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GNOME Canvas Library Reference Manual | ![]() |
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Top | Description | Object Hierarchy |
#include <libgnomecanvas/libgnomecanvas.h> GnomeCanvasPathDef; GnomeCanvasPathDef * gnome_canvas_path_def_new (void
); GnomeCanvasPathDef * gnome_canvas_path_def_new_sized (gint length
); GnomeCanvasPathDef * gnome_canvas_path_def_new_from_bpath (ArtBpath *bpath
); GnomeCanvasPathDef * gnome_canvas_path_def_new_from_static_bpath (ArtBpath *bpath
); GnomeCanvasPathDef * gnome_canvas_path_def_new_from_foreign_bpath (ArtBpath *bpath
); void gnome_canvas_path_def_ref (GnomeCanvasPathDef *path
); void gnome_canvas_path_def_finish (GnomeCanvasPathDef *path
); void gnome_canvas_path_def_ensure_space (GnomeCanvasPathDef *path
,gint space
); void gnome_canvas_path_def_copy (GnomeCanvasPathDef *dst
,const GnomeCanvasPathDef *src
); GnomeCanvasPathDef * gnome_canvas_path_def_duplicate (const GnomeCanvasPathDef *path
); GnomeCanvasPathDef * gnome_canvas_path_def_concat (const GSList *list
); GSList * gnome_canvas_path_def_split (const GnomeCanvasPathDef *path
); GnomeCanvasPathDef * gnome_canvas_path_def_open_parts (const GnomeCanvasPathDef *path
); GnomeCanvasPathDef * gnome_canvas_path_def_closed_parts (const GnomeCanvasPathDef *path
); GnomeCanvasPathDef * gnome_canvas_path_def_close_all (const GnomeCanvasPathDef *path
); void gnome_canvas_path_def_unref (GnomeCanvasPathDef *path
); void gnome_canvas_path_def_reset (GnomeCanvasPathDef *path
); void gnome_canvas_path_def_moveto (GnomeCanvasPathDef *path
,gdouble x
,gdouble y
); void gnome_canvas_path_def_lineto (GnomeCanvasPathDef *path
,gdouble x
,gdouble y
); void gnome_canvas_path_def_lineto_moving (GnomeCanvasPathDef *path
,gdouble x
,gdouble y
); void gnome_canvas_path_def_curveto (GnomeCanvasPathDef *path
,gdouble x0
,gdouble y0
,gdouble x1
,gdouble y1
,gdouble x2
,gdouble y2
); void gnome_canvas_path_def_closepath (GnomeCanvasPathDef *path
); void gnome_canvas_path_def_closepath_current (GnomeCanvasPathDef *path
); ArtBpath * gnome_canvas_path_def_bpath (const GnomeCanvasPathDef *path
); gint gnome_canvas_path_def_length (const GnomeCanvasPathDef *path
); gboolean gnome_canvas_path_def_is_empty (const GnomeCanvasPathDef *path
); gboolean gnome_canvas_path_def_has_currentpoint (const GnomeCanvasPathDef *path
); void gnome_canvas_path_def_currentpoint (const GnomeCanvasPathDef *path
,ArtPoint *p
); ArtBpath * gnome_canvas_path_def_last_bpath (const GnomeCanvasPathDef *path
); ArtBpath * gnome_canvas_path_def_first_bpath (const GnomeCanvasPathDef *path
); gboolean gnome_canvas_path_def_any_open (const GnomeCanvasPathDef *path
); gboolean gnome_canvas_path_def_all_open (const GnomeCanvasPathDef *path
); gboolean gnome_canvas_path_def_any_closed (const GnomeCanvasPathDef *path
); gboolean gnome_canvas_path_def_all_closed (const GnomeCanvasPathDef *path
);
Convenient container and functions for manipulating ArtBpaths, which are paths defined by line and curve segments.
typedef struct _GnomeCanvasPathDef GnomeCanvasPathDef;
This structure should not be accessed directly. Use the functions defined below.
GnomeCanvasPathDef * gnome_canvas_path_def_new (void
);
This function creates a new empty gnome_canvas_path_def.
Returns : |
the new canvas path definition. |
GnomeCanvasPathDef * gnome_canvas_path_def_new_sized (gint length
);
This function creates a new gnome_canvas_path_def with length
number of points allocated. It is useful, if you know the exact
number of points in path, so you can avoid automatic point
array reallocation.
|
number of points to allocate for the path |
Returns : |
the new canvas path definition |
GnomeCanvasPathDef * gnome_canvas_path_def_new_from_bpath
(ArtBpath *bpath
);
This function constructs a new gnome_canvas_path_def and uses the
passed bpath
as the contents. The passed bpath should not be
static as the path definition is editable when constructed with
this function. Also, passed bpath will be freed with art_free, if
path is destroyed, so use it with caution.
For constructing a gnome_canvas_path_def
from (non-modifiable) bpath use
gnome_canvas_path_def_new_from_static_bpath.
|
libart bezier path |
Returns : |
the new canvas path definition that is populated with the
passed bezier path, if the bpath is bad NULL is returned. |
GnomeCanvasPathDef * gnome_canvas_path_def_new_from_static_bpath
(ArtBpath *bpath
);
This function constructs a new gnome_canvas_path_def and
references the passed bpath
as its contents. The
gnome_canvas_path_def returned from this function is to be
considered static and non-editable (meaning you cannot change the
path from what you passed in bpath
). The bpath will not be freed,
if path will be destroyed, so use it with caution.
|
libart bezier path |
Returns : |
the new canvas path definition that references the passed
bpath , or if the path is bad NULL is returned. |
GnomeCanvasPathDef * gnome_canvas_path_def_new_from_foreign_bpath
(ArtBpath *bpath
);
This function constructs a new gnome_canvas_path_def and
duplicates the contents of the passed bpath
in the definition.
|
libart bezier path |
Returns : |
the newly created gnome_canvas_path_def or NULL if the path is invalid. |
void gnome_canvas_path_def_ref (GnomeCanvasPathDef *path
);
Increment the reference count of the GnomeCanvasPathDef.
|
a GnomeCanvasPathDef |
void gnome_canvas_path_def_finish (GnomeCanvasPathDef *path
);
Trims dynamic point array to exact length of path.
|
a GnomeCanvasPathDef |
void gnome_canvas_path_def_ensure_space (GnomeCanvasPathDef *path
,gint space
);
This function ensures that enough space for space
points is
allocated at the end of the path.
|
a GnomeCanvasPathDef |
|
number of points to guarantee are allocated at the end of the path. |
void gnome_canvas_path_def_copy (GnomeCanvasPathDef *dst
,const GnomeCanvasPathDef *src
);
This function copies the contents src
to dest
. The old dest
path
array is freed and dest
is marked as non-static (editable),
regardless of the status of src
.
|
a GnomeCanvasPathDef where the contents of src will be stored. |
|
a GnomeCanvasPathDef whose contents will be copied it src . |
GnomeCanvasPathDef * gnome_canvas_path_def_duplicate (const GnomeCanvasPathDef *path
);
This function duplicates the passed path
. The new path is
marked as non-static regardless of the state of original.
|
a GnomeCanvasPathDef to duplicate |
Returns : |
a GnomeCanvasPathDef which is a duplicate of path . |
GnomeCanvasPathDef * gnome_canvas_path_def_concat (const GSList *list
);
This function concatenates a list of GnomeCanvasPathDefs into one newly created GnomeCanvasPathDef.
|
a GSList of GnomeCanvasPathDefs to concatenate into one new path. |
Returns : |
a new GnomeCanvasPathDef |
GSList * gnome_canvas_path_def_split (const GnomeCanvasPathDef *path
);
This function splits the passed path
into a list of
GnomeCanvasPathDefs which represent each segment of the origional
path. The path is split when ever an ART_MOVETO or ART_MOVETO_OPEN
is encountered. The closedness of resulting paths is set accordingly
to closedness of corresponding segment.
|
a GnomeCanvasPathDef |
Returns : |
a list of GnomeCanvasPathDef(s). |
GnomeCanvasPathDef * gnome_canvas_path_def_open_parts (const GnomeCanvasPathDef *path
);
This function creates a new GnomeCanvasPathDef that contains all of
the open segments on the passed path
.
|
a GnomeCanvasPathDef |
Returns : |
a new GnomeCanvasPathDef that contains all of the open segemtns in path . |
GnomeCanvasPathDef * gnome_canvas_path_def_closed_parts
(const GnomeCanvasPathDef *path
);
This function returns a new GnomeCanvasPathDef that contains the
all of close parts of passed path
.
|
a GnomeCanvasPathDef |
Returns : |
a new GnomeCanvasPathDef that contains all of the closed
parts of passed path . |
GnomeCanvasPathDef * gnome_canvas_path_def_close_all (const GnomeCanvasPathDef *path
);
This function closes all of the open segments in the passed path and returns a new GnomeCanvasPathDef.
|
a GnomeCanvasPathDef |
Returns : |
a GnomeCanvasPathDef that contains the contents of path
but has modified the path is fully closed |
void gnome_canvas_path_def_unref (GnomeCanvasPathDef *path
);
Decrease the reference count of the passed path
. If the reference
count is < 1 the path is deallocated.
|
a GnomeCanvasPathDef |
void gnome_canvas_path_def_reset (GnomeCanvasPathDef *path
);
This function clears the contents of the passed path
.
|
a GnomeCanvasPathDef |
void gnome_canvas_path_def_moveto (GnomeCanvasPathDef *path
,gdouble x
,gdouble y
);
This function adds starts new subpath on path
, and sets its
starting point to x
and y
. If current subpath is empty, it
simply changes its starting coordinates to new values.
|
a GnomeCanvasPathDef |
|
x coordinate |
|
y coordinate |
void gnome_canvas_path_def_lineto (GnomeCanvasPathDef *path
,gdouble x
,gdouble y
);
This function add a line segment to the passed path
with the
specified x
and y
coordinates.
|
a GnomeCanvasPathDef |
|
x coordinate |
|
y coordinate |
void gnome_canvas_path_def_lineto_moving (GnomeCanvasPathDef *path
,gdouble x
,gdouble y
);
This functions adds a new line segment with loose endpoint to the path, or
if endpoint is already loose, changes its coordinates to x
, y
. You
can change the coordinates of loose endpoint as many times as you want,
the last ones set will be fixed, if you continue line. This is useful
for handling drawing with mouse.
|
a GnomeCanvasPathDef |
|
x coordinate |
|
y coordinate |
void gnome_canvas_path_def_curveto (GnomeCanvasPathDef *path
,gdouble x0
,gdouble y0
,gdouble x1
,gdouble y1
,gdouble x2
,gdouble y2
);
This function adds a bezier curve segment to the path definition.
|
a GnomeCanvasPathDef |
|
first control point x coordinate |
|
first control point y coordinate |
|
second control point x coordinate |
|
second control point y coordinate |
|
end of curve x coordinate |
|
end of curve y coordinate |
void gnome_canvas_path_def_closepath (GnomeCanvasPathDef *path
);
This function closes the last subpath of path
, adding a ART_LINETO to
subpath starting point, if needed and changing starting pathcode to
ART_MOVETO
|
a GnomeCanvasPathDef |
void gnome_canvas_path_def_closepath_current
(GnomeCanvasPathDef *path
);
This function closes the last subpath by setting the coordinates of the endpoint of the last segment (line or curve) to starting point.
|
a GnomeCanvasPathDef |
ArtBpath * gnome_canvas_path_def_bpath (const GnomeCanvasPathDef *path
);
This function returns a ArtBpath that consists of the path definition.
|
a GnomeCanvasPathDef |
Returns : |
ArtBpath |
gint gnome_canvas_path_def_length (const GnomeCanvasPathDef *path
);
This function returns the length of the path definition. Not Euclidian length of the path but rather the number of points on the path.
|
a GnomeCanvasPathDef |
Returns : |
integer, number of points on the path. |
gboolean gnome_canvas_path_def_is_empty (const GnomeCanvasPathDef *path
);
This function is a boolean test to see if the path is empty, meaning containing no line segments.
|
a GnomeCanvasPathDef |
Returns : |
boolean, indicating if the path is empty. |
gboolean gnome_canvas_path_def_has_currentpoint
(const GnomeCanvasPathDef *path
);
This function is a boolean test checking to see if the path has a current point defined. Current point will be set by line operators, and cleared by closing subpath.
|
a GnomeCanvasPathdef |
Returns : |
boolean, indicating if the path has a current point defined. |
void gnome_canvas_path_def_currentpoint (const GnomeCanvasPathDef *path
,ArtPoint *p
);
Stores the current point of the path definition in the passed ArtPoint p
.
|
a GnomeCanvasPathDef |
|
a ArtPoint where to store the current point |
ArtBpath * gnome_canvas_path_def_last_bpath (const GnomeCanvasPathDef *path
);
This function returns pointer to the last ArtBpath segment in the path definition.
|
a GnomeCanvasPathDef |
Returns : |
ArtBpath, being the last segment in the path definition or null if no line segments have been defined. |
ArtBpath * gnome_canvas_path_def_first_bpath (const GnomeCanvasPathDef *path
);
This function returns the first ArtBpath point in the definition.
|
a GnomeCanvasPathDef |
Returns : |
ArtBpath being the first point in the path definition or null if no points are defined |
gboolean gnome_canvas_path_def_any_open (const GnomeCanvasPathDef *path
);
This function returns a boolean value indicating if the path has any open segments.
|
a GnomeCanvasPathDef |
Returns : |
boolean, indicating if the path has any open segments. |
gboolean gnome_canvas_path_def_all_open (const GnomeCanvasPathDef *path
);
This function returns a boolean value indicating if the path only contains open segments.
|
a GnomeCanvasPathDef |
Returns : |
boolean, indicating if the path has all open segments. |
gboolean gnome_canvas_path_def_any_closed (const GnomeCanvasPathDef *path
);
This function returns a boolean valid indicating if the path has any closed segements.
|
a GnomeCanvasPathDef |
Returns : |
boolean, indicating if the path has any closed segments. |
gboolean gnome_canvas_path_def_all_closed (const GnomeCanvasPathDef *path
);
This function returns a boolean value indicating if the path only contains closed segments.
|
a GnomeCanvasPathDef |
Returns : |
boolean, indicating if the path has all closed segments. |