## GtkStyleContext GtkStyleContext — Rendering UI elements |

## Synopsis

    #include <gtk/gtk.h>

    #define             GTK_STYLE_PROPERTY_BACKGROUND_COLOR
    #define             GTK_STYLE_PROPERTY_COLOR
    #define             GTK_STYLE_PROPERTY_FONT
    #define             GTK_STYLE_PROPERTY_MARGIN
    #define             GTK_STYLE_PROPERTY_PADDING
    #define             GTK_STYLE_PROPERTY_BORDER_WIDTH
    #define             GTK_STYLE_PROPERTY_BORDER_RADIUS
    #define             GTK_STYLE_PROPERTY_BORDER_STYLE
    #define             GTK_STYLE_PROPERTY_BORDER_COLOR
    #define             GTK_STYLE_PROPERTY_BACKGROUND_IMAGE

    #define             GTK_STYLE_CLASS_BACKGROUND
    #define             GTK_STYLE_CLASS_BUTTON
    #define             GTK_STYLE_CLASS_CALENDAR
    #define             GTK_STYLE_CLASS_CELL
    #define             GTK_STYLE_CLASS_CHECK
    #define             GTK_STYLE_CLASS_DEFAULT
    #define             GTK_STYLE_CLASS_ENTRY
    #define             GTK_STYLE_CLASS_HEADER
    #define             GTK_STYLE_CLASS_MENU
    #define             GTK_STYLE_CLASS_RADIO
    #define             GTK_STYLE_CLASS_RUBBERBAND
    #define             GTK_STYLE_CLASS_SCROLLBAR
    #define             GTK_STYLE_CLASS_SLIDER
    #define             GTK_STYLE_CLASS_TOOLTIP
    #define             GTK_STYLE_CLASS_TROUGH
    #define             GTK_STYLE_CLASS_ACCELERATOR
    #define             GTK_STYLE_CLASS_DOCK
    #define             GTK_STYLE_CLASS_GRIP
    #define             GTK_STYLE_CLASS_MENUBAR
    #define             GTK_STYLE_CLASS_MENUITEM
    #define             GTK_STYLE_CLASS_PROGRESSBAR
    #define             GTK_STYLE_CLASS_SPINNER
    #define             GTK_STYLE_CLASS_TOOLBAR
    #define             GTK_STYLE_CLASS_PRIMARY_TOOLBAR
    #define             GTK_STYLE_CLASS_PANE_SEPARATOR
    #define             GTK_STYLE_CLASS_SEPARATOR
    #define             GTK_STYLE_CLASS_DND
    #define             GTK_STYLE_CLASS_ERROR
    #define             GTK_STYLE_CLASS_EXPANDER
    #define             GTK_STYLE_CLASS_FRAME
    #define             GTK_STYLE_CLASS_HIGHLIGHT
    #define             GTK_STYLE_CLASS_INFO
    #define             GTK_STYLE_CLASS_MARK
    #define             GTK_STYLE_CLASS_NOTEBOOK
    #define             GTK_STYLE_CLASS_QUESTION
    #define             GTK_STYLE_CLASS_SCALE
    #define             GTK_STYLE_CLASS_SPINBUTTON
    #define             GTK_STYLE_CLASS_VIEW
    #define             GTK_STYLE_CLASS_WARNING
    #define             GTK_STYLE_CLASS_HORIZONTAL
    #define             GTK_STYLE_CLASS_VERTICAL
    #define             GTK_STYLE_REGION_COLUMN
    #define             GTK_STYLE_REGION_COLUMN_HEADER
    #define             GTK_STYLE_REGION_ROW
    #define             GTK_STYLE_REGION_TAB

