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Xfc::Gdk::Pixbuf Class Reference

A GdkPixbuf C++ wrapper class. More...

#include <xfc/gdk-pixbuf/pixbuf.hh>

Inheritance diagram for Xfc::Gdk::Pixbuf:
Xfc::G::Object Xfc::G::TypeInstance Xfc::Trackable

List of all members.

Public Types

Public Member Functions

Static Public Member Functions

Constructors


Detailed Description

A GdkPixbuf C++ wrapper class.

Pixbuf is an object that contains information describing an image in memory.

The XFC demo program has several examples of using G::Error with Pixbufs. See <demowindow.cc> and <image.cc> in the <demos/gfc-demo> subdirectory.

Note: dynamically allocated objects must either be unreferenced or assigned to a smart pointer. Stack objects are automatically unreferenced when they go out of scope.


Member Typedef Documentation

typedef sigc::slot<bool, const char*, size_t, G::Error*> Xfc::Gdk::Pixbuf::SaveSlot

Signature of the callback slot to be called when saving a pixbuf.

Example: Method signature for SaveSlot.

< bool method(const char *buffer, size_t count, G::Error *error);
<
< // buffer: The bytes to be written. 
< // count:  The number of bytes in <EM>buffer</EM>. 
< // error:  The return location for any error.
< // return: true if successful, false (with error set) if failed. 
<

SaveSlot is called once for each block of bytes that is "written" by one of the overloaded save methods. If successful it should return true. If an error occurs it should set error and return false, in which case the save method will fail with the same error.


Constructor & Destructor Documentation

Xfc::Gdk::Pixbuf::Pixbuf ( GdkPixbuf *  pixbuf,
bool  owns_reference = true 
) [explicit, protected]

Construct a new Pixbuf from an existing GdkPixbuf.

Parameters:
pixbufA pointer to a GdkPixbuf.
owns_referenceSet false if the initial reference count is floating, set true if it's not.

The pixbuf can be a newly created GdkPixbuf or an existing GdkPixbuf. (see G::Object::Object).

Xfc::Gdk::Pixbuf::Pixbuf ( const Pixbuf src,
int  src_x,
int  src_y,
int  width,
int  height 
)

Constructs a new pixbuf (a sub-pixbuf) which represents a sub-region of src.

Parameters:
srcA Pixbuf.
src_xThe source X coordinate in src.
src_yThe source Y coordinate in src.
widthThe width of the region in src.
heightThe height of region in src.

The new pixbuf shares its pixels with the original pixbuf, so writing to one affects both. The new pixbuf holds a reference to src pixbuf, so src pixbuf will not be finalized until the new pixbuf is finalized. Pixbuf is created with a reference count of 1 that the caller owns.

Xfc::Gdk::Pixbuf::Pixbuf ( const unsigned char *  data,
int  width,
int  height,
int  rowstride,
bool  has_alpha,
GdkPixbufDestroyNotify  destroy_fn = 0,
void *  destroy_fn_data = 0,
int  bits_per_sample = 8,
Colorspace  colorspace = COLORSPACE_RGB 
)

Constructs a new pixbuf out of in-memory image data.

Parameters:
dataThe image data in 8-bit/sample packed format.
widthThe width of the image in pixels.
heightThe height of the image in pixels.
rowstrideThe distance in bytes between rows.
has_alphaWhether the data has an opacity channel.
destroy_fnThe function used to free the data when the pixbuf's reference count drops to zero, or null if the data should not be freed.
destroy_fn_dataThe closure data to pass to the destroy notification function.
bits_per_sampleThe number of bits per sample.
colorspaceThe Gdk::Colorspace for the image data.

Currently only RGB images with 8 bits per sample are supported. Wrapping an existing pixel buffer is the most basic way to construct a pixbuf. You need to specify the destroy notification function that will be called when the data buffer needs to be freed; this will happen when a Gdk::Pixbuf is finalized by the reference counting functions. If you have a chunk of static data compiled into your application, you can pass in null as the destroy notification function so that the data will not be freed. Pixbuf is created with a reference count of 1 that the caller owns.

