces",
                  &Window::IsVisibleOnAllWorkspaces)
+#if defined(OS_WIN)
+      .SetMethod("hookWindowMessage", &Window::HookWindowMessage)
+      .SetMethod("isWindowMessageHooked", &Window::IsWindowMessageHooked)
+      .SetMethod("unhookWindowMessage", &Window::UnhookWindowMessage)
+      .SetMethod("unhookAllWindowMessages", &Window::UnhookAllWindowMessages)
+#endif
 #if defined(OS_MACOSX)
       .SetMethod("showDefinitionForSelection",
                  &Window::ShowDefinitionForSelection)

atom/browser/api/atom_api_window.h

@@ -5,6 +5,7 @@
 #ifndef ATOM_BROWSER_API_ATOM_API_WINDOW_H_
 #define ATOM_BROWSER_API_ATOM_API_WINDOW_H_
 
+#include <map>
 #include <string>
 #include <vector>
 
@@ -76,8 +77,8 @@ class Window : public mate::TrackableObject<Window>,
   void OnExecuteWindowsCommand(const std::string& command_name) override;
 
   #if defined(OS_WIN)
-  void OnWindowMessage(unsigned int message, LPARAM l_param,
-                       WPARAM w_param) override;
+  void OnWindowMessage(UINT message, WPARAM w_param,
+                       LPARAM l_param) override;
   #endif
 
   // mate::Wrappable:
@@ -148,6 +149,18 @@ class Window : public mate::TrackableObject<Window>,
   bool IsMenuBarVisible();
   void SetAspectRatio(double aspect_ratio, mate::Arguments* args);
 
+#if defined(OS_WIN)
+  typedef base::Callback<void(WPARAM, LPARAM)> MessageCallback;
+  typedef std::map<UINT, MessageCallback> MessageCallbackMap;
+  MessageCallbackMap messages_callback_map_;
+
+  bool HookWindowMessage(UINT message,
+                         const MessageCallback& callback);
+  bool IsWindowMessageHooked(UINT message);
+  void UnhookWindowMessage(UINT message);
+  void UnhookAllWindowMessages();
+#endif
+
 #if defined(OS_MACOSX)
   void ShowDefinitionForSelection();
 #endif

atom/browser/native_window_observer.h

@@ -61,7 +61,7 @@ class NativeWindowObserver {
 
   // Called when window message received
   #if defined(OS_WIN)
-  virtual void OnWindowMessage(UINT message, LPARAM l_param, WPARAM w_param) {}
+  virtual void OnWindowMessage(UINT message, WPARAM w_param, LPARAM l_param) {}
   #endif
 
   // Called when renderer is hung.

docs/api/browser-window.md

@@ -232,10 +232,6 @@ Emitted when the window enters full screen state triggered by html api.
 
 Emitted when the window leaves full screen state triggered by html api.
 
-### Event: 'message' _WINDOWS_
-
-Emitted when the window receives a message from the operating system.
-
 ### Event: 'app-command':
 
 Emitted when an [App Command](https://msdn.microsoft.com/en-us/library/windows/desktop/ms646275(v=vs.85).aspx)
@@ -556,6 +552,30 @@ Enters or leaves the kiosk mode.
 
 Returns whether the window is in kiosk mode.
 
+### `win.hookWindowMessage(message, callback)` _WINDOWS_
+
+* `message` Integer
+* `callback` Function
+
+Hooks a windows message. The `callback` is called when
+the message is received in the WndProc.
+
+### `win.isWindowMessageHooked(message)` _WINDOWS_
+
+* `message` Integer
+
+Returns `true` or `false` depending on whether the message is hooked.
+
+### `win.unhookWindowMessage(message)` _WINDOWS_
+
+* `message` Integer
+
+Unhook the window message.
+
+### `win.unhookAllWindowMessages()` _WINDOWS_
+
+Unhooks all of the window messages.
+
 ### `win.setRepresentedFilename(filename)` _OS X_
 
 * `filename` String