libcucul canvas frame handling


Functions

__extern int cucul_get_frame_count (cucul_canvas_t const *)
 Get the number of frames in a canvas.
__extern int cucul_set_frame (cucul_canvas_t *, int)
 Activate a given canvas frame.
__extern char const * cucul_get_frame_name (cucul_canvas_t const *)
 Get the current frame's name.
__extern int cucul_set_frame_name (cucul_canvas_t *, char const *)
 Set the current frame's name.
__extern int cucul_create_frame (cucul_canvas_t *, int)
 Add a frame to a canvas.
__extern int cucul_free_frame (cucul_canvas_t *, int)
 Remove a frame from a canvas.

Detailed Description

These functions provide high level routines for canvas frame insertion, removal, copying etc.

Function Documentation

__extern int cucul_get_frame_count ( cucul_canvas_t const *  cv  ) 

Return the current canvas' frame count.

This function never fails.

Parameters:
cv A libcucul canvas
Returns:
The frame count

Referenced by cucul_set_canvas_boundaries().

__extern int cucul_set_frame ( cucul_canvas_t cv,
int  id 
)

Set the active canvas frame. All subsequent drawing operations will be performed on that frame. The current painting context set by cucul_set_attr() is inherited.

If the frame index is outside the canvas' frame range, nothing happens.

If an error occurs, -1 is returned and errno is set accordingly:

  • EINVAL Requested frame is out of range.

Parameters:
cv A libcucul canvas
id The canvas frame to activate
Returns:
0 in case of success, -1 if an error occurred.

Referenced by cucul_set_canvas_boundaries().

__extern char const* cucul_get_frame_name ( cucul_canvas_t const *  cv  ) 

Return the current frame's name. The returned string is valid until the frame is deleted or cucul_set_frame_name() is called to change the frame name again.

This function never fails.

Parameters:
cv A libcucul canvas.
Returns:
The current frame's name.

__extern int cucul_set_frame_name ( cucul_canvas_t cv,
char const *  name 
)

Set the current frame's name. Upon creation, a frame has a default name of "frame#xxxxxxxx" where xxxxxxxx is a self-incrementing hexadecimal number.

If an error occurs, -1 is returned and errno is set accordingly:

  • ENOMEM Not enough memory to allocate new frame.

Parameters:
cv A libcucul canvas.
name The name to give to the current frame.
Returns:
0 in case of success, -1 if an error occurred.

__extern int cucul_create_frame ( cucul_canvas_t cv,
int  id 
)

Create a new frame within the given canvas. Its contents and attributes are copied from the currently active frame.

The frame index indicates where the frame should be inserted. Valid values range from 0 to the current canvas frame count. If the frame index is greater than or equals the current canvas frame count, the new frame is appended at the end of the canvas. If the frame index is less than zero, the new frame is inserted at index 0.

The active frame does not change, but its index may be renumbered due to the insertion.

If an error occurs, -1 is returned and errno is set accordingly:

  • ENOMEM Not enough memory to allocate new frame.

Parameters:
cv A libcucul canvas
id The index where to insert the new frame
Returns:
0 in case of success, -1 if an error occurred.

Referenced by cucul_set_canvas_boundaries().

__extern int cucul_free_frame ( cucul_canvas_t cv,
int  id 
)

Delete a frame from a given canvas.

The frame index indicates the frame to delete. Valid values range from 0 to the current canvas frame count minus 1. If the frame index is greater than or equals the current canvas frame count, the last frame is deleted.

If the active frame is deleted, frame 0 becomes the new active frame. Otherwise, the active frame does not change, but its index may be renumbered due to the deletion.

If an error occurs, -1 is returned and errno is set accordingly:

  • EINVAL Requested frame is out of range, or attempt to delete the last frame of the canvas.

Parameters:
cv A libcucul canvas
id The index of the frame to delete
Returns:
0 in case of success, -1 if an error occurred.