Xfc::Gdk::Pixbuf::Pixbuf ( const char **  data)

Constructs a new pixbuf by parsing XPM data in memory.

Parameters:
dataA pointer to inline XPM data.

This data is commonly the result of including an XPM file into a program's C source. Pixbuf is created with a reference count of 1 that the caller owns.


Member Function Documentation

Pointer<Pixbuf> Xfc::Gdk::Pixbuf::add_alpha ( bool  substitute_color,
unsigned char  red,
unsigned char  green,
unsigned char  blue 
)

Adds an alpha channel to this pixbuf and returns the result as a new pixbuf.

Parameters:
substitute_colorWhether to set a color to zero opacity. If this is false, then the (r, g, b) arguments will be ignored.
redThe red value to substitute.
greenThe green value to substitute.
bluethe blue value to substitute.
Returns:
A newly-created pixbuf.

If the existing pixbuf already had an alpha channel, the channel values are copied from the original; otherwise, the alpha channel is initialized to 255 (full opacity). If substitute_color is true, then the color specified by (r, g, b) will be assigned zero opacity. That is, if you pass (255, 255, 255) for the substitute color, all white pixels will become fully transparent.

void Xfc::Gdk::Pixbuf::composite ( const Pixbuf src,
int  dest_x,
int  dest_y,
int  dest_width,
int  dest_height,
double  offset_x,
double  offset_y,
double  scale_x,
double  scale_y,
InterpType  interp_type,
int  overall_alpha 
)

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y, then composites the rectangle (dest_x, dest_y, dest_width, dest_height) of the resulting image onto the destination image.

Parameters:
srcThe source pixbuf.
dest_xThe left coordinate for the region to render.
dest_yThe top coordinate for the region to render.
dest_widthThe width of the region to render.
dest_heightThe height of the region to render
offset_xThe offset in the X direction (currently rounded to an integer).
offset_yThe offset in the Y direction (currently rounded to an integer).
scale_xThe scale factor in the X direction.
scale_yThe scale factor in the Y direction.
interp_typeThe interpolation type for the transformation.
overall_alphaThe overall alpha for source image (0..255).
void Xfc::Gdk::Pixbuf::composite ( const Pixbuf src,
const Rectangle dest_rect,
double  offset_x,
double  offset_y,
double  scale_x,
double  scale_y,
InterpType  interp_type,
int  overall_alpha 
)

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y, then composites the rectangle dest_rect of the resulting image onto the destination image.

Parameters:
srcThe source pixbuf.
dest_rectThe rectangular region to render.
offset_xThe offset in the X direction (currently rounded to an integer).
offset_yThe offset in the Y direction (currently rounded to an integer).
scale_xThe scale factor in the X direction.
scale_yThe scale factor in the Y direction.
interp_typeThe interpolation type for the transformation.
overall_alphaThe overall alpha for source image (0..255).
void Xfc::Gdk::Pixbuf::composite_color ( const Pixbuf src,
int  dest_x,
int  dest_y,
int  dest_width,
int  dest_height,
double  offset_x,
double  offset_y,
double  scale_x,
double  scale_y,
InterpType  interp_type,
int  overall_alpha,
int  check_x,
int  check_y,
int  check_size,
unsigned int  color1,
unsigned int  color2 
)

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y, then composites the rectangle (dest_x, dest_y, dest_width, dest_height) of the resulting image with a checkboard of the colors color1 and color2 and renders it onto the destination image.

Parameters:
srcThe source pixbuf.
dest_xThe left coordinate for the region to render.
dest_yThe top coordinate for the region to render.
dest_widthThe width of the region to render.
dest_heightThe height of the region to render
offset_xThe offset in the X direction (currently rounded to an integer).
offset_yThe offset in the Y direction (currently rounded to an integer).
scale_xThe scale factor in the X direction.
scale_yThe scale factor in the Y direction.
interp_typeThe interpolation type for the transformation.
overall_alphaThe overall alpha for source image (0..255).
check_xThe X offset for the checkboard (origin of checkboard is at -check_x, -check_y).
check_yThe Y offset for the checkboard.
check_sizeThe size of checks in the checkboard (must be a power of two).
color1The color of check at upper left.
color2The color of the other check.

See composite_color_simple() for a simpler variant of this method suitable for many tasks.

void Xfc::Gdk::Pixbuf::composite_color ( const Pixbuf src,
const Rectangle dest_rect,
double  offset_x,
double  offset_y,
double  scale_x,
double  scale_y,
InterpType  interp_type,
int  overall_alpha,
const Point check_offset,
int  check_size,
unsigned int  color1,
unsigned int  color2 
)

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y, then composites the rectangle dest_rect of the resulting image with a checkboard of the colors color1 and color2 and renders it onto the destination image.

Parameters:
srcThe source pixbuf.
dest_rectThe rectangular region to render.
offset_xThe offset in the X direction (currently rounded to an integer).
offset_yThe offset in the Y direction (currently rounded to an integer).
scale_xThe scale factor in the X direction.
scale_yThe scale factor in the Y direction.
interp_typeThe interpolation type for the transformation.
overall_alphaThe overall alpha for source image (0..255).
check_offsetA Point holding the x, y offset for the checkboard (origin of the checkboard is at -check_offset.x, -check_offset.y).
check_sizeThe size of checks in the checkboard (must be a power of two).
color1The color of check at upper left.
color2The color of the other check.

See composite_color_simple() for a simpler variant of this method suitable for many tasks.

Pointer<Pixbuf> Xfc::Gdk::Pixbuf::composite_color_simple ( int  width,
int  height,
InterpType  interp_type,
int  overall_alpha,
int  check_size,
unsigned int  color1,
unsigned int  color2 
)

Creates a new pixbuf by scaling this pixbuf to width x height and compositing the result with a checkboard of colors color1 and color2.

Parameters:
widthThe width of new image.
heightThe height of new image.
interp_typeThe interpolation type for the transformation.
overall_alphaThe overall alpha for this (source) pixbuf (0..255).
check_sizeThe size of checks in the checkboard (must be a power of two).
color1The color of check at upper left.
color2The color of the other check.
Returns:
A smart pointer to the new pixbuf, or null if not enough memory could be allocated for it.

Creates a new pixbuf from a copy of the information in this pixbuf.

Returns:
A newly created pixbuf, or null if not enough memory could be allocated.

This is not the same as just doing a ref() on the old pixbuf; the copy method will actually duplicate the pixel data in memory and create a new Pixbuf for it.

void Xfc::Gdk::Pixbuf::copy_area ( const Pixbuf src,
int  src_x,
int  src_y,
int  width,
int  height,
int  dest_x,
int  dest_y 
)

Copies a rectangular area from src to this pixbuf; conversion of pixbuf formats is done automatically.

Parameters:
srcThe source pixbuf.
src_xThe source X coordinate within src.
src_yThe source Y coordinate within src.
widthThe width of the area to copy.
heightThe height of the area to copy.
dest_xThe destination X coordinate within this pixbuf.
dest_yThe destination Y coordinate within this pixbuf.
void Xfc::Gdk::Pixbuf::copy_area ( const Pixbuf src,
const Rectangle src_rect,
int  dest_x,
int  dest_y 
)

Copies a rectangular area from src to this pixbuf; conversion of pixbuf formats is done automatically.

Parameters:
srcThe source pixbuf.
src_rectThe rectangular area within src to copy.
dest_xThe destination X coordinate within this pixbuf.
dest_yThe destination Y coordinate within this pixbuf.
static Pointer<Pixbuf> Xfc::Gdk::Pixbuf::create ( const String filename,
G::Error error = 0 
) [static]

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

Parameters:
filenameThe name of file to load.
errorThe return location for an error.
Returns:
A newly-created pixbuf, or null if any of several error conditions occurred.

The file format is detected automatically. If an error occurs, then error will be set and G::Error::get() will return true. Possible errors are in the GDK_PIXBUF_ERROR and G_FILE_ERROR domains.

The image is loaded from the file in a synchronous fashion. This means that the GDK-PIXBUF library takes control of the application while the file is being loaded; from the user's point of view, the application will block until the image is done loading. This constructor can be used by applications in which blocking is acceptable while an image is being loaded. It can also be used to load small images in general. Applications that need progressive loading can use the PixbufLoader functionality instead.

static Pointer<Pixbuf> Xfc::Gdk::Pixbuf::create ( const String filename,
int  width,
int  height,
bool  preserve_aspect_ratio,
G::Error error = 0 
) [static]

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

Parameters:
filenameThe name of file to load.
widthThe width the image should have.
heightThe height the image should have.
preserve_aspect_ratioSet to true to preserve the image's aspect ratio.
errorThe return location for an error.
Returns:
A newly-created pixbuf, or null if any of several error conditions occurred.

The file format is detected automatically. If an error occurs, then error will be set and G::Error::get() will return true. Possible errors are in the GDK_PIXBUF_ERROR and G_FILE_ERROR domains. The image will be scaled to fit in the requested size, preserving its aspect ratio.

Possible error conditions include: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.

static Pointer<Pixbuf> Xfc::Gdk::Pixbuf::create ( int  width,
int  height,
bool  has_alpha,
int  bits_per_sample = 8,
Colorspace  colorspace = COLORSPACE_RGB 
) [static]

Creates a new (blank) pixbuf with an optimal rowstride and a new buffer.

Parameters:
widthThe width of the image in pixels.
heightThe height of the image in pixels.
has_alphaWhether the image should have transparency information.
bits_per_sampleThe number of bits per color sample.
colorspaceThe Gdk::Colorspace for the image.
Returns:
A smart pointer to the new pixbuf, or null if not enough memory could be allocated.

Note that the buffer is not cleared; you will have to fill it completely yourself. This is a convenience constructor used to create a pixbuf with an empty buffer. This is equivalent to constructing a pixbuf with a newly allocating data buffer. It computes an optimal rowstride so that rendering can be performed with an efficient algorithm.

static Pointer<Pixbuf> Xfc::Gdk::Pixbuf::create ( const Drawable drawable,
int  x,
int  y,
int  width,
int  height,
Colormap colormap = 0 
) [static]

Creates a new pixbuf with image data from a server-side drawable (see get_from_drawable() for full details).

Parameters:
drawableThe source drawable.
xThe source X coordinate within drawable.
yThe source Y coordinate within drawable.
widthThe width in pixels of region to get.
heightThe height in pixels of region to get.
colormapA colormap if drawable doesn't have one set.
Returns:
A smart pointer to the new pixbuf, or null if an error occurs; The new pixbuf has no alpha channel.
static Pointer<Pixbuf> Xfc::Gdk::Pixbuf::create ( const Image image,
int  x,
int  y,
int  width,
int  height,
Colormap colormap = 0 
) [static]

Creates a new pixbuf from the specified image (see get_from_drawable() for full details).

Parameters:
imageThe source image.
xThe source X coordinate within image.
yThe source Y coordinate within image.
widthThe width in pixels of region to get.
heightThe height in pixels of region to get.
colormapA colormap if image doesn't have one set.
Returns:
true if successful, false if an error occurs.
static Pointer<Pixbuf> Xfc::Gdk::Pixbuf::create ( int  data_length,
const unsigned char *  data,
bool  copy_pixels,
G::Error error = 0 
) [static]

Creates a pixbuf from a flat representation that is suitable for storing as inline data in a program.

