static void
draw_function (Gtk::DrawingArea *area,
               cairo_::t        *cr,
               int             width,
               int             height,
               gpointer        data)
{
  Gdk::RGBA color;
  Gtk::StyleContext *context;

  context = gtk_widget_get_style_context (GTK_WIDGET (area));

  cairo_::arc (cr,
             width / 2.0, height / 2.0,
             MIN (width, height) / 2.0,
             0, 2 * G_PI);

  gtk_style_context_get_color (context,
                               &color);
  gdk_cairo_::set_source_rgba (cr, &color);

  cairo_::fill (cr);
}

int
main (int argc, char **argv)
{
  gtk_init ();

  Gtk::Widget *area = gtk_drawing_area_new ();
  gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (area), 100);
  gtk_drawing_area_set_content_height (GTK_DRAWING_AREA (area), 100);
  gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (area),
                                  draw_function,
                                  NULL, NULL);
  return 0;
}

Instance methods inherited from module Gtk::ConstraintTarget

to_unsafe to_unsafe

Constructor methods inherited from module Gtk::ConstraintTarget

cast(obj : GObject::Object) : self cast

Class methods inherited from module Gtk::ConstraintTarget

cast?(obj : GObject::Object) : self | Nil cast?, g_type : UInt64 g_type

Instance methods inherited from module Gtk::Buildable

buildable_id : String | Nil buildable_id, to_unsafe to_unsafe

Constructor methods inherited from module Gtk::Buildable

cast(obj : GObject::Object) : self cast

Class methods inherited from module Gtk::Buildable

cast?(obj : GObject::Object) : self | Nil cast?, g_type : UInt64 g_type

Instance methods inherited from module Gtk::Accessible

accessible_role : Gtk::AccessibleRole accessible_role, accessible_role=(value : Gtk::AccessibleRole) : Gtk::AccessibleRole accessible_role=, reset_property(property : Gtk::AccessibleProperty) : Nil reset_property, reset_relation(relation : Gtk::AccessibleRelation) : Nil reset_relation, reset_state(state : Gtk::AccessibleState) : Nil reset_state, to_unsafe to_unsafe, update_property(properties : Enumerable(Gtk::AccessibleProperty), values : Enumerable(_)) : Nil update_property, update_relation(relations : Enumerable(Gtk::AccessibleRelation), values : Enumerable(_)) : Nil update_relation, update_state(states : Enumerable(Gtk::AccessibleState), values : Enumerable(_)) : Nil update_state

