Transition animations

GtkStyleContext has built-in support for state change transitions. Note that these animations respect the "gtk-enable-animations" setting.

For simple widgets where state changes affect the whole widget area, calling gtk_style_context_notify_state_change() with a NULL region is sufficient to trigger the transition animation. And GTK+ already does that when gtk_widget_set_state() or gtk_widget_set_state_flags() are called.

If a widget needs to declare several animatable regions (i.e. not affecting the whole widget area), its "draw" signal handler needs to wrap the render operations for the different regions with calls to gtk_style_context_push_animatable_region() and gtk_style_context_pop_animatable_region(). These functions 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:

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enum {
  REGION_ENTRY,
  REGION_BUTTON_UP,
  REGION_BUTTON_DOWN
};

...

gboolean
spin_button_draw (GtkWidget *widget,
                  cairo_t   *cr)
{
  GtkStyleContext *context;

  context = gtk_widget_get_style_context (widget);

  gtk_style_context_push_animatable_region (context,
                                            GUINT_TO_POINTER (REGION_ENTRY));

  gtk_render_background (cr, 0, 0, 100, 30);
  gtk_render_frame (cr, 0, 0, 100, 30);

  gtk_style_context_pop_animatable_region (context);

  ...
}

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 structs is one way to achieve this:

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void
notebook_draw_tab (GtkWidget    *widget,
                   NotebookPage *page,
                   cairo_t      *cr)
{
  gtk_style_context_push_animatable_region (context, page);
  gtk_render_extension (cr, page->x, page->y, page->width, page->height);
  gtk_style_context_pop_animatable_region (context);
}

The widget also needs to notify the style context about a state change for a given animatable region so the animation is triggered.

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gboolean
notebook_motion_notify (GtkWidget      *widget,
                        GdkEventMotion *event)
{
  GtkStyleContext *context;
  NotebookPage *page;

  context = gtk_widget_get_style_context (widget);
  page = find_page_under_pointer (widget, event);
  gtk_style_context_notify_state_change (context,
                                         gtk_widget_get_window (widget),
                                         page,
                                         GTK_STATE_PRELIGHT,
                                         TRUE);
  ...
}

gtk_style_context_notify_state_change() accepts NULL region IDs as a special value, in this case, the whole widget area will be updated by the animation.

Style classes and regions

Widgets can add style classes to their context, which can be used to associate different styles by class (see the section called “Selectors”). Theme engines can also use style classes to vary their rendering. GTK+ has a number of predefined style classes:

Widgets can also add regions with flags to their context. The regions used by GTK+ widgets are:

Custom styling in UI libraries and applications

If you are developing a library with custom GtkWidgets that render differently than standard components, you may need to add a GtkStyleProvider yourself with the GTK_STYLE_PROVIDER_PRIORITY_FALLBACK priority, either a GtkCssProvider or a custom object implementing the GtkStyleProvider interface. This way theming engines may still attempt to style your UI elements in a different way if needed so.

If you are using custom styling on an applications, you probably want then to make your style information prevail to the theme's, so you must use a GtkStyleProvider with the GTK_STYLE_PROVIDER_PRIORITY_APPLICATION priority, keep in mind that the user settings in XDG_CONFIG_HOME/gtk-3.0/gtk.css will still take precedence over your changes, as it uses the GTK_STYLE_PROVIDER_PRIORITY_USER priority.

If a custom theming engine is needed, you probably want to implement a GtkStyleProvider yourself so it points to your GtkThemingEngine implementation, as GtkCssProvider uses gtk_theming_engine_load() which loads the theming engine module from the standard paths.

GTK_STYLE_PROPERTY_BACKGROUND_COLOR

#define GTK_STYLE_PROPERTY_BACKGROUND_COLOR "background-color"

A property holding the background color of rendered elements as a GdkRGBA.

GTK_STYLE_PROPERTY_COLOR

#define GTK_STYLE_PROPERTY_COLOR "color"

A property holding the foreground color of rendered elements as a GdkRGBA.

GTK_STYLE_PROPERTY_FONT

#define GTK_STYLE_PROPERTY_FONT "font"

A property holding the font properties used when rendering text as a PangoFontDescription.

GTK_STYLE_PROPERTY_MARGIN

#define GTK_STYLE_PROPERTY_MARGIN "margin"

A property holding the rendered element's margin as a GtkBorder. The margin is defined as the spacing between the border of the element and its surrounding elements. It is external to GtkWidgets's size allocations, and the most external spacing property of the padding/border/margin series.

