Gtk::DrawingArea Class Reference

A widget for custom user interface elements. More...

#include <gtkmm/drawingarea.h>

Inheritance diagram for Gtk::DrawingArea:

Public Types
using	SlotDraw = sigc::slot< void(const Cairo::RefPtr< Cairo::Context > &, int, int)>
	Whenever the drawing area needs to redraw, this slot will be called.
Public Types inherited from Gtk::Widget
using	PreferredSize = MinimumNatural< Requisition >
	Structure returned by the non-output-parameter overload of get_preferred_size().
using	SlotTick = sigc::slot< bool(const Glib::RefPtr< Gdk::FrameClock > &)>
	Callback type for adding a function to update animations.
Public Types inherited from Gtk::Accessible
enum class	Role {   Role::ALERT ,   Role::ALERT_DIALOG ,   Role::BANNER ,   Role::BUTTON ,   Role::CAPTION ,   Role::CELL ,   Role::CHECKBOX ,   Role::COLUMN_HEADER ,   Role::COMBO_BOX ,   Role::COMMAND ,   Role::COMPOSITE ,   Role::DIALOG ,   Role::DOCUMENT ,   Role::FEED ,   Role::FORM ,   Role::GENERIC ,   Role::GRID ,   Role::GRID_CELL ,   Role::GROUP ,   Role::HEADING ,   Role::IMG ,   Role::INPUT ,   Role::LABEL ,   Role::LANDMARK ,   Role::LEGEND ,   Role::LINK ,   Role::LIST ,   Role::LIST_BOX ,   Role::LIST_ITEM ,   Role::LOG ,   Role::MAIN ,   Role::MARQUEE ,   Role::MATH ,   Role::METER ,   Role::MENU ,   Role::MENU_BAR ,   Role::MENU_ITEM ,   Role::MENU_ITEM_CHECKBOX ,   Role::MENU_ITEM_RADIO ,   Role::NAVIGATION ,   Role::NONE ,   Role::NOTE ,   Role::OPTION ,   Role::PRESENTATION ,   Role::PROGRESS_BAR ,   Role::RADIO ,   Role::RADIO_GROUP ,   Role::RANGE ,   Role::REGION ,   Role::ROW ,   Role::ROW_GROUP ,   Role::ROW_HEADER ,   Role::SCROLLBAR ,   Role::SEARCH ,   Role::SEARCH_BOX ,   Role::SECTION ,   Role::SECTION_HEAD ,   Role::SELECT ,   Role::SEPARATOR ,   Role::SLIDER ,   Role::SPIN_BUTTON ,   Role::STATUS ,   Role::STRUCTURE ,   Role::SWITCH ,   Role::TAB ,   Role::TABLE ,   Role::TAB_LIST ,   Role::TAB_PANEL ,   Role::TEXT_BOX ,   Role::TIME ,   Role::TIMER ,   Role::TOOLBAR ,   Role::TOOLTIP ,   Role::TREE ,   Role::TREE_GRID ,   Role::TREE_ITEM ,   Role::WIDGET ,   Role::WINDOW ,   Role::TOGGLE_BUTTON ,   Role::APPLICATION ,   Role::PARAGRAPH ,   Role::BLOCK_QUOTE ,   Role::ARTICLE ,   Role::COMMENT ,   Role::TERMINAL }
	The accessible role for a Gtk::Accessible implementation. More...
enum class	State {   State::BUSY ,   State::CHECKED ,   State::DISABLED ,   State::EXPANDED ,   State::HIDDEN ,   State::INVALID ,   State::PRESSED ,   State::SELECTED ,   State::VISITED }
	The possible accessible states of a Gtk::Accessible. More...
enum class	Property {   Property::AUTOCOMPLETE ,   Property::DESCRIPTION ,   Property::HAS_POPUP ,   Property::KEY_SHORTCUTS ,   Property::LABEL ,   Property::LEVEL ,   Property::MODAL ,   Property::MULTI_LINE ,   Property::MULTI_SELECTABLE ,   Property::ORIENTATION ,   Property::PLACEHOLDER ,   Property::READ_ONLY ,   Property::REQUIRED ,   Property::ROLE_DESCRIPTION ,   Property::SORT ,   Property::VALUE_MAX ,   Property::VALUE_MIN ,   Property::VALUE_NOW ,   Property::VALUE_TEXT ,   Property::HELP_TEXT }
	The possible accessible properties of a Gtk::Accessible. More...
enum class	Relation {   Relation::ACTIVE_DESCENDANT ,   Relation::COL_COUNT ,   Relation::COL_INDEX ,   Relation::COL_INDEX_TEXT ,   Relation::COL_SPAN ,   Relation::CONTROLS ,   Relation::DESCRIBED_BY ,   Relation::DETAILS ,   Relation::ERROR_MESSAGE ,   Relation::FLOW_TO ,   Relation::LABELLED_BY ,   Relation::OWNS ,   Relation::POS_IN_SET ,   Relation::ROW_COUNT ,   Relation::ROW_INDEX ,   Relation::ROW_INDEX_TEXT ,   Relation::ROW_SPAN ,   Relation::SET_SIZE }
	The possible accessible relations of a Gtk::Accessible. More...
enum class	PlatformState {   PlatformState::FOCUSABLE ,   PlatformState::FOCUSED ,   PlatformState::ACTIVE }
	The various platform states which can be queried using Gtk::Accessible::get_platform_state(). More...
enum class	AnnouncementPriority {   AnnouncementPriority::LOW ,   AnnouncementPriority::MEDIUM ,   AnnouncementPriority::HIGH }
	The priority of an accessibility announcement. More...

Public Member Functions
	DrawingArea (DrawingArea &&src) noexcept
DrawingArea &	operator= (DrawingArea &&src) noexcept
	DrawingArea (const DrawingArea &)=delete
DrawingArea &	operator= (const DrawingArea &)=delete
	~DrawingArea () noexcept override
GtkDrawingArea *	gobj ()
	Provides access to the underlying C GObject.
const GtkDrawingArea *	gobj () const
	Provides access to the underlying C GObject.
	DrawingArea ()
void	set_content_width (int width)
	Sets the desired width of the contents of the drawing area.
int	get_content_width () const
	Retrieves the content width of the Gtk::DrawingArea.
void	set_content_height (int width)
	Sets the desired height of the contents of the drawing area.
int	get_content_height () const
	Retrieves the content height of the Gtk::DrawingArea.
void	set_draw_func (const SlotDraw &slot)
	Sets a draw function.
Glib::SignalProxy< void(int, int)>	signal_resize ()
Glib::PropertyProxy< int >	property_content_width ()
	The content width.
Glib::PropertyProxy_ReadOnly< int >	property_content_width () const
	The content width.
Glib::PropertyProxy< int >	property_content_height ()
	The content height.
Glib::PropertyProxy_ReadOnly< int >	property_content_height () const
	The content height.
Public Member Functions inherited from Gtk::Widget
	Widget (Widget &&src) noexcept
Widget &	operator= (Widget &&src) noexcept
	Widget (const Widget &)=delete
Widget &	operator= (const Widget &)=delete
	~Widget () noexcept override
	Destroys the widget.
GtkWidget *	gobj ()
	Provides access to the underlying C GObject.
const GtkWidget *	gobj () const
	Provides access to the underlying C GObject.
Glib::RefPtr< ConstraintTarget >	make_refptr_constrainttarget ()
	Converts this widget to a reference counted Gtk::ConstraintTarget.
Glib::RefPtr< const ConstraintTarget >	make_refptr_constrainttarget () const
	Converts this widget to a reference counted Gtk::ConstraintTarget.
void	show ()
	Flags a widget to be displayed.
void	hide ()
	Reverses the effects of show().
void	queue_draw ()
	Schedules this widget to be redrawn in the paint phase of the current or the next frame.
void	queue_resize ()
	Flags a widget to have its size renegotiated.
void	queue_allocate ()
	Flags the widget for a rerun of the size_allocate_vfunc() function.
void	size_allocate (const Allocation &allocation, int baseline)
	Allocates widget with a transformation that translates the origin to the position in allocation.
SizeRequestMode	get_request_mode () const
	Gets whether the widget prefers a height-for-width layout or a width-for-height layout.
void	measure (Orientation orientation, int for_size, int & minimum, int & natural, int &minimum_baseline, int &natural_baseline) const
	Measures widget in the orientation orientation and for the given for_size.
Measurements	measure (Orientation orientation, int for_size=-1) const
	Like the other overload of measure() but returns a structure holding the sizes/baselines instead of using output parameters.
void	get_preferred_size (Requisition &minimum_size, Requisition &natural_size) const
	Retrieves the minimum and natural size of a widget, taking into account the widget’s preference for height-for-width management.
PreferredSize	get_preferred_size () const
	Like the other overload of get_preferred_size() but returns a structure holding the sizes instead of using output parameters.
void	set_layout_manager (const Glib::RefPtr< LayoutManager > &layout_manager)
	Sets the layout manager delegate instance that provides an implementation for measuring and allocating the children of widget.
void	unset_layout_manager ()
	Undoes the effect of a previous call to set_layout_manager().
Glib::RefPtr< LayoutManager >	get_layout_manager ()
	Retrieves the layout manager used by widget.
Glib::RefPtr< const LayoutManager >	get_layout_manager () const
	Retrieves the layout manager used by widget.
bool	mnemonic_activate (bool group_cycling)
	Emits the signal_mnemonic_activate() signal.
bool	activate ()
	For widgets that can be “activated” (buttons, menu items, etc.) this function activates them.
void	set_can_focus (bool can_focus=true)
	Specifies whether the input focus can enter the widget or any of its children.
bool	get_can_focus () const
	Determines whether the input focus can enter widget or any of its children.
void	set_focusable (bool focusable=true)
	Specifies whether widget can own the input focus.
bool	get_focusable () const
	Determines whether widget can own the input focus.
bool	has_focus () const
	Determines if the widget has the global input focus.
bool	is_focus () const
	Determines if the widget is the focus widget within its toplevel.
bool	has_visible_focus () const
	Determines if the widget should show a visible indication that it has the global input focus.
bool	grab_focus ()
	Causes widget to have the keyboard focus for the Gtk::Window it's inside.
void	set_focus_on_click (bool focus_on_click=true)
	Sets whether the widget should grab focus when it is clicked with the mouse.
bool	get_focus_on_click () const
	Returns whether the widget should grab focus when it is clicked with the mouse.
void	set_can_target (bool can_target=true)
	Sets whether widget can be the target of pointer events.
bool	get_can_target () const
	Queries whether widget can be the target of pointer events.
bool	has_default () const
	Determines whether widget is the current default widget within its toplevel.
void	set_receives_default (bool receives_default=true)
	Specifies whether widget will be treated as the default widget within its toplevel when it has the focus, even if another widget is the default.
bool	get_receives_default () const
	Determines whether widget is always treated as the default widget within its toplevel when it has the focus, even if another widget is the default.
void	set_name (const Glib::ustring & name)
	Sets a widgets name.
void	unset_name ()
Glib::ustring	get_name () const
	Retrieves the name of a widget.
void	set_state_flags (StateFlags flags, bool clear=true)
	Turns on flag values in the current widget state.
void	unset_state_flags (StateFlags flags)
	Turns off flag values for the current widget state.
StateFlags	get_state_flags () const
	Returns the widget state as a flag set.
void	set_sensitive (bool sensitive=true)
	Sets the sensitivity of a widget.
bool	get_sensitive () const
	Returns the widget’s sensitivity.
bool	is_sensitive () const
	Returns the widget’s effective sensitivity.
void	set_visible (bool visible=true)
	Sets the visibility state of widget.
bool	get_visible () const
	Determines whether the widget is visible.
bool	is_visible () const
	Determines whether the widget and all its parents are marked as visible.
bool	is_drawable () const
	Determines whether widget can be drawn to.
bool	get_realized () const
	Determines whether widget is realized.
bool	get_mapped () const
	Whether the widget is mapped.
void	set_child_visible (bool visible=true)
	Sets whether widget should be mapped along with its parent.
bool	get_child_visible () const
	Gets the value set with set_child_visible().
int	get_allocated_width () const
	Returns the width that has currently been allocated to widget.
int	get_allocated_height () const
	Returns the height that has currently been allocated to widget.
int	get_allocated_baseline () const
	Returns the baseline that has currently been allocated to widget.
Allocation	get_allocation () const
	Retrieves the widget’s location.
std::optional< Gdk::Graphene::Rect >	compute_bounds (const Widget & target) const
	Computes the bounds for the widget in the coordinate space of target.
std::optional< Gdk::Graphene::Point >	compute_point (const Widget & target, const Gdk::Graphene::Point &point) const
	Translates the given point in the widget's coordinates to coordinates relative to target’s coordinate system.
int	get_width () const
	Returns the content width of the widget.
int	get_height () const
	Returns the content height of the widget.
int	get_baseline () const
	Returns the baseline that has currently been allocated to widget.
int	get_size (Orientation orientation) const
	Returns the content width or height of the widget.
Widget *	get_parent ()
