LibGUI+WindowServer: Remove now-obsolete cursor tracking feature

This feature was problematic for several reasons:
- Tracking *all* the user activity seems like a privacy nightmare.
- LibGUI actually only supports one globally tracking widget per window,
  even if no window is necessary, or if multiple callbacks are desired.
- Widgets can easily get confused whether an event is actually directed
  at it, or is actually just the result of global tracking.

The third item caused an issue where right-clicking CatDog opened two
context menus instead of one.

Userland/Libraries/LibGUI/Widget.cpp

@@ -757,22 +757,6 @@ void Widget::set_font_fixed_width(bool fixed_width)
         set_font(Gfx::FontDatabase::the().get(Gfx::FontDatabase::the().default_font().family(), m_font->presentation_size(), m_font->weight()));
 }
 
-void Widget::set_global_cursor_tracking(bool enabled)
-{
-    auto* win = window();
-    if (!win)
-        return;
-    win->set_global_cursor_tracking_widget(enabled ? this : nullptr);
-}
-
-bool Widget::global_cursor_tracking() const
-{
-    auto* win = window();
-    if (!win)
-        return false;
-    return win->global_cursor_tracking_widget() == this;
-}
-
 void Widget::set_min_size(const Gfx::IntSize& size)
 {
     if (m_min_size == size)

Userland/Libraries/LibGUI/Widget.h

@@ -223,9 +223,6 @@ public:
     void set_font_weight(unsigned);
     void set_font_fixed_width(bool);
 
-    void set_global_cursor_tracking(bool);
-    bool global_cursor_tracking() const;
-
     void notify_layout_changed(Badge<Layout>);
     void invalidate_layout();
 

Userland/Libraries/LibGUI/Window.cpp

@@ -347,13 +347,6 @@ void Window::handle_drop_event(DropEvent& event)
 
 void Window::handle_mouse_event(MouseEvent& event)
 {
-    if (m_global_cursor_tracking_widget) {
-        auto window_relative_rect = m_global_cursor_tracking_widget->window_relative_rect();
-        Gfx::IntPoint local_point { event.x() - window_relative_rect.x(), event.y() - window_relative_rect.y() };
-        auto local_event = MouseEvent((Event::Type)event.type(), local_point, event.buttons(), event.button(), event.modifiers(), event.wheel_delta());
-        m_global_cursor_tracking_widget->dispatch_event(local_event, this);
-        return;
-    }
     if (m_automatic_cursor_tracking_widget) {
         auto window_relative_rect = m_automatic_cursor_tracking_widget->window_relative_rect();
         Gfx::IntPoint local_point { event.x() - window_relative_rect.x(), event.y() - window_relative_rect.y() };
@@ -371,8 +364,7 @@ void Window::handle_mouse_event(MouseEvent& event)
     set_hovered_widget(result.widget);
     if (event.buttons() != 0 && !m_automatic_cursor_tracking_widget)
         m_automatic_cursor_tracking_widget = *result.widget;
-    if (result.widget != m_global_cursor_tracking_widget.ptr())
+    result.widget->dispatch_event(local_event, this);
-        result.widget->dispatch_event(local_event, this);
 
     if (!m_pending_paint_event_rects.is_empty()) {
         MultiPaintEvent paint_event(move(m_pending_paint_event_rects), size());
@@ -755,13 +747,6 @@ void Window::set_focused_widget(Widget* widget, FocusSource source)
     }
 }
 
-void Window::set_global_cursor_tracking_widget(Widget* widget)
-{
-    if (widget == m_global_cursor_tracking_widget)
-        return;
-    m_global_cursor_tracking_widget = widget;
-}
-
 void Window::set_automatic_cursor_tracking_widget(Widget* widget)
 {
     if (widget == m_automatic_cursor_tracking_widget)
@@ -1138,8 +1123,6 @@ void Window::did_remove_widget(Badge<Widget>, Widget& widget)
         m_focused_widget = nullptr;
     if (m_hovered_widget == &widget)
         m_hovered_widget = nullptr;
-    if (m_global_cursor_tracking_widget == &widget)
-        m_global_cursor_tracking_widget = nullptr;
     if (m_automatic_cursor_tracking_widget == &widget)
         m_automatic_cursor_tracking_widget = nullptr;
 }

