gtkmm: Gtk::StyleContext Class Reference

This object stores styling information affecting a widget defined by WidgetPath. More...

Inheritance diagram for Gtk::StyleContext:

Public Member Functions
virtual	~StyleContext ()
GtkStyleContext*	gobj ()
	Provides access to the underlying C GObject.
const GtkStyleContext*	gobj () const
	Provides access to the underlying C GObject.
GtkStyleContext*	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
void	add_provider (const Glib::RefPtr< StyleProvider >& provider, guint priority)
	Adds a style provider to context, to be used in style construction.
void	remove_provider (const Glib::RefPtr< StyleProvider >& provider)
	Removes provider from the style providers list in context.
void	context_save ()
	Saves the context state, so all modifications done through add_class(), remove_class(), add_region(), remove_region() or set_junction_sides() can be reverted in one go through restore().
void	context_restore ()
	Restores context state to a previous stage.
void	set_state (StateFlags flags)
	Sets the state to be used when rendering with any of the gtk_render_*() functions.
StateFlags	get_state () const
	Returns the state used when rendering.
bool	state_is_running (StateType state, gdouble* progress)
	Returns `true` if there is a transition animation running for the current region (see push_animatable_region()).
void	set_path (const WidgetPath& path)
	Sets the Gtk::WidgetPath used for style matching.
WidgetPath	get_path () const
	Returns the widget path used for style matching.
void	set_parent (const Glib::RefPtr< StyleContext >& parent)
	Sets the parent style context for context.
void	unset_parent ()
Glib::RefPtr< StyleContext >	get_parent ()
	Gets the parent context set via set_parent().
Glib::RefPtr< const StyleContext >	get_parent () const
	Gets the parent context set via set_parent().
std::vector< Glib::ustring >	list_classes () const
	Returns the list of classes currently defined in context.
void	add_class (const Glib::ustring& class_name)
	Adds a style class to context, so posterior calls to get() or any of the gtk_render_*() functions will make use of this new class for styling.
void	remove_class (const Glib::ustring& class_name)
	Removes class_name from context.
bool	has_class (const Glib::ustring& class_name)
	Returns `true` if context currently has defined the given class name.
GList*	list_regions ()
	Returns the list of regions currently defined in context.
void	add_region (const Glib::ustring& region_name, RegionFlags flags)
	Adds a region to context, so posterior calls to get() or any of the gtk_render_*() functions will make use of this new region for styling.
void	remove_region (const Glib::ustring& region_name)
	Removes a region from context.
bool	has_region (const Glib::ustring& region_name, RegionFlags& flags_return)
	Returns `true` if context has the region defined.
template<class PropertyType >
void	get_style_property (const Glib::ustring& property_name, PropertyType& value) const
	Gets the value of a style property.
void	get_style_property_value (const Glib::ustring& property_name, Glib::ValueBase& value) const
	Gets the value for a widget style property.
Glib::RefPtr< IconSet >	lookup_icon_set (const Glib::ustring& stock_id)
	Looks up stock_id in the icon factories associated to context and the default icon factory, returning an icon set if found, otherwise `0`.
void	set_screen (const Glib::RefPtr< Gdk::Screen >& screen)
	Attaches context to the given screen.
Glib::RefPtr< Gdk::Screen >	get_screen ()
	Returns the Gdk::Screen to which context is attached.
Glib::RefPtr< const Gdk::Screen >	get_screen () const
	Returns the Gdk::Screen to which context is attached.
void	set_direction (TextDirection direction)
	Sets the reading direction for rendering purposes.
TextDirection	get_direction () const
	Returns the widget direction used for rendering.
void	set_junction_sides (JunctionSides sides)
	Sets the sides where rendered elements (mostly through gtk_render_frame()) will visually connect with other visual elements.
JunctionSides	get_junction_sides () const
	Returns the sides where rendered elements connect visually with others.
bool	lookup_color (const Glib::ustring& color_name, Gdk::RGBA& color)
	Looks up and resolves a color name in the context color map.
void	notify_state_change (const Glib::RefPtr< Gdk::Window >& window, gpointer region_id, StateType state, bool state_value)
	Notifies a state change on context, so if the current style makes use of transition animations, one will be started so all rendered elements under region_id are animated for state state being set to value state_value.
void	cancel_animations (gpointer region_id)
	Stops all running animations for region_id and all animatable regions underneath.
void	scroll_animations (const Glib::RefPtr< Gdk::Window >& window, int dx, int dy)
	This function is analogous to gdk_window_scroll(), and should be called together with it so the invalidation areas for any ongoing animation are scrolled together with it.
void	push_animatable_region (gpointer region_id)
	Pushes an animatable region, so all further gtk_render_*() calls between this call and the following pop_animatable_region() will potentially show transition animations for this region if notify_state_change() is called for a given state, and the current theme/style defines transition animations for state changes.
void	pop_animatable_region ()
	Pops an animatable region from context.
Gdk::RGBA	get_color (StateFlags state=(StateFlags) 0) const
Gdk::RGBA	get_background_color (StateFlags state=(StateFlags) 0) const
Gdk::RGBA	get_border_color (StateFlags state=(StateFlags) 0) const
Pango::FontDescription	get_font (StateFlags state=(StateFlags) 0) const
	Returns the font description for a given state.
Border	get_border (StateFlags state=(StateFlags) 0) const
Border	get_padding (StateFlags state=(StateFlags) 0) const
Border	get_margin (StateFlags state=(StateFlags) 0) const
void	invalidate ()
	Invalidates context style information, so it will be reconstructed again.
void	set_background (const Glib::RefPtr< Gdk::Window >& window)
	Sets the background of window to the background pattern or color specified in context for its current state.
void	render_check (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders a checkmark (as in a Gtk::CheckButton).
void	render_option (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders an option mark (as in a Gtk::RadioButton), the Gtk::STATE_FLAG_ACTIVE state will determine whether the option is on or off, and Gtk::STATE_FLAG_INCONSISTENT whether it should be marked as undefined.
void	render_arrow (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double angle, double x, double y, double size)
	Renders an arrow pointing to angle.
void	render_background (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders the background of an element.
void	render_frame (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders a frame around the rectangle defined by x, y, width, height.
void	render_expander (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders an expander (as used in Gtk::TreeView and Gtk::Expander) in the area defined by x, y, width, height.
void	render_focus (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders a focus indicator on the rectangle determined by x, y, width, height.
void	render_layout (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, PangoLayout* layout)
	Renders layout on the coordinates x, y.
void	render_layout (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, const Glib::RefPtr< Pango::Layout >& layout)
	Renders layout on the coordinates x, y.
void	render_line (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x0, double y0, double x1, double y1)
	Renders a line from (x0, y0) to (x1, y1).
void	render_slider (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height, Orientation orientation)
	Renders a slider (as in Gtk::Scale) in the rectangle defined by x, y, width, height.
void	render_frame_gap (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height, PositionType gap_side, double xy0_gap, double xy1_gap)
	Renders a frame around the rectangle defined by ( x, y, width, height), leaving a gap on one side.
void	render_extension (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height, PositionType gap_side)
	Renders a extension (as in a Gtk::Notebook tab) in the rectangle defined by x, y, width, height.
void	render_handle (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders a handle (as in Gtk::HandleBox, Gtk::Paned and Gtk::Window's resize grip), in the rectangle determined by x, y, width, height.
void	render_activity (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, double width, double height)
	Renders an activity area (Such as in Gtk::Spinner or the fill line in Gtk::Range), the state Gtk::STATE_FLAG_ACTIVE determines whether there is activity going on.
Glib::RefPtr< Gdk::Pixbuf >	render_icon_pixbuf (const IconSource& source, IconSize size)
	Renders the icon specified by source at the given size, returning the result in a pixbuf.
void	render_icon (const ::Cairo::RefPtr< ::Cairo::Context >& cr, const Glib::RefPtr< Gdk::Pixbuf >& pixbuf, double x, double y)
	Renders the icon in pixbuf at the specified x and y coordinates.
void	render_insertion_cursor (const ::Cairo::RefPtr< ::Cairo::Context >& cr, double x, double y, const Glib::RefPtr< Pango::Layout >& layout, int index, Pango::Direction direction)
	Draws a text caret on cr at the specified index of layout.
Glib::SignalProxy0< void >	signal_changed ()
Glib::PropertyProxy < Glib::RefPtr< Gdk::Screen > >	property_screen ()
	The associated GdkScreen.
Glib::PropertyProxy_ReadOnly < Glib::RefPtr< Gdk::Screen > >	property_screen () const
	The associated GdkScreen.
Glib::PropertyProxy < TextDirection >	property_direction ()
	Text direction.
Glib::PropertyProxy_ReadOnly < TextDirection >	property_direction () const
	Text direction.
Glib::PropertyProxy < Glib::RefPtr< StyleContext > >	property_parent ()
	The parent style context.
Glib::PropertyProxy_ReadOnly < Glib::RefPtr< StyleContext > >	property_parent () const
	The parent style context.
Public Member Functions inherited from Glib::Object
void *	get_data (const QueryQuark &key)
void	set_data (const Quark &key, void *data)
void	set_data (const Quark &key, void *data, DestroyNotify notify)
void	remove_data (const QueryQuark &quark)
void *	steal_data (const QueryQuark &quark)
void	set_property_value (const Glib::ustring &property_name, const Glib::ValueBase &value)
void	get_property_value (const Glib::ustring &property_name, Glib::ValueBase &value) const
void	set_property (const Glib::ustring &property_name, const PropertyType &value)
void	get_property (const Glib::ustring &property_name, PropertyType &value) const
void	connect_property_changed (const Glib::ustring &property_name, const sigc::slot< void > &slot)
sigc::connection	connect_property_changed_with_return (const Glib::ustring &property_name, const sigc::slot< void > &slot)
void	freeze_notify ()
void	thaw_notify ()
virtual void	reference () const
virtual void	unreference () const
GObject *	gobj_copy () const
Glib::RefPtr< Glib::Object >	wrap (GObject *object, bool take_copy=false)