GTK_STYLE_PROPERTY_PADDING

#define GTK_STYLE_PROPERTY_PADDING "padding"

A property holding the rendered element's padding as a GtkBorder. The padding is defined as the spacing between the inner part of the element border and its child. It's the innermost spacing property of the padding/border/margin series.

GTK_STYLE_PROPERTY_BORDER_WIDTH

#define GTK_STYLE_PROPERTY_BORDER_WIDTH "border-width"

A property holding the rendered element's border width in pixels as a GtkBorder. The border is the intermediary spacing property of the padding/border/margin series.

gtk_render_frame() uses this property to find out the frame line width, so GtkWidgets rendering frames may need to add up this padding when requesting size

GTK_STYLE_PROPERTY_BORDER_RADIUS

#define GTK_STYLE_PROPERTY_BORDER_RADIUS "border-radius"

A property holding the rendered element's border radius in pixels as a gint.

GTK_STYLE_PROPERTY_BORDER_STYLE

#define GTK_STYLE_PROPERTY_BORDER_STYLE "border-style"

A property holding the element's border style as a GtkBorderStyle.

GTK_STYLE_PROPERTY_BORDER_COLOR

#define GTK_STYLE_PROPERTY_BORDER_COLOR "border-color"

A property holding the element's border color as a GdkRGBA.

GTK_STYLE_PROPERTY_BACKGROUND_IMAGE

#define GTK_STYLE_PROPERTY_BACKGROUND_IMAGE "background-image"

A property holding the element's background as a cairo_pattern_t.

GTK_STYLE_CLASS_BACKGROUND

#define GTK_STYLE_CLASS_BACKGROUND "background"

A CSS class to match the window background.

GTK_STYLE_CLASS_BUTTON

#define GTK_STYLE_CLASS_BUTTON "button"

A CSS class to match buttons.

GTK_STYLE_CLASS_CALENDAR

#define GTK_STYLE_CLASS_CALENDAR "calendar"

A CSS class to match calendars.

GTK_STYLE_CLASS_CELL

#define GTK_STYLE_CLASS_CELL "cell"

A CSS class to match content rendered in cell views.

GTK_STYLE_CLASS_CHECK

#define GTK_STYLE_CLASS_CHECK "check"

A CSS class to match check boxes.

GTK_STYLE_CLASS_DEFAULT

#define GTK_STYLE_CLASS_DEFAULT "default"

A CSS class to match the default widget.

GTK_STYLE_CLASS_ENTRY

#define GTK_STYLE_CLASS_ENTRY "entry"

A CSS class to match text entries.

GTK_STYLE_CLASS_HEADER

#define GTK_STYLE_CLASS_HEADER "header"

A CSS class to match a header element.

GTK_STYLE_CLASS_MENU

#define GTK_STYLE_CLASS_MENU "menu"

A CSS class to match popup menus.

GTK_STYLE_CLASS_RADIO

#define GTK_STYLE_CLASS_RADIO "radio"

A CSS class to match radio buttons.

GTK_STYLE_CLASS_RUBBERBAND

#define GTK_STYLE_CLASS_RUBBERBAND "rubberband"

A CSS class to match the rubberband selection rectangle.

GTK_STYLE_CLASS_SCROLLBAR

#define GTK_STYLE_CLASS_SCROLLBAR "scrollbar"

A CSS class to match scrollbars.

GTK_STYLE_CLASS_SLIDER

#define GTK_STYLE_CLASS_SLIDER "slider"

A CSS class to match sliders.

GTK_STYLE_CLASS_TOOLTIP

#define GTK_STYLE_CLASS_TOOLTIP "tooltip"

A CSS class to match tooltip windows.

GTK_STYLE_CLASS_TROUGH

#define GTK_STYLE_CLASS_TROUGH "trough"

A CSS class to match troughs, as in scrollbars and progressbars.

GTK_STYLE_CLASS_ACCELERATOR

#define GTK_STYLE_CLASS_ACCELERATOR "accelerator"

A CSS class to match an accelerator.

GTK_STYLE_CLASS_DOCK

#define GTK_STYLE_CLASS_DOCK "dock"

A widget class defining a dock area

GTK_STYLE_CLASS_GRIP

#define GTK_STYLE_CLASS_GRIP "grip"

A widget class defining a resize grip

GTK_STYLE_CLASS_MENUBAR

#define GTK_STYLE_CLASS_MENUBAR "menubar"

A CSS class to menubars.