	Returns the parent widget of widget.
const Widget *	get_parent () const
	Returns the parent widget of widget.
Root *	get_root ()
	Returns the Gtk::Root widget of widget.
const Root *	get_root () const
	Returns the Gtk::Root widget of widget.
Native *	get_native ()
	Returns the nearest Gtk::Native ancestor of widget.
const Native *	get_native () const
	Returns the nearest Gtk::Native ancestor of widget.
bool	child_focus (DirectionType direction)
	Called by widgets as the user moves around the window using keyboard shortcuts.
bool	keynav_failed (DirectionType direction)
	Emits the keynav-failed signal on the widget.
void	error_bell ()
	Notifies the user about an input-related error on this widget.
void	set_size_request (int width=-1, int height=-1)
	Sets the minimum size of a widget.
void	get_size_request (int & width, int &height) const
	Gets the size request that was explicitly set for the widget using set_size_request().
Requisition	get_size_request () const
	Like the other overload of get_size_request() but returns a structure holding the sizes instead of using output parameters.
void	set_opacity (double opacity)
	Request the widget to be rendered partially transparent.
double	get_opacity () const
	Fetches the requested opacity for this widget.
void	set_overflow (Overflow overflow)
	Sets how widget treats content that is drawn outside the widget's content area.
Overflow	get_overflow () const
	Returns the widget’s overflow value.
Widget *	get_ancestor (GType widget_type)
	Gets the first ancestor of widget with type widget_type.
const Widget *	get_ancestor (GType widget_type) const
	Gets the first ancestor of widget with type widget_type.
int	get_scale_factor () const
	Retrieves the internal scale factor that maps from window coordinates to the actual device pixels.
Glib::RefPtr< Gdk::Display >	get_display ()
	Get the Gdk::Display for the toplevel window associated with this widget.
Glib::RefPtr< const Gdk::Display >	get_display () const
	Get the Gdk::Display for the toplevel window associated with this widget.
Glib::RefPtr< Settings >	get_settings ()
	Gets the settings object holding the settings used for this widget.
Glib::RefPtr< Gdk::Clipboard >	get_clipboard ()
	Gets the clipboard object for widget.
Glib::RefPtr< const Gdk::Clipboard >	get_clipboard () const
	Gets the clipboard object for widget.
Glib::RefPtr< Gdk::Clipboard >	get_primary_clipboard ()
	Gets the primary clipboard of widget.
Glib::RefPtr< const Gdk::Clipboard >	get_primary_clipboard () const
	Gets the primary clipboard of widget.
bool	get_hexpand () const
	Gets whether the widget would like any available extra horizontal space.
void	set_hexpand (bool expand=true)
	Sets whether the widget would like any available extra horizontal space.
bool	get_hexpand_set () const
	Gets whether set_hexpand() has been used to explicitly set the expand flag on this widget.
void	set_hexpand_set (bool set=true)
	Sets whether the hexpand flag will be used.
bool	get_vexpand () const
	Gets whether the widget would like any available extra vertical space.
void	set_vexpand (bool expand=true)
	Sets whether the widget would like any available extra vertical space.
bool	get_vexpand_set () const
	Gets whether set_vexpand() has been used to explicitly set the expand flag on this widget.
void	set_vexpand_set (bool set=true)
	Sets whether the vexpand flag will be used.
bool	compute_expand (Orientation orientation)
	Computes whether a container should give this widget extra space when possible.
void	set_expand (bool expand=true)
	Sets whether the widget would like any available extra space in both directions.
Align	get_halign () const
	Gets the horizontal alignment of widget.
void	set_halign (Align align)
	Sets the horizontal alignment of widget.
Align	get_valign () const
	Gets the vertical alignment of widget.
void	set_valign (Align align)
	Sets the vertical alignment of widget.
int	get_margin_start () const
	Gets the start margin of widget.
void	set_margin_start (int margin)
	Sets the start margin of widget.
int	get_margin_end () const
	Gets the end margin of widget.
void	set_margin_end (int margin)
	Sets the end margin of widget.
int	get_margin_top () const
	Gets the top margin of widget.
void	set_margin_top (int margin)
	Sets the top margin of widget.
int	get_margin_bottom () const
	Gets the bottom margin of widget.
void	set_margin_bottom (int margin)
	Sets the bottom margin of widget.
void	set_margin (int margin)
	Set all 4 margins to the same value.
bool	is_ancestor (Widget &ancestor) const
	Determines whether widget is somewhere inside ancestor, possibly with intermediate containers.
bool	translate_coordinates (Widget &dest_widget, double src_x, double src_y, double &dest_x, double &dest_y)
	Translate coordinates relative to src_widget’s allocation to coordinates relative to dest_widget’s allocations.
bool	contains (double x, double y) const
	Tests if the point at ( x, y) is contained in widget.
Widget *	pick (double x, double y, PickFlags flags=PickFlags::DEFAULT)
	Finds the descendant of widget closest to the point ( x, y).
const Widget *	pick (double x, double y, PickFlags flags=PickFlags::DEFAULT) const
	Finds the descendant of widget closest to the point ( x, y).
void	add_controller (const Glib::RefPtr< EventController > &controller)
	Adds controller to widget so that it will receive events.
void	remove_controller (const Glib::RefPtr< EventController > &controller)
	Removes controller from widget, so that it doesn't process events anymore.
Glib::RefPtr< Pango::Context >	create_pango_context ()
	Creates a new Pango::Context with the appropriate font map, font options, font description, and base direction for drawing text for this widget.
Glib::RefPtr< Pango::Context >	get_pango_context ()
	Gets a Pango::Context with the appropriate font map, font description, and base direction for this widget.
void	set_font_options (const Cairo::FontOptions &options)
	Sets the cairo_font_options_t used for Pango rendering in this widget.
void	unset_font_options ()
	Undoes the effect of previous calls to set_font_options().
Cairo::FontOptions	get_font_options () const
	Returns the cairo_font_options_t of widget.
Glib::RefPtr< Pango::Layout >	create_pango_layout (const Glib::ustring &text)
	Creates a new Pango::Layout with the appropriate font map, font description, and base direction for drawing text for this widget.
void	set_direction (TextDirection dir)
	Sets the reading direction on a particular widget.
TextDirection	get_direction () const
	Gets the reading direction for a particular widget.
void	set_cursor (const Glib::RefPtr< Gdk::Cursor > &cursor)
	Sets the cursor to be shown when pointer devices point towards widget.
void	set_cursor (const Glib::ustring & name={})
	Sets a named cursor to be shown when pointer devices point towards the widget.
Glib::RefPtr< Gdk::Cursor >	get_cursor ()
	Queries the cursor set on widget.
Glib::RefPtr< const Gdk::Cursor >	get_cursor () const
	Queries the cursor set on widget.
std::vector< Widget * >	list_mnemonic_labels ()
	Returns the widgets for which this widget is the target of a mnemonic.
std::vector< const Widget * >	list_mnemonic_labels () const
	Returns the widgets for which this widget is the target of a mnemonic.
void	add_mnemonic_label (Widget &label)
	Adds a widget to the list of mnemonic labels for this widget.
void	remove_mnemonic_label (Widget &label)
	Removes a widget from the list of mnemonic labels for this widget.
bool	drag_check_threshold (int start_x, int start_y, int current_x, int current_y)
	Checks to see if a drag movement has passed the GTK drag threshold.
Glib::RefPtr< Gdk::FrameClock >	get_frame_clock ()
	Obtains the frame clock for a widget.
Glib::RefPtr< const Gdk::FrameClock >	get_frame_clock () const
	Obtains the frame clock for a widget.
void	set_parent (Widget & parent)
	Sets parent as the parent widget of widget.
void	unparent ()
	Dissociate widget from its parent.
void	map ()
	Causes a widget to be mapped if it isn’t already.
void	unmap ()
	Causes a widget to be unmapped if it’s currently mapped.
void	trigger_tooltip_query ()
	Triggers a tooltip query on the display where the toplevel of widget is located.