Constructor methods inherited from module Gtk::Accessible

cast(obj : GObject::Object) : self cast

Class methods inherited from module Gtk::Accessible

cast?(obj : GObject::Object) : self | Nil cast?, g_type : UInt64 g_type

Instance methods inherited from class Gtk::Widget

==(other : self) ==, action_set_enabled(action_name : String, enabled : Bool) : Nil action_set_enabled, activate : Bool activate, activate_action(name : String, args : _ | Nil) : Bool activate_action, activate_default : Nil activate_default, add_controller(controller : Gtk::EventController) : Nil add_controller, add_css_class(css_class : String) : Nil add_css_class, add_mnemonic_label(label : Gtk::Widget) : Nil add_mnemonic_label, add_tick_callback(callback : Gtk::TickCallback) : UInt32 add_tick_callback, allocate(width : Int32, height : Int32, baseline : Int32, transform : Gsk::Transform | Nil) : Nil allocate, allocated_baseline : Int32 allocated_baseline, allocated_height : Int32 allocated_height, allocated_width : Int32 allocated_width, allocation : Gdk::Rectangle allocation, ancestor(widget_type : UInt64) : Gtk::Widget | Nil ancestor, can_focus : Bool can_focus, can_focus=(can_focus : Bool) : Nil can_focus=, can_focus? : Bool can_focus?, can_target : Bool can_target, can_target=(can_target : Bool) : Nil can_target=, can_target? : Bool can_target?, child_focus(direction : Gtk::DirectionType) : Bool child_focus, child_visible : Bool child_visible, child_visible=(child_visible : Bool) : Nil child_visible=, children : Iterator(Widget) children, clipboard : Gdk::Clipboard clipboard, compute_bounds(target : Gtk::Widget) : Graphene::Rect compute_bounds, compute_expand(orientation : Gtk::Orientation) : Bool compute_expand, compute_point(target : Gtk::Widget, point : Graphene::Point) : Graphene::Point compute_point, compute_transform(target : Gtk::Widget) : Graphene::Matrix compute_transform, contains(x : Float64, y : Float64) : Bool contains, create_pango_context : Pango::Context create_pango_context, create_pango_layout(text : String | Nil) : Pango::Layout create_pango_layout, css_classes : Enumerable(String) css_classes, css_classes=(classes : Enumerable(String)) : Nil css_classes=, css_name : String css_name, css_name=(value : String) : String css_name=, cursor : Gdk::Cursor | Nil cursor, cursor=(cursor : Gdk::Cursor | Nil) : Nil cursor=, cursor_from_name=(name : String | Nil) : Nil cursor_from_name=, destroy_signal destroy_signal, direction : Gtk::TextDirection direction, direction=(dir : Gtk::TextDirection) : Nil direction=, direction_changed_signal direction_changed_signal, display : Gdk::Display display, drag_check_threshold(start_x : Int32, start_y : Int32, current_x : Int32, current_y : Int32) : Bool drag_check_threshold, error_bell : Nil error_bell, first_child : Gtk::Widget | Nil first_child, focus_child : Gtk::Widget | Nil focus_child, focus_child=(child : Gtk::Widget | Nil) : Nil focus_child=, focus_on_click : Bool focus_on_click, focus_on_click=(focus_on_click : Bool) : Nil focus_on_click=, focus_on_click? : Bool focus_on_click?, focusable : Bool focusable, focusable=(focusable : Bool) : Nil focusable=, focusable? : Bool focusable?, font_map : Pango::FontMap | Nil font_map, font_map=(font_map : Pango::FontMap | Nil) : Nil font_map=, font_options : Cairo::FontOptions | Nil font_options, font_options=(options : Cairo::FontOptions | Nil) : Nil font_options=, frame_clock : Gdk::FrameClock | Nil frame_clock, grab_focus : Bool grab_focus, halign : Gtk::Align halign, halign=(align : Gtk::Align) : Nil halign=, has_css_class(css_class : String) : Bool has_css_class, has_default : Bool has_default, has_default? : Bool has_default?, has_focus : Bool has_focus, has_focus? : Bool has_focus?, has_tooltip : Bool has_tooltip, has_tooltip=(has_tooltip : Bool) : Nil has_tooltip=, has_tooltip? : Bool has_tooltip?, has_visible_focus : Bool has_visible_focus, hash(hasher) hash, height : Int32 height, height_request : Int32 height_request, height_request=(value : Int32) : Int32 height_request=, hexpand : Bool hexpand, hexpand=(expand : Bool) : Nil hexpand=, hexpand? : Bool hexpand?, hexpand_set : Bool hexpand_set, hexpand_set=(set : Bool) : Nil hexpand_set=, hexpand_set? : Bool hexpand_set?, hide : Nil hide, hide_signal hide_signal, in_destruction : Bool in_destruction, init_template : Nil init_template, insert_action_group(name : String, group : Gio::ActionGroup | Nil) : Nil insert_action_group, insert_after(parent : Gtk::Widget, previous_sibling : Gtk::Widget | Nil) : Nil insert_after, insert_before(parent : Gtk::Widget, next_sibling : Gtk::Widget | Nil) : Nil insert_before, is_ancestor(ancestor : Gtk::Widget) : Bool is_ancestor, is_drawable : Bool is_drawable, is_focus : Bool is_focus, is_sensitive : Bool is_sensitive, is_visible : Bool is_visible, keynav_failed(direction : Gtk::DirectionType) : Bool keynav_failed, keynav_failed_signal keynav_failed_signal, last_child : Gtk::Widget | Nil last_child, layout_manager : Gtk::LayoutManager | Nil layout_manager, layout_manager=(layout_manager : Gtk::LayoutManager | Nil) : Nil layout_manager=, list_mnemonic_labels : GLib::List list_mnemonic_labels, map : Nil map, map_signal map_signal, mapped : Bool mapped, margin_bottom : Int32 margin_bottom, margin_bottom=(margin : Int32) : Nil margin_bottom=, margin_end : Int32 margin_end, margin_end=(margin : Int32) : Nil margin_end=, margin_start : Int32 margin_start, margin_start=(margin : Int32) : Nil margin_start=, margin_top : Int32 margin_top, margin_top=(margin : Int32) : Nil margin_top=, measure(orientation : Gtk::Orientation, for_size : Int32) : Nil measure, mnemonic_activate(group_cycling : Bool) : Bool mnemonic_activate, mnemonic_activate_signal mnemonic_activate_signal, move_focus_signal move_focus_signal, name : String name, name=(name : String) : Nil name=, native : Gtk::Native | Nil native, next_sibling : Gtk::Widget | Nil next_sibling, observe_children : Gio::ListModel observe_children, observe_controllers : Gio::ListModel observe_controllers, opacity : Float64 opacity, opacity=(opacity : Float64) : Nil opacity=, overflow : Gtk::Overflow overflow, overflow=(overflow : Gtk::Overflow) : Nil overflow=, pango_context : Pango::Context pango_context, parent : Gtk::Widget | Nil parent, parent=(parent : Gtk::Widget) : Nil parent=, pick(x : Float64, y : Float64, flags : Gtk::PickFlags) : Gtk::Widget | Nil pick, preferred_size : Gtk::Requisition preferred_size, prev_sibling : Gtk::Widget | Nil prev_sibling, primary_clipboard : Gdk::Clipboard primary_clipboard, query_tooltip_signal query_tooltip_signal, queue_allocate : Nil queue_allocate, queue_draw : Nil queue_draw, queue_resize : Nil queue_resize, realize : Nil realize, realize_signal realize_signal, realized : Bool realized, receives_default : Bool receives_default, receives_default=(receives_default : Bool) : Nil receives_default=, receives_default? : Bool receives_default?, remove_controller(controller : Gtk::EventController) : Nil remove_controller, remove_css_class(css_class : String) : Nil remove_css_class, remove_mnemonic_label(label : Gtk::Widget) : Nil remove_mnemonic_label, remove_tick_callback(id : UInt32) : Nil remove_tick_callback, request_mode : Gtk::SizeRequestMode request_mode, root : Gtk::Root | Nil root, scale_factor : Int32 scale_factor, sensitive : Bool sensitive, sensitive=(sensitive : Bool) : Nil sensitive=, sensitive? : Bool sensitive?, set_size_request(width : Int32, height : Int32) : Nil set_size_request, set_state_flags(flags : Gtk::StateFlags, clear : Bool) : Nil set_state_flags, settings : Gtk::Settings settings, should_layout : Bool should_layout, show : Nil show, show_signal show_signal, size(orientation : Gtk::Orientation) : Int32 size, size_allocate(allocation : Gdk::Rectangle, baseline : Int32) : Nil size_allocate, size_request : Nil size_request, snapshot_child(child : Gtk::Widget, snapshot : Gtk::Snapshot) : Nil snapshot_child, state_flags : Gtk::StateFlags state_flags, state_flags_changed_signal state_flags_changed_signal, style_context : Gtk::StyleContext style_context, template_child(widget_type : UInt64, name : String) : GObject::Object
template_child(name : String) : GObject::Object template_child, tooltip_markup : String | Nil tooltip_markup, tooltip_markup=(value : String) : String
tooltip_markup=(markup : String | Nil) : Nil tooltip_markup=, tooltip_text : String | Nil tooltip_text, tooltip_text=(value : String) : String
tooltip_text=(text : String | Nil) : Nil tooltip_text=, translate_coordinates(dest_widget : Gtk::Widget, src_x : Float64, src_y : Float64) : Bool translate_coordinates, trigger_tooltip_query : Nil trigger_tooltip_query, unmap : Nil unmap, unmap_signal unmap_signal, unparent : Nil unparent, unrealize : Nil unrealize, unrealize_signal unrealize_signal, unset_state_flags(flags : Gtk::StateFlags) : Nil unset_state_flags, valign : Gtk::Align valign, valign=(align : Gtk::Align) : Nil valign=, vexpand : Bool vexpand, vexpand=(expand : Bool) : Nil vexpand=, vexpand? : Bool vexpand?, vexpand_set : Bool vexpand_set, vexpand_set=(set : Bool) : Nil vexpand_set=, vexpand_set? : Bool vexpand_set?, visible : Bool visible, visible=(visible : Bool) : Nil visible=, visible? : Bool visible?, width : Int32 width, width_request : Int32 width_request, width_request=(value : Int32) : Int32 width_request=

