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A canvas is a managed plain X (sub)window. It it different from the
free object in that a canvas is guaranteed to be associated with a
window that is not shared with any other object, thus an application
program has more freedom in utilizing a canvas, such as using its own
colormap or rendering double-buffered OpenGL in it etc. A canvas is
also different from a raw application window because a canvas is
decorated differently and its geometry is managed, e.g., you can use
fl_set_object_resize()
to control its position and size
after its parent form is resized.
You also should be aware that when using a canvas you’ll
probably mostly program directly using basic Xlib functions,
XForms doesn’t supply much more than a few helper functions.
You’ll rather likely draw to it with Xlib functions and will
be dealing with XEvent
s yourself (instead having them
taken care of by XForms and cenverted to some simpler to
use events that then just return the object from
fl_do_forms()
or invoke an associated callback
function. Thus you will typically need a basic knowledge of how to
program via the X11 Xlib.
• Adding Canvas Objects: | ||
• Canvas Types: | ||
• Canvas Interaction: | ||
• Other Canvas Routines: | ||
• Canvas Attributes: | ||
• OpenGL Canvas: |