void	set_tooltip_text (const Glib::ustring &text)
	Sets text as the contents of the tooltip.
Glib::ustring	get_tooltip_text () const
	Gets the contents of the tooltip for widget.
void	set_tooltip_markup (const Glib::ustring &markup)
	Sets markup as the contents of the tooltip, which is marked up with Pango markup.
Glib::ustring	get_tooltip_markup () const
	Gets the contents of the tooltip for widget.
void	set_has_tooltip (bool has_tooltip=TRUE)
	Sets the has-tooltip property on widget to has_tooltip.
bool	get_has_tooltip () const
	Returns the current value of the has-tooltip property.
bool	in_destruction () const
	Returns whether the widget is currently being destroyed.
Glib::RefPtr< StyleContext >	get_style_context ()
	Returns the style context associated to widget.
Glib::RefPtr< const StyleContext >	get_style_context () const
	Returns the style context associated to widget.
guint	add_tick_callback (const SlotTick &slot)
	Queues an animation frame update and adds a callback to be called before each frame.
void	remove_tick_callback (guint id)
	Removes a tick callback previously registered with add_tick_callback().
void	insert_action_group (const Glib::ustring & name, const Glib::RefPtr< Gio::ActionGroup > & group)
	Inserts group into widget.
void	remove_action_group (const Glib::ustring & name)
	Removes a group from the widget.
bool	activate_action (const Glib::ustring & name, const Glib::VariantBase &args={})
	Looks up the action in the action groups associated with the widget and its ancestors, and activates it.
void	activate_default ()
	Activates the default.activate action from widget.
void	set_font_map (const Glib::RefPtr< Pango::FontMap > &font_map)
	Sets the font map to use for Pango rendering.
Glib::RefPtr< Pango::FontMap >	get_font_map ()
	Gets the font map of widget.
Glib::RefPtr< const Pango::FontMap >	get_font_map () const
	Gets the font map of widget.
Widget *	get_first_child ()
	Returns the widget’s first child.
const Widget *	get_first_child () const
	Returns the widget’s first child.
Widget *	get_last_child ()
	Returns the widget’s last child.
const Widget *	get_last_child () const
	Returns the widget’s last child.
Widget *	get_next_sibling ()
	Returns the widget’s next sibling.
const Widget *	get_next_sibling () const
	Returns the widget’s next sibling.
Widget *	get_prev_sibling ()
	Returns the widget’s previous sibling.
const Widget *	get_prev_sibling () const
	Returns the widget’s previous sibling.
std::vector< Widget * >	get_children ()
	Gets a vector of the widgetʼs current children, from first child to last.
std::vector< const Widget * >	get_children () const
	Gets a vector of the widgetʼs current children, from first child to last.
Glib::RefPtr< Gio::ListModel >	observe_children ()
	Returns a Gio::ListModel to track the children of widget.
Glib::RefPtr< const Gio::ListModel >	observe_children () const
	Returns a Gio::ListModel to track the children of widget.
Glib::RefPtr< Gio::ListModel >	observe_controllers ()
	Returns a Gio::ListModel to track the Gtk::EventControllers of widget.
Glib::RefPtr< const Gio::ListModel >	observe_controllers () const
	Returns a Gio::ListModel to track the Gtk::EventControllers of widget.
void	insert_after (Widget & parent, const Widget &previous_sibling)
	Inserts the Widget into the child widget list of parent after previous_sibling.
void	insert_before (Widget & parent, const Widget &next_sibling)
	Inserts the Widget into the child widget list of parent before next_sibling.
void	insert_at_start (Widget & parent)
	Inserts the Widget at the beginning of the child widget list of parent.
void	insert_at_end (Widget & parent)
	Inserts the Widget at the end of the child widget list of parent.
void	snapshot_child (Widget &child, const Glib::RefPtr< Gtk::Snapshot > & snapshot)
	Snapshot the a child of widget.
bool	should_layout () const
	Returns whether widget should contribute to the measuring and allocation of its parent.
Glib::ustring	get_css_name () const
	Returns the CSS name that is used for self.
void	add_css_class (const Glib::ustring &css_class)
	Adds a style class to widget.
void	remove_css_class (const Glib::ustring &css_class)
	Removes a style from widget.
bool	has_css_class (const Glib::ustring &css_class) const
	Returns whether css_class is currently applied to widget.
std::vector< Glib::ustring >	get_css_classes () const
	Returns the list of style classes applied to widget.
void	set_css_classes (const std::vector< Glib::ustring > &classes)
	Clear all style classes applied to widget and replace them with classes.
Gdk::RGBA	get_color () const
	Gets the current foreground color for the widget's CSS style.
Glib::SignalProxy< void()>	signal_show ()
Glib::SignalProxy< void()>	signal_hide ()
Glib::SignalProxy< void()>	signal_map ()
	Emitted on mapping of a widget to the screen.
Glib::SignalProxy< void()>	signal_unmap ()
Glib::SignalProxy< void()>	signal_realize ()
	Emitted on realization of a widget.
Glib::SignalProxy< void()>	signal_unrealize ()
Glib::SignalProxy< void(Gtk::StateFlags)>	signal_state_flags_changed ()
Glib::SignalProxy< void(TextDirection)>	signal_direction_changed ()
Glib::SignalProxy< bool(bool)>	signal_mnemonic_activate ()
Glib::SignalProxy< void()>	signal_destroy ()
	Emitted during the dispose phase.
Glib::SignalProxy< bool(int, int, bool, const Glib::RefPtr< Tooltip > &)>	signal_query_tooltip ()
Glib::PropertyProxy< Glib::ustring >	property_name ()
	The name of the widget.
Glib::PropertyProxy_ReadOnly< Glib::ustring >	property_name () const
	The name of the widget.
Glib::PropertyProxy_ReadOnly< Widget * >	property_parent () const
	The parent widget of this widget.
Glib::PropertyProxy_ReadOnly< Root * >	property_root () const
	The Gtk::Root widget of the widget tree containing this widget.
Glib::PropertyProxy< int >	property_width_request ()
	Override for width request of the widget.
Glib::PropertyProxy_ReadOnly< int >	property_width_request () const
	Override for width request of the widget.
Glib::PropertyProxy< int >	property_height_request ()
	Override for height request of the widget.
Glib::PropertyProxy_ReadOnly< int >	property_height_request () const
	Override for height request of the widget.
Glib::PropertyProxy< bool >	property_visible ()
	Whether the widget is visible.
Glib::PropertyProxy_ReadOnly< bool >	property_visible () const
	Whether the widget is visible.
Glib::PropertyProxy< bool >	property_sensitive ()
	Whether the widget responds to input.
Glib::PropertyProxy_ReadOnly< bool >	property_sensitive () const
	Whether the widget responds to input.
Glib::PropertyProxy< bool >	property_can_focus ()
	Whether the widget or any of its descendents can accept the input focus.
Glib::PropertyProxy_ReadOnly< bool >	property_can_focus () const
	Whether the widget or any of its descendents can accept the input focus.
Glib::PropertyProxy_ReadOnly< bool >	property_has_focus () const
	Whether the widget has the input focus.
Glib::PropertyProxy< bool >	property_can_target ()
	Whether the widget can receive pointer events.
Glib::PropertyProxy_ReadOnly< bool >	property_can_target () const
	Whether the widget can receive pointer events.
Glib::PropertyProxy< bool >	property_focus_on_click ()
	Whether the widget should grab focus when it is clicked with the mouse.
Glib::PropertyProxy_ReadOnly< bool >	property_focus_on_click () const
	Whether the widget should grab focus when it is clicked with the mouse.
Glib::PropertyProxy< bool >	property_focusable ()
	Whether this widget itself will accept the input focus.
Glib::PropertyProxy_ReadOnly< bool >	property_focusable () const
	Whether this widget itself will accept the input focus.
Glib::PropertyProxy_ReadOnly< bool >	property_has_default () const
	Whether the widget is the default widget.
Glib::PropertyProxy< bool >	property_receives_default ()
	Whether the widget will receive the default action when it is focused.
Glib::PropertyProxy_ReadOnly< bool >	property_receives_default () const
	Whether the widget will receive the default action when it is focused.
Glib::PropertyProxy< Glib::RefPtr< Gdk::Cursor > >	property_cursor ()
	The cursor used by widget.
Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Gdk::Cursor > >	property_cursor () const
	The cursor used by widget.
Glib::PropertyProxy< bool >	property_has_tooltip ()
	Enables or disables the emission of the signal_query_tooltip() signal on widget.
Glib::PropertyProxy_ReadOnly< bool >	property_has_tooltip () const
	Enables or disables the emission of the signal_query_tooltip() signal on widget.
Glib::PropertyProxy< Glib::ustring >	property_tooltip_markup ()
	Sets the text of tooltip to be the given string, which is marked up with Pango markup.
Glib::PropertyProxy_ReadOnly< Glib::ustring >	property_tooltip_markup () const
	Sets the text of tooltip to be the given string, which is marked up with Pango markup.
Glib::PropertyProxy< Glib::ustring >	property_tooltip_text ()
	Sets the text of tooltip to be the given string.
Glib::PropertyProxy_ReadOnly< Glib::ustring >	property_tooltip_text () const
	Sets the text of tooltip to be the given string.
Glib::PropertyProxy< Align >	property_halign ()
	How to distribute horizontal space if widget gets extra space.
Glib::PropertyProxy_ReadOnly< Align >	property_halign () const
	How to distribute horizontal space if widget gets extra space.
Glib::PropertyProxy< Align >	property_valign ()
	How to distribute vertical space if widget gets extra space.
Glib::PropertyProxy_ReadOnly< Align >	property_valign () const
	How to distribute vertical space if widget gets extra space.
Glib::PropertyProxy< int >	property_margin_start ()
	Margin on start of widget, horizontally.
Glib::PropertyProxy_ReadOnly< int >	property_margin_start () const
	Margin on start of widget, horizontally.
Glib::PropertyProxy< int >	property_margin_end ()
	Margin on end of widget, horizontally.
Glib::PropertyProxy_ReadOnly< int >	property_margin_end () const
	Margin on end of widget, horizontally.
Glib::PropertyProxy< int >	property_margin_top ()
	Margin on top side of widget.
Glib::PropertyProxy_ReadOnly< int >	property_margin_top () const
	Margin on top side of widget.
Glib::PropertyProxy< int >	property_margin_bottom ()
	Margin on bottom side of widget.
Glib::PropertyProxy_ReadOnly< int >	property_margin_bottom () const
	Margin on bottom side of widget.
Glib::PropertyProxy< bool >	property_hexpand ()
	Whether to expand horizontally.
Glib::PropertyProxy_ReadOnly< bool >	property_hexpand () const
	Whether to expand horizontally.
Glib::PropertyProxy< bool >	property_hexpand_set ()
	Whether to use the hexpand property.
Glib::PropertyProxy_ReadOnly< bool >	property_hexpand_set () const
	Whether to use the hexpand property.
Glib::PropertyProxy< bool >	property_vexpand ()
	Whether to expand vertically.
Glib::PropertyProxy_ReadOnly< bool >	property_vexpand () const
	Whether to expand vertically.
Glib::PropertyProxy< bool >	property_vexpand_set ()
	Whether to use the vexpand property.
Glib::PropertyProxy_ReadOnly< bool >	property_vexpand_set () const
	Whether to use the vexpand property.
Glib::PropertyProxy< double >	property_opacity ()
	The requested opacity of the widget.
Glib::PropertyProxy_ReadOnly< double >	property_opacity () const
	The requested opacity of the widget.
Glib::PropertyProxy< Overflow >	property_overflow ()
	How content outside the widget's content area is treated.
Glib::PropertyProxy_ReadOnly< Overflow >	property_overflow () const
	How content outside the widget's content area is treated.
Glib::PropertyProxy_ReadOnly< int >	property_scale_factor () const
	The scale factor of the widget.
Glib::PropertyProxy_ReadOnly< Glib::ustring >	property_css_name () const
	The name of this widget in the CSS tree.
Glib::PropertyProxy< std::vector< Glib::ustring > >	property_css_classes ()
	A list of css classes applied to this widget.
Glib::PropertyProxy_ReadOnly< std::vector< Glib::ustring > >	property_css_classes () const
	A list of css classes applied to this widget.
Glib::PropertyProxy< Glib::RefPtr< LayoutManager > >	property_layout_manager ()
	The Gtk::LayoutManager instance to use to compute the preferred size of the widget, and allocate its children.
Glib::PropertyProxy_ReadOnly< Glib::RefPtr< LayoutManager > >	property_layout_manager () const
	The Gtk::LayoutManager instance to use to compute the preferred size of the widget, and allocate its children.
Public Member Functions inherited from Gtk::Object
	Object (Object &&src) noexcept
Object &	operator= (Object &&src) noexcept
	~Object () noexcept override
Public Member Functions inherited from Gtk::Accessible
	Accessible (Accessible &&src) noexcept
Accessible &	operator= (Accessible &&src) noexcept
	~Accessible () noexcept override
GtkAccessible *	gobj ()
	Provides access to the underlying C GObject.
const GtkAccessible *	gobj () const
	Provides access to the underlying C GObject.
Glib::RefPtr< ATContext >	get_at_context ()
	Retrieves the accessible implementation for the given Gtk::Accessible.
Glib::RefPtr< const ATContext >	get_at_context () const
	Retrieves the accessible implementation for the given Gtk::Accessible.
bool	get_platform_state (PlatformState state) const
	Query a platform state, such as focus.
Glib::RefPtr< Accessible >	get_accessible_parent ()
	Retrieves the accessible parent for an accessible object.
Glib::RefPtr< const Accessible >	get_accessible_parent () const
	Retrieves the accessible parent for an accessible object.
void	set_accessible_parent (const Glib::RefPtr< Accessible > & parent, const Glib::RefPtr< Accessible > &next_sibling)
	Sets the parent and sibling of an accessible object.
Glib::RefPtr< Accessible >	get_first_accessible_child ()
	Retrieves the first accessible child of an accessible object.
Glib::RefPtr< const Accessible >	get_first_accessible_child () const
	Retrieves the first accessible child of an accessible object.
Glib::RefPtr< Accessible >	get_next_accessible_sibling ()
	Retrieves the next accessible sibling of an accessible object.
Glib::RefPtr< const Accessible >	get_next_accessible_sibling () const
	Retrieves the next accessible sibling of an accessible object.
void	update_next_accessible_sibling (const Glib::RefPtr< Accessible > &new_sibling)
	Updates the next accessible sibling of self.
bool	get_bounds (int &x, int &y, int & width, int &height) const
	Queries the coordinates and dimensions of this accessible.
Role	get_accessible_role () const
	Retrieves the accessible role of an accessible object.
void	update_state (State state, const Glib::ValueBase & value)
	Updates an accessible state.
void	update_property (Property property, const Glib::ValueBase & value)
	Updates an accessible property.
void	update_relation (Relation relation, const Glib::ValueBase & value)
	Updates an accessible relation.
void	reset_state (State state)
	Resets the accessible state to its default value.
void	reset_property (Property property)
	Resets the accessible property to its default value.
void	reset_relation (Relation relation)
	Resets the accessible relation to its default value.
void	announce (const Glib::ustring & message, AnnouncementPriority priority)
	Requests the user's screen reader to announce the given message.
Glib::PropertyProxy< Role >	property_accessible_role ()
	The accessible role of the given Gtk::Accessible implementation.
Glib::PropertyProxy_ReadOnly< Role >	property_accessible_role () const
	The accessible role of the given Gtk::Accessible implementation.
Public Member Functions inherited from Gtk::Buildable
	Buildable (Buildable &&src) noexcept
Buildable &	operator= (Buildable &&src) noexcept
	~Buildable () noexcept override
GtkBuildable *	gobj ()
	Provides access to the underlying C GObject.
const GtkBuildable *	gobj () const
	Provides access to the underlying C GObject.
Glib::ustring	get_buildable_id () const
	Gets the ID of the buildable object.
Public Member Functions inherited from Gtk::ConstraintTarget
	ConstraintTarget (ConstraintTarget &&src) noexcept
ConstraintTarget &	operator= (ConstraintTarget &&src) noexcept
	~ConstraintTarget () noexcept override
GtkConstraintTarget *	gobj ()
	Provides access to the underlying C GObject.
const GtkConstraintTarget *	gobj () const
	Provides access to the underlying C GObject.