GTK_STYLE_CLASS_MENUITEM

#define GTK_STYLE_CLASS_MENUITEM "menuitem"

A CSS class to match menu items.

GTK_STYLE_CLASS_PROGRESSBAR

#define GTK_STYLE_CLASS_PROGRESSBAR "progressbar"

A widget class defining a resize grip

GTK_STYLE_CLASS_SPINNER

#define GTK_STYLE_CLASS_SPINNER "spinner"

A widget class defining a spinner

GTK_STYLE_CLASS_TOOLBAR

#define GTK_STYLE_CLASS_TOOLBAR "toolbar"

A CSS class to match toolbars.

GTK_STYLE_CLASS_PRIMARY_TOOLBAR

#define GTK_STYLE_CLASS_PRIMARY_TOOLBAR "primary-toolbar"

A CSS class to match primary toolbars.

GTK_STYLE_CLASS_PANE_SEPARATOR

#define GTK_STYLE_CLASS_PANE_SEPARATOR "pane-separator"

A CSS class for a pane separator, such as those in GtkPaned.

GTK_STYLE_CLASS_SEPARATOR

#define GTK_STYLE_CLASS_SEPARATOR "separator"

A CSS class for a separator.

GTK_STYLE_CLASS_DND

#define GTK_STYLE_CLASS_DND "dnd"

A CSS class for a drag-and-drop indicator

GTK_STYLE_CLASS_ERROR

#define GTK_STYLE_CLASS_ERROR "error"

A widget class for an area displaying an error message, such as those in infobars

GTK_STYLE_CLASS_EXPANDER

#define GTK_STYLE_CLASS_EXPANDER "expander"

A widget class defining an expander, such as those in treeviews

GTK_STYLE_CLASS_FRAME

#define GTK_STYLE_CLASS_FRAME "frame"

A CSS class defining a frame delimiting content, such as GtkFrame or the scrolled window frame around the scrollable area.

GTK_STYLE_CLASS_HIGHLIGHT

#define GTK_STYLE_CLASS_HIGHLIGHT "highlight"

A CSS class defining a highlighted area, such as headings in assistants.

GTK_STYLE_CLASS_INFO

#define GTK_STYLE_CLASS_INFO "info"

A widget class for an area displaying an informational message, such as those in infobars

GTK_STYLE_CLASS_MARK

#define GTK_STYLE_CLASS_MARK "mark"

A widget class defining marks in a widget, such as in scales

GTK_STYLE_CLASS_NOTEBOOK

#define GTK_STYLE_CLASS_NOTEBOOK "notebook"

A widget class defining a notebook

GTK_STYLE_CLASS_QUESTION

#define GTK_STYLE_CLASS_QUESTION "question"

A widget class for an area displaying a question to the user, such as those in infobars

GTK_STYLE_CLASS_SCALE

#define GTK_STYLE_CLASS_SCALE "scale"

A CSS class to match scale widgets.

GTK_STYLE_CLASS_SPINBUTTON

#define GTK_STYLE_CLASS_SPINBUTTON "spinbutton"

A widget class defining an spinbutton

GTK_STYLE_CLASS_VIEW

#define GTK_STYLE_CLASS_VIEW "view"

A widget class defining a view, such as iconviews or treeviews

GTK_STYLE_CLASS_WARNING

#define GTK_STYLE_CLASS_WARNING "warning"

A widget class for an area displaying a warning message, such as those in infobars

GTK_STYLE_CLASS_HORIZONTAL

#define GTK_STYLE_CLASS_HORIZONTAL "horizontal"

A widget class for horizontally layered widgets.

GTK_STYLE_CLASS_VERTICAL

#define GTK_STYLE_CLASS_VERTICAL "vertical"

A widget class for vertically layered widgets.

GTK_STYLE_REGION_COLUMN

#define GTK_STYLE_REGION_COLUMN "column"

A widget region name to define a treeview column.

GTK_STYLE_REGION_COLUMN_HEADER

#define GTK_STYLE_REGION_COLUMN_HEADER "column-header"

A widget region name to define a treeview column header.

GTK_STYLE_REGION_ROW

#define GTK_STYLE_REGION_ROW "row"

A widget region name to define a treeview row.

