Exercises, examples and other material relating to training module T219. This topic is presented on public course Tcl/Tk

Tcl/Tk GUIs consist largely of components such as buttons, labels entry boxes and sliders. Sometimes you'll need something that's much more graphic and for this you'll use a canvas widget. You can write to a canvas down to individual pixel level, and you can also draw lines, ovals, rectangles, text and polygons. This module studies the options for drawing to and manipulating a canvas, and introduces computer graphic techniques such as world to pixel co-ordinