LibCore: Introduce a C_OBJECT macro.

This macro goes at the top of every CObject-derived class like so:

class SomeClass : public CObject {
    C_OBJECT(SomeClass)
public:
    ...

At the moment, all it does is create an override for the class_name() getter
but in the future this will be used to automatically insert member functions
into these classes.

Libraries/LibCore/CFile.h

@@ -4,6 +4,7 @@
 #include <LibCore/CIODevice.h>
 
 class CFile final : public CIODevice {
+    C_OBJECT(CFile)
 public:
     CFile() {}
     explicit CFile(const StringView&);
@@ -20,8 +21,6 @@ public:
     };
     bool open(int fd, CIODevice::OpenMode, ShouldCloseFileDescription);
 
-    virtual const char* class_name() const override { return "CFile"; }
-
 private:
     String m_filename;
     ShouldCloseFileDescription m_should_close_file_descriptor { ShouldCloseFileDescription::Yes };

Libraries/LibCore/CHttpJob.h

@@ -7,14 +7,13 @@
 class CTCPSocket;
 
 class CHttpJob final : public CNetworkJob {
+    C_OBJECT(CHttpJob)
 public:
     explicit CHttpJob(const CHttpRequest&);
     virtual ~CHttpJob() override;
 
     virtual void start() override;
 
-    virtual const char* class_name() const override { return "CHttpJob"; }
-
 private:
     void on_socket_connected();
 

Libraries/LibCore/CIODevice.h

@@ -5,6 +5,7 @@
 #include <LibCore/CObject.h>
 
 class CIODevice : public CObject {
+    C_OBJECT(CIODevice)
 public:
     enum OpenMode {
         NotOpen = 0,
@@ -52,8 +53,6 @@ public:
 
     int printf(const char*, ...);
 
-    virtual const char* class_name() const override { return "CIODevice"; }
-
 protected:
     explicit CIODevice(CObject* parent = nullptr);
 

Libraries/LibCore/CLocalSocket.h

@@ -2,6 +2,7 @@
 #include <LibCore/CSocket.h>
 
 class CLocalSocket final : public CSocket {
+    C_OBJECT(CLocalSocket)
 public:
     explicit CLocalSocket(CObject* parent = nullptr);
     virtual ~CLocalSocket() override;

Libraries/LibCore/CNetworkJob.h

@@ -6,6 +6,7 @@
 class CNetworkResponse;
 
 class CNetworkJob : public CObject {
+    C_OBJECT(CNetworkJob)
 public:
     enum class Error {
         None,
@@ -24,8 +25,6 @@ public:
 
     virtual void start() = 0;
 
-    virtual const char* class_name() const override { return "CNetworkJob"; }
-
 protected:
     CNetworkJob();
     void did_finish(NonnullRefPtr<CNetworkResponse>&&);

Libraries/LibCore/CNotifier.h

@@ -4,6 +4,7 @@
 #include "CObject.h"
 
 class CNotifier : public CObject {
+    C_OBJECT(CNotifier)
 public:
     enum Event {
         None = 0,
@@ -12,7 +13,7 @@ public:
         Exceptional = 4,
     };
     CNotifier(int fd, unsigned event_mask);
-    ~CNotifier();
+    virtual ~CNotifier() override;
 
     void set_enabled(bool);
 
@@ -23,8 +24,7 @@ public:
     unsigned event_mask() const { return m_event_mask; }
     void set_event_mask(unsigned event_mask) { m_event_mask = event_mask; }
 
-    const char* class_name() const override { return "CNotifier"; }
-    void event(CEvent& event) override;
+    void event(CEvent&) override;
 
 private:
     int m_fd { -1 };

Libraries/LibCore/CObject.h

@@ -11,13 +11,16 @@ class CChildEvent;
 class CCustomEvent;
 class CTimerEvent;
 
+#define C_OBJECT(klass) \
+public:                 \
+    virtual const char* class_name() const override { return #klass; }
+
 class CObject : public Weakable<CObject> {
+    // NOTE: No C_OBJECT macro for CObject itself.
 public:
-    CObject(CObject* parent = nullptr, bool is_widget = false);
     virtual ~CObject();
 
