-<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:See_Also ##### -->
-<para>
+<!-- ##### SECTION ./tmpl/from-drawables.sgml:Long_Description ##### -->
+ <para>
+ The functions in this section allow you to take the image data
+ from a GDK drawable and dump it into a #GdkPixbuf. This can be
+ used for screenshots and other special effects. Note that these
+ operations can be expensive, since the image data has to be
+ transferred from the X server to the client program and converted.
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/from-drawables.sgml:Short_Description ##### -->
+Getting parts of a drawable's image data into a pixbuf.
+
+
+<!-- ##### SECTION ./tmpl/from-drawables.sgml:Title ##### -->
+Drawables to Pixbufs
+
+
+<!-- ##### SECTION ./tmpl/gnome-canvas-pixbuf.sgml:Long_Description ##### -->
+ <para>
+ This canvas item displays #GdkPixbuf images. It handles full
+ affine transformations in both GDK and antialiased modes, and also
+ supports the <ulink url="http://www.w3.org">W3C</ulink>'s <ulink
+ url="http://www.w3.org/Graphics/SVG/">SVG</ulink>-like scaling and
+ translation semantics for absolute pixel values.
+ </para>
+
+ <para>
+ #GdkPixbuf structures may be shared among different pixbuf canvas
+ items; the pixbuf item uses #GdkPixbuf's reference counting
+ functions for this.
+ </para>
+
+ <refsect2>
+ <title>Custom Scaling and Translation</title>
+
+ <para>
+ In addition to the normal affine transformations supported by
+ canvas items, the #GnomeCanvasPixbuf item supports independent
+ object arguments for scaling and translation. This is useful
+ for explicitly setting a size to which the pixbuf's image will
+ be scaled, and for specifying translation offsets that take
+ place in the item's local coordinate system.
+ </para>
+
+ <para>
+ By default, the pixbuf canvas item will attain the size in units
+ of the #GdkPixbuf it contains. If a #GnomeCanvasPixbuf is
+ configured to use a #GdkPixbuf that has a size of 300 by 200
+ pixels, then the pixbuf item will automatically obtain a size of
+ 300 by 200 units in the item's local coordinate system. If the
+ item is transformed with a scaling transformation of (0.5, 2.0),
+ then the final image size will be of 150 by 400 pixels.
+ </para>
+
+ <para>
+ To set custom width and height values, you must set the <link
+ linkend="GnomeCanvasPixbuf--width-set">width_set</link> or <link
+ linkend="GnomeCanvasPixbuf--height-set">height_set</link>
+ arguments to %TRUE, and then set the <link
+ linkend="GnomeCanvasPixbuf--width">width</link> or <link
+ linkend="GnomeCanvasPixbuf--height">height</link> arguments to
+ the desired values. The former two arguments control whether
+ the latter two are used when computing the final image's size;
+ they are both %FALSE by default so that the pixbuf item will
+ attain a size in units equal to the size in pixels of the
+ #GdkPixbuf that the item contains.
+ </para>
+
+ <para>
+ The custom translation offsets are controlled by the <link
+ linkend="GnomeCanvasPixbuf--x">x</link> and <link
+ linkend="GnomeCanvasPixbuf--y">y</link> arguments. The logical
+ upper-left vertex of the image will be translated by the
+ specified distance, aligned with the item's local coordinate
+ system.
+ </para>
+ </refsect2>
+
+ <refsect2>
+ <title>Absolute Pixel Scaling and Translation</title>
+
+ <para>
+ The <ulink url="http://www.w3.org/Graphics/SVG/">Scalable Vector
+ Graphics</ulink> specification (SVG) of the <ulink
+ url="http://www.w3.org">World Wide Web Consortium</ulink> also
+ allows images to be translated and scaled by absolute pixel
+ values that are independent of an item's normal affine
+ transformation.
+ </para>
+
+ <para>
+ Normally, the pixbuf item's translation and scaling arguments
+ are interpreted in units, so they will be modified by the item's
+ affine transformation. The <link
+ linkend="GnomeCanvasPixbuf--width-in-pixels">width_in_pixels</link>,
+ <link
+ linkend="GnomeCanvasPixbuf--height-in-pixels">height_in_pixels</link>,
+ <link
+ linkend="GnomeCanvasPixbuf--x-in-pixels">x_in_pixels</link>, and
+ <link
+ linkend="GnomeCanvasPixbuf--y-in-pixels">y_in_pixels</link>
+ object arguments can be used to modify this behavior. If one of
+ these arguments is %TRUE, then the corresponding scaling or
+ translation value will not be affected lengthwise by the pixbuf
+ item's affine transformation.
+ </para>
+
+ <para>
+ For example, consider a pixbuf item whose size is (300, 200).
+ If the item is modified with a scaling transformation of (0.5,
+ 2.0) but the <link
+ linkend="GnomeCanvasPixbuf--width-in-pixels">width_in_pixels</link>
+ is set to %TRUE, then the item will appear to be (300, 400)
+ pixels in size. This means that in this case the item's affine
+ transformation only applies to the height value, while the width
+ value is kept in absolute pixels.
+ </para>
+
+ <para>
+ Likewise, consider a pixbuf item whose (<link
+ linkend="GnomeCanvasPixbuf--x">x</link>, <link
+ linkend="GnomeCanvasPixbuf--y">y</link>) arguments are set to
+ (30, 40). If the item is then modified by the same scaling
+ transformation of (0.5, 2.0) but the <link
+ linkend="GnomeCanvasPixbuf--y-in-pixels">y_in_pixels</link>
+ argument is set to %TRUE, then the image's upper-left corner
+ will appear to be at position (15, 40). In this case, the
+ affine transformation is applied only to the x offset, while the
+ y offset is kept in absolute pixels.
+ </para>
+
+ <para>
+ In short, these arguments control whether a particular dimension
+ of a pixbuf item is scaled or not in the normal way by the
+ item's affine transformation.
+ </para>
+ </refsect2>
+
+ <refsect2>
+ <title>Resource Management</title>
+
+ <para>
+ When you set the #GdkPixbuf structure that a #GnomeCanvasPixbuf
+ item will use by setting the <link
+ linkend="GnomeCanvasPixbuf--pixbuf">pixbuf</link> argument, a
+ reference count will be added to that #GdkPixbuf structure.
+ When the pixbuf item no longer needs the #GdkPixbuf structure,
+ such as when the item is destroyed or when a new pixbuf
+ structure is passed to it, then the old #GdkPixbuf structure
+ will be automatically unreferenced.
+ </para>
+
+ <para>
+ This means that if an application just needs to load a pixbuf
+ image and set it into a pixbuf canvas item, it can do the
+ following to ‘forget’ about the pixbuf structure:
+
+ <programlisting>
+ GdkPixbuf *pixbuf;
+ GnomeCanvasItem *item;
+
+ pixbuf = gdk_pixbuf_new_from_file ("foo.png");
+ g_assert (pixbuf != NULL);
+
+ item = gnome_canvas_item_new (gnome_canvas_root (my_canvas),
+ gnome_canvas_pixbuf_get_type (),
+ "pixbuf", pixbuf,
+ NULL);
+ gdk_pixbuf_unref (pixbuf);
+ </programlisting>
+ </para>
+
+ <para>
+ After this happens, the reference count of the pixbuf structure
+ will be 1: the gdk_pixbuf_new_from_file() function creates it
+ with a reference count of 1, then setting the <link
+ linkend="GnomeCanvasPixbuf--pixbuf">pixbuf</link> argument of
+ the #GnomeCanvasPixbuf item increases it to 2, and then it is
+ decremented to 1 by the call to gdk_pixbuf_unref(). When the
+ canvas item is destroyed, it will automatically unreference the
+ pixbuf structure again, causing its reference count to drop to
+ zero and thus be freed.
+ </para>
+ </refsect2>
+
+
+<!-- ##### SECTION ./tmpl/gnome-canvas-pixbuf.sgml:See_Also ##### -->
+ <para>
+ #GnomeCanvas, #GdkPixbuf
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/gnome-canvas-pixbuf.sgml:Short_Description ##### -->
+Canvas item to display #GdkPixbuf images.
-</para>
+<!-- ##### SECTION ./tmpl/gnome-canvas-pixbuf.sgml:Title ##### -->
+GnomeCanvasPixbuf
-<!-- ##### FUNCTION gdk_pixbuf_load_module ##### -->
+
+<!-- ##### SECTION ./tmpl/rendering.sgml:Long_Description ##### -->
+ <para>
+ The &gdk-pixbuf; library provides several convenience functions to
+ render pixbufs to GDK drawables. It uses the GdkRGB to render the
+ image data.
+ </para>
+
+ <para>
+ At this point there is not a standard alpha channel extension for
+ the X Window System, so it is not possible to use full opacity
+ information when painting images to arbitrary drawables. The
+ &gdk-pixbuf; convenience functions will threshold the opacity
+ information to create a bi-level clipping mask (black and white),
+ and use that to draw the image onto a drawable.
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/rendering.sgml:See_Also ##### -->
+ <para>
+ GdkRGB
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/rendering.sgml:Short_Description ##### -->
+Rendering a pixbuf to a GDK drawable.
+
+
+<!-- ##### SECTION ./tmpl/rendering.sgml:Title ##### -->
+Rendering
+
+
+<!-- ##### SECTION ./tmpl/xlib-from-drawables.sgml:Long_Description ##### -->
+ <para>
+ The functions in this section allow you to take the image data
+ from an X drawable and dump it into a #GdkPixbuf. This can be
+ used for screenshots and other special effects. Note that these
+ operations can be expensive, since the image data has to be
+ transferred from the X server to the client program and converted.
+ </para>
+
+ <para>
+ These functions are analogous to those for the Gdk version of
+ &gdk-pixbuf;.
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/xlib-from-drawables.sgml:See_Also ##### -->
<para>
</para>
-@image_module:
-<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:Short_Description ##### -->
+<!-- ##### SECTION ./tmpl/xlib-from-drawables.sgml:Short_Description ##### -->
+Getting parts of an X drawable's image data into a pixbuf.
+
+
+<!-- ##### SECTION ./tmpl/xlib-from-drawables.sgml:Title ##### -->
+X Drawables to Pixbufs
+
+
+<!-- ##### SECTION ./tmpl/xlib-init.sgml:Long_Description ##### -->
+ <para>
+ In addition to the normal Gdk-specific functions, the &gdk-pixbuf;
+ package provides a small library that lets Xlib-only applications
+ use #GdkPixbuf structures and render them to X drawables. The
+ functions in this section are used to initialize the &gdk-pixbuf;
+ Xlib library. This library must be initialized near the beginning
+ or the program or before calling any of the other &gdk-pixbuf;
+ Xlib functions; it cannot be initialized automatically since
+ Xlib-only applications do not call gdk_rgb_init() like GNOME
+ applications do.
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/xlib-init.sgml:See_Also ##### -->
+ <para>
+ XlibRGB
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/xlib-init.sgml:Short_Description ##### -->
+Initializing the &gdk-pixbuf; Xlib library.
+<!-- ##### SECTION ./tmpl/xlib-init.sgml:Title ##### -->
+&gdk-pixbuf; Xlib initialization
-<!-- ##### ARG GnomeCanvasPixbuf:height_pixels ##### -->
+
+<!-- ##### SECTION ./tmpl/xlib-rendering.sgml:Long_Description ##### -->
+ <para>
+ The &gdk-pixbuf; Xlib library provides several convenience
+ functions to render pixbufs to X drawables. It uses XlibRGB to
+ render the image data.
+ </para>
+
+ <para>
+ These functions are analogous to those for the Gdk version of
+ &gdk-pixbuf;.
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/xlib-rendering.sgml:See_Also ##### -->
<para>
</para>
-<!-- ##### STRUCT GdkPixbufModule ##### -->
-<para>
+<!-- ##### SECTION ./tmpl/xlib-rendering.sgml:Short_Description ##### -->
+Rendering a pixbuf to an X drawable.
+
+
+<!-- ##### SECTION ./tmpl/xlib-rendering.sgml:Title ##### -->
+Xlib Rendering
+
+
+<!-- ##### SECTION ./tmpl/xlib-rgb.sgml:Long_Description ##### -->
+ <para>
+ The XlibRGB set of functions is a port of the GdkRGB library to
+ use plain Xlib and X drawables. You can use these functions to
+ render RGB buffers into drawables very quickly with high-quality
+ dithering.
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/xlib-rgb.sgml:See_Also ##### -->
+ <para>
+ GdkRGB
+ </para>
+
+
+<!-- ##### SECTION ./tmpl/xlib-rgb.sgml:Short_Description ##### -->
+Functions for rendering RGB buffers to X drawables.
