Fix window state events on Windows

This commit fixes the issue we had with window state events not firing
when triggered through Aero Snap.
Instead of listening to command from the system menu (SC_MAXIMIZE etc.),
we use the WM_SIZE event.

This resolves #1381.

atom/browser/native_window_views.cc

@@ -169,9 +169,6 @@ NativeWindowViews::NativeWindowViews(
       menu_bar_autohide_(false),
       menu_bar_visible_(false),
       menu_bar_alt_pressed_(false),
-#if defined(OS_WIN)
-      is_minimized_(false),
-#endif
       keyboard_event_handler_(new views::UnhandledKeyboardEventHandler),
       use_content_size_(false),
       resizable_(true) {
@@ -228,6 +225,9 @@ NativeWindowViews::NativeWindowViews(
 
   window_->Init(params);
 
+  bool fullscreen = false;
+  options.Get(switches::kFullscreen, &fullscreen);
+
 #if defined(USE_X11)
   // Start monitoring window states.
   window_state_watcher_.reset(new WindowStateWatcher(this));
@@ -253,8 +253,7 @@ NativeWindowViews::NativeWindowViews(
   }
 
   // Before the window is mapped, there is no SHOW_FULLSCREEN_STATE.
-  bool fullscreen = false;
+  if (fullscreen) {
-  if (options.Get(switches::kFullscreen, & fullscreen) && fullscreen) {
     state_atom_list.push_back(GetAtom("_NET_WM_STATE_FULLSCREEN"));
   }
 
@@ -278,6 +277,12 @@ NativeWindowViews::NativeWindowViews(
     bounds = ContentBoundsToWindowBounds(bounds);
 
 #if defined(OS_WIN)
+  // Save initial window state.
+  if (fullscreen)
+    last_window_state_ = ui::SHOW_STATE_FULLSCREEN;
+  else
+    last_window_state_ = ui::SHOW_STATE_NORMAL;
+
   if (!has_frame()) {
     // Set Window style so that we get a minimize and maximize animation when
     // frameless.
@@ -391,11 +396,16 @@ bool NativeWindowViews::IsMinimized() {
 void NativeWindowViews::SetFullScreen(bool fullscreen) {
 #if defined(OS_WIN)
   // There is no native fullscreen state on Windows.
-  window_->SetFullscreen(fullscreen);
+  if (fullscreen) {
-  if (fullscreen)
+    last_window_state_ = ui::SHOW_STATE_FULLSCREEN;
     NotifyWindowEnterFullScreen();
-  else
+  } else {
+    last_window_state_ = ui::SHOW_STATE_NORMAL;
     NotifyWindowLeaveFullScreen();
+  }
+  // We set the new value after notifying, so we can handle the size event
+  // correctly.
+  window_->SetFullscreen(fullscreen);
 #else
   if (IsVisible())
     window_->SetFullscreen(fullscreen);
@@ -807,24 +817,8 @@ void NativeWindowViews::OnWidgetMove() {
 
 #if defined(OS_WIN)
 bool NativeWindowViews::ExecuteWindowsCommand(int command_id) {
-  // Windows uses the 4 lower order bits of |command_id| for type-specific
-  // information so we must exclude this when comparing.
-  static const int sc_mask = 0xFFF0;
-  if ((command_id & sc_mask) == SC_MINIMIZE) {
-    NotifyWindowMinimize();
-    is_minimized_ = true;
-  } else if ((command_id & sc_mask) == SC_RESTORE) {
-    if (is_minimized_)
-      NotifyWindowRestore();
-    else
-      NotifyWindowUnmaximize();
-    is_minimized_ = false;
-  } else if ((command_id & sc_mask) == SC_MAXIMIZE) {
-    NotifyWindowMaximize();
-  } else {
   std::string command = AppCommandToString(command_id);
   NotifyWindowExecuteWindowsCommand(command);
-  }
   return false;
 }
 #endif
@@ -844,11 +838,54 @@ void NativeWindowViews::GetDevToolsWindowWMClass(
 #if defined(OS_WIN)
 bool NativeWindowViews::PreHandleMSG(
     UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) {
+  switch (message) {
+    case WM_COMMAND:
       // Handle thumbar button click message.
-  if (message == WM_COMMAND && HIWORD(w_param) == THBN_CLICKED)
+      if (HIWORD(w_param) == THBN_CLICKED)
         return taskbar_host_.HandleThumbarButtonEvent(LOWORD(w_param));
-  else
       return false;
+    case WM_SIZE:
+      // Handle window state change.
+      HandleSizeEvent(w_param, l_param);
+      return false;
+    default:
+      return false;
+  }
+}
+
+void NativeWindowViews::HandleSizeEvent(WPARAM w_param, LPARAM l_param) {
+  // Here we handle the WM_SIZE event in order to figure out what is the current
+  // window state and notify the user accordingly.
+  switch (w_param) {
+    case SIZE_MAXIMIZED:
+      last_window_state_ = ui::SHOW_STATE_MAXIMIZED;
+      NotifyWindowMaximize();
+      break;
+    case SIZE_MINIMIZED:
+      last_window_state_ = ui::SHOW_STATE_MINIMIZED;
+      NotifyWindowMinimize();
+      break;
+    case SIZE_RESTORED:
+      if (last_window_state_ == ui::SHOW_STATE_NORMAL)
+        return;
+
+      switch (last_window_state_) {
+        case ui::SHOW_STATE_MAXIMIZED:
+          last_window_state_ = ui::SHOW_STATE_NORMAL;
+          NotifyWindowUnmaximize();
+          break;
+        case ui::SHOW_STATE_MINIMIZED:
+          if (IsFullscreen()) {
+            last_window_state_ = ui::SHOW_STATE_FULLSCREEN;
+            NotifyWindowEnterFullScreen();
+          } else {
+            last_window_state_ = ui::SHOW_STATE_NORMAL;
+            NotifyWindowRestore();
+          }
+          break;
+      }
+      break;
+  }
 }
 #endif
 

atom/browser/native_window_views.h

@@ -142,6 +142,8 @@ class NativeWindowViews : public NativeWindow,
   // MessageHandlerDelegate:
   bool PreHandleMSG(
       UINT message, WPARAM w_param, LPARAM l_param, LRESULT* result) override;
+
+  void HandleSizeEvent(WPARAM w_param, LPARAM l_param);
 #endif
 
   // NativeWindow:
@@ -178,9 +180,9 @@ class NativeWindowViews : public NativeWindow,
 #elif defined(OS_WIN)
   // Weak ref.
   AtomDesktopWindowTreeHostWin* atom_desktop_window_tree_host_win_;
-  // Records window was whether restored from minimized state or maximized
+
-  // state.
+  ui::WindowShowState last_window_state_;
-  bool is_minimized_;
+
   // In charge of running taskbar related APIs.
   TaskbarHost taskbar_host_;
 #endif