Class: GdkPixbuf::PixbufLoader

Inherits:
Object
  • Object
show all
Defined in:
lib/gdk_pixbuf2/pixbuf-loader.rb

Instance Method Summary collapse

Constructor Details

#initialize(image_type) ⇒ GdkPixbuf::PixbufLoader

Creates a new pixbuf loader object that always attempts to parse image data as if it were an image of type image_type, instead of identifying the type automatically.

This function is useful if you want an error if the image isn't the expected type; for loading image formats that can't be reliably identified by looking at the data; or if the user manually forces a specific type.

The list of supported image formats depends on what image loaders are installed, but typically "png", "jpeg", "gif", "tiff" and "xpm" are among the supported formats. To obtain the full list of supported image formats, call gdk_pixbuf_format_get_name() on each of the Gdk::PixbufFormat structs returned by gdk_pixbuf_get_formats().

Parameters:

  • image_type (String) —

    name of the image format to be loaded with the image

Instance Method Details

#animation ⇒ GdkPixbuf::PixbufAnimation

Queries the Gdk::PixbufAnimation that a pixbuf loader is currently creating.

In general it only makes sense to call this function after the [signalGdkPixbuf.PixbufLoader::area-prepared] signal has been emitted by the loader.

If the loader doesn't have enough bytes yet, and hasn't emitted the area-prepared signal, this function will return NULL.

Returns:

#close ⇒ Boolean

Informs a pixbuf loader that no further writes with gdk_pixbuf_loader_write() will occur, so that it can free its internal loading structures.

This function also tries to parse any data that hasn't yet been parsed; if the remaining data is partial or corrupt, an error will be returned.

If FALSE is returned, error will be set to an error from the GDK_PIXBUF_ERROR or G_FILE_ERROR domains.

If you're just cancelling a load rather than expecting it to be finished, passing NULL for error to ignore it is reasonable.

Remember that this function does not release a reference on the loader, so you will need to explicitly release any reference you hold.

Returns:

  • (Boolean) —

    TRUE if all image data written so far was successfully passed out via the update_area signal

#format ⇒ GdkPixbuf::PixbufFormat

Obtains the available information about the format of the currently loading image file.

Returns:

#last_write(data) ⇒ Object 



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# File 'lib/gdk_pixbuf2/pixbuf-loader.rb', line 19

def last_write(data)
  write(data)
  close
end

#pixbuf ⇒ GdkPixbuf::Pixbuf

Queries the Gdk::Pixbuf that a pixbuf loader is currently creating.

In general it only makes sense to call this function after the [signalGdkPixbuf.PixbufLoader::area-prepared] signal has been emitted by the loader; this means that enough data has been read to know the size of the image that will be allocated.

If the loader has not received enough data via gdk_pixbuf_loader_write(), then this function returns NULL.

The returned pixbuf will be the same in all future calls to the loader, so if you want to keep using it, you should acquire a reference to it.

Additionally, if the loader is an animation, it will return the "static image" of the animation (see gdk_pixbuf_animation_get_static_image()).

Returns:

#set_size(width, height) ⇒ nil

Causes the image to be scaled while it is loaded.

The desired image size can be determined relative to the original size of the image by calling gdk_pixbuf_loader_set_size() from a signal handler for the ::size-prepared signal.

Attempts to set the desired image size are ignored after the emission of the ::size-prepared signal.

Parameters:

  • width (Integer) —

    The desired width of the image being loaded.

  • height (Integer) —

    The desired height of the image being loaded.

Returns:

  • (nil)

#write(buf, count) ⇒ Boolean

Parses the next count bytes in the given image buffer.

Parameters:

  • buf (Array<Integer>) —

    Pointer to image data.

  • count (Integer) —

    Length of the buf buffer in bytes.

Returns:

  • (Boolean) —

    TRUE if the write was successful, or FALSE if the loader cannot parse the buffer

#write_bytes(buffer) ⇒ Boolean

Parses the next contents of the given image buffer.

Parameters:

  • buffer (GLib::Bytes) —

    The image data as a GBytes buffer.

Returns:

  • (Boolean) —

    TRUE if the write was successful, or FALSE if the loader cannot parse the buffer