-    virtual const char* class_name() const { return "CObject"; }
-
+    virtual const char* class_name() const = 0;
     virtual void event(CEvent&);
 
     const String& name() const { return m_name; }
@@ -58,6 +61,8 @@ public:
     virtual bool is_window() const { return false; }
 
 protected:
+    CObject(CObject* parent = nullptr, bool is_widget = false);
+
     virtual void timer_event(CTimerEvent&);
     virtual void child_event(CChildEvent&);
     virtual void custom_event(CCustomEvent&);

Libraries/LibCore/CSocket.h

@@ -6,6 +6,7 @@
 class CNotifier;
 
 class CSocket : public CIODevice {
+    C_OBJECT(CSocket)
 public:
     enum class Type {
         Invalid,
@@ -35,8 +36,6 @@ public:
 
     Function<void()> on_connected;
 
-    virtual const char* class_name() const override { return "CSocket"; }
-
 protected:
     CSocket(Type, CObject* parent);
 

Libraries/LibCore/CTCPSocket.h

@@ -1,6 +1,7 @@
 #include <LibCore/CSocket.h>
 
 class CTCPSocket final : public CSocket {
+    C_OBJECT(CTCPSocket)
 public:
     explicit CTCPSocket(CObject* parent = nullptr);
     virtual ~CTCPSocket() override;

Libraries/LibCore/CTimer.h

@@ -4,6 +4,7 @@
 #include <LibCore/CObject.h>
 
 class CTimer final : public CObject {
+    C_OBJECT(CTimer)
 public:
     explicit CTimer(CObject* parent = nullptr);
     CTimer(int interval, Function<void()>&& timeout_handler, CObject* parent = nullptr);
@@ -29,8 +30,6 @@ public:
 
     Function<void()> on_timeout;
 
-    virtual const char* class_name() const override { return "CTimer"; }
-
 private:
     virtual void timer_event(CTimerEvent&) override;
 

Libraries/LibCore/CoreIPCClient.h

@@ -49,6 +49,7 @@ private:
 
 template <typename ServerMessage, typename ClientMessage>
 class Connection : public CObject {
+    C_OBJECT(Connection)
 public:
     Connection(const StringView& address)
         : m_notifier(CNotifier(m_connection.fd(), CNotifier::Read))

Libraries/LibCore/CoreIPCServer.h

@@ -55,8 +55,8 @@ T* new_connection_for_client(Args&& ... args)
 };
 
 template <typename ServerMessage, typename ClientMessage>
-class Connection : public CObject
-{
+class Connection : public CObject {
+    C_OBJECT(Connection)
 public:
     Connection(int fd, int client_id)
         : m_socket(fd)
@@ -168,8 +168,6 @@ public:
         m_notifier.set_enabled(false);
     }
 
-    const char* class_name() const override { return "Connection"; }
-
     int client_id() const { return m_client_id; }
     pid_t client_pid() const { return m_pid; }
     void set_client_pid(pid_t pid) { m_pid = pid; }
@@ -194,10 +192,9 @@ protected:
 
 private:
     // TODO: A way to create some kind of CIODevice with an open FD would be nice.
-    class COpenedSocket : public CIODevice
-    {
+    class COpenedSocket : public CIODevice {
+        C_OBJECT(COpenedSocket)
     public:
-        const char* class_name() const override { return "COpenedSocket"; }
         COpenedSocket(int fd)
         {
             set_fd(fd);

Libraries/LibGUI/GAbstractButton.h

@@ -7,6 +7,7 @@
 class GPainter;
 
 class GAbstractButton : public GWidget {
+    C_OBJECT(GAbstractButton)
 public:
     virtual ~GAbstractButton() override;
 
@@ -28,7 +29,6 @@ public:
     bool is_being_pressed() const { return m_being_pressed; }
 
     virtual void click() = 0;
-    virtual const char* class_name() const override { return "GAbstractButton"; }
     virtual bool accepts_focus() const override { return true; }
     virtual bool supports_keyboard_activation() const override { return true; }
     virtual bool is_uncheckable() const { return true; }

Libraries/LibGUI/GAbstractView.h

@@ -7,8 +7,8 @@
 class GModelEditingDelegate;
 
 class GAbstractView : public GScrollableWidget {
+    C_OBJECT(GAbstractView)
     friend class GModel;
-
 public:
     explicit GAbstractView(GWidget* parent);
     virtual ~GAbstractView() override;
@@ -38,8 +38,6 @@ public:
 
