gtkmm  4.8.0
Public Member Functions | Static Public Member Functions | Protected Member Functions | Related Functions | List of all members
Gdk::Texture Class Reference

Pixel data. More...

#include <gdkmm/texture.h>

Inheritance diagram for Gdk::Texture:
Inheritance graph
[legend]

Public Member Functions

 Texture (Texture && src) noexcept
 
Textureoperator= (Texture && src) noexcept
 
 ~Texture () noexcept override
 
GdkTexture * gobj ()
 Provides access to the underlying C GObject. More...
 
const GdkTexture * gobj () const
 Provides access to the underlying C GObject. More...
 
GdkTexture * gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
 
int get_width () const
 Returns the width of texture, in pixels. More...
 
int get_height () const
 Returns the height of the texture, in pixels. More...
 
void download (guchar *data, gsize stride) const
 Downloads the texture into local memory. More...
 
bool save_to_png (const Glib::ustring & filename) const
 Store the given texture to the filename as a PNG file. More...
 
Glib::RefPtr< Glib::Bytes > save_to_png_bytes () const
 Store the given texture in memory as a PNG file. More...
 
bool save_to_tiff (const std::string & filename) const
 Store the given texture to the filename as a TIFF file. More...
 
Glib::RefPtr< Glib::Bytes > save_to_tiff_bytes () const
 Store the given texture in memory as a TIFF file. More...
 
Glib::PropertyProxy_ReadOnly< int > property_width () const
 The width of the texture, in pixels. More...
 
Glib::PropertyProxy_ReadOnly< int > property_height () const
 The height of the texture, in pixels. More...
 
- Public Member Functions inherited from Gdk::Paintable
 Paintable (Paintable && src) noexcept
 
Paintableoperator= (Paintable && src) noexcept
 
 ~Paintable () noexcept override
 
GdkPaintable * gobj ()
 Provides access to the underlying C GObject. More...
 
const GdkPaintable * gobj () const
 Provides access to the underlying C GObject. More...
 
void snapshot (const Glib::RefPtr< Gdk::Snapshot > & snapshot, double width, double height)
 Snapshots the given paintable with the given width and height. More...
 
Glib::RefPtr< const Paintableget_current_image () const
 Gets an immutable paintable for the current contents displayed by paintable. More...
 
Flags get_flags () const
 Get flags for the paintable. More...
 
int get_intrinsic_width () const
 Gets the preferred width the paintable would like to be displayed at. More...
 
int get_intrinsic_height () const
 Gets the preferred height the paintable would like to be displayed at. More...
 
double get_intrinsic_aspect_ratio () const
 Gets the preferred aspect ratio the paintable would like to be displayed at. More...
 
void compute_concrete_size (double specified_width, double specified_height, double default_width, double default_height, double & concrete_width, double & concrete_height) const
 Compute a concrete size for the Gdk::Paintable. More...
 
void invalidate_contents ()
 Called by implementations of Gdk::Paintable to invalidate their contents. More...
 
void invalidate_size ()
 Called by implementations of Gdk::Paintable to invalidate their size. More...
 
Glib::SignalProxy< void()> signal_invalidate_contents ()
 
Glib::SignalProxy< void()> signal_invalidate_size ()
 

Static Public Member Functions

static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...
 
static Glib::RefPtr< Texturecreate_for_pixbuf (const Glib::RefPtr< Pixbuf > & pixbuf)
 Creates a new texture object representing the Gdk::Pixbuf. More...
 
static Glib::RefPtr< Texturecreate_from_resource (const std::string & resource_path)
 Creates a new texture by loading an image from a resource. More...
 
static Glib::RefPtr< Texturecreate_from_file (const Glib::RefPtr< Gio::File > & file)
 Creates a new texture by loading an image from a file. More...
 
static Glib::RefPtr< Texturecreate_from_filename (const std::string & path)
 Creates a new texture by loading an image from a file. More...
 
static Glib::RefPtr< Texturecreate_from_bytes (const Glib::RefPtr< const Glib::Bytes > & bytes)
 Creates a new texture by loading an image from memory,. More...
 