+
+
+<!-- ##### SECTION ./tmpl/xlib-rgb.sgml:Title ##### -->
+XlibRGB
+
+<!-- ##### MACRO GDK_PIXBUF_LOADER ##### -->
+ <para>
+ Casts a #GtkObject to a #GdkPixbufLoader.
+ </para>
+
+@obj: A GTK+ object.
+
+<!-- ##### MACRO GNOME_CANVAS_PIXBUF ##### -->
+ <para>
+ Casts a #GtkOjbect to a #GnomeCanvasPixbuf.
+ </para>
+
+@obj: A GTK+ object.
+
+<!-- ##### STRUCT GdkPixbufFrame ##### -->
+<para>
+ This object describes an individual frame of an animation.
</para>
-@module_name:
-@format_check:
-@module:
-@load:
-@load_xpm_data:
-@begin_load:
-@stop_load:
-@load_increment:
-<!-- ##### ARG GnomeCanvasPixbuf:y_pixels ##### -->
+<!-- ##### ENUM GdkPixbufFrameAction ##### -->
<para>
</para>
+@GDK_PIXBUF_FRAME_RETAIN:
+@GDK_PIXBUF_FRAME_DISPOSE:
+@GDK_PIXBUF_FRAME_REVERT:
+
+<!-- ##### USER_FUNCTION GdkPixbufLastUnref ##### -->
+ <para>
+ A function of this type can be used to override the default
+ operation when a pixbuf loses its last reference, i.e. when
+ gdk_pixbuf_unref() is called on a #GdkPixbuf structure that has a
+ reference count of 1. This function should determine whether to
+ finalize the pixbuf by calling gdk_pixbuf_finalize(), or whether
+ to just resume normal execution. The last unref handler for a
+ #GdkPixbuf can be set using the
+ gdk_pixbuf_set_last_unref_handler() function. By default, pixbufs
+ will be finalized automatically if no last unref handler has been
+ defined.
+ </para>
+
+@pixbuf: The pixbuf that is losing its last reference.
+@data: User closure data.
+
+<!-- ##### ARG GnomeCanvasPixbuf:height ##### -->
+ <para>
+ Indicates the height the pixbuf will be scaled to. This argument
+ will only be used if the <link
+ linkend="GnomeCanvasPixbuf--height-set">height_set</link> argument
+ is %TRUE. Works in the same way as the <link
+ linkend="GnomeCanvasPixbuf--width">width</link> argument.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:height-in-pixels ##### -->
+ <para>
+ Works in the same way as the <link
+ linkend="GnomeCanvasPixbuf--width-in-pixels">width_in_pixels</link>
+ argument. The default is %FALSE.
+ </para>
-<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:Long_Description ##### -->
+
+<!-- ##### ARG GnomeCanvasPixbuf:height-pixels ##### -->
<para>
</para>
-<!-- ##### USER_FUNCTION ModuleUpdatedNotifyFunc ##### -->
+<!-- ##### ARG GnomeCanvasPixbuf:height-set ##### -->
+ <para>
+ Determines whether the <link
+ linkend="GnomeCanvasPixbuf--height">height</link> argument is
+ taken into account when scaling the pixbuf item. Works in the
+ same way as the <link
+ linkend="GnomeCanvasPixbuf--width-set">width_set</link> argument.