GTK_STYLE_REGION_TAB

#define GTK_STYLE_REGION_TAB "tab"

A widget region name to define a notebook tab.

struct GtkStyleContext

struct GtkStyleContext;

gtk_style_context_new ()

GtkStyleContext *   gtk_style_context_new               (void);

Creates a standalone GtkStyleContext, this style context won't be attached to any widget, so you may want to call gtk_style_context_set_path() yourself.

gtk_style_context_add_provider ()

void                gtk_style_context_add_provider      (GtkStyleContext *context,
                                                         GtkStyleProvider *provider,
                                                         guint priority);

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

Since 3.0

gtk_style_context_add_provider_for_screen ()

void                gtk_style_context_add_provider_for_screen
                                                        (GdkScreen *screen,
                                                         GtkStyleProvider *provider,
                                                         guint priority);

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

GTK+ uses this to make styling information from GtkSettings available.

Since 3.0

gtk_style_context_get ()

void                gtk_style_context_get               (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         ...);

Retrieves several style property values from context for a given state.

Since 3.0

gtk_style_context_get_direction ()

GtkTextDirection    gtk_style_context_get_direction     (GtkStyleContext *context);

Returns the widget direction used for rendering.

Since 3.0

gtk_style_context_get_junction_sides ()

GtkJunctionSides    gtk_style_context_get_junction_sides
                                                        (GtkStyleContext *context);

Returns the sides where rendered elements connect visually with others.

Since 3.0

gtk_style_context_get_path ()

const GtkWidgetPath *  gtk_style_context_get_path       (GtkStyleContext *context);

Returns the widget path used for style matching.

Since 3.0

gtk_style_context_get_property ()

void                gtk_style_context_get_property      (GtkStyleContext *context,
                                                         const gchar *property,
                                                         GtkStateFlags state,
                                                         GValue *value);

Gets a style property from context for the given state.

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

Since 3.0

gtk_style_context_get_screen ()

GdkScreen *         gtk_style_context_get_screen        (GtkStyleContext *context);

Returns the GdkScreen to which context is attached.

gtk_style_context_get_state ()

GtkStateFlags       gtk_style_context_get_state         (GtkStyleContext *context);

Returns the state used when rendering.

Since 3.0

gtk_style_context_get_style ()

void                gtk_style_context_get_style         (GtkStyleContext *context,
                                                         ...);

Retrieves several widget style properties from context according to the current style.

Since 3.0

gtk_style_context_get_style_property ()

void                gtk_style_context_get_style_property
                                                        (GtkStyleContext *context,
                                                         const gchar *property_name,
                                                         GValue *value);

Gets the value for a widget style property.

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

gtk_style_context_get_style_valist ()

void                gtk_style_context_get_style_valist  (GtkStyleContext *context,
                                                         va_list args);

Retrieves several widget style properties from context according to the current style.

Since 3.0

gtk_style_context_get_valist ()

void                gtk_style_context_get_valist        (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         va_list args);

Retrieves several style property values from context for a given state.

Since 3.0

gtk_style_context_get_color ()

void                gtk_style_context_get_color         (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         GdkRGBA *color);

Gets the foreground color for a given state.

Since 3.0

gtk_style_context_get_background_color ()

void                gtk_style_context_get_background_color
                                                        (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         GdkRGBA *color);

Gets the background color for a given state.

Since 3.0

gtk_style_context_get_border_color ()

void                gtk_style_context_get_border_color  (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         GdkRGBA *color);

Gets the border color for a given state.

Since 3.0

gtk_style_context_get_border ()

void                gtk_style_context_get_border        (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         GtkBorder *border);

Gets the border for a given state as a GtkBorder. See GTK_STYLE_PROPERTY_BORDER_WIDTH.

Since 3.0

gtk_style_context_get_padding ()

void                gtk_style_context_get_padding       (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         GtkBorder *padding);

Gets the padding for a given state as a GtkBorder. See GTK_STYLE_PROPERTY_PADDING.

Since 3.0

gtk_style_context_get_margin ()

void                gtk_style_context_get_margin        (GtkStyleContext *context,
                                                         GtkStateFlags state,
                                                         GtkBorder *margin);

Gets the margin for a given state as a GtkBorder. See GTK_STYLE_PROPERTY_MARGIN.

Since 3.0

gtk_style_context_get_font ()

const PangoFontDescription * gtk_style_context_get_font (GtkStyleContext *context,
                                                         GtkStateFlags state);

Returns the font description for a given state. The returned object is const and will remain valid until the "changed" signal happens.

