gtkmm  4.8.0
Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | Related Functions | List of all members
Gtk::StyleContext Class Reference

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

#include <gtkmm/stylecontext.h>

Inherits Glib::Object.

Public Types

enum class  PrintFlags {
  NONE = 0x0 ,
  RECURSE = 1 << 0 ,
  SHOW_STYLE = 1 << 1 ,
  SHOW_CHANGE = 1 << 2
}
 Flags that modify the behavior of Gtk::StyleContext::to_string(). More...
 

Public Member Functions

 StyleContext (StyleContext && src) noexcept
 
StyleContextoperator= (StyleContext && src) noexcept
 
 ~StyleContext () noexcept override
 
GtkStyleContext * gobj ()
 Provides access to the underlying C GObject. More...
 
const GtkStyleContext * gobj () const
 Provides access to the underlying C GObject. More...
 
GtkStyleContext * gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
 
void add_provider (const Glib::RefPtr< StyleProvider > & provider, guint priority)
 Adds a style provider to context, to be used in style construction. More...
 
void remove_provider (const Glib::RefPtr< StyleProvider > & provider)
 Removes provider from the style providers list in context. More...
 
void context_save ()
 Saves the context state. More...
 
void context_restore ()
 Restores context state to a previous stage. More...
 
void set_state (StateFlags flags)
 Sets the state to be used for style matching. More...
 
StateFlags get_state () const
 Returns the state used for style matching. More...
 
void set_scale (int scale)
 Sets the scale to use when getting image assets for the style. More...
 
int get_scale () const
 Returns the scale used for assets. More...
 
void add_class (const Glib::ustring & class_name)
 Adds a style class to context, so later uses of the style context will make use of this new class for styling. More...
 
void remove_class (const Glib::ustring & class_name)
 Removes class_name from context. More...
 
bool has_class (const Glib::ustring & class_name)
 Returns true if context currently has defined the given class name. More...
 
void set_display (const Glib::RefPtr< Gdk::Display > & display)
 Attaches context to the given display. More...
 
Glib::RefPtr< Gdk::Displayget_display ()
 Returns the Gdk::Display to which context is attached. More...
 
Glib::RefPtr< const Gdk::Displayget_display () const
 Returns the Gdk::Display to which context is attached. More...
 
bool lookup_color (const Glib::ustring & color_name, Gdk::RGBA & color)
 Looks up and resolves a color name in the context color map. More...
 
Gdk::RGBA get_color () const
 Gets the foreground color for a given state. More...
 
Border get_border () const
 
Border get_padding () const
 
Border get_margin () const
 
void render_check (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders a checkmark (as in a Gtk::CheckButton). More...
 
void render_option (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders an option mark (as in a radio button), the Gtk::StateFlags::CHECKED state will determine whether the option is on or off, and Gtk::StateFlags::INCONSISTENT whether it should be marked as undefined. More...
 
void render_arrow (const Cairo::RefPtr< Cairo::Context > & cr, double angle, double x, double y, double size)
 Renders an arrow pointing to angle. More...
 
void render_background (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders the background of an element. More...
 
void render_frame (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders a frame around the rectangle defined by x, y, width, height. More...
 
void render_expander (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders an expander (as used in Gtk::TreeView and Gtk::Expander) in the area defined by x, y, width, height. More...
 
void render_focus (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders a focus indicator on the rectangle determined by x, y, width, height. More...
 
void render_layout (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, const Glib::RefPtr< Pango::Layout > & layout)
 Renders layout on the coordinates x, y. More...
 
void render_line (const Cairo::RefPtr< Cairo::Context > & cr, double x0, double y0, double x1, double y1)
 Renders a line from (x0, y0) to (x1, y1). More...
 
void render_handle (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders a handle (as in Gtk::Paned and Gtk::Window’s resize grip), in the rectangle determined by x, y, width, height. More...
 
void render_activity (const Cairo::RefPtr< Cairo::Context > & cr, double x, double y, double width, double height)
 Renders an activity indicator (such as in Gtk::Spinner). More...
 
void render_icon (const Cairo::RefPtr< Cairo::Context > & cr, const Glib::RefPtr< Gdk::Texture > & texture, double x, double y)
 Renders the icon in texture at the specified x and y coordinates. More...
 