    struct              GtkStyleContext;
    GtkStyleContext *   gtk_style_context_new               (void);
    void                gtk_style_context_add_provider      (GtkStyleContext *context,
                                                             GtkStyleProvider *provider,
                                                             guint priority);
    void                gtk_style_context_add_provider_for_screen
                                                            (GdkScreen *screen,
                                                             GtkStyleProvider *provider,
                                                             guint priority);
    void                gtk_style_context_get               (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             ...);
    GtkTextDirection    gtk_style_context_get_direction     (GtkStyleContext *context);
    GtkJunctionSides    gtk_style_context_get_junction_sides
                                                            (GtkStyleContext *context);
    const GtkWidgetPath * gtk_style_context_get_path        (GtkStyleContext *context);
    void                gtk_style_context_get_property      (GtkStyleContext *context,
                                                             const gchar *property,
                                                             GtkStateFlags state,
                                                             GValue *value);
    GdkScreen *         gtk_style_context_get_screen        (GtkStyleContext *context);
    GtkStateFlags       gtk_style_context_get_state         (GtkStyleContext *context);
    void                gtk_style_context_get_style         (GtkStyleContext *context,
                                                             ...);
    void                gtk_style_context_get_style_property
                                                            (GtkStyleContext *context,
                                                             const gchar *property_name,
                                                             GValue *value);
    void                gtk_style_context_get_style_valist  (GtkStyleContext *context,
                                                             va_list args);
    void                gtk_style_context_get_valist        (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             va_list args);
    void                gtk_style_context_get_color         (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             GdkRGBA *color);
    void                gtk_style_context_get_background_color
                                                            (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             GdkRGBA *color);
    void                gtk_style_context_get_border_color  (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             GdkRGBA *color);
    void                gtk_style_context_get_border        (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             GtkBorder *border);
    void                gtk_style_context_get_padding       (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             GtkBorder *padding);
    void                gtk_style_context_get_margin        (GtkStyleContext *context,
                                                             GtkStateFlags state,
                                                             GtkBorder *margin);
    const PangoFontDescription * gtk_style_context_get_font (GtkStyleContext *context,
                                                             GtkStateFlags state);
    void                gtk_style_context_invalidate        (GtkStyleContext *context);
    gboolean            gtk_style_context_state_is_running  (GtkStyleContext *context,
                                                             GtkStateType state,
                                                             gdouble *progress);
    gboolean            gtk_style_context_lookup_color      (GtkStyleContext *context,
                                                             const gchar *color_name,
                                                             GdkRGBA *color);
    GtkIconSet *        gtk_style_context_lookup_icon_set   (GtkStyleContext *context,
                                                             const gchar *stock_id);
    void                gtk_style_context_notify_state_change
                                                            (GtkStyleContext *context,
                                                             GdkWindow *window,
                                                             gpointer region_id,
                                                             GtkStateType state,
                                                             gboolean state_value);
    void                gtk_style_context_pop_animatable_region
                                                            (GtkStyleContext *context);
    void                gtk_style_context_push_animatable_region
                                                            (GtkStyleContext *context,
                                                             gpointer region_id);
    void                gtk_style_context_cancel_animations (GtkStyleContext *context,
                                                             gpointer region_id);
    void                gtk_style_context_scroll_animations (GtkStyleContext *context,
                                                             GdkWindow *window,
                                                             gint dx,
                                                             gint dy);
    void                gtk_style_context_remove_provider   (GtkStyleContext *context,
                                                             GtkStyleProvider *provider);
    void                gtk_style_context_remove_provider_for_screen
                                                            (GdkScreen *screen,
                                                             GtkStyleProvider *provider);
    void                gtk_style_context_reset_widgets     (GdkScreen *screen);
    void                gtk_style_context_set_background    (GtkStyleContext *context,
                                                             GdkWindow *window);
    void                gtk_style_context_restore           (GtkStyleContext *context);
    void                gtk_style_context_save              (GtkStyleContext *context);
    void                gtk_style_context_set_direction     (GtkStyleContext *context,
                                                             GtkTextDirection direction);
    void                gtk_style_context_set_junction_sides
                                                            (GtkStyleContext *context,
                                                             GtkJunctionSides sides);
    void                gtk_style_context_set_path          (GtkStyleContext *context,
                                                             GtkWidgetPath *path);
    void                gtk_style_context_add_class         (GtkStyleContext *context,
                                                             const gchar *class_name);
    void                gtk_style_context_remove_class      (GtkStyleContext *context,
                                                             const gchar *class_name);
    gboolean            gtk_style_context_has_class         (GtkStyleContext *context,
                                                             const gchar *class_name);
    GList *             gtk_style_context_list_classes      (GtkStyleContext *context);
    void                gtk_style_context_add_region        (GtkStyleContext *context,
                                                             const gchar *region_name,
                                                             GtkRegionFlags flags);
    void                gtk_style_context_remove_region     (GtkStyleContext *context,
                                                             const gchar *region_name);
    gboolean            gtk_style_context_has_region        (GtkStyleContext *context,
                                                             const gchar *region_name,
                                                             GtkRegionFlags *flags_return);
    GList *             gtk_style_context_list_regions      (GtkStyleContext *context);
    void                gtk_style_context_set_screen        (GtkStyleContext *context,
                                                             GdkScreen *screen);
    void                gtk_style_context_set_state         (GtkStyleContext *context,
                                                             GtkStateFlags flags);