Since 3.0

gtk_style_context_invalidate ()

void                gtk_style_context_invalidate        (GtkStyleContext *context);

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

If you're using a GtkStyleContext returned from gtk_widget_get_style_context(), you do not need to call this yourself.

Since 3.0

gtk_style_context_state_is_running ()

gboolean            gtk_style_context_state_is_running  (GtkStyleContext *context,
                                                         GtkStateType state,
                                                         gdouble *progress);

Returns TRUE if there is a transition animation running for the current region (see gtk_style_context_push_animatable_region()).

If progress is not NULL, the animation progress will be returned there, 0.0 means the state is closest to being unset, while 1.0 means it's closest to being set. This means transition animation will run from 0 to 1 when state is being set and from 1 to 0 when it's being unset.

Since 3.0

gtk_style_context_lookup_color ()

gboolean            gtk_style_context_lookup_color      (GtkStyleContext *context,
                                                         const gchar *color_name,
                                                         GdkRGBA *color);

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

gtk_style_context_lookup_icon_set ()

GtkIconSet *        gtk_style_context_lookup_icon_set   (GtkStyleContext *context,
                                                         const gchar *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 NULL.

gtk_style_context_notify_state_change ()

void                gtk_style_context_notify_state_change
                                                        (GtkStyleContext *context,
                                                         GdkWindow *window,
                                                         gpointer region_id,
                                                         GtkStateType state,
                                                         gboolean 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 NULL, all rendered elements using context will be affected by this state transition.

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

gtk_style_context_notify_state_change (context,
                                       gtk_widget_get_window (widget),
                                       NULL,
                                       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 3.0

gtk_style_context_pop_animatable_region ()

void                gtk_style_context_pop_animatable_region
                                                        (GtkStyleContext *context);

Pops an animatable region from context. See gtk_style_context_push_animatable_region().

Since 3.0

gtk_style_context_push_animatable_region ()

void                gtk_style_context_push_animatable_region
                                                        (GtkStyleContext *context,
                                                         gpointer region_id);

Pushes an animatable region, so all further gtk_render_*() calls between this call and the following gtk_style_context_pop_animatable_region() will potentially show transition animations for this region if gtk_style_context_notify_state_change() is called for a given state, and the current theme/style defines transition animations for state changes.

The region_id used must be unique in context so the theming engine can uniquely identify rendered elements subject to a state transition.

Since 3.0

gtk_style_context_cancel_animations ()

void                gtk_style_context_cancel_animations (GtkStyleContext *context,
                                                         gpointer region_id);

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

A NULL region_id will stop all ongoing animations in context, when dealing with a GtkStyleContext 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 3.0

gtk_style_context_scroll_animations ()

void                gtk_style_context_scroll_animations (GtkStyleContext *context,
                                                         GdkWindow *window,
                                                         gint dx,
                                                         gint 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.

Since 3.0

gtk_style_context_remove_provider ()

void                gtk_style_context_remove_provider   (GtkStyleContext *context,
                                                         GtkStyleProvider *provider);

Removes provider from the style providers list in context.

Since 3.0

gtk_style_context_remove_provider_for_screen ()

void                gtk_style_context_remove_provider_for_screen
                                                        (GdkScreen *screen,
                                                         GtkStyleProvider *provider);

Removes provider from the global style providers list in screen.

Since 3.0

gtk_style_context_reset_widgets ()

void                gtk_style_context_reset_widgets     (GdkScreen *screen);

This function recomputes the styles for all widgets under a particular GdkScreen. This is useful when some global parameter has changed that affects the appearance of all widgets, because when a widget gets a new style, it will both redraw and recompute any cached information about its appearance. As an example, it is used when the color scheme changes in the related GtkSettings object.

Since 3.0

gtk_style_context_set_background ()

void                gtk_style_context_set_background    (GtkStyleContext *context,
                                                         GdkWindow *window);

Sets the background of window to the background pattern or color specified in context for its current state.

Since 3.0

gtk_style_context_restore ()

void                gtk_style_context_restore           (GtkStyleContext *context);

Restores context state to a previous stage. See gtk_style_context_save().

Since 3.0

gtk_style_context_save ()

void                gtk_style_context_save              (GtkStyleContext *context);

Saves the context state, so all modifications done through gtk_style_context_add_class(), gtk_style_context_remove_class(), gtk_style_context_add_region(), gtk_style_context_remove_region() or gtk_style_context_set_junction_sides() can be reverted in one go through gtk_style_context_restore().

