Memory-managed wrapper type.

Type class for types which can be safely cast to StyleContext, for instance with toStyleContext.

Cast to StyleContext, for types for which this is known to be safe. For general casts, use castTo.

A convenience alias for Nothing :: Maybe StyleContext.

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 Entry defining a “search” class, would be matched by:

 <!-- language="CSS" -->
entry.search { ... }

While any widget defining a “search” class would be matched by: > language="CSS" -- >.search { ... }

Since: 3.0

Adds a style provider to context, to be used in style construction. Note that a style provider added by this function only affects the style of the widget to which context belongs. If you want to affect the style of all widgets, use styleContextAddProviderForScreen.

Note: If both priorities are the same, a StyleProvider added through this function takes precedence over another added through styleContextAddProviderForScreen.

Since: 3.0

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 Settings available.

Note: If both priorities are the same, A StyleProvider added through styleContextAddProvider takes precedence over another added through this function.

Since: 3.0

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 TreeView defining a “row” region, would be matched by:

 <!-- language="CSS" -->
treeview row { ... }

Pseudo-classes are used for matching flags, so the two following rules: > language="CSS" -- >treeview row:nth-child(even) { ... } >treeview row:nth-child(odd) { ... }

would apply to even and odd rows, respectively.

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

Since: 3.0

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

A Nothing regionId will stop all ongoing animations in context, when dealing with a StyleContext obtained through widgetGetStyleContext, 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

Gets the background color for a given state.

This function is far less useful than it seems, and it should not be used in newly written code. CSS has no concept of "background color", as a background can be an image, or a gradient, or any other pattern including solid colors.

The only reason why you would call styleContextGetBackgroundColor is to use the returned value to draw the background with it; the correct way to achieve this result is to use renderBackground instead, along with CSS style classes to modify the color to be rendered.

Since: 3.0

Gets the border for a given state as a Border.

See styleContextGetProperty and STYLE_PROPERTY_BORDER_WIDTH for details.

Since: 3.0

Gets the border color for a given state.

Since: 3.0

Gets the foreground color for a given state.

See styleContextGetProperty and STYLE_PROPERTY_COLOR for details.

Since: 3.0

Returns the widget direction used for rendering.

Since: 3.0

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

Since: 3.0

Returns the FrameClock to which context is attached.

Since: 3.8

Returns the sides where rendered elements connect visually with others.

Since: 3.0

Gets the margin for a given state as a Border. See gtk_style_property_get() and STYLE_PROPERTY_MARGIN for details.

Since: 3.0

Gets the padding for a given state as a Border. See gtk_style_context_get() and STYLE_PROPERTY_PADDING for details.

Since: 3.0

Gets the parent context set via styleContextSetParent. See that function for details.

Since: 3.4

Returns the widget path used for style matching.

Since: 3.0

Gets a style property from context for the given state.

Note that not all CSS properties that are supported by GTK+ can be retrieved in this way, since they may not be representable as Value. GTK+ defines macros for a number of properties that can be used with this function.

Note that passing a state other than the current state of context is not recommended unless the style context has been saved with styleContextSave.

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

Since: 3.0

Returns the scale used for assets.

Since: 3.10

Returns the Screen to which context is attached.

Queries the location in the CSS where property was defined for the current context. Note that the state to be queried is taken from styleContextGetState.

If the location is not available, Nothing will be returned. The location might not be available for various reasons, such as the property being overridden, property not naming a supported CSS property or tracking of definitions being disabled for performance reasons.

Shorthand CSS properties cannot be queried for a location and will always return Nothing.

Returns the state used for style matching.

This method should only be used to retrieve the StateFlags to pass to StyleContext methods, like styleContextGetPadding. If you need to retrieve the current state of a Widget, use widgetGetStateFlags.

Since: 3.0

Gets the value for a widget style property.

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

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

Since: 3.0

Returns True if context has the region defined. If flagsReturn is not Nothing, it is set to the flags affecting the region.

Since: 3.0

Invalidates context style information, so it will be reconstructed again. It is useful if you modify the context and need the new information immediately.

Since: 3.0

Returns the list of classes currently defined in context.

Since: 3.0

Returns the list of regions currently defined in context.

Since: 3.0

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

Looks up stockId in the icon factories associated to context and the default icon factory, returning an icon set if found, otherwise Nothing.

Creates a standalone StyleContext, this style context won’t be attached to any widget, so you may want to call styleContextSetPath yourself.

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

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 regionId are animated for state state being set to value stateValue.

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 regionId is Nothing, all rendered elements using context will be affected by this state transition.

