WindowServer+LibGUI: Change cursor icon if DragEnter event was accepted

Author: https://github.com/krkk
Commit: https://github.com/SerenityOS/serenity/commit/2e244fc85b
Pull-request: https://github.com/SerenityOS/serenity/pull/14957

Userland/Libraries/LibGUI/Application.cpp

@@ -295,6 +295,7 @@ void Application::set_drag_hovered_widget_impl(Widget* widget, Gfx::IntPoint con
         m_drag_hovered_widget->dispatch_event(enter_event, m_drag_hovered_widget->window());
         if (enter_event.is_accepted())
             set_pending_drop_widget(m_drag_hovered_widget);
+        ConnectionToWindowServer::the().async_set_accepts_drag(enter_event.is_accepted());
     }
 }
 

Userland/Services/WindowServer/ConnectionFromClient.cpp

@@ -824,6 +824,13 @@ Messages::WindowServer::StartDragResponse ConnectionFromClient::start_drag(Strin
     return true;
 }
 
+void ConnectionFromClient::set_accepts_drag(bool accepts)
+{
+    auto& wm = WindowManager::the();
+    VERIFY(wm.dnd_client());
+    wm.set_accepts_drag(accepts);
+}
+
 Messages::WindowServer::SetSystemThemeResponse ConnectionFromClient::set_system_theme(String const& theme_path, String const& theme_name, bool keep_desktop_background)
 {
     bool success = WindowManager::the().update_theme(theme_path, theme_name, keep_desktop_background);

Userland/Services/WindowServer/ConnectionFromClient.h

@@ -142,6 +142,7 @@ private:
     virtual void dismiss_menu(i32) override;
     virtual void set_window_icon_bitmap(i32, Gfx::ShareableBitmap const&) override;
     virtual Messages::WindowServer::StartDragResponse start_drag(String const&, HashMap<String, ByteBuffer> const&, Gfx::ShareableBitmap const&) override;
+    virtual void set_accepts_drag(bool) override;
     virtual Messages::WindowServer::SetSystemThemeResponse set_system_theme(String const&, String const&, bool keep_desktop_background) override;
     virtual Messages::WindowServer::GetSystemThemeResponse get_system_theme() override;
     virtual Messages::WindowServer::SetSystemThemeOverrideResponse set_system_theme_override(Core::AnonymousBuffer const&) override;

Userland/Services/WindowServer/WindowManager.cpp

@@ -1016,14 +1016,13 @@ bool WindowManager::process_ongoing_drag(MouseEvent& event)
         m_dnd_overlay->cursor_moved();
 
         // We didn't let go of the drag yet, see if we should send some drag move events..
-        for_each_visible_window_from_front_to_back([&](Window& window) {
-            if (!window.rect().contains(event.position()))
-                return IterationDecision::Continue;
+        if (auto* window = current_window_stack().window_at(event.position(), WindowStack::IncludeWindowFrame::No)) {
             event.set_drag(true);
             event.set_mime_data(*m_dnd_mime_data);
-            deliver_mouse_event(window, event, false);
-            return IterationDecision::Break;
-        });
+            deliver_mouse_event(*window, event, false);
+        } else {
+            set_accepts_drag(false);
+        }
     }
 
     if (!(event.type() == Event::MouseUp && event.button() == MouseButton::Primary))
@@ -1918,8 +1917,11 @@ ConnectionFromClient const* WindowManager::active_client() const
 
 Cursor const& WindowManager::active_cursor() const
 {
-    if (m_dnd_client)
+    if (m_dnd_client) {
+        if (m_dnd_accepts_drag)
+            return *m_drag_copy_cursor;
         return *m_drag_cursor;
+    }
 
     if (m_move_window)
         return *m_move_cursor;
@@ -2061,6 +2063,14 @@ void WindowManager::end_dnd_drag()
     m_dnd_client = nullptr;
     m_dnd_text = {};
     m_dnd_overlay = nullptr;
+    m_dnd_accepts_drag = false;
+}
+
+void WindowManager::set_accepts_drag(bool accepts)
+{
+    VERIFY(m_dnd_client);
+    m_dnd_accepts_drag = accepts;
+    Compositor::the().invalidate_cursor();
 }
 
 void WindowManager::invalidate_after_theme_or_font_change()

Userland/Services/WindowServer/WindowManager.h

@@ -96,6 +96,8 @@ public:
     void start_dnd_drag(ConnectionFromClient&, String const& text, Gfx::Bitmap const*, Core::MimeData const&);
     void end_dnd_drag();
 
+    void set_accepts_drag(bool);
+
     Window* active_window()
     {
         VERIFY(m_current_window_stack);
@@ -480,6 +482,7 @@ private:
     OwnPtr<DndOverlay> m_dnd_overlay;
     WeakPtr<ConnectionFromClient> m_dnd_client;
     String m_dnd_text;
+    bool m_dnd_accepts_drag { false };
 
     RefPtr<Core::MimeData> m_dnd_mime_data;
 

Userland/Services/WindowServer/WindowServer.ipc

@@ -123,6 +123,7 @@ endpoint WindowServer
     set_window_custom_cursor(i32 window_id, Gfx::ShareableBitmap cursor) =|
 
     start_drag([UTF8] String text, HashMap<String,ByteBuffer> mime_data, Gfx::ShareableBitmap drag_bitmap) => (bool started)
+    set_accepts_drag(bool accepts) =|
 
     set_system_theme(String theme_path, [UTF8] String theme_name, bool keep_desktop_background) => (bool success)
     get_system_theme() => ([UTF8] String theme_name)