Since 3.0

gtk_style_context_set_direction ()

void                gtk_style_context_set_direction     (GtkStyleContext *context,
                                                         GtkTextDirection direction);

Sets the reading direction for rendering purposes.

If you are using a GtkStyleContext returned from gtk_widget_get_style_context(), you do not need to call this yourself.

Since 3.0

gtk_style_context_set_junction_sides ()

void                gtk_style_context_set_junction_sides
                                                        (GtkStyleContext *context,
                                                         GtkJunctionSides sides);

Sets the sides where rendered elements (mostly through gtk_render_frame()) will visually connect with other visual elements.

This is merely a hint that may or may not be honored by theming engines.

Container widgets are expected to set junction hints as appropriate for their children, so it should not normally be necessary to call this function manually.

Since 3.0

gtk_style_context_set_path ()

void                gtk_style_context_set_path          (GtkStyleContext *context,
                                                         GtkWidgetPath *path);

Sets the GtkWidgetPath used for style matching. As a consequence, the style will be regenerated to match the new given path.

If you are using a GtkStyleContext returned from gtk_widget_get_style_context(), you do not need to call this yourself.

Since 3.0

gtk_style_context_add_class ()

void                gtk_style_context_add_class         (GtkStyleContext *context,
                                                         const gchar *class_name);

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

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

GtkEntry.entry { ... }

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

.entry { ... }

Since 3.0

gtk_style_context_remove_class ()

void                gtk_style_context_remove_class      (GtkStyleContext *context,
                                                         const gchar *class_name);

Removes class_name from context.

Since 3.0

gtk_style_context_has_class ()

gboolean            gtk_style_context_has_class         (GtkStyleContext *context,
                                                         const gchar *class_name);

Returns TRUE if context currently has defined the given class name

Since 3.0

gtk_style_context_list_classes ()

GList *             gtk_style_context_list_classes      (GtkStyleContext *context);

Returns the list of classes currently defined in context.

Since 3.0

gtk_style_context_add_region ()

void                gtk_style_context_add_region        (GtkStyleContext *context,
                                                         const gchar *region_name,
                                                         GtkRegionFlags flags);

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

In the CSS file format, a GtkTreeView 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.

Since 3.0

gtk_style_context_remove_region ()

void                gtk_style_context_remove_region     (GtkStyleContext *context,
                                                         const gchar *region_name);

Removes a region from context.

Since 3.0

gtk_style_context_has_region ()

gboolean            gtk_style_context_has_region        (GtkStyleContext *context,
                                                         const gchar *region_name,
                                                         GtkRegionFlags *flags_return);

Returns TRUE if context has the region defined. If flags_return is not NULL, it is set to the flags affecting the region.

Since 3.0

gtk_style_context_list_regions ()

GList *             gtk_style_context_list_regions      (GtkStyleContext *context);

Returns the list of regions currently defined in context.

Since 3.0

gtk_style_context_set_screen ()

void                gtk_style_context_set_screen        (GtkStyleContext *context,
                                                         GdkScreen *screen);

Attaches context to the given screen.

The screen is used to add style information from 'global' style providers, such as the screens GtkSettings instance.

If you are using a GtkStyleContext returned from gtk_widget_get_style_context(), you do not need to call this yourself.

Since 3.0

gtk_style_context_set_state ()

void                gtk_style_context_set_state         (GtkStyleContext *context,
                                                         GtkStateFlags flags);

Sets the state to be used when rendering with any of the gtk_render_*() functions.

Since 3.0

struct GtkBorder

struct GtkBorder;

A struct that specifies a border around a rectangular area that can be of different width on each side.

gtk_border_new ()

GtkBorder *         gtk_border_new                      (void);

Allocates a new GtkBorder structure and initializes its elements to zero.

Since 2.14

gtk_border_copy ()

GtkBorder *         gtk_border_copy                     (const GtkBorder *border_);

Copies a GtkBorder structure.

gtk_border_free ()

void                gtk_border_free                     (GtkBorder *border_);

Frees a GtkBorder structure.

gtk_render_arrow ()

void                gtk_render_arrow                    (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble angle,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble size);

Renders an arrow pointing to angle.