    struct              GtkBorder;
    GtkBorder *         gtk_border_new                      (void);
    GtkBorder *         gtk_border_copy                     (const GtkBorder *border_);
    void                gtk_border_free                     (GtkBorder *border_);

    void                gtk_render_arrow                    (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble angle,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble size);
    void                gtk_render_background               (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    void                gtk_render_check                    (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    void                gtk_render_expander                 (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    void                gtk_render_extension                (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height,
                                                             GtkPositionType gap_side);
    void                gtk_render_focus                    (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    void                gtk_render_frame                    (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    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);
    void                gtk_render_handle                   (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    void                gtk_render_layout                   (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             PangoLayout *layout);
    void                gtk_render_line                     (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x0,
                                                             gdouble y0,
                                                             gdouble x1,
                                                             gdouble y1);
    void                gtk_render_option                   (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    void                gtk_render_slider                   (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height,
                                                             GtkOrientation orientation);
    void                gtk_render_activity                 (GtkStyleContext *context,
                                                             cairo_t *cr,
                                                             gdouble x,
                                                             gdouble y,
                                                             gdouble width,
                                                             gdouble height);
    GdkPixbuf *         gtk_render_icon_pixbuf              (GtkStyleContext *context,
                                                             const GtkIconSource *source,
                                                             GtkIconSize size);

## Object Hierarchy

      GObject
       +----GtkStyleContext

      GBoxed
       +----GtkBorder

## Properties

      "direction"                GtkTextDirection      : Read / Write
      "screen"                   GdkScreen*            : Read / Write

## Signals

      "changed"                                        : Run First

## Description

GtkStyleContext is an object that stores styling information affecting a widget defined by GtkWidgetPath.

In order to construct the final style information, GtkStyleContext queries information from all attached GtkStyleProviders. Style providers can be either attached explicitly to the context through `gtk_style_context_add_provider()`, or to the screen through `gtk_style_context_add_provider_for_screen()`. The resulting style is a combination of all providers' information in priority order.

For GTK+ widgets, any GtkStyleContext returned by `gtk_widget_get_style_context()` will already have a GtkWidgetPath, a GdkScreen 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 `gtk_style_context_set_path()` and `gtk_style_context_set_screen()`, as well as updating the context yourself using `gtk_style_context_invalidate()` whenever any of the conditions change, such as a change in the "gtk-theme-name" setting or a hierarchy change in the rendered widget.

### 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:

Example 9. Using an enumeration to identify animatable regions

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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:

Example 10. Using struct pointers to identify animatable regions

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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.