     Function<OwnPtr<GModelEditingDelegate>(const GModelIndex&)> aid_create_editing_delegate;
 
-    virtual const char* class_name() const override { return "GAbstractView"; }
-
 protected:
     virtual void model_notification(const GModelNotification&);
     virtual void did_scroll() override;

Libraries/LibGUI/GButton.h

@@ -10,6 +10,7 @@
 class GAction;
 
 class GButton : public GAbstractButton {
+    C_OBJECT(GButton)
 public:
     GButton(const StringView& text, GWidget* parent);
     explicit GButton(GWidget* parent);
@@ -31,7 +32,6 @@ public:
 
     void set_action(GAction&);
 
-    virtual const char* class_name() const override { return "GButton"; }
     virtual bool accepts_focus() const override { return m_focusable; }
     virtual bool supports_keyboard_activation() const override;
     virtual bool is_uncheckable() const override;

Libraries/LibGUI/GCheckBox.h

@@ -5,6 +5,7 @@
 #include <LibGUI/GAbstractButton.h>
 
 class GCheckBox : public GAbstractButton {
+    C_OBJECT(GCheckBox)
 public:
     GCheckBox(const StringView&, GWidget* parent);
     explicit GCheckBox(GWidget* parent);
@@ -12,8 +13,6 @@ public:
 
     virtual void click() override;
 
-    virtual const char* class_name() const override { return "GCheckBox"; }
-
 private:
     // These don't make sense for a check box, so hide them.
     using GAbstractButton::auto_repeat_interval;

Libraries/LibGUI/GComboBox.h

@@ -7,6 +7,7 @@ class GButton;
 class GTextEditor;
 
 class GComboBox : public GWidget {
+    C_OBJECT(GComboBox)
 public:
     explicit GComboBox(GWidget* parent = nullptr);
     virtual ~GComboBox() override;
@@ -28,8 +29,6 @@ public:
     Function<void(const String&)> on_change;
     Function<void()> on_return_pressed;
 
-    virtual const char* class_name() const override { return "GComboBox"; }
-
 protected:
     virtual void resize_event(GResizeEvent&) override;
 

Libraries/LibGUI/GDialog.h

@@ -4,6 +4,7 @@
 #include <LibGUI/GWindow.h>
 
 class GDialog : public GWindow {
+    C_OBJECT(GDialog)
 public:
     enum ExecResult {
         ExecOK = 0,
@@ -18,8 +19,6 @@ public:
     int result() const { return m_result; }
     void done(int result);
 
-    virtual const char* class_name() const override { return "GDialog"; }
-
 protected:
     explicit GDialog(CObject* parent);
 

Libraries/LibGUI/GFilePicker.h

@@ -7,6 +7,7 @@ class GDirectoryModel;
 class GLabel;
 
 class GFilePicker final : public GDialog {
+    C_OBJECT(GFilePicker)
 public:
     enum class Mode {
         Open,
@@ -22,8 +23,6 @@ public:
 
     FileSystemPath selected_file() const { return m_selected_file; }
 
-    virtual const char* class_name() const override { return "GFilePicker"; }
-
 private:
     void set_preview(const FileSystemPath&);
     void clear_preview();
@@ -48,4 +47,4 @@ private:
     GLabel* m_preview_name_label { nullptr };
     GLabel* m_preview_geometry_label { nullptr };
     Mode m_mode { Mode::Open };
-};
+};

Libraries/LibGUI/GFrame.h

@@ -4,6 +4,7 @@
 #include <LibDraw/StylePainter.h>
 
 class GFrame : public GWidget {
+    C_OBJECT(GFrame)
 public:
     explicit GFrame(GWidget* parent = nullptr);
     virtual ~GFrame() override;
@@ -20,8 +21,6 @@ public:
     Rect frame_inner_rect_for_size(const Size& size) const { return { m_thickness, m_thickness, size.width() - m_thickness * 2, size.height() - m_thickness * 2 }; }
     Rect frame_inner_rect() const { return frame_inner_rect_for_size(size()); }
 
-    virtual const char* class_name() const override { return "GFrame"; }
-
 protected:
     void paint_event(GPaintEvent&) override;
 

