gtkmm: Gdk::DrawContext Class Reference

Drawing context base class. More...

#include <gdkmm/drawcontext.h>

Inheritance diagram for Gdk::DrawContext:

[legend]

Public Member Functions
	DrawContext (DrawContext &&src) noexcept

DrawContext &	operator= (DrawContext &&src) noexcept

	~DrawContext () noexcept override

GdkDrawContext *	gobj ()
	Provides access to the underlying C GObject.

const GdkDrawContext *	gobj () const
	Provides access to the underlying C GObject.

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

Glib::RefPtr< Display >	get_display ()
	Retrieves the `Gdk::Display` the context is created for.

Glib::RefPtr< const Display >	get_display () const
	Retrieves the `Gdk::Display` the context is created for.

Glib::RefPtr< Surface >	get_surface ()
	Retrieves the surface that context is bound to.

Glib::RefPtr< const Surface >	get_surface () const
	Retrieves the surface that context is bound to.

void	begin_frame (const ::Cairo::RefPtr< const ::Cairo::Region > &region)
	Indicates that you are beginning the process of redrawing region on the context's surface.

void	end_frame ()
	Ends a drawing operation started with begin_frame().

bool	is_in_frame () const
	Returns `true` if context is in the process of drawing to its surface.

::Cairo::RefPtr< const ::Cairo::Region >	get_frame_region () const
	Retrieves the region that is currently being repainted.

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Display > >	property_display () const
	The `Gdk::Display` used to create the `Gdk::DrawContext`.

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Surface > >	property_surface () const
	The `Gdk::Surface` the context is bound to.

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Member Functions
	DrawContext ()
	This constructor is protected because only derived classes shall be instantiated.

Related Symbols
(Note that these are not member symbols.)
Glib::RefPtr< Gdk::DrawContext >	wrap (GdkDrawContext *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

Drawing context base class.

Gdk::DrawContext is the base object used by contexts implementing different rendering methods, such as GLContext or VulkanContext. It provides shared functionality between those contexts.

You will always interact with one of those subclasses.

Since gtkmm 3.90:

Constructor & Destructor Documentation

◆ DrawContext() [1/2]

Gdk::DrawContext::DrawContext ( DrawContext && src )

noexcept

◆ ~DrawContext()

Gdk::DrawContext::~DrawContext ( )

overridenoexcept

◆ DrawContext() [2/2]

Gdk::DrawContext::DrawContext ( )

protected

This constructor is protected because only derived classes shall be instantiated.

Member Function Documentation

◆ begin_frame()

void Gdk::DrawContext::begin_frame ( const ::Cairo::RefPtr< const ::Cairo::Region > & region )

Indicates that you are beginning the process of redrawing region on the context's surface.

Calling this function begins a drawing operation using context on the surface that context was created from. The actual requirements and guarantees for the drawing operation vary for different implementations of drawing, so a Gdk::CairoContext and a Gdk::GLContext need to be treated differently.

A call to this function is a requirement for drawing and must be followed by a call to end_frame(), which will complete the drawing operation and ensure the contents become visible on screen.

Note that the region passed to this function is the minimum region that needs to be drawn and depending on implementation, windowing system and hardware in use, it might be necessary to draw a larger region. Drawing implementation must use get_frame_region() to query the region that must be drawn.

When using GTK, the widget system automatically places calls to begin_frame() and end_frame() via the use of GskRenderers, so application code does not need to call these functions explicitly.

Deprecated: 4.16: Drawing directly to the surface is no longer recommended. Use Gsk::RenderNode and Gsk::Renderer.

Deprecated:: 4.16: Drawing directly to the surface is no longer recommended. Use GskRenderNode and GskRenderer (no C++ equivalents).

Parameters

region Minimum region that should be drawn.

◆ end_frame()

void Gdk::DrawContext::end_frame ( )

Ends a drawing operation started with begin_frame().

This makes the drawing available on screen. See begin_frame() for more details about drawing.

When using a Gdk::GLContext, this function may call glFlush() implicitly before returning; it is not recommended to call glFlush() explicitly before calling this function.

Deprecated: 4.16: Drawing directly to the surface is no longer recommended. Use Gsk::RenderNode and Gsk::Renderer.

Deprecated:: 4.16: Drawing directly to the surface is no longer recommended. Use GskRenderNode and GskRenderer (no C++ equivalents).

◆ get_display() [1/2]

Glib::RefPtr< Display > Gdk::DrawContext::get_display ( )

Retrieves the Gdk::Display the context is created for.

Returns: The Gdk::Display.

◆ get_display() [2/2]

Glib::RefPtr< const Display > Gdk::DrawContext::get_display ( ) const

Retrieves the Gdk::Display the context is created for.

Returns: The Gdk::Display.

◆ get_frame_region()

::Cairo::RefPtr< const ::Cairo::Region > Gdk::DrawContext::get_frame_region ( ) const

Retrieves the region that is currently being repainted.

After a call to begin_frame() this function will return a union of the region passed to that function and the area of the surface that the context determined needs to be repainted.

If context is not in between calls to begin_frame() and end_frame(), nullptr will be returned.

Deprecated: 4.16: Drawing directly to the surface is no longer recommended. Use Gsk::RenderNode and Gsk::Renderer.

Deprecated:: 4.16: Drawing directly to the surface is no longer recommended. Use GskRenderNode and GskRenderer (no C++ equivalents).

Returns: A Cairo region.

◆ get_surface() [1/2]

Glib::RefPtr< Surface > Gdk::DrawContext::get_surface ( )

Retrieves the surface that context is bound to.

Returns: A Gdk::Surface.

◆ get_surface() [2/2]

Glib::RefPtr< const Surface > Gdk::DrawContext::get_surface ( ) const

Retrieves the surface that context is bound to.

Returns: A Gdk::Surface.

◆ get_type()

static GType Gdk::DrawContext::get_type ( )

static

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

◆ gobj() [1/2]

GdkDrawContext * Gdk::DrawContext::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GdkDrawContext * Gdk::DrawContext::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GdkDrawContext * Gdk::DrawContext::gobj_copy ( )

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

◆ is_in_frame()

bool Gdk::DrawContext::is_in_frame ( ) const

Returns true if context is in the process of drawing to its surface.

This is the case between calls to begin_frame() and end_frame(). In this situation, drawing commands may be effecting the contents of the context's surface.

Deprecated: 4.16: Drawing directly to the surface is no longer recommended. Use Gsk::RenderNode and Gsk::Renderer.

Deprecated:: 4.16: Drawing directly to the surface is no longer recommended. Use GskRenderNode and GskRenderer (no C++ equivalents).

Returns: true if the context is between begin_frame() and end_frame() calls.

◆ operator=()

DrawContext & Gdk::DrawContext::operator= ( DrawContext && src )

noexcept

◆ property_display()

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Display > > Gdk::DrawContext::property_display ( ) const

The Gdk::Display used to create the Gdk::DrawContext.

Returns: A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_surface()

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Surface > > Gdk::DrawContext::property_surface ( ) const

The Gdk::Surface the context is bound to.

Returns: A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

Friends And Related Symbol Documentation

◆ wrap()

Glib::RefPtr< Gdk::DrawContext > wrap	(	GdkDrawContext *	object,
		bool	take_copy = `false`
	)

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

Parameters

object	The C instance.
take_copy	False 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.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Related Symbols

Detailed Description

Constructor & Destructor Documentation

◆ DrawContext() [1/2]

◆ ~DrawContext()

◆ DrawContext() [2/2]

Member Function Documentation

◆ begin_frame()

◆ end_frame()

◆ get_display() [1/2]

◆ get_display() [2/2]

◆ get_frame_region()

◆ get_surface() [1/2]

◆ get_surface() [2/2]

◆ get_type()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ is_in_frame()

◆ operator=()

◆ property_display()

◆ property_surface()

Friends And Related Symbol Documentation

◆ wrap()