Example 11. Triggering a state change animation on a region

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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:

Style class | Macro | Used by
--- | --- | ---
button | GTK_STYLE_CLASS_BUTTON | GtkButton, GtkToggleButton, GtkRadioButton, GtkCheckButton
default | GTK_STYLE_CLASS_DEFAULT | GtkButton
check | GTK_STYLE_CLASS_CHECK | GtkCheckButton, GtkCheckMenuItem, GtkCellRendererToggle
radio | GTK_STYLE_CLASS_RADIO | GtkRadioButton, GtkRadioMenuItem, GtkCellRendererToggle
arrow | GTK_STYLE_CLASS_ARROW | GtkArrow
calendar | GTK_STYLE_CLASS_CALENDAR | GtkCalendar
entry | GTK_STYLE_CLASS_ENTRY | GtkEntry
cell | GTK_STYLE_CLASS_CELL | GtkCellRendererToggle
menu | GTK_STYLE_CLASS_MENU | GtkMenu, GtkMenuItem, GtkCheckMenuItem, GtkRadioMenuItem
expander | GTK_STYLE_CLASS_EXPANDER | GtkExpander
tooltip | GTK_STYLE_CLASS_TOOLTIP | GtkTooltip
frame | GTK_STYLE_CLASS_FRAME | GtkFrame
scrolled-window |  | GtkScrolledWindow
viewport |  | GtkViewport
trough | GTK_STYLE_CLASS_TROUGH | GtkScrollbar, GtkProgressBar, GtkScale
progressbar | GTK_STYLE_CLASS_PROGRESSBAR | GtkProgressBar, GtkCellRendererProgress
slider | GTK_STYLE_CLASS_SLIDER | GtkScrollbar, GtkScale
menuitem | GTK_STYLE_CLASS_MENUITEM | GtkMenuItem
popup |  | GtkMenu
accelerator | GTK_STYLE_CLASS_ACCELERATOR | GtkAccelLabel
menubar | GTK_STYLE_CLASS_MENUBAR | GtkMenuBar
toolbar | GTK_STYLE_CLASS_TOOLBAR | GtkToolbar
dock | GTK_STYLE_CLASS_DOCK | GtkHandleBox
notebook |  | GtkNotebook
background | GTK_STYLE_CLASS_BACKGROUND | GtkWindow
rubberband | GTK_STYLE_CLASS_RUBBERBAND |
header | GTK_STYLE_CLASS_HEADER |
grip | GTK_STYLE_CLASS_GRIP | GtkWindow
spinner | GTK_STYLE_CLASS_SPINNER | GtkSpinner

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

Region | Flags | Macro | Used by
--- | --- | --- | ---
row | even, odd | GTK_STYLE_REGION_ROW | GtkTreeView
column | first, last, sorted | GTK_STYLE_REGION_COLUMN | GtkTreeView
column-header |  | GTK_STYLE_REGION_COLUMN_HEADER |
tab | even, odd, first, last | GTK_STYLE_REGION_TAB | GtkNotebook

### 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.

## Details

### 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.

### Note

This function is only useful when using the theming layer separated from GTK+, if you are using GtkStyleContext to theme GtkWidgets, use `gtk_widget_get_style_context()` in order to get a style context ready to theme the widget.

Returns : | A newly created GtkStyleContext.

### 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.

### Note

If both priorities are the same, A GtkStyleProvider added through this function takes precedence over another added through `gtk_style_context_add_provider_for_screen()`.

`context` : | a GtkStyleContext
`provider` : | a GtkStyleProvider
`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`

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.

### Note

If both priorities are the same, A GtkStyleProvider added through `gtk_style_context_add_provider()` takes precedence over another added through this function.

`screen` : | a GdkScreen
`provider` : | a GtkStyleProvider
`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`

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.

`context` : | a GtkStyleContext
`state` : | state to retrieve the property values for
`...` : | property name /return value pairs, followed by `NULL`

Since 3.0

### gtk_style_context_get_direction ()

    GtkTextDirection    gtk_style_context_get_direction     (GtkStyleContext *context);

Returns the widget direction used for rendering.