Parameters:
data_lengthThe length in bytes of the data argument.
dataThe byte data containing a serialized GdkPixdata structure.
copy_pixelsSet true to copy the pixel data, or use direct pointers data for the resulting pixbuf.
errorThe G::Error return location, may be null to ignore errors.
Returns:
A newly-created Pixbuf, or null if an error occurred.

This is useful if you want to ship a program with images, but don't want to depend on any external files. GTK+ ships with a program called gdk-pixbuf-csource which allows for conversion of GdkPixbufs into such a inline representation. In almost all cases, you should pass the --raw flag to gdk-pixbuf-csource. A sample invocation would be:

< gdk-pixbuf-csource --raw --name=myimage_inline myimage.png
<

For the typical case where the inline pixbuf is read-only static data, you don't need to copy the pixel data unless you intend to write to it, so you can pass false for copy_pixels. (If you pass --rle to gdk-pixbuf-csource, a copy will be made even if copy_pixels is false, so using this option is generally a bad idea.)

If you create a pixbuf from const inline data compiled into your program, it's probably safe to ignore errors, since things will always succeed. For non-const inline data, you could get out of memory. For untrusted inline data located at runtime, you could have corrupt inline data in addition.

void Xfc::Gdk::Pixbuf::fill ( unsigned int  pixel)

Clears a pixbuf to the given RGBA value, converting the RGBA value into the pixbuf's pixel format.

Parameters:
pixelThe RGBA pixel to clear to (0xffffffff is opaque white, 0x00000000 transparent black).

The alpha will be ignored if the pixbuf doesn't have an alpha channel.

Pointer<Pixbuf> Xfc::Gdk::Pixbuf::flip ( bool  horizontal)

Flips the pixbuf horizontally or vertically and returns the result in a new pixbuf.

Parameters:
horizontalSet to true to flip horizontally, false to flip vertically.
Returns:
A new pixbuf.
bool Xfc::Gdk::Pixbuf::get_from_drawable ( const Drawable src,
int  src_x,
int  src_y,
int  dest_x,
int  dest_y,
int  width,
int  height,
Colormap colormap = 0 
)

Transfers (copies) image data from a server-side drawable to the client-side RGB(A) buffer inside this pixbuf.

Parameters:
srcThe source drawable.
src_xThe source X coordinate within the src drawable.
src_yThe source Y coordinate within the src drawable.
dest_xThe destination X coordinate in this pixbuf.
dest_yThe destination Y coordinate in this pixbuf.
widthThe width in pixels of region to get.
heightThe height in pixels of region to get.
colormapA colormap if src doesn't have one set.
Returns:
true if successful, false if an error occurs.

This allows you to efficiently read individual pixels on the client side. If the drawable is a pixmap, a colormap must be specified. If the src drawable src has no colormap (Gdk::drawable::get_colormap() returns null), then a suitable colormap must be specified. Typically a Gdk::Window or a pixmap created from a Gdk::Window will already have a colormap associated with it. If the drawable has a colormap, the colormap argument will be ignored. If the drawable is a bitmap (1 bit per pixel pixmap), then a colormap is not required; pixels with a value of 1 are assumed to be white, and pixels with a value of 0 are assumed to be black. For taking screenshots, Gdk::Colormap::get_system() returns the correct colormap to use. If this pixbuf contains alpha information, then the filled pixels will be set to full opacity (alpha = 255).

If the specified drawable is a pixmap, then the requested source rectangle must be completely contained within the pixmap, otherwise the method will return false. For pixmaps only (not for windows) passing -1 for width or height is allowed to mean the full width or height of the pixmap.

If the specified drawable is a window, and the window is off the screen, then there is no image data in the obscured/offscreen regions to be placed in the pixbuf. The contents of portions of the pixbuf corresponding to the offscreen region are undefined. If the window you're obtaining data from is partially obscured by other windows, then the contents of the pixbuf areas corresponding to the obscured regions are undefined.

If the target drawable is not mapped (typically because it's iconified/minimized or not on the current workspace), then false will be returned. If memory can't be allocated for the return value, false will be returned instead.

