WindowServer: Cancel any ongoing input tracking when a menu pops up

When the user opens a context menu by right-clicking on something,
we now immediately stop sending mouse events to whoever was doing
active input window tracking before.

There are probably more situations where we should do this, and maybe
there's also a more generic way to express it, but this works for now.

Services/WindowServer/Menu.cpp

@@ -551,6 +551,8 @@ void Menu::popup(const Gfx::Point& position, bool is_submenu)
     window.move_to(adjusted_pos);
     window.set_visible(true);
     MenuManager::the().set_current_menu(this, is_submenu);
+
+    WindowManager::the().did_popup_a_menu({});
 }
 
 bool Menu::is_menu_ancestor_of(const Menu& other) const

Services/WindowServer/WindowManager.cpp

@@ -1314,4 +1314,13 @@ bool WindowManager::update_theme(String theme_path, String theme_name)
     return true;
 }
 
+void WindowManager::did_popup_a_menu(Badge<Menu>)
+{
+    // Clear any ongoing input gesture
+    if (!m_active_input_window)
+        return;
+    m_active_input_window->set_automatic_cursor_tracking_enabled(false);
+    m_active_input_window = nullptr;
+}
+
 }

Services/WindowServer/WindowManager.h

@@ -173,6 +173,8 @@ public:
     void set_hovered_window(Window*);
     void deliver_mouse_event(Window& window, MouseEvent& event);
 
+    void did_popup_a_menu(Badge<Menu>);
+
 private:
     NonnullRefPtr<Cursor> get_cursor(const String& name);
     NonnullRefPtr<Cursor> get_cursor(const String& name, const Gfx::Point& hotspot);