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.
Static Public Member Functions inherited from Gtk::Widget
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.
static void	set_default_direction (TextDirection dir)
	Sets the default reading direction for widgets.
static TextDirection	get_default_direction ()
	Obtains the current default reading direction.
Static Public Member Functions inherited from Gtk::Accessible
static void	add_interface (GType gtype_implementer)
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.
Static Public Member Functions inherited from Gtk::Buildable
static void	add_interface (GType gtype_implementer)
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.
Static Public Member Functions inherited from Gtk::ConstraintTarget
static void	add_interface (GType gtype_implementer)
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Member Functions
virtual void	on_resize (int width, int height)
	This is a default handler for the signal signal_resize().
Protected Member Functions inherited from Gtk::Widget
virtual void	root_vfunc ()
virtual void	unroot_vfunc ()
virtual void	size_allocate_vfunc (int width, int height, int baseline)
virtual SizeRequestMode	get_request_mode_vfunc () const
virtual void	measure_vfunc (Orientation orientation, int for_size, int & minimum, int & natural, int &minimum_baseline, int &natural_baseline) const
virtual bool	grab_focus_vfunc ()
virtual void	set_focus_child_vfunc (Widget *child)
	Sets the focused child of widget.
virtual void	compute_expand_vfunc (bool &hexpand_p, bool &vexpand_p)
virtual bool	contains_vfunc (double x, double y) const
virtual void	snapshot_vfunc (const Glib::RefPtr< Gtk::Snapshot > & snapshot)
	Widget ()
void	realize ()
	Creates the GDK resources associated with a widget.
void	unrealize ()
	Causes a widget to be unrealized (frees all GDK resources associated with the widget).
void	realize_if_needed ()
void	set_focus_child (Widget &child)
	Set child as the current focus child of widget.
void	unset_focus_child ()
	Unsets the focus child of the widget.
Widget *	get_focus_child ()
	Returns the current focus child of widget.
const Widget *	get_focus_child () const
	Returns the current focus child of widget.
virtual void	on_show ()
	This is a default handler for the signal signal_show().
virtual void	on_hide ()
	This is a default handler for the signal signal_hide().
virtual void	on_map ()
	This is a default handler for the signal signal_map().
virtual void	on_unmap ()
	This is a default handler for the signal signal_unmap().
virtual void	on_realize ()
	This is a default handler for the signal signal_realize().
virtual void	on_unrealize ()
	This is a default handler for the signal signal_unrealize().
virtual void	on_state_flags_changed (Gtk::StateFlags previous_state_flags)
	This is a default handler for the signal signal_state_flags_changed().
virtual void	on_direction_changed (TextDirection direction)
	This is a default handler for the signal signal_direction_changed().
virtual bool	on_mnemonic_activate (bool group_cycling)
	This is a default handler for the signal signal_mnemonic_activate().
virtual bool	on_query_tooltip (int x, int y, bool keyboard_tooltip, const Glib::RefPtr< Tooltip > &tooltip)
	This is a default handler for the signal signal_query_tooltip().
Protected Member Functions inherited from Gtk::Accessible
	Accessible ()
	You should derive from this class to use it.
Protected Member Functions inherited from Gtk::Buildable
	Buildable ()
	You should derive from this class to use it.
Protected Member Functions inherited from Gtk::ConstraintTarget
	ConstraintTarget ()
	You should derive from this class to use it.