Note: There are several ways this method can fail, and if it fails it returns false; so check the return value.

This method calls Gdk::Drawable::get_image() internally and converts the resulting image to a Gdk::Pixbuf, so the documentation for Gdk::Drawable::get_image() may also be relevant.

bool Xfc::Gdk::Pixbuf::get_from_image ( const Image src,
int  src_x,
int  src_y,
int  dest_x,
int  dest_y,
int  width,
int  height,
Colormap colormap = 0 
)

Copies image data from an Image to this pixbuf (see get_from_drawable() for details).

Parameters:
srcThe source image.
src_xThe source X coordinate within the src image.
src_yThe source Y coordinate within the src image.
dest_xThe destination X coordinate within this pixbuf.
dest_yThe destination Y coordinate within this pixbuf.
widthThe width in pixels of region to get.
heightThe height in pixels of region to get.
colormapA colormap if src doesn't have one set.
Returns:
true if successful, false if an error occurs.
String Xfc::Gdk::Pixbuf::get_option ( const String key) const

Looks up key in the list of options that may have been attached to the pixbuf when it was loaded.

Parameters:
keyA String.
Returns:
The value associated with key, or a null String if key was not found.
unsigned char* Xfc::Gdk::Pixbuf::get_pixels ( ) const

Gets a pointer to the pixel data of a pixbuf.

Returns:
A pointer to the pixbuf's pixel data.
void Xfc::Gdk::Pixbuf::render_pixmap_and_mask ( Pointer< Pixmap > *  pixmap_return,
Pointer< Bitmap > *  mask_return,
int  alpha_threshold,
Colormap colormap = 0 
)

Creates a pixmap and a mask bitmap which are returned in the pixmap_return and mask_return arguments, respectively, and renders a pixbuf and its corresponding thresholded alpha mask to them.

Parameters:
pixmap_returnThe location to store a pointer to the created pixmap, or null if the pixmap is not needed.
mask_returnThe location to store a pointer to the created mask, or null if the mask is not needed.
alpha_thresholdThe threshold value for opacity values.
colormapA Colormap, or null to use the colormap returned by gdk_rgb_get_colormap().

This is merely a convenience method; applications that need to render pixbufs with dither offsets or to given drawables should use render_threshold_alpha() or Gdk::Drawable::draw_pixbuf().

If colormap is null the pixmap is created with the Colormap returned by gdk_rgb_get_colormap(). Normally you will want to use the actual colormap for a widget instead. If the pixbuf does not have an alpha channel, then mask_return will be set to null.

void Xfc::Gdk::Pixbuf::render_threshold_alpha ( Bitmap bitmap,
int  src_x,
int  src_y,
int  dest_x,
int  dest_y,
int  width,
int  height,
int  alpha_threshold 
)

Takes the opacity values in a rectangular portion of the pixbuf and thresholds them to produce a bi-level alpha mask that can be used as a clipping mask for a drawable.

Parameters:
bitmapThe Bitmap where the bilevel mask will be painted to.
src_xThe source X coordinate within the pixbuf.
src_yThe source Y coordinate within the pixbuf.
dest_xThe destination X coordinate within the bitmap.
dest_yThe destination Y coordinate within the bitmap.
widthThe width of the region to threshold, or -1 to use the pixbuf width.
heightThe height of the region to threshold, or -1 to use the pixbuf height.
alpha_thresholdOpacity values below this will be painted as zero; all other values will be painted as one.

Rotates a the pixbuf by a multiple of 90 degrees, and returns the result in a new pixbuf.

Parameters:
angleThe angle to rotate by.
Returns:
A new pixbuf.
void Xfc::Gdk::Pixbuf::saturate_and_pixelate ( const Pixbuf src,
float  saturation,
bool  pixelate 
)

Modifies saturation and optionally pixelates src, placing the result this pixbuf.

Parameters:
srcThe source image.
saturationThe saturation factor.
pixelateWhether to pixelate.