Libraries/LibGUI/GGroupBox.h

@@ -3,6 +3,7 @@
 #include <LibGUI/GWidget.h>
 
 class GGroupBox : public GWidget {
+    C_OBJECT(GGroupBox)
 public:
     explicit GGroupBox(GWidget* parent);
     GGroupBox(const StringView& title, GWidget* parent);
@@ -11,8 +12,6 @@ public:
     String title() const { return m_title; }
     void set_title(const StringView&);
 
-    virtual const char* class_name() const override { return "GGroupBox"; }
-
 protected:
     virtual void paint_event(GPaintEvent&) override;
 

Libraries/LibGUI/GInputBox.h

@@ -6,14 +6,13 @@ class GButton;
 class GTextEditor;
 
 class GInputBox : public GDialog {
+    C_OBJECT(GInputBox)
 public:
     explicit GInputBox(const StringView& prompt, const StringView& title, CObject* parent = nullptr);
     virtual ~GInputBox() override;
 
     String text_value() const { return m_text_value; }
 
-    virtual const char* class_name() const override { return "GInputBox"; }
-
 private:
     void build();
     String m_prompt;

Libraries/LibGUI/GItemView.h

@@ -9,6 +9,7 @@ class GScrollBar;
 class Painter;
 
 class GItemView : public GAbstractView {
+    C_OBJECT(GItemView)
 public:
     explicit GItemView(GWidget* parent);
     virtual ~GItemView() override;
@@ -22,8 +23,6 @@ public:
     int model_column() const { return m_model_column; }
     void set_model_column(int column) { m_model_column = column; }
 
-    virtual const char* class_name() const override { return "GItemView"; }
-
 private:
     virtual void did_update_model() override;
     virtual void paint_event(GPaintEvent&) override;

Libraries/LibGUI/GLabel.h

@@ -6,6 +6,7 @@
 class GraphicsBitmap;
 
 class GLabel : public GFrame {
+    C_OBJECT(GLabel)
 public:
     explicit GLabel(GWidget* parent = nullptr);
     GLabel(const StringView& text, GWidget* parent = nullptr);
@@ -26,8 +27,6 @@ public:
 
     void size_to_fit();
 
-    virtual const char* class_name() const override { return "GLabel"; }
-
 private:
     virtual void paint_event(GPaintEvent&) override;
 

Libraries/LibGUI/GListView.h

@@ -9,6 +9,7 @@ class GScrollBar;
 class Painter;
 
 class GListView : public GAbstractView {
+    C_OBJECT(GListView)
 public:
     explicit GListView(GWidget* parent);
     virtual ~GListView() override;
@@ -26,8 +27,6 @@ public:
 
     virtual Rect content_rect(const GModelIndex&) const override;
 
-    virtual const char* class_name() const override { return "GListView"; }
-
 private:
     virtual void did_update_model() override;
     virtual void paint_event(GPaintEvent&) override;

Libraries/LibGUI/GMessageBox.h

@@ -3,6 +3,7 @@
 #include <LibGUI/GDialog.h>
 
 class GMessageBox : public GDialog {
+    C_OBJECT(GMessageBox)
 public:
     enum class Type {
         None,
@@ -21,8 +22,6 @@ public:
 
     static void show(const StringView& text, const StringView& title, Type type = Type::None, InputType = InputType::OK, CObject* parent = nullptr);
 
-    virtual const char* class_name() const override { return "GMessageBox"; }
-
 private:
     bool should_include_ok_button() const;
     bool should_include_cancel_button() const;

Libraries/LibGUI/GRadioButton.h

@@ -3,12 +3,11 @@
 #include <LibGUI/GAbstractButton.h>
 
 class GRadioButton : public GAbstractButton {
+    C_OBJECT(GRadioButton)
 public:
     GRadioButton(const StringView& text, GWidget* parent);
     virtual ~GRadioButton() override;
 
-    virtual const char* class_name() const override { return "GRadioButton"; }
-
     virtual void click() override;
 
 protected:

Libraries/LibGUI/GResizeCorner.h

@@ -1,12 +1,11 @@
 #include <LibGUI/GWidget.h>
 
 class GResizeCorner : public GWidget {
+    C_OBJECT(GResizeCorner)
 public:
     explicit GResizeCorner(GWidget* parent);
     virtual ~GResizeCorner() override;
 