Userland/Libraries/LibGUI/Window.h

@@ -146,10 +146,6 @@ public:
     void update();
     void update(const Gfx::IntRect&);
 
-    void set_global_cursor_tracking_widget(Widget*);
-    Widget* global_cursor_tracking_widget() { return m_global_cursor_tracking_widget.ptr(); }
-    const Widget* global_cursor_tracking_widget() const { return m_global_cursor_tracking_widget.ptr(); }
-
     void set_automatic_cursor_tracking_widget(Widget*);
     Widget* automatic_cursor_tracking_widget() { return m_automatic_cursor_tracking_widget.ptr(); }
     const Widget* automatic_cursor_tracking_widget() const { return m_automatic_cursor_tracking_widget.ptr(); }
@@ -253,7 +249,6 @@ private:
     float m_alpha_hit_threshold { 0.0f };
     RefPtr<Widget> m_main_widget;
     WeakPtr<Widget> m_focused_widget;
-    WeakPtr<Widget> m_global_cursor_tracking_widget;
     WeakPtr<Widget> m_automatic_cursor_tracking_widget;
     WeakPtr<Widget> m_hovered_widget;
     Gfx::IntRect m_rect_when_windowless;

Userland/Services/WindowServer/ClientConnection.cpp

@@ -653,16 +653,6 @@ void ClientConnection::set_window_backing_store(i32 window_id, [[maybe_unused]]
         window.invalidate(false);
 }
 
-void ClientConnection::set_global_cursor_tracking(i32 window_id, bool enabled)
-{
-    auto it = m_windows.find(window_id);
-    if (it == m_windows.end()) {
-        did_misbehave("SetGlobalCursorTracking: Bad window ID");
-        return;
-    }
-    it->value->set_global_cursor_tracking_enabled(enabled);
-}
-
 void ClientConnection::set_global_mouse_tracking(bool enabled)
 {
     m_does_global_mouse_tracking = enabled;

Userland/Services/WindowServer/ClientConnection.h

@@ -113,7 +113,6 @@ private:
     virtual Messages::WindowServer::GetAppletRectOnScreenResponse get_applet_rect_on_screen(i32) override;
     virtual void invalidate_rect(i32, Vector<Gfx::IntRect> const&, bool) override;
     virtual void did_finish_painting(i32, Vector<Gfx::IntRect> const&) override;
-    virtual void set_global_cursor_tracking(i32, bool) override;
     virtual void set_global_mouse_tracking(bool) override;
     virtual void set_window_opacity(i32, float) override;
     virtual void set_window_backing_store(i32, i32, i32, IPC::File const&, i32, bool, Gfx::IntSize const&, bool) override;

Userland/Services/WindowServer/WindowManager.cpp

@@ -1201,12 +1201,6 @@ void WindowManager::process_mouse_event(MouseEvent& event)
         return;
 
     // 2. Send the mouse event to all clients with global cursor tracking enabled.
-    auto& window_stack = current_window_stack();
-    for_each_visible_window_from_front_to_back([&](Window& window) {
-        if (window.global_cursor_tracking() && &window != window_stack.active_input_tracking_window())
-            deliver_mouse_event(window, event, false);
-        return IterationDecision::Continue;
-    });
     ClientConnection::for_each_client([&](ClientConnection& conn) {
         if (conn.does_global_mouse_tracking()) {
             conn.async_track_mouse_move(event.position());

Userland/Services/WindowServer/WindowServer.ipc

@@ -74,7 +74,6 @@ endpoint WindowServer
     invalidate_rect(i32 window_id, Vector<Gfx::IntRect> rects, bool ignore_occlusion) =|
     did_finish_painting(i32 window_id, Vector<Gfx::IntRect> rects) =|
 
-    set_global_cursor_tracking(i32 window_id, bool enabled) =|
     set_global_mouse_tracking(bool enabled) =|
     set_window_opacity(i32 window_id, float opacity) =|