Related Symbols
(Note that these are not member symbols.)
Gtk::DrawingArea *	wrap (GtkDrawingArea *object, bool take_copy=false)
	A Glib::wrap() method for this object.
Related Symbols inherited from Gtk::Widget
Gtk::Widget *	wrap (GtkWidget *object, bool take_copy=false)
	A Glib::wrap() method for this object.
Related Symbols inherited from Gtk::Accessible
Glib::RefPtr< Gtk::Accessible >	wrap (GtkAccessible *object, bool take_copy=false)
	A Glib::wrap() method for this object.
Related Symbols inherited from Gtk::Buildable
Glib::RefPtr< Gtk::Buildable >	wrap (GtkBuildable *object, bool take_copy=false)
	A Glib::wrap() method for this object.
Related Symbols inherited from Gtk::ConstraintTarget
Glib::RefPtr< Gtk::ConstraintTarget >	wrap (GtkConstraintTarget *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

A widget for custom user interface elements.

The DrawingArea widget is used for creating custom user interface elements. It’s essentially a blank widget; you can draw on it. After creating a drawing area, the application may want to connect to:

• Mouse and button press signals to respond to input from the user. (Use Gtk::Widget::add_events() to enable events you wish to receive.)
• Gtk::Widget::signal_realize() to take any necessary actions when the widget is instantiated on a particular display. (Create GDK resources in response to this signal.)
• Gtk::Widget::signal_size_allocate() to take any necessary actions when the widget changes size.
• Call set_draw_func() to handle redrawing the contents of the widget.

The following code portion demonstrates using a drawing area to display a circle in the normal widget foreground color.

Note that GDK automatically clears the exposed area before causing a redraw, and that drawing is implicitly clipped to the exposed area. If you want to have a theme-provided background, you need to call Gtk::StyleContext::render_background() in your draw function.