`context` : | a GtkStyleContext
Returns : | the widget direction

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.

`context` : | a GtkStyleContext
Returns : | the junction sides

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.

`context` : | a GtkStyleContext
Returns : | A GtkWidgetPath. [transfer none]

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.

`context` : | a GtkStyleContext
`property` : | style property name
`state` : | state to retrieve the property value for
`value` : | return location for the style property value. [out][transfer full]

Since 3.0

### gtk_style_context_get_screen ()

    GdkScreen *         gtk_style_context_get_screen        (GtkStyleContext *context);

Returns the GdkScreen to which `context` is attached.

`context` : | a GtkStyleContext
Returns : | a GdkScreen. [transfer none]

### gtk_style_context_get_state ()

    GtkStateFlags       gtk_style_context_get_state         (GtkStyleContext *context);

Returns the state used when rendering.

`context` : | a GtkStyleContext
Returns : | the state flags

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.

`context` : | a GtkStyleContext
`...` : | property name /return value pairs, followed by `NULL`

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.

`context` : | a GtkStyleContext
`property_name` : | the name of the widget style property
`value` : | Return location for the property value

### 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.

`context` : | a GtkStyleContext
`args` : | va_list of property name/return location pairs, followed by `NULL`

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.

`context` : | a GtkStyleContext
`state` : | state to retrieve the property values for
`args` : | va_list of property name/return location pairs, followed by `NULL`

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.

`context` : | a GtkStyleContext
`state` : | state to retrieve the color for
`color` : | return value for the foreground color. [out]

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.

`context` : | a GtkStyleContext
`state` : | state to retrieve the color for
`color` : | return value for the background color. [out]

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.

`context` : | a GtkStyleContext
`state` : | state to retrieve the color for
`color` : | return value for the border color. [out]

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`.

`context` : | a GtkStyleContext
`state` : | state to retrieve the border for
`border` : | return value for the border settings. [out]

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`.

`context` : | a GtkStyleContext
`state` : | state to retrieve the padding for
`padding` : | return value for the padding settings. [out]

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`.

`context` : | a GtkStyleContext
`state` : | state to retrieve the border for
`margin` : | return value for the margin settings. [out]

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.

`context` : | a GtkStyleContext
`state` : | state to retrieve the font for
Returns : | the PangoFontDescription for the given state. This object is owned by GTK+ and should not be freed. [transfer none]

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.

`context` : | a GtkStyleContext.

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.

`context` : | a GtkStyleContext
`state` : | a widget state
`progress` : | return location for the transition progress. [out]
Returns : | `TRUE` if there is a running transition animation for `state`.

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.

`context` : | a GtkStyleContext
`color_name` : | color name to lookup
`color` : | Return location for the looked up color. [out]
Returns : | `TRUE` if `color_name` was found and resolved, `FALSE` otherwise

### 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`.

`context` : | a GtkStyleContext
`stock_id` : | an icon name
Returns : | The looked up `GtkIconSet`, or `NULL`. [transfer none]

### 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.

`context` : | a GtkStyleContext
`window` : | a GdkWindow
`region_id` : | animatable region to notify on, or `NULL`. See `gtk_style_context_push_animatable_region()`. [allow-none]
`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

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()`.

`context` : | a GtkStyleContext

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.

`context` : | a GtkStyleContext
`region_id` : | unique identifier for the animatable region

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.

`context` : | a GtkStyleContext
`region_id` : | animatable region to stop, or `NULL`. See `gtk_style_context_push_animatable_region()`. [allow-none]

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.

`context` : | a GtkStyleContext
`window` : | a GdkWindow used previously in `gtk_style_context_notify_state_change()`
`dx` : | Amount to scroll in the X axis
`dy` : | Amount to scroll in the Y axis

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`.

`context` : | a GtkStyleContext
`provider` : | a GtkStyleProvider

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`.

