LibGUI+WindowServer: Replace WindowInput{Enter,Leave} Events

with WindowInput{Preempted,Restored} Events and allow Widgets to save
the state of their focus preemption. As of now, only Popups will
preempt input and trigger these events.

Userland/Libraries/LibGUI/ConnectionToWindowServer.cpp

@@ -120,16 +120,16 @@ void ConnectionToWindowServer::window_deactivated(i32 window_id)
         Core::EventLoop::current().post_event(*window, make<Event>(Event::WindowBecameInactive));
 }
 
-void ConnectionToWindowServer::window_input_entered(i32 window_id)
+void ConnectionToWindowServer::window_input_preempted(i32 window_id)
 {
     if (auto* window = Window::from_window_id(window_id))
-        Core::EventLoop::current().post_event(*window, make<Event>(Event::WindowInputEntered));
+        Core::EventLoop::current().post_event(*window, make<Event>(Event::WindowInputPreempted));
 }
 
-void ConnectionToWindowServer::window_input_left(i32 window_id)
+void ConnectionToWindowServer::window_input_restored(i32 window_id)
 {
     if (auto* window = Window::from_window_id(window_id))
-        Core::EventLoop::current().post_event(*window, make<Event>(Event::WindowInputLeft));
+        Core::EventLoop::current().post_event(*window, make<Event>(Event::WindowInputRestored));
 }
 
 void ConnectionToWindowServer::window_close_request(i32 window_id)

Userland/Libraries/LibGUI/ConnectionToWindowServer.h

@@ -37,8 +37,8 @@ private:
     virtual void key_up(i32, u32, u32, u32, u32) override;
     virtual void window_activated(i32) override;
     virtual void window_deactivated(i32) override;
-    virtual void window_input_entered(i32) override;
-    virtual void window_input_left(i32) override;
+    virtual void window_input_preempted(i32) override;
+    virtual void window_input_restored(i32) override;
     virtual void window_close_request(i32) override;
     virtual void window_resized(i32, Gfx::IntRect const&) override;
     virtual void window_moved(i32, Gfx::IntRect const&) override;

Userland/Libraries/LibGUI/Event.h

@@ -42,8 +42,8 @@ public:
         WindowLeft,
         WindowBecameInactive,
         WindowBecameActive,
-        WindowInputEntered,
-        WindowInputLeft,
+        WindowInputPreempted,
+        WindowInputRestored,
         FocusIn,
         FocusOut,
         WindowCloseRequest,

Userland/Libraries/LibGUI/Widget.h

@@ -214,6 +214,9 @@ public:
     bool is_focused() const;
     void set_focus(bool, FocusSource = FocusSource::Programmatic);
 
+    bool focus_preempted() const { return m_focus_preempted; }
+    void set_focus_preempted(bool b) { m_focus_preempted = b; }
+
     Function<void(bool const, const FocusSource)> on_focus_change;
 
     // Returns true if this widget or one of its descendants is focused.
@@ -440,6 +443,7 @@ private:
     bool m_visible { true };
     bool m_greedy_for_hits { false };
     bool m_auto_focusable { true };
+    bool m_focus_preempted { false };
     bool m_enabled { true };
     bool m_updates_enabled { true };
     bool m_accepts_command_palette { true };

Userland/Libraries/LibGUI/Window.cpp

@@ -522,15 +522,14 @@ void Window::handle_resize_event(ResizeEvent& event)
         m_main_widget->set_relative_rect({ {}, new_size });
 }
 
-void Window::handle_input_entered_or_left_event(Core::Event& event)
+void Window::handle_input_preemption_event(Core::Event& event)
 {
-    m_is_active_input = event.type() == Event::WindowInputEntered;
-    if (on_active_input_change)
-        on_active_input_change(m_is_active_input);
-    if (m_main_widget)
-        m_main_widget->dispatch_event(event, this);
-    if (m_focused_widget)
-        m_focused_widget->update();
+    if (on_input_preemption_change)
+        on_input_preemption_change(event.type() == Event::WindowInputPreempted);
+    if (!m_focused_widget)
+        return;
+    m_focused_widget->set_focus_preempted(event.type() == Event::WindowInputPreempted);
+    m_focused_widget->update();
 }
 
 void Window::handle_became_active_or_inactive_event(Core::Event& event)
@@ -543,8 +542,11 @@ void Window::handle_became_active_or_inactive_event(Core::Event& event)
         on_active_window_change(event.type() == Event::WindowBecameActive);
     if (m_main_widget)
         m_main_widget->dispatch_event(event, this);
-    if (m_focused_widget)
+    if (m_focused_widget) {
+        if (event.type() == Event::WindowBecameActive)
+            m_focused_widget->set_focus_preempted(false);
         m_focused_widget->update();
+    }
 }
 
 void Window::handle_close_request()
@@ -678,8 +680,8 @@ void Window::event(Core::Event& event)
     if (event.type() == Event::WindowBecameActive || event.type() == Event::WindowBecameInactive)
         return handle_became_active_or_inactive_event(event);
 
-    if (event.type() == Event::WindowInputEntered || event.type() == Event::WindowInputLeft)
-        return handle_input_entered_or_left_event(event);
+    if (event.type() == Event::WindowInputPreempted || event.type() == Event::WindowInputRestored)
+        return handle_input_preemption_event(event);
 
     if (event.type() == Event::WindowCloseRequest)
         return handle_close_request();

Userland/Libraries/LibGUI/Window.h

@@ -97,6 +97,7 @@ public:
     Function<void()> on_close;
     Function<CloseRequestDecision()> on_close_request;
     Function<void(bool is_active_input)> on_active_input_change;
+    Function<void(bool is_preempted)> on_input_preemption_change;
     Function<void(bool is_active_window)> on_active_window_change;
     Function<void(InputPreemptor)> on_input_preemption;
 
@@ -259,7 +260,7 @@ private:
     void handle_multi_paint_event(MultiPaintEvent&);
     void handle_key_event(KeyEvent&);
     void handle_resize_event(ResizeEvent&);
-    void handle_input_entered_or_left_event(Core::Event&);
+    void handle_input_preemption_event(Core::Event&);
     void handle_became_active_or_inactive_event(Core::Event&);
     void handle_close_request();
     void handle_theme_change_event(ThemeChangeEvent&);