Simple DrawingArea usage:

class MyDrawingArea : public Gtk::DrawingArea
{
public:
  MyDrawingArea()
  {
    set_draw_func(sigc::mem_fun(*this, &MyDrawingArea::on_draw));
  }
 
  void on_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int height)
  {
    auto style_context = get_style_context();
 
    style_context->render_background(cr, 0, 0, width, height);
 
    cr->arc(width / 2.0, height / 2.0, std::min(width, height) / 2.0, 0, 2 * M_PI);
 
    auto color = style_context->get_color();
    Gdk::Cairo::set_source_rgba(cr, color);
 
    cr->fill();
  }
//...
}; // end MyDrawingArea
 
//...
auto area = Gtk::manage(new MyDrawingArea)
area->set_content_width(100);
area->set_content_height(100);

The draw function is normally called when a drawing area first comes onscreen, or when it’s covered by another window and then uncovered. You can also force a redraw by adding to the “damage region” of the drawing area’s window using Gtk::Widget::queue_draw_region(), Gtk::Widget::queue_draw_area() or Gtk::Widget::queue_draw(). This will cause the drawing area to call the draw function again.

To receive mouse events on a drawing area, you will need to use event controllers. To receive keyboard events, you will need to set the “can-focus” property on the drawing area, and you should probably draw some user-visible indication that the drawing is focused.

Member Typedef Documentation

SlotDraw

using Gtk::DrawingArea::SlotDraw = sigc::slot<void(const Cairo::RefPtr<Cairo::Context>&, int, int)>

Whenever the drawing area needs to redraw, this slot will be called.

For instance:

void on_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int height);

This slot should exclusively redraw the contents of the drawing area and must not call any widget functions that cause changes.

Parameters

cr	The context to draw to.
width	The actual width of the contents. This value will be at least as wide as property_content_width().
height	The actual height of the contents. This value will be at least as high as property_content_height().

Since gtkmm 3.90:

Constructor & Destructor Documentation

DrawingArea() [1/3]

Gtk::DrawingArea::DrawingArea ( DrawingArea &&  src )

noexcept

DrawingArea() [2/3]

Gtk::DrawingArea::DrawingArea ( const DrawingArea &  )

delete

~DrawingArea()

Gtk::DrawingArea::~DrawingArea ( )

overridenoexcept

DrawingArea() [3/3]

Gtk::DrawingArea::DrawingArea

(

)

Member Function Documentation

get_content_height()

int Gtk::DrawingArea::get_content_height

(

)

const

Retrieves the content height of the Gtk::DrawingArea.

Returns

The height requested for content of the drawing area.

get_content_width()

int Gtk::DrawingArea::get_content_width

(

)

const

Retrieves the content width of the Gtk::DrawingArea.

Returns

The width requested for content of the drawing area.

get_type()

static GType Gtk::DrawingArea::get_type ( )

static

Get the GType for this class, for use with the underlying GObject type system.

gobj() [1/2]

GtkDrawingArea * Gtk::DrawingArea::gobj ( )

inline

Provides access to the underlying C GObject.

gobj() [2/2]

const GtkDrawingArea * Gtk::DrawingArea::gobj ( ) const

inline

Provides access to the underlying C GObject.

on_resize()

virtual void Gtk::DrawingArea::on_resize ( int  width, int  height  )

protectedvirtual

This is a default handler for the signal signal_resize().

operator=() [1/2]

DrawingArea & Gtk::DrawingArea::operator= ( const DrawingArea &  )

delete

operator=() [2/2]

DrawingArea & Gtk::DrawingArea::operator= ( DrawingArea &&  src )

noexcept

property_content_height() [1/2]

Glib::PropertyProxy< int > Gtk::DrawingArea::property_content_height

(

)

The content height.

Default value: 0

Returns

A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

property_content_height() [2/2]

Glib::PropertyProxy_ReadOnly< int > Gtk::DrawingArea::property_content_height

(

)

const

The content height.

Default value: 0

Returns

A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

property_content_width() [1/2]

Glib::PropertyProxy< int > Gtk::DrawingArea::property_content_width

(

)

The content width.

Default value: 0

Returns

A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

property_content_width() [2/2]

Glib::PropertyProxy_ReadOnly< int > Gtk::DrawingArea::property_content_width

(

)

const

The content width.

Default value: 0

Returns

A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

set_content_height()

void Gtk::DrawingArea::set_content_height

(

int

width

)

Sets the desired height of the contents of the drawing area.

Note that because widgets may be allocated larger sizes than they requested, it is possible that the actual height passed to your draw function is larger than the height set here. You can use Gtk::Widget::set_valign() to avoid that.

If the height is set to 0 (the default), the drawing area may disappear.

Parameters

width

The height of contents.

set_content_width()

void Gtk::DrawingArea::set_content_width

(

int

width

)

Sets the desired width of the contents of the drawing area.

Note that because widgets may be allocated larger sizes than they requested, it is possible that the actual width passed to your draw function is larger than the width set here. You can use Gtk::Widget::set_halign() to avoid that.

If the width is set to 0 (the default), the drawing area may disappear.

Parameters

width

The width of contents.

set_draw_func()

void Gtk::DrawingArea::set_draw_func

(

const SlotDraw &

slot

)

Sets a draw function.

Setting a draw function is the main thing you want to do when using a drawing area. It is called whenever GTK needs to draw the contents of the drawing area to the screen.

The draw function will be called during the drawing stage of GTK. In the drawing stage it is not allowed to change properties of any GTK widgets or call any functions that would cause any properties to be changed. You should restrict yourself exclusively to drawing your contents in the draw function.

If what you are drawing does change, call Gtk::Widget::queue_draw() on the drawing area. This will call a redraw and will call slot again.

Since gtkmm 3.90:

Parameters

slot	Callback that lets you draw the drawing area's contents.

signal_resize()

Glib::SignalProxy< void(int, int)> Gtk::DrawingArea::signal_resize

(

)

Slot Prototype:

void on_my_resize(int width, int height)

Flags: Run Last

Emitted once when the widget is realized, and then each time the widget is changed while realized.

This is useful in order to keep state up to date with the widget size, like for instance a backing surface.

Parameters

width	The width of the viewport.
height	The height of the viewport.

Friends And Related Symbol Documentation

wrap()

Gtk::DrawingArea * wrap ( GtkDrawingArea *  object, bool  take_copy = false  )

related

A Glib::wrap() method for this object.

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns

A C++ instance that wraps this C instance.