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.
static Glib::RefPtr< StyleContext >	create ()
static void	add_provider_for_screen (const Glib::RefPtr< Gdk::Screen >& screen, const Glib::RefPtr< StyleProvider >& provider, guint priority)
	Adds a global style provider to screen, which will be used in style construction for all Gtk::StyleContexts under screen.
static void	remove_provider_for_screen (const Glib::RefPtr< Gdk::Screen >& screen, const Glib::RefPtr< StyleProvider >& provider)
	Removes provider from the global style providers list in screen.

Protected Member Functions
	StyleContext ()
virtual void	on_changed ()
	This is a default handler for the signal signal_changed().
Protected Member Functions inherited from Glib::Object
	Object ()
	Object (const Glib::ConstructParams &construct_params)
	Object (GObject *castitem)
virtual	~Object ()
	ObjectBase ()
	ObjectBase (const char *custom_type_name)
	ObjectBase (const std::type_info &custom_type_info)
virtual	~ObjectBase ()=0
void	initialize (GObject *castitem)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gtk::StyleContext >	wrap (GtkStyleContext* object, bool take_copy=false)
	A Glib::wrap() method for this object.

Additional Inherited Members
Public Types inherited from Glib::Object
typedef void(*	DestroyNotify )(gpointer data)

Detailed Description

This object stores styling information affecting a widget defined by WidgetPath.

In order to construct the final style information, StyleContext queries information from all attached StyleProviders. Style providers can be either attached explicitly to the context through add_provider(), or to the screen through add_provider_for_screen(). The resulting style is a combination of all providers' information in priority order.

For GTK+ widgets, any StyleContext returned by Widget::get_style_context() will already have a WidgetPath, a Gdk::Screen and RTL/LTR information set, The style context will be also updated automatically if any of these settings change on the widget.

If you are using the theming layer standalone, you will need to set a widget path and a screen yourself to the created style context through set_path() and set_screen(), as well as updating the context yourself using invalidate() whenever any of the conditions change, such as a change in the Settings::property_gtk_theme_name() setting or a hierarchy change in the rendered widget.

Transition animations

StyleContext has built-in support for state change transitions. Note that these animations respect the Settings::property_gtk_enable_animations() setting.

For simple widgets where state changes affect the whole widget area, calling notify_state_change() with a no region is sufficient to trigger the transition animation. And GTK+ already does that when Widget::set_state() or Widget::set_state_flags() are called.

If a widget needs to declare several animatable regions (i.e. not affecting the whole widget area), its Widget::signal_draw() signal handler needs to wrap the render operations for the different regions with calls to push_animatable_region() and pop_animatable_region(). These methods take an identifier for the region which must be unique within the style context. For simple widgets with a fixed set of animatable regions, using an enumeration works well.

For complex widgets with an arbitrary number of animatable regions, it is up to the implementation to come up with a way to uniquely identify each animatable region. Using pointers to internal objects is one way to achieve this.

The widget also needs to notify the style context about a state change for a given animatable region so the animation is triggered. notify_state_change() can take no region IDs, meaning that the whole widget area will be updated by the animation.

Since gtkmm 3.0:

Constructor & Destructor Documentation

virtual Gtk::StyleContext::~StyleContext ( )

virtual

Gtk::StyleContext::StyleContext ( )

protected

Member Function Documentation

void Gtk::StyleContext::add_class ( const Glib::ustring & class_name )

Adds a style class to context, so posterior calls to get() or any of the gtk_render_*() functions will make use of this new class for styling.

In the CSS file format, a Gtk::Entry defining an "entry" class, would be matched by:

GtkEntry.entry { ... }

While any widget defining an "entry" class would be matched by:

.entry { ... }

Since gtkmm 3.0:

Parameters:

class_name Class name to use in styling.

void Gtk::StyleContext::add_provider	(	const Glib::RefPtr< StyleProvider >&	provider,
		guint	priority
	)

Adds a style provider to context, to be used in style construction.

Note that a style provider added by this function only affects the style of the widget to which context belongs. If you want to affect the style of all widgets, use add_provider_for_screen().

<note>If both priorities are the same, A Gtk::StyleProvider added through this function takes precedence over another added through add_provider_for_screen().</note>

Since gtkmm 3.0:

Parameters:

provider	A Gtk::StyleProvider.
priority	The priority of the style provider. The lower it is, the earlier it will be used in the style construction. Typically this will be in the range between Gtk::STYLE_PROVIDER_PRIORITY_FALLBACK and Gtk::STYLE_PROVIDER_PRIORITY_USER.

static void Gtk::StyleContext::add_provider_for_screen	(	const Glib::RefPtr< Gdk::Screen >&	screen,
		const Glib::RefPtr< StyleProvider >&	provider,
		guint	priority
	)

static

Adds a global style provider to screen, which will be used in style construction for all Gtk::StyleContexts under screen.

GTK+ uses this to make styling information from Gtk::Settings available.

<note>If both priorities are the same, A Gtk::StyleProvider added through add_provider() takes precedence over another added through this function.</note>

Since gtkmm 3.0:

Parameters:

screen	A Gdk::Screen.
provider	A Gtk::StyleProvider.
priority	The priority of the style provider. The lower it is, the earlier it will be used in the style construction. Typically this will be in the range between Gtk::STYLE_PROVIDER_PRIORITY_FALLBACK and Gtk::STYLE_PROVIDER_PRIORITY_USER.

void Gtk::StyleContext::add_region	(	const Glib::ustring &	region_name,
		RegionFlags	flags
	)

Adds a region to context, so posterior calls to get() or any of the gtk_render_*() functions will make use of this new region for styling.

In the CSS file format, a Gtk::TreeView defining a "row" region, would be matched by:

GtkTreeView row { ... }

Pseudo-classes are used for matching flags, so the two following rules:

GtkTreeView row:nth-child(even) { ... } GtkTreeView row:nth-child(odd) { ... }

would apply to even and odd rows, respectively.

<note>Region names must only contain lowercase letters and '-', starting always with a lowercase letter.</note>

Since gtkmm 3.0:

Parameters:

region_name	Region name to use in styling.
flags	Flags that apply to the region.

void Gtk::StyleContext::cancel_animations ( gpointer region_id )

Stops all running animations for region_id and all animatable regions underneath.

A 0 region_id will stop all ongoing animations in context, when dealing with a Gtk::StyleContext obtained through Gtk::Widget::get_style_context(), this is normally done for you in all circumstances you would expect all widget to be stopped, so this should be only used in complex widgets with different animatable regions.

Since gtkmm 3.0:

Deprecated: 3.6: This function does nothing.

Deprecated:: This function does nothing.

Parameters:

region_id Animatable region to stop, or 0. See push_animatable_region().

void Gtk::StyleContext::context_restore ( )

Restores context state to a previous stage.

See save().

Since gtkmm 3.0:

void Gtk::StyleContext::context_save ( )

Saves the context state, so all modifications done through add_class(), remove_class(), add_region(), remove_region() or set_junction_sides() can be reverted in one go through restore().

Since gtkmm 3.0:

static Glib::RefPtr<StyleContext> Gtk::StyleContext::create ( )

static

Gdk::RGBA Gtk::StyleContext::get_background_color ( StateFlags state = (StateFlags) 0 ) const

Border Gtk::StyleContext::get_border ( StateFlags state = (StateFlags) 0 ) const

Gdk::RGBA Gtk::StyleContext::get_border_color ( StateFlags state = (StateFlags) 0 ) const

Gdk::RGBA Gtk::StyleContext::get_color ( StateFlags state = (StateFlags) 0 ) const

TextDirection Gtk::StyleContext::get_direction ( ) const

Returns the widget direction used for rendering.

Since gtkmm 3.0:

Returns:: The widget direction.

Pango::FontDescription Gtk::StyleContext::get_font ( StateFlags state = (StateFlags) 0 ) const

Returns the font description for a given state.

The returned object is const and will remain valid until the Gtk::StyleContext::signal_changed() signal happens.

Since gtkmm 3.0:

Parameters:

state State to retrieve the font for.

Returns:: The Pango::FontDescription for the given state. This object is owned by GTK+ and should not be freed.

JunctionSides Gtk::StyleContext::get_junction_sides ( ) const

Returns the sides where rendered elements connect visually with others.

Since gtkmm 3.0:

Returns:: The junction sides.

Border Gtk::StyleContext::get_margin ( StateFlags state = (StateFlags) 0 ) const

Border Gtk::StyleContext::get_padding ( StateFlags state = (StateFlags) 0 ) const

Glib::RefPtr<StyleContext> Gtk::StyleContext::get_parent ( )

Gets the parent context set via set_parent().

See that function for details.

Since gtkmm 3.4:

Returns:: The parent context or 0.

Glib::RefPtr<const StyleContext> Gtk::StyleContext::get_parent ( ) const

Gets the parent context set via set_parent().

See that function for details.

Since gtkmm 3.4:

Returns:: The parent context or 0.

WidgetPath Gtk::StyleContext::get_path ( ) const

Returns the widget path used for style matching.

Since gtkmm 3.0:

Returns:: A Gtk::WidgetPath.

Glib::RefPtr<Gdk::Screen> Gtk::StyleContext::get_screen ( )

Returns the Gdk::Screen to which context is attached.

Returns:: A Gdk::Screen.

Glib::RefPtr<const Gdk::Screen> Gtk::StyleContext::get_screen ( ) const

Returns the Gdk::Screen to which context is attached.

Returns:: A Gdk::Screen.

StateFlags Gtk::StyleContext::get_state ( ) const

Returns the state used when rendering.

Since gtkmm 3.0:

Returns:: The state flags.

template <class PropertyType >

void Gtk::StyleContext::get_style_property	(	const Glib::ustring &	property_name,
		PropertyType &	value
	)		const

Gets the value of a style property.

Parameters:

property_name	The name of a style property.
value	Location to return the property value.

void Gtk::StyleContext::get_style_property_value	(	const Glib::ustring &	property_name,
		Glib::ValueBase &	value
	)		const

Gets the value for a widget style property.

When value is no longer needed, Glib::value_unset() must be called to free any allocated memory.

Parameters:

property_name	The name of the widget style property.
value	Return location for the property value.

static GType Gtk::StyleContext::get_type ( )

static

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

GtkStyleContext* Gtk::StyleContext::gobj ( )

inline

Provides access to the underlying C GObject.