-    virtual const char* class_name() const override { return "GResizeCorner"; }
-
 protected:
     virtual void paint_event(GPaintEvent&) override;
     virtual void mousedown_event(GMouseEvent&) override;

Libraries/LibGUI/GScrollBar.h

@@ -5,6 +5,7 @@
 #include <LibGUI/GWidget.h>
 
 class GScrollBar final : public GWidget {
+    C_OBJECT(GScrollBar)
 public:
     explicit GScrollBar(Orientation, GWidget* parent);
     virtual ~GScrollBar() override;
@@ -27,8 +28,6 @@ public:
 
     Function<void(int)> on_change;
 
-    virtual const char* class_name() const override { return "GScrollBar"; }
-
     enum Component {
         Invalid,
         DecrementButton,

Libraries/LibGUI/GScrollableWidget.h

@@ -5,6 +5,7 @@
 class GScrollBar;
 
 class GScrollableWidget : public GFrame {
+    C_OBJECT(GScrollableWidget)
 public:
     virtual ~GScrollableWidget() override;
 
@@ -37,8 +38,6 @@ public:
     int width_occupied_by_vertical_scrollbar() const;
     int height_occupied_by_horizontal_scrollbar() const;
 
-    virtual const char* class_name() const override { return "GScrollableWidget"; }
-
 protected:
     explicit GScrollableWidget(GWidget* parent);
     virtual void resize_event(GResizeEvent&) override;

Libraries/LibGUI/GSpinBox.h

@@ -6,6 +6,7 @@ class GButton;
 class GTextEditor;
 
 class GSpinBox : public GWidget {
+    C_OBJECT(GSpinBox)
 public:
     GSpinBox(GWidget* parent = nullptr);
     virtual ~GSpinBox() override;
@@ -21,8 +22,6 @@ public:
 
     Function<void(int value)> on_change;
 
-    virtual const char* class_name() const override { return "GSpinBox"; }
-
 protected:
     virtual void resize_event(GResizeEvent&) override;
 

Libraries/LibGUI/GStackWidget.h

@@ -3,6 +3,7 @@
 #include <LibGUI/GWidget.h>
 
 class GStackWidget : public GWidget {
+    C_OBJECT(GStackWidget)
 public:
     explicit GStackWidget(GWidget* parent);
     virtual ~GStackWidget() override;
@@ -12,8 +13,6 @@ public:
 
     Function<void(GWidget*)> on_active_widget_change;
 
-    virtual const char* class_name() const override { return "GStackWidget"; }
-
 protected:
     virtual void child_event(CChildEvent&) override;
     virtual void resize_event(GResizeEvent&) override;

Libraries/LibGUI/GStatusBar.h

@@ -6,6 +6,7 @@ class GLabel;
 class GResizeCorner;
 
 class GStatusBar : public GWidget {
+    C_OBJECT(GStatusBar)
 public:
     explicit GStatusBar(GWidget* parent);
     virtual ~GStatusBar() override;
@@ -13,8 +14,6 @@ public:
     String text() const;
     void set_text(const StringView&);
 
-    virtual const char* class_name() const override { return "GStatusBar"; }
-
 private:
     virtual void paint_event(GPaintEvent&) override;
 

Libraries/LibGUI/GTabWidget.h

@@ -3,6 +3,7 @@
 #include <LibGUI/GWidget.h>
 
 class GTabWidget : public GWidget {
+    C_OBJECT(GTabWidget)
 public:
     explicit GTabWidget(GWidget* parent);
     virtual ~GTabWidget() override;
@@ -15,8 +16,6 @@ public:
 
     void add_widget(const StringView&, GWidget*);
 
-    virtual const char* class_name() const override { return "GTabWidget"; }
-
 protected:
     virtual void paint_event(GPaintEvent&) override;
     virtual void child_event(CChildEvent&) override;

Libraries/LibGUI/GTableView.h

@@ -9,6 +9,7 @@ class GScrollBar;
 class Painter;
 
 class GTableView : public GAbstractView {
+    C_OBJECT(GTableView)
 public:
     explicit GTableView(GWidget* parent);
     virtual ~GTableView() override;
@@ -34,8 +35,6 @@ public:
 
     virtual Rect content_rect(const GModelIndex&) const override;
 