- Static Public Member Functions inherited from Gdk::Paintable
static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...
 

Protected Member Functions

 Texture ()
 
- Protected Member Functions inherited from Gdk::Paintable
 Paintable ()
 You should derive from this class to use it. More...
 
virtual void snapshot_vfunc (const Glib::RefPtr< Gdk::Snapshot > &snapshot, double width, double height)
 
virtual Glib::RefPtr< Paintableget_current_image_vfunc () const
 
virtual Flags get_flags_vfunc () const
 
virtual int get_intrinsic_width_vfunc () const
 
virtual int get_intrinsic_height_vfunc () const
 
virtual double get_intrinsic_aspect_ratio_vfunc () const
 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gdk::Texturewrap (GdkTexture * object, bool take_copy=false)
 A Glib::wrap() method for this object. More...
 

Additional Inherited Members

- Public Types inherited from Gdk::Paintable
enum class  Flags {
  STATIC_SIZE = 1 << 0 ,
  STATIC_CONTENTS = 1 << 1
}
 Flags about a paintable object. More...
 

Detailed Description

Pixel data.

Gdk::Texture is the basic element used to refer to pixel data. It is primarily meant for pixel data that will not change over multiple frames, and will be used for a long time.

There are various ways to create Gdk::Texture objects from a Gdk::Pixbuf, or a Cairo surface, or other pixel data.

The ownership of the pixel data is transferred to the Gdk::Texture instance; you can only make a copy of it, via download().

Gdk::Texture is an immutable object: That means you cannot change anything about it.

Since gtkmm 3.94:

Constructor & Destructor Documentation

◆ Texture() [1/2]

Gdk::Texture::Texture ( Texture &&  src)
noexcept

◆ ~Texture()

Gdk::Texture::~Texture ( )
overridenoexcept

◆ Texture() [2/2]

Gdk::Texture::Texture ( )
protected

Member Function Documentation

◆ create_for_pixbuf()

static Glib::RefPtr<Texture> Gdk::Texture::create_for_pixbuf ( const Glib::RefPtr< Pixbuf > &  pixbuf)
static

Creates a new texture object representing the Gdk::Pixbuf.

This function is threadsafe, so that you can e.g. use GTask and Gio::Task::run_in_thread() to avoid blocking the main thread while loading a big image.

Parameters
pixbufA Gdk::Pixbuf.
Returns
A new Gdk::Texture.

◆ create_from_bytes()

static Glib::RefPtr<Texture> Gdk::Texture::create_from_bytes ( const Glib::RefPtr< const Glib::Bytes > &  bytes)
static

Creates a new texture by loading an image from memory,.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

If nullptr is returned, then error will be set.

This function is threadsafe, so that you can e.g. use GTask and Gio::Task::run_in_thread() to avoid blocking the main thread while loading a big image.

Since gtkmm 4.6:
Parameters
bytesA Glib::Bytes containing the data to load.
Returns
A newly-created Gdk::Texture.
Exceptions
Glib::Error

◆ create_from_file()

static Glib::RefPtr<Texture> Gdk::Texture::create_from_file ( const Glib::RefPtr< Gio::File > &  file)
static

Creates a new texture by loading an image from a file.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

If nullptr is returned, then error will be set.

This function is threadsafe, so that you can e.g. use GTask and Gio::Task::run_in_thread() to avoid blocking the main thread while loading a big image.

Parameters
fileFile to load.
Returns
A newly-created Gdk::Texture.
Exceptions
Glib::Error

◆ create_from_filename()

static Glib::RefPtr<Texture> Gdk::Texture::create_from_filename ( const std::string path)
static

Creates a new texture by loading an image from a file.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

If nullptr is returned, then error will be set.

This function is threadsafe, so that you can e.g. use GTask and Gio::Task::run_in_thread() to avoid blocking the main thread while loading a big image.

Since gtkmm 4.6:
Parameters
pathThe filename to load.
Returns
A newly-created Gdk::Texture.
Exceptions
Glib::Error

◆ create_from_resource()

static Glib::RefPtr<Texture> Gdk::Texture::create_from_resource ( const std::string resource_path)
static

Creates a new texture by loading an image from a resource.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

It is a fatal error if resource_path does not specify a valid image resource and the program will abort if that happens. If you are unsure about the validity of a resource, use new_from_file() to load it.

This function is threadsafe, so that you can e.g. use GTask and Gio::Task::run_in_thread() to avoid blocking the main thread while loading a big image.

Parameters
resource_pathThe path of the resource file.
Returns
A newly-created Gdk::Texture.

◆ download()

void Gdk::Texture::download ( guchar *  data,
gsize  stride 
) const

Downloads the texture into local memory.

This may be an expensive operation, as the actual texture data may reside on a GPU or on a remote display server.

The data format of the downloaded data is equivalent to Cairo::Surface::Format::ARGB32, so every downloaded pixel requires 4 bytes of memory.

Downloading a texture into a Cairo image surface:

[C example ellipted]

Parameters
dataPointer to enough memory to be filled with the downloaded data of texture.
strideRowstride in bytes.

◆ get_height()

int Gdk::Texture::get_height ( ) const

Returns the height of the texture, in pixels.

Returns
The height of the Gdk::Texture.

◆ get_type()

static GType Gdk::Texture::get_type ( )
static

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

◆ get_width()

int Gdk::Texture::get_width ( ) const

Returns the width of texture, in pixels.

Returns
The width of the Gdk::Texture.

◆ gobj() [1/2]

GdkTexture* Gdk::Texture::gobj ( )
inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GdkTexture* Gdk::Texture::gobj ( ) const
inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GdkTexture* Gdk::Texture::gobj_copy ( )

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

◆ operator=()

Texture& Gdk::Texture::operator= ( Texture &&  src)
noexcept

◆ property_height()

Glib::PropertyProxy_ReadOnly< int > Gdk::Texture::property_height ( ) const

The height of the texture, in pixels.

Default value: 1

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_width()

Glib::PropertyProxy_ReadOnly< int > Gdk::Texture::property_width ( ) const

The width of the texture, in pixels.

Default value: 1

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

◆ save_to_png()

bool Gdk::Texture::save_to_png ( const Glib::ustring &  filename) const

Store the given texture to the filename as a PNG file.

This is a utility function intended for debugging and testing. If you want more control over formats, proper error handling or want to store to a Gio::File or other location, you might want to use save_to_png_bytes() or look into the gdk-pixbuf library.

Parameters
filenameThe filename to store to.
Returns
true if saving succeeded, false on failure.

◆ save_to_png_bytes()

Glib::RefPtr<Glib::Bytes> Gdk::Texture::save_to_png_bytes ( ) const

Store the given texture in memory as a PNG file.

Use new_from_bytes() to read it back.

If you want to serialize a texture, this is a convenient and portable way to do that.

If you need more control over the generated image, such as attaching metadata, you should look into an image handling library such as the gdk-pixbuf library.

If you are dealing with high dynamic range float data, you might also want to consider save_to_tiff_bytes() instead.

Since gtkmm 4.6:
Returns
A newly allocated Glib::Bytes containing PNG data.

◆ save_to_tiff()

bool Gdk::Texture::save_to_tiff ( const std::string filename) const

Store the given texture to the filename as a TIFF file.

GTK will attempt to store data without loss.

Since gtkmm 4.6:
Parameters
filenameThe filename to store to.
Returns
true if saving succeeded, false on failure.

◆ save_to_tiff_bytes()

Glib::RefPtr<Glib::Bytes> Gdk::Texture::save_to_tiff_bytes ( ) const

Store the given texture in memory as a TIFF file.

Use new_from_bytes() to read it back.

This function is intended to store a representation of the texture's data that is as accurate as possible. This is particularly relevant when working with high dynamic range images and floating-point texture data.

If that is not your concern and you are interested in a smaller size and a more portable format, you might want to use save_to_png_bytes().

Since gtkmm 4.6:
Returns
A newly allocated Glib::Bytes containing TIFF data.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gdk::Texture > wrap ( GdkTexture *  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.