Constructor methods inherited from class Gtk::Widget

new
new(*, accessible_role : Gtk::AccessibleRole | Nil = nil, can_focus : Bool | Nil = nil, can_target : Bool | Nil = nil, css_classes : Enumerable(String) | Nil = nil, css_name : String | Nil = nil, cursor : Gdk::Cursor | Nil = nil, focus_on_click : Bool | Nil = nil, focusable : Bool | Nil = nil, halign : Gtk::Align | Nil = nil, has_default : Bool | Nil = nil, has_focus : Bool | Nil = nil, has_tooltip : Bool | Nil = nil, height_request : Int32 | Nil = nil, hexpand : Bool | Nil = nil, hexpand_set : Bool | Nil = nil, layout_manager : Gtk::LayoutManager | Nil = nil, margin_bottom : Int32 | Nil = nil, margin_end : Int32 | Nil = nil, margin_start : Int32 | Nil = nil, margin_top : Int32 | Nil = nil, name : String | Nil = nil, opacity : Float64 | Nil = nil, overflow : Gtk::Overflow | Nil = nil, parent : Gtk::Widget | Nil = nil, receives_default : Bool | Nil = nil, root : Gtk::Root | Nil = nil, scale_factor : Int32 | Nil = nil, sensitive : Bool | Nil = nil, tooltip_markup : String | Nil = nil, tooltip_text : String | Nil = nil, valign : Gtk::Align | Nil = nil, vexpand : Bool | Nil = nil, vexpand_set : Bool | Nil = nil, visible : Bool | Nil = nil, width_request : Int32 | Nil = nil) new