`screen` : | a GdkScreen
`provider` : | a GtkStyleProvider

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.

`screen` : | a GdkScreen

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.

`context` : | a GtkStyleContext
`window` : | a GdkWindow

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()`.

`context` : | a GtkStyleContext

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()`.

`context` : | a GtkStyleContext

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.

`context` : | a GtkStyleContext
`direction` : | the new direction.

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.

`context` : | a GtkStyleContext
`sides` : | sides where rendered elements are visually connected to other elements

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.

`context` : | a GtkStyleContext
`path` : | a GtkWidgetPath

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 { ... }

`context` : | a GtkStyleContext
`class_name` : | class name to use in styling

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`.

`context` : | a GtkStyleContext
`class_name` : | class name to remove

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

`context` : | a GtkStyleContext
`class_name` : | a class name
Returns : | `TRUE` if `context` has `class_name` defined

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`.

`context` : | a GtkStyleContext
Returns : | a GList of strings with the currently defined classes. The contents of the list are owned by GTK+, but you must free the list itself with `g_list_free()` when you are done with it. [transfer container][element-type utf8]

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.

### Note

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

`context` : | a GtkStyleContext
`region_name` : | region name to use in styling
`flags` : | flags that apply to the region

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`.

`context` : | a GtkStyleContext
`region_name` : | region name to unset

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.

`context` : | a GtkStyleContext
`region_name` : | a region name
`flags_return` : | return location for region flags. [out][allow-none]
Returns : | `TRUE` if region is defined

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`.

`context` : | a GtkStyleContext
Returns : | a GList of strings with the currently defined regions. The contents of the list are owned by GTK+, but you must free the list itself with `g_list_free()` when you are done with it. [transfer container][element-type utf8]

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.

`context` : | a GtkStyleContext
`screen` : | a GdkScreen

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.

`context` : | a GtkStyleContext
`flags` : | state to represent

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.

Returns : | a newly allocated GtkBorder. Free with `gtk_border_free()`

Since 2.14

### gtk_border_copy ()

    GtkBorder *         gtk_border_copy                     (const GtkBorder *border_);

Copies a GtkBorder structure.

`border_` : | a GtkBorder
Returns : | a copy of `border_`.

### gtk_border_free ()

    void                gtk_border_free                     (GtkBorder *border_);

Frees a GtkBorder structure.

`border_` : | a GtkBorder

### 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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`angle` : | arrow angle from 0 to 2 * `G_PI`, being 0 the arrow pointing to the north
`x` : | Center X for the render area
`y` : | Center Y for the render area
`size` : | square side for render area

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`

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height
`gap_side` : | side where the gap is

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height
`gap_side` : | side where the gap is
`xy0_gap` : | initial coordinate (X or Y depending on `gap_side`) for the gap
`xy1_gap` : | end coordinate (X or Y depending on `gap_side`) for the 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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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`

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin
`y` : | Y origin
`layout` : | the PangoLayout to render

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).

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x0` : | X coordinate for the origin of the line
`y0` : | Y coordinate for the origin of the line
`x1` : | X coordinate for the end of the line
`y1` : | Y coordinate for the end of the line

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height
`orientation` : | orientation of the slider

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.

`context` : | a GtkStyleContext
`cr` : | a cairo_t
`x` : | X origin of the rectangle
`y` : | Y origin of the rectangle
`width` : | rectangle width
`height` : | rectangle height

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.

`context` : | a GtkStyleContext
`source` : | the GtkIconSource specifying the icon to render
`size` : | the size to render the icon at. A size of (GtkIconSize) -1 means render at the size of the source and don't scale. [type int]
Returns : | a newly-created GdkPixbuf containing the rendered icon. [transfer full]

Since 3.0

## Property Details

### 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.

## Signal Details

### The `"changed"` signal

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

`stylecontext` : | the object which received the signal.
`user_data` : | user data set when the signal handler was connected.