If saturation is 1.0 then saturation is not changed. If it's less than 1.0, saturation is reduced (the image is darkened); if greater than 1.0, saturation is increased (the image is brightened). If pixelate is true, then pixels are faded in a checkerboard pattern to create a pixelated image. This pixbuf and src must have the same image format, size, and rowstride.

void Xfc::Gdk::Pixbuf::saturate_and_pixelate ( float  saturation,
bool  pixelate 
)

Modifies saturation and optionally pixelates the pixbuf.

Parameters:
saturationThe saturation factor.
pixelateWhether to pixelate.

If saturation is 1.0 then saturation is not changed. If it's less than 1.0, saturation is reduced (the image is darkened); if greater than 1.0, saturation is increased (the image is brightened). If pixelate is true, then pixels are faded in a checkerboard pattern to create a pixelated image. This pixbuf and src must have the same image format, size, and rowstride.

bool Xfc::Gdk::Pixbuf::save ( const String filename,
const char *  type,
G::Error error,
  ... 
)

Saves the pixbuf to a file in type, which is currently "jpeg" or "png".

Parameters:
filenameThe name of the file to save.
typeThe name of the file format.
errorThe return location for any error, or null to ignore errors.
...A variable list of key-value (char* / char*) save options.
Returns:
true if an error was set.

If error is set, false will be returned. Possible errors include those in the GDK_PIXBUF_ERROR and the G_FILE_ERROR domains. The variable argument list should be null-terminated; if not empty, it should contain pairs of character strings that modify the save parameters. For example:

< G::Error error;
< pixbuf->save(filename, "jpeg", &error, "quality", "100", 0);
<

Currently only a few parameters exist. JPEG images can be saved with a "quality" parameter with a value in the range [0,100]. Text chunks can be attached to PNG images by specifying parameters of the form "tEXt::key", where key is an ASCII string of length 1-79. The values are UTF-8 encoded strings.

bool Xfc::Gdk::Pixbuf::save ( const String filename,
const char *  type,
char **  option_keys,
char **  option_values,
G::Error error = 0 
)

Saves the pixbuf to a file in type, which is currently "jpeg" or "png".

Parameters:
filenameThe name of the file to save.
typeThe name of the file format.
option_keysThe name of the options to set, null-terminated;
option_valuesThe values for the named options.
errorThe return location for any error, or null to ignore errors.
Returns:
true if an error was set.

If error is set, false will be returned. Possible errors include those in the GDK_PIXBUF_ERROR and the G_FILE_ERROR domains.

bool Xfc::Gdk::Pixbuf::save ( const SaveSlot slot,
const char *  type,
G::Error error,
  ... 
)

Saves the pixbuf in format type by feeding the produced data to a callback slot.

Parameters:
slotA callback slot that is called to save each block of data that the save routine generates.
typeThe name of file format.
errorThe return location for any error, or null.
...A variable list of key-value (char* / char*) save options.
Returns:
Whether an error was set.

Can be used when you want to store the image to something other than a file, such as an in-memory buffer or a socket. If error is set, false will be returned. Possible errors include those in the GDK_PIXBUF_ERROR domain and whatever the save function generates.

bool Xfc::Gdk::Pixbuf::save ( const SaveSlot slot,
const char *  type,
char **  option_keys,
char **  option_values,
G::Error error = 0 
)

Saves the pixbuf to a callback slot in format type, which is currently "jpeg", "png" or "ico".

Parameters:
slotA callback slot that is called to save each block of data that the save routine generates.
typeThe name of file format.
option_keysThe name of options to set, null-terminated.
option_valuesThe values for the named options.
errorThe return location for any error, or null.
Returns:
Whether an error was set.

If error is set, false will be returned.

bool Xfc::Gdk::Pixbuf::save ( char **  buffer,
size_t *  buffer_size,
const char *  type,
G::Error error,
  ... 
)

Saves the pixbuf to a new buffer in format type, which is currently "jpeg", "png" or "ico".