+ The default is %FALSE.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:pixbuf ##### -->
+ <para>
+ Contains a pointer to a #GdkPixbuf structure that will be used by
+ the pixbuf canvas item as an image source. When a pixbuf is set
+ its reference count is incremented; if the pixbuf item kept a
+ pointer to another #GdkPixbuf structure, the reference count of
+ this structure will be decremented. Also, the GdkPixbuf's
+ reference count will automatically be decremented when the
+ #GnomeCanvasPixbuf item is destroyed. When a pixbuf is queried, a
+ reference count will not be added to the return value; you must do
+ this yourself if you intend to keep the pixbuf structure around.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:width ##### -->
+ <para>
+ Indicates the width the pixbuf will be scaled to. This argument
+ will only be used if the <link
+ linkend="GnomeCanvasPixbuf--width-set">width_set</link> argument
+ is %TRUE. If the <link
+ linkend="GnomeCanvasPixbuf--width-in-pixels">width_in_pixels</link>
+ argument is %FALSE, the width will be taken to be in canvas units,
+ and thus will be scaled along with the canvas item's affine
+ transformation. If width_in_pixels is %TRUE, the width will be
+ taken to be in pixels, and will visually remain a constant size
+ even if the item's affine transformation changes.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:width-in-pixels ##### -->
+ <para>
+ If this argument is %TRUE, then the width of the pixbuf will be
+ considered to be in pixels, that is, it will not be visually
+ scaled even if the item's affine transformation changes. If this
+ is %FALSE, then the width of the pixbuf will be considered to be
+ in canvas units, and so will be scaled normally by affine
+ transformations. The default is %FALSE.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:width-pixels ##### -->
<para>
</para>
-@pixbuf:
-@user_data:
-@x:
-@y:
-@width:
-@height:
-<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:Title ##### -->
-gdk-pixbuf-io
+<!-- ##### ARG GnomeCanvasPixbuf:width-set ##### -->
+ <para>
+ Determines whether the <link
+ linkend="GnomeCanvasPixbuf--width">width</link> argument is taken
+ into account when scaling the pixbuf item. If this argument is
+ %FALSE, then the width value of the pixbuf will be used instead.
+ This argument is %FALSE by default.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:x ##### -->
+ <para>
+ Indicates the horizontal translation offset of the pixbuf item's
+ image. This offset may not actually appear horizontal, since it
+ will be affected by the item's affine transformation. The default
+ is 0.0.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:x-in-pixels ##### -->
+ <para>
+ If this argument is %TRUE, the pixbuf's translation with respect
+ to its logical origin in item-relative coordinates will be in
+ pixels, that is, the visible offset will not change even if the
+ item's affine transformation changes. If it is %FALSE, the
+ pixbuf's translation will be taken to be in canvas units, and thus
+ will change along with the item's affine transformation. The
+ default is %FALSE.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:x-pixels ##### -->
+<para>
+
+</para>
-<!-- ##### ARG GnomeCanvasPixbuf:x_set ##### -->
+<!-- ##### ARG GnomeCanvasPixbuf:x-set ##### -->
<para>
Determines whether the <link
linkend="GnomeCanvasPixbuf--x">x</link> argument is used to
</para>
-<!-- ##### ARG GnomeCanvasPixbuf:y_set ##### -->
+<!-- ##### ARG GnomeCanvasPixbuf:y ##### -->
+ <para>
+ Indicates the vertical translation offset of the pixbuf item's
+ image. Works in the same way as the <link
+ linkend="GnomeCanvasPixbuf--x">x</link> argument. The default is
+ 0.0.
+ </para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:y-in-pixels ##### -->
+ <para>
+ Works in the same way as the <link
+ linkend="GnomeCanvasPixbuf--x-in-pixels">x_in_pixels</link>
+ argument, but controls whether the <link
+ linkend="GnomeCanvasPixbuf--y">y</link> translation offset is
+ scaled or not. The default is %FALSE.
+ </para>
+
+<!--
+Local variables:
+mode: sgml
+sgml-parent-document: ("../gdk-pixbuf.sgml" "book" "refsect2" "")
+End:
+-->
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:y-pixels ##### -->
+<para>
+
+</para>
+
+
+<!-- ##### ARG GnomeCanvasPixbuf:y-set ##### -->
<para>
Determines whether the <link
linkend="GnomeCanvasPixbuf--y">y</link> argument is used to
</para>
-<!-- ##### USER_FUNCTION ModulePreparedNotifyFunc ##### -->
+<!-- ##### FUNCTION gdk_pixbuf_animation_ref ##### -->
<para>
</para>
-@pixbuf:
-@user_data:
+@animation:
+@Returns:
-<!-- ##### ARG GnomeCanvasPixbuf:x_pixels ##### -->
+<!-- ##### FUNCTION gdk_pixbuf_animation_unref ##### -->
<para>
</para>
+@animation:
-<!-- ##### FUNCTION gdk_pixbuf_get_module ##### -->
-<para>
+<!-- ##### FUNCTION gdk_pixbuf_ref ##### -->
-</para>
+ </para>
-@buffer:
-@size:
+@pixbuf:
@Returns:
-<!-- ##### ARG GnomeCanvasPixbuf:width_pixels ##### -->
+<!-- ##### FUNCTION gdk_pixbuf_unref ##### -->
<para>
</para>
+@pixbuf:
projects / ~andy / gtk / blobdiff