As a practical example, a Button notifying a state transition on the prelight state: > language="C" -- >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: > language="CSS" -- >button { > background-color: #f00 >} > >button: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

Pops an animatable region from context. See styleContextPushAnimatableRegion.

Since: 3.0

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

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

Since: 3.0

Removes className from context.

Since: 3.0

Removes provider from the style providers list in context.

Since: 3.0

Removes provider from the global style providers list in screen.

Since: 3.0

Removes a region from context.

Since: 3.0

This function recomputes the styles for all widgets under a particular Screen. 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 Settings object.

Since: 3.0

Restores context state to a previous stage. See styleContextSave.

Since: 3.0

Saves the context state, so temporary modifications done through styleContextAddClass, styleContextRemoveClass, styleContextSetState, etc. can quickly be reverted in one go through styleContextRestore.

The matching call to styleContextRestore must be done before GTK returns to the main loop.

Since: 3.0

This function is analogous to windowScroll, and should be called together with it so the invalidation areas for any ongoing animation are scrolled together with it.

Since: 3.0

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

Since: 3.0

Sets the reading direction for rendering purposes.

If you are using a StyleContext returned from widgetGetStyleContext, you do not need to call this yourself.

Since: 3.0

Attaches context to the given frame clock.

The frame clock is used for the timing of animations.

If you are using a StyleContext returned from widgetGetStyleContext, you do not need to call this yourself.

Since: 3.8

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

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

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

Sets the parent style context for context. The parent style context is used to implement inheritance of properties.

If you are using a StyleContext returned from widgetGetStyleContext, the parent will be set for you.

Since: 3.4

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

If you are using a StyleContext returned from widgetGetStyleContext, you do not need to call this yourself.

Since: 3.0

Sets the scale to use when getting image assets for the style.

Since: 3.10

Attaches context to the given screen.

The screen is used to add style information from “global” style providers, such as the screen’s Settings instance.

If you are using a StyleContext returned from widgetGetStyleContext, you do not need to call this yourself.

Since: 3.0

Sets the state to be used for style matching.

Since: 3.0

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

If progress is not Nothing, 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

Converts the style context into a string representation.

The string representation always includes information about the name, state, id, visibility and style classes of the CSS node that is backing context. Depending on the flags, more information may be included.

This function is intended for testing and debugging of the CSS implementation in GTK+. There are no guarantees about the format of the returned string, it may change.

Since: 3.20

Construct a GValueConstruct with valid value for the “direction” property. This is rarely needed directly, but it is used by new.

Get the value of the “direction” property. When overloading is enabled, this is equivalent to

get styleContext #direction

Set the value of the “direction” property. When overloading is enabled, this is equivalent to

set styleContext [ #direction := value ]

Set the value of the “paint-clock” property to Nothing. When overloading is enabled, this is equivalent to

clear #paintClock

Construct a GValueConstruct with valid value for the “paint-clock” property. This is rarely needed directly, but it is used by new.

Get the value of the “paint-clock” property. When overloading is enabled, this is equivalent to

get styleContext #paintClock

Set the value of the “paint-clock” property. When overloading is enabled, this is equivalent to

set styleContext [ #paintClock := value ]

Set the value of the “parent” property to Nothing. When overloading is enabled, this is equivalent to

clear #parent

Construct a GValueConstruct with valid value for the “parent” property. This is rarely needed directly, but it is used by new.

Get the value of the “parent” property. When overloading is enabled, this is equivalent to

get styleContext #parent

Set the value of the “parent” property. When overloading is enabled, this is equivalent to

set styleContext [ #parent := value ]

Construct a GValueConstruct with valid value for the “screen” property. This is rarely needed directly, but it is used by new.

Get the value of the “screen” property. When overloading is enabled, this is equivalent to

get styleContext #screen

Set the value of the “screen” property. When overloading is enabled, this is equivalent to

set styleContext [ #screen := value ]

Type for the callback on the (unwrapped) C side.

The ::changed signal is emitted when there is a change in the StyleContext.

For a StyleContext returned by widgetGetStyleContext, the Widget::style-updated signal/vfunc might be more convenient to use.

This signal is useful when using the theming layer standalone.

Since: 3.0

Connect a signal handler for the “changed” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after styleContext #changed callback

Wrap the callback into a GClosure.

Generate a function pointer callable from C code, from a C_StyleContextChangedCallback.

A convenience synonym for Nothing :: Maybe StyleContextChangedCallback.

Connect a signal handler for the “changed” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on styleContext #changed callback

Wrap a StyleContextChangedCallback into a C_StyleContextChangedCallback.