Parameters:
bufferThe location to receive a pointer to the new buffer.
buffer_sizeThe location to receive the size of the new buffer.
typeThe name of file format.
errorThe return location for any error, or null.
...A variable list of key-value (char* / char*) save options.
Returns:
Whether an error was set.

This is a convenience function that uses gdk_pixbuf_save_to_callback() to do the real work. Note that the buffer is not null-terminated and may contain embedded nulls. If error is set, false will be returned and the string will be set to null. Possible errors include those in the GDK_PIXBUF_ERROR domain.

bool Xfc::Gdk::Pixbuf::save ( char **  buffer,
size_t *  buffer_size,
const char *  type,
char **  option_keys,
char **  option_values,
G::Error error = 0 
)

Saves the pixbuf to a new buffer in format type, which is currently "jpeg", "png" or "ico".

Parameters:
bufferThe location to receive a pointer to the new buffer.
buffer_sizeThe location to receive the size of the new buffer.
typeThe name of file format.
option_keysThe name of options to set, null-terminated.
option_valuesThe values for the named options.
errorThe return location for any error, or null.
void Xfc::Gdk::Pixbuf::scale ( const Pixbuf src,
int  dest_x,
int  dest_y,
int  dest_width,
int  dest_height,
double  offset_x,
double  offset_y,
double  scale_x,
double  scale_y,
InterpType  interp_type 
)

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y, then renders the rectangle (dest_x, dest_y, dest_width, dest_height) of the resulting image onto the destination image replacing the previous contents.

Parameters:
srcThe source pixbuf.
dest_xThe left coordinate for the region to render.
dest_yThe top coordinate for the region to render.
dest_widthThe width of the region to render.
dest_heightThe height of the region to render
offset_xThe offset in the X direction (currently rounded to an integer).
offset_yThe offset in the Y direction (currently rounded to an integer).
scale_xThe scale factor in the X direction.
scale_yThe scale factor in the Y direction.
interp_typeThe interpolation type for the transformation.

Try to use scale_simple() first, this method is the industrial-strength power tool you can fall back to if scale_simple() isn't powerful enough.

void Xfc::Gdk::Pixbuf::scale ( const Pixbuf src,
const Rectangle dest_rect,
double  offset_x,
double  offset_y,
double  scale_x,
double  scale_y,
InterpType  interp_type 
)

Creates a transformation of the source image src by scaling by scale_x and scale_y then translating by offset_x and offset_y, then renders the rectangle dest_rect of the resulting image onto the destination image replacing the previous contents.

Parameters:
srcThe source pixbuf.
dest_rectThe rectangular region to render.
offset_xThe offset in the X direction (currently rounded to an integer).
offset_yThe offset in the Y direction (currently rounded to an integer).
scale_xThe scale factor in the X direction.
scale_yThe scale factor in the Y direction.
interp_typeThe interpolation type for the transformation.

Try to use scale_simple() first, this method is the industrial-strength power tool you can fall back to if scale_simple() isn't powerful enough.

Pointer<Pixbuf> Xfc::Gdk::Pixbuf::scale_simple ( int  width,
int  height,
InterpType  interp_type 
)

Create a new pixbuf containing a copy of this pixbuf scaled to width x height.

Parameters:
widthThe width of destination image.
heightThe height of destination image.
interp_typeThe interpolation type for the transformation.
Returns:
A smart pointer to the new pixbuf, or null if not enough memory could be allocated for it.

Leaves this pixbuf unaffected. interp_type should be Gdk::INTERP_NEAREST if you want maximum speed (but when scaling down, Gdk::INTERP_NEAREST is usually unusably ugly). The default interp_type should be Gdk::INTERP_BILINEAR which offers reasonable quality and speed. You can scale a sub-portion of this pixbuf by constructing a sub-pixbuf pointing into this pixbuf.

For more complicated scaling/compositing see scale() and composite().


The documentation for this class was generated from the following file:
Xfce Foundation Classes
Copyright © 2004-2005 The XFC Development Team XFC