-    virtual const char* class_name() const override { return "GTableView"; }
-
 private:
     virtual void did_update_model() override;
     virtual void paint_event(GPaintEvent&) override;

Libraries/LibGUI/GTextBox.h

@@ -4,9 +4,8 @@
 #include <LibGUI/GTextEditor.h>
 
 class GTextBox final : public GTextEditor {
+    C_OBJECT(GTextBox)
 public:
     explicit GTextBox(GWidget* parent);
     virtual ~GTextBox() override;
-
-    virtual const char* class_name() const override { return "GTextBox"; }
 };

Libraries/LibGUI/GTextEditor.h

@@ -78,6 +78,7 @@ private:
 };
 
 class GTextEditor : public GScrollableWidget {
+    C_OBJECT(GTextEditor)
 public:
     enum Type {
         MultiLine,
@@ -134,8 +135,6 @@ public:
     Function<void()> on_return_pressed;
     Function<void()> on_escape_pressed;
 
-    virtual const char* class_name() const override { return "GTextEditor"; }
-
     GAction& undo_action() { return *m_undo_action; }
     GAction& redo_action() { return *m_redo_action; }
     GAction& cut_action() { return *m_cut_action; }

Libraries/LibGUI/GToolBar.cpp

@@ -45,6 +45,7 @@ void GToolBar::add_action(GAction& action)
 }
 
 class SeparatorWidget final : public GWidget {
+    C_OBJECT(SeparatorWidget)
 public:
     SeparatorWidget(GWidget* parent)
         : GWidget(parent)
@@ -63,9 +64,6 @@ public:
         painter.draw_line({ 0, 0 }, { 0, rect().bottom() }, Color::MidGray);
         painter.draw_line({ 1, 0 }, { 1, rect().bottom() }, Color::White);
     }
-
-private:
-    virtual const char* class_name() const override { return "SeparatorWidget"; }
 };
 
 void GToolBar::add_separator()

Libraries/LibGUI/GToolBar.h

@@ -6,6 +6,7 @@
 class GAction;
 
 class GToolBar : public GWidget {
+    C_OBJECT(GToolBar)
 public:
     explicit GToolBar(GWidget* parent);
     virtual ~GToolBar() override;
@@ -16,8 +17,6 @@ public:
     bool has_frame() const { return m_has_frame; }
     void set_has_frame(bool has_frame) { m_has_frame = has_frame; }
 
-    virtual const char* class_name() const override { return "GToolBar"; }
-
 private:
     virtual void paint_event(GPaintEvent&) override;
 

Libraries/LibGUI/GTreeView.h

@@ -3,12 +3,12 @@
 #include <LibGUI/GAbstractView.h>
 
 class GTreeView : public GAbstractView {
+    C_OBJECT(GTreeView)
 public:
     explicit GTreeView(GWidget*);
     virtual ~GTreeView() override;
 
     virtual void scroll_into_view(const GModelIndex&, Orientation);
-    virtual const char* class_name() const override { return "GTreeView"; }
 
 protected:
     virtual void paint_event(GPaintEvent&) override;

Libraries/LibGUI/GWidget.h

@@ -32,6 +32,7 @@ enum class VerticalDirection {
 };
 
 class GWidget : public CObject {
+    C_OBJECT(GWidget)
 public:
     explicit GWidget(GWidget* parent = nullptr);
     virtual ~GWidget() override;
@@ -113,8 +114,6 @@ public:
     HitTestResult hit_test(const Point&);
     GWidget* child_at(const Point&) const;
 
-    virtual const char* class_name() const override { return "GWidget"; }
-
     void set_relative_rect(const Rect&);
     void set_relative_rect(int x, int y, int width, int height) { set_relative_rect({ x, y, width, height }); }
 

Libraries/LibGUI/GWindow.h

@@ -22,6 +22,7 @@ enum class GStandardCursor {
 };
 
 class GWindow : public CObject {
+    C_OBJECT(GWindow)
 public:
     GWindow(CObject* parent = nullptr);
     virtual ~GWindow() override;
@@ -123,8 +124,6 @@ public:
 
     Vector<GWidget*> focusable_widgets() const;
 
-    virtual const char* class_name() const override { return "GWindow"; }
-
 protected:
     virtual void wm_event(GWMEvent&);