Example 12. Typical arrow rendering at 0, 1⁄2 π, π and 3⁄2 π

Since 3.0

gtk_render_background ()

void                gtk_render_background               (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders the background of an element.

Example 13. Typical background rendering, showing the effect of background-image, border-width and border-radius

Since 3.0.

gtk_render_check ()

void                gtk_render_check                    (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders a checkmark (as in a GtkCheckButton).

The GTK_STATE_FLAG_ACTIVE state determines whether the check is on or off, and GTK_STATE_FLAG_INCONSISTENT determines whether it should be marked as undefined.

Example 14. Typical checkmark rendering

Since 3.0

gtk_render_expander ()

void                gtk_render_expander                 (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders an expander (as used in GtkTreeView and GtkExpander) in the area defined by x, y, width, height. The state GTK_STATE_FLAG_ACTIVE determines whether the expander is collapsed or expanded.

Example 15. Typical expander rendering

Since 3.0

gtk_render_extension ()

void                gtk_render_extension                (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height,
                                                         GtkPositionType gap_side);

Renders a extension (as in a GtkNotebook tab) in the rectangle defined by x, y, width, height. The side where the extension connects to is defined by gap_side.

Example 16. Typical extension rendering

Since 3.0

gtk_render_focus ()

void                gtk_render_focus                    (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders a focus indicator on the rectangle determined by x, y, width, height.

Example 17. Typical focus rendering

Since 3.0

gtk_render_frame ()

void                gtk_render_frame                    (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders a frame around the rectangle defined by x, y, width, height.

Example 18. Examples of frame rendering, showing the effect of border-image, border-color, border-width, border-radius and junctions

Since 3.0

gtk_render_frame_gap ()

void                gtk_render_frame_gap                (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height,
                                                         GtkPositionType gap_side,
                                                         gdouble xy0_gap,
                                                         gdouble xy1_gap);

Renders a frame around the rectangle defined by (x, y, width, height), leaving a gap on one side. xy0_gap and xy1_gap will mean X coordinates for GTK_POS_TOP and GTK_POS_BOTTOM gap sides, and Y coordinates for GTK_POS_LEFT and GTK_POS_RIGHT.

Example 19. Typical rendering of a frame with a gap

Since 3.0

gtk_render_handle ()

void                gtk_render_handle                   (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders a handle (as in GtkHandleBox, GtkPaned and GtkWindow's resize grip), in the rectangle determined by x, y, width, height.

Example 20. Handles rendered for the paned and grip classes

Since 3.0

gtk_render_layout ()

void                gtk_render_layout                   (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         PangoLayout *layout);

Renders layout on the coordinates x, y

Since 3.0

gtk_render_line ()

void                gtk_render_line                     (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x0,
                                                         gdouble y0,
                                                         gdouble x1,
                                                         gdouble y1);

Renders a line from (x0, y0) to (x1, y1).

Since 3.0

gtk_render_option ()

void                gtk_render_option                   (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders an option mark (as in a GtkRadioButton), 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.

Example 21. Typical option mark rendering

Since 3.0

gtk_render_slider ()

void                gtk_render_slider                   (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height,
                                                         GtkOrientation orientation);

Renders a slider (as in GtkScale) in the rectangle defined by x, y, width, height. orientation defines whether the slider is vertical or horizontal.

Example 22. Typical slider rendering

Since 3.0

gtk_render_activity ()

void                gtk_render_activity                 (GtkStyleContext *context,
                                                         cairo_t *cr,
                                                         gdouble x,
                                                         gdouble y,
                                                         gdouble width,
                                                         gdouble height);

Renders an activity area (Such as in GtkSpinner or the fill line in GtkRange), the state GTK_STATE_FLAG_ACTIVE determines whether there is activity going on.

Since 3.0

gtk_render_icon_pixbuf ()

GdkPixbuf *         gtk_render_icon_pixbuf              (GtkStyleContext *context,
                                                         const GtkIconSource *source,
                                                         GtkIconSize size);

Renders the icon specified by source at the given size, returning the result in a pixbuf.

Since 3.0

The "direction" property

  "direction"                GtkTextDirection      : Read / Write

Text direction.

Default value: GTK_TEXT_DIR_LTR

The "screen" property

  "screen"                   GdkScreen*            : Read / Write

The associated GdkScreen.

The "changed" signal

void                user_function                      (GtkStyleContext *stylecontext,
                                                        gpointer         user_data)         : Run First