Glib::ustring to_string (PrintFlags flags) const
 Converts the style context into a string representation. More...
 
Glib::PropertyProxy< Glib::RefPtr< Gdk::Display > > property_display ()
 
Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Gdk::Display > > property_display () const
 

Static Public Member Functions

static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...
 
static void add_provider_for_display (const Glib::RefPtr< Gdk::Display > & display, const Glib::RefPtr< StyleProvider > & provider, guint priority)
 Adds a global style provider to display, which will be used in style construction for all Gtk::StyleContexts under display. More...
 
static void remove_provider_for_display (const Glib::RefPtr< Gdk::Display > & display, const Glib::RefPtr< StyleProvider > & provider)
 Removes provider from the global style providers list in display. More...
 

Protected Member Functions

 StyleContext ()
 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gtk::StyleContextwrap (GtkStyleContext * object, bool take_copy=false)
 A Glib::wrap() method for this object. More...
 

Detailed Description

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

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

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

Transition animations

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

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

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

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

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

Since gtkmm 3.0:
Deprecated:
4.10: The relevant API has been moved to Gtk::Widget and Gtk::StyleProvider where applicable; otherwise, there is no replacement for querying the style machinery. Stylable UI elements should use widgets.

Constructor & Destructor Documentation

◆ StyleContext() [1/2]

Gtk::StyleContext::StyleContext ( StyleContext &&  src)
noexcept

◆ ~StyleContext()

Gtk::StyleContext::~StyleContext ( )
overridenoexcept

◆ StyleContext() [2/2]

Gtk::StyleContext::StyleContext ( )
protected

Member Function Documentation

◆ add_class()

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

Adds a style class to context, so later uses of the style context will make use of this new class for styling.

In the CSS file format, a Gtk::Entry defining a “search” class, would be matched by:

[C example ellipted]

While any widget defining a “search” class would be matched by:

[C example ellipted] Deprecated: 4.10: Use Gtk::Widget::add_css_class() instead

Deprecated:
Use Gtk::Widget::add_css_class() instead.
Parameters
class_nameClass name to use in styling.

◆ add_provider()

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

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

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

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

Deprecated: 4.10: Use style classes instead

Parameters
providerA Gtk::StyleProvider.
priorityThe 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.

◆ add_provider_for_display()

static void Gtk::StyleContext::add_provider_for_display ( const Glib::RefPtr< Gdk::Display > &  display,
const Glib::RefPtr< StyleProvider > &  provider,
guint  priority 
)
static

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

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

Note
If both priorities are the same, A Gtk::StyleProvider added through add_provider() takes precedence over another added through this function.
Deprecated:
Use Gtk::StyleProvider::add_provider_for_display() instead.
Parameters
displayA Gdk::Display.
providerA Gtk::StyleProvider.
priorityThe 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.

◆ context_restore()

void Gtk::StyleContext::context_restore ( )

Restores context state to a previous stage.

See save().

Deprecated: 4.10: This API will be removed in GTK 5

◆ context_save()

void Gtk::StyleContext::context_save ( )

Saves the context state.

This allows temporary modifications done through add_class(), remove_class(), set_state() to be quickly reverted in one go through restore().

The matching call to restore() must be done before GTK returns to the main loop.

Deprecated: 4.10: This API will be removed in GTK 5

◆ get_border()

Border Gtk::StyleContext::get_border ( ) const

◆ get_color()

Gdk::RGBA Gtk::StyleContext::get_color ( ) const

Gets the foreground color for a given state.

Since gtkmm 3.0:
Deprecated:
Use Gtk::Widget::get_color() instead.
Returns
The foreground color for the given state.

◆ get_display() [1/2]

Glib::RefPtr<Gdk::Display> Gtk::StyleContext::get_display ( )

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

Deprecated: 4.10: Use Gtk::Widget::get_display() instead

Deprecated:
Use Gtk::Widget::get_display() instead.
Returns
A Gdk::Display.

◆ get_display() [2/2]

Glib::RefPtr<const Gdk::Display> Gtk::StyleContext::get_display ( ) const

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

Deprecated: 4.10: Use Gtk::Widget::get_display() instead

Deprecated:
Use Gtk::Widget::get_display() instead.
Returns
A Gdk::Display.

◆ get_margin()

Border Gtk::StyleContext::get_margin ( ) const

◆ get_padding()

Border Gtk::StyleContext::get_padding ( ) const

◆ get_scale()

int Gtk::StyleContext::get_scale ( ) const

Returns the scale used for assets.

Deprecated:
Use Gtk::Widget::get_scale_factor() instead.
Returns
The scale

Deprecated 4.10: Use Gtk::Widget::get_scale_factor() instead.

◆ get_state()

StateFlags Gtk::StyleContext::get_state ( ) const

Returns the state used for style matching.

This method should only be used to retrieve the Gtk::StateFlags to pass to Gtk::StyleContext methods, like get_padding(). If you need to retrieve the current state of a Gtk::Widget, use Gtk::Widget::get_state_flags().

Deprecated: 4.10: Use Gtk::Widget::get_state_flags() instead

Deprecated:
Use Gtk::Widget::get_state_flags() instead.
Returns
The state flags.

◆ get_type()

static GType Gtk::StyleContext::get_type ( )
static

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

◆ gobj() [1/2]

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

Provides access to the underlying C GObject.

◆ gobj() [2/2]

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

Provides access to the underlying C GObject.

◆ gobj_copy()

GtkStyleContext* Gtk::StyleContext::gobj_copy ( )

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

◆ has_class()

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

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

Deprecated: 4.10: Use Gtk::Widget::has_css_class() instead

Deprecated:
Use Gtk::Widget::has_css_class() instead.
Parameters
class_nameA class name.
Returns
true if context has class_name defined.

◆ lookup_color()

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

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

Deprecated: 4.10: This api will be removed in GTK 5

Parameters
color_nameColor name to lookup.
colorReturn location for the looked up color.
Returns
true if color_name was found and resolved, false otherwise.

◆ operator=()

StyleContext& Gtk::StyleContext::operator= ( StyleContext &&  src)
noexcept

◆ property_display() [1/2]

Glib::PropertyProxy< Glib::RefPtr<Gdk::Display> > Gtk::StyleContext::property_display ( )
Returns
A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

◆ property_display() [2/2]

Glib::PropertyProxy_ReadOnly< Glib::RefPtr<Gdk::Display> > Gtk::StyleContext::property_display ( ) const
Returns
A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ remove_class()

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

Removes class_name from context.

Deprecated: 4.10: Use Gtk::Widget::remove_css_class() instead

Deprecated:
Use Gtk::Widget::remove_css_class() instead.
Parameters
class_nameClass name to remove.

◆ remove_provider()

void Gtk::StyleContext::remove_provider ( const Glib::RefPtr< StyleProvider > &  provider)

Removes provider from the style providers list in context.

Deprecated: 4.10

Parameters
providerA Gtk::StyleProvider.

◆ remove_provider_for_display()

static void Gtk::StyleContext::remove_provider_for_display ( const Glib::RefPtr< Gdk::Display > &  display,
const Glib::RefPtr< StyleProvider > &  provider 
)
static

Removes provider from the global style providers list in display.

Deprecated:
Use Gtk::StyleProvider::remove_provider_for_display() instead.
Parameters
displayA Gdk::Display.
providerA Gtk::StyleProvider.

◆ render_activity()

void Gtk::StyleContext::render_activity ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

Renders an activity indicator (such as in Gtk::Spinner).

The state Gtk::StateFlags::CHECKED determines whether there is activity going on.

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_arrow()

void Gtk::StyleContext::render_arrow ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  angle,
double  x,
double  y,
double  size 
)

Renders an arrow pointing to angle.

Typical arrow rendering at 0, 1⁄2 π;, π; and 3⁄2 π:

Deprecated: 4.10

Parameters
crA cairo_t.
angleArrow angle from 0 to 2 * G_PI, being 0 the arrow pointing to the north.
xX origin of the render area.
yY origin of the render area.
sizeSquare side for render area.