Class methods inherited from class Gtk::Widget

default_direction : Gtk::TextDirection default_direction, default_direction=(dir : Gtk::TextDirection) : Nil default_direction=, g_type : UInt64 g_type

Instance methods inherited from module Gtk::ConstraintTarget

to_unsafe to_unsafe

Constructor methods inherited from module Gtk::ConstraintTarget

cast(obj : GObject::Object) : self cast

Class methods inherited from module Gtk::ConstraintTarget

cast?(obj : GObject::Object) : self | Nil cast?, g_type : UInt64 g_type

Instance methods inherited from module Gtk::Buildable

buildable_id : String | Nil buildable_id, to_unsafe to_unsafe

Constructor methods inherited from module Gtk::Buildable

cast(obj : GObject::Object) : self cast

Class methods inherited from module Gtk::Buildable

cast?(obj : GObject::Object) : self | Nil cast?, g_type : UInt64 g_type

Instance methods inherited from module Gtk::Accessible

accessible_role : Gtk::AccessibleRole accessible_role, accessible_role=(value : Gtk::AccessibleRole) : Gtk::AccessibleRole accessible_role=, reset_property(property : Gtk::AccessibleProperty) : Nil reset_property, reset_relation(relation : Gtk::AccessibleRelation) : Nil reset_relation, reset_state(state : Gtk::AccessibleState) : Nil reset_state, to_unsafe to_unsafe, update_property(properties : Enumerable(Gtk::AccessibleProperty), values : Enumerable(_)) : Nil update_property, update_relation(relations : Enumerable(Gtk::AccessibleRelation), values : Enumerable(_)) : Nil update_relation, update_state(states : Enumerable(Gtk::AccessibleState), values : Enumerable(_)) : Nil update_state

Constructor methods inherited from module Gtk::Accessible

cast(obj : GObject::Object) : self cast

Class methods inherited from module Gtk::Accessible

cast?(obj : GObject::Object) : self | Nil cast?, g_type : UInt64 g_type

Instance methods inherited from class GObject::InitiallyUnowned

==(other : self) ==, hash(hasher) hash

Constructor methods inherited from class GObject::InitiallyUnowned

new new

Class methods inherited from class GObject::InitiallyUnowned

g_type : UInt64 g_type

Instance methods inherited from class GObject::Object

==(other : self) ==, bind_property(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags) : GObject::Binding bind_property, bind_property_full(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags, transform_to : GObject::Closure, transform_from : GObject::Closure) : GObject::Binding bind_property_full, data(key : String) : Pointer(Void) | Nil data, finalize finalize, freeze_notify : Nil freeze_notify, getv(names : Enumerable(String), values : Enumerable(_)) : Nil getv, hash(hasher) hash, notify(property_name : String) : Nil notify, notify_by_pspec(pspec : GObject::ParamSpec) : Nil notify_by_pspec, notify_signal notify_signal, property(property_name : String, value : _) : Nil property, qdata(quark : UInt32) : Pointer(Void) | Nil qdata, ref_count : UInt32 ref_count, run_dispose : Nil run_dispose, set_data(key : String, data : Pointer(Void) | Nil) : Nil set_data, set_property(property_name : String, value : _) : Nil set_property, steal_data(key : String) : Pointer(Void) | Nil steal_data, steal_qdata(quark : UInt32) : Pointer(Void) | Nil steal_qdata, thaw_notify : Nil thaw_notify, to_unsafe : Pointer(Void) to_unsafe, watch_closure(closure : GObject::Closure) : Nil watch_closure

Constructor methods inherited from class GObject::Object

cast(obj : GObject::Object) : self cast, new(pointer : Pointer(Void), transfer : GICrystal::Transfer)
new new, newv(object_type : UInt64, parameters : Enumerable(GObject::Parameter)) : self newv

Class methods inherited from class GObject::Object

cast?(obj : GObject::Object) : self | Nil cast?, compat_control(what : UInt64, data : Pointer(Void) | Nil) : UInt64 compat_control, g_type : UInt64 g_type, interface_find_property(g_iface : GObject::TypeInterface, property_name : String) : GObject::ParamSpec interface_find_property, interface_list_properties(g_iface : GObject::TypeInterface) : Enumerable(GObject::ParamSpec) interface_list_properties

Macros inherited from class GObject::Object

previous_vfunc(*args) previous_vfunc, previous_vfunc!(*args) previous_vfunc!, signal(signature) signal