Reimplemented from Glib::Object.

const GtkStyleContext* Gtk::StyleContext::gobj ( ) const

inline

Provides access to the underlying C GObject.

Reimplemented from Glib::Object.

GtkStyleContext* Gtk::StyleContext::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

bool Gtk::StyleContext::has_class ( const Glib::ustring & class_name )

Returns true if context currently has defined the given class name.

Since gtkmm 3.0:

Parameters:

class_name A class name.

Returns:: true if context has class_name defined.

bool Gtk::StyleContext::has_region	(	const Glib::ustring &	region_name,
		RegionFlags&	flags_return
	)

Returns true if context has the region defined.

If flags_return is not 0, it is set to the flags affecting the region.

Since gtkmm 3.0:

Parameters:

region_name	A region name.
flags_return	Return location for region flags.

Returns:: true if region is defined.

void Gtk::StyleContext::invalidate ( )

Invalidates context style information, so it will be reconstructed again.

If you're using a Gtk::StyleContext returned from Gtk::Widget::get_style_context(), you do not need to call this yourself.

Since gtkmm 3.0:

std::vector<Glib::ustring> Gtk::StyleContext::list_classes ( ) const

Returns the list of classes currently defined in context.

Since gtkmm 3.0:

Returns:: A List of strings with the currently defined classes. The contents of the list are owned by GTK+, but you must free the list itself with Glib::list_free() when you are done with it.

GList* Gtk::StyleContext::list_regions ( )

Returns the list of regions currently defined in context.

Since gtkmm 3.0:

Returns:: A List of strings with the currently defined regions. The contents of the list are owned by GTK+, but you must free the list itself with Glib::list_free() when you are done with it.

bool Gtk::StyleContext::lookup_color	(	const Glib::ustring &	color_name,
		Gdk::RGBA&	color
	)

Looks up and resolves a color name in the context color map.

Parameters:

color_name	Color name to lookup.
color	Return location for the looked up color.

Returns:: true if color_name was found and resolved, false otherwise.

Glib::RefPtr<IconSet> Gtk::StyleContext::lookup_icon_set ( const Glib::ustring & stock_id )

Looks up stock_id in the icon factories associated to context and the default icon factory, returning an icon set if found, otherwise 0.

Parameters:

stock_id An icon name.

Returns:: The looked up Gtk::IconSet, or 0.

void Gtk::StyleContext::notify_state_change	(	const Glib::RefPtr< Gdk::Window >&	window,
		gpointer	region_id,
		StateType	state,
		bool	state_value
	)

Notifies a state change on context, so if the current style makes use of transition animations, one will be started so all rendered elements under region_id are animated for state state being set to value state_value.

The window parameter is used in order to invalidate the rendered area as the animation runs, so make sure it is the same window that is being rendered on by the gtk_render_*() functions.

If region_id is 0, all rendered elements using context will be affected by this state transition.

As a practical example, a Gtk::Button notifying a state transition on the prelight state:

gtk_style_context_notify_state_change (context, gtk_widget_get_window (widget), 0, GTK_STATE_PRELIGHT, button->in_button);

Can be handled in the CSS file like this:

GtkButton { background-color: #f00 }

GtkButton:hover { background-color: #fff; transition: 200ms linear }

This combination will animate the button background from red to white if a pointer enters the button, and back to red if the pointer leaves the button.

Note that state is used when finding the transition parameters, which is why the style places the transition under the :hover pseudo-class.

Since gtkmm 3.0:

Deprecated: 3.6: This function does nothing.

Deprecated:: This function does nothing.

Parameters:

window	A Gdk::Window.
region_id	Animatable region to notify on, or `0`. See push_animatable_region().
state	State to trigger transition for.
state_value	`true` if state is the state we are changing to, `false` if we are changing away from it.

virtual void Gtk::StyleContext::on_changed ( )

protectedvirtual

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

void Gtk::StyleContext::pop_animatable_region ( )

Pops an animatable region from context.

See push_animatable_region().

Since gtkmm 3.0:

Deprecated: 3.6: This function does nothing.

Deprecated:: This function does nothing.

Glib::PropertyProxy< TextDirection > Gtk::StyleContext::property_direction ( )

Text direction.