◆ render_background()

void Gtk::StyleContext::render_background ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

Renders the background of an element.

Typical background rendering, showing the effect of background-image, border-width and border-radius:

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_check()

void Gtk::StyleContext::render_check ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

Renders a checkmark (as in a Gtk::CheckButton).

The Gtk::StateFlags::CHECKED state determines whether the check is on or off, and Gtk::StateFlags::INCONSISTENT determines whether it should be marked as undefined.

Typical checkmark rendering:

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_expander()

void Gtk::StyleContext::render_expander ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

Renders an expander (as used in Gtk::TreeView and Gtk::Expander) in the area defined by x, y, width, height.

The state Gtk::StateFlags::CHECKED determines whether the expander is collapsed or expanded.

Typical expander rendering:

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_focus()

void Gtk::StyleContext::render_focus ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

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

Typical focus rendering:

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_frame()

void Gtk::StyleContext::render_frame ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

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

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

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_handle()

void Gtk::StyleContext::render_handle ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

Renders a handle (as in Gtk::Paned and Gtk::Window’s resize grip), in the rectangle determined by x, y, width, height.

Handles rendered for the paned and grip classes:

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ render_icon()

void Gtk::StyleContext::render_icon ( const Cairo::RefPtr< Cairo::Context > &  cr,
const Glib::RefPtr< Gdk::Texture > &  texture,
double  x,
double  y 
)

Renders the icon in texture at the specified x and y coordinates.

This function will render the icon in texture at exactly its size, regardless of scaling factors, which may not be appropriate when drawing on displays with high pixel densities.

Deprecated: 4.10

Parameters
crA cairo_t.
textureA Gdk::Texture containing the icon to draw.
xX position for the texture.
yY position for the texture.

◆ render_layout()

void Gtk::StyleContext::render_layout ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
const Glib::RefPtr< Pango::Layout > &  layout 
)

Renders layout on the coordinates x, y.

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin.
yY origin.
layoutThe Pango::Layout to render.

◆ render_line()

void Gtk::StyleContext::render_line ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x0,
double  y0,
double  x1,
double  y1 
)

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

Deprecated: 4.10

Parameters
crA cairo_t.
x0X coordinate for the origin of the line.
y0Y coordinate for the origin of the line.
x1X coordinate for the end of the line.
y1Y coordinate for the end of the line.

◆ render_option()

void Gtk::StyleContext::render_option ( const Cairo::RefPtr< Cairo::Context > &  cr,
double  x,
double  y,
double  width,
double  height 
)

Renders an option mark (as in a radio button), the Gtk::StateFlags::CHECKED state will determine whether the option is on or off, and Gtk::StateFlags::INCONSISTENT whether it should be marked as undefined.

Typical option mark rendering:

Deprecated: 4.10

Parameters
crA cairo_t.
xX origin of the rectangle.
yY origin of the rectangle.
widthRectangle width.
heightRectangle height.

◆ set_display()

void Gtk::StyleContext::set_display ( const Glib::RefPtr< Gdk::Display > &  display)

Attaches context to the given display.

The display is used to add style information from “global” style providers, such as the display's Gtk::Settings instance.

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

Deprecated: 4.10: You should not use this api

Deprecated:
You should not use this api.
Parameters
displayA Gdk::Display.

◆ set_scale()

void Gtk::StyleContext::set_scale ( int  scale)

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

Deprecated: 4.10: You should not use this api

Deprecated:
You should not use this api.
Parameters
scaleScale.

◆ set_state()

void Gtk::StyleContext::set_state ( StateFlags  flags)

Sets the state to be used for style matching.

Deprecated: 4.10: You should not use this api

Deprecated:
You should not use this api.
Parameters
flagsState to represent.

◆ to_string()

Glib::ustring Gtk::StyleContext::to_string ( PrintFlags  flags) const

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.

Deprecated: 4.10: This api will be removed in GTK 5

Parameters
flagsFlags that determine what to print.
Returns
A newly allocated string representing context.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gtk::StyleContext > wrap ( GtkStyleContext *  object,
bool  take_copy = false 
)
related

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

Parameters
objectThe C instance.
take_copyFalse if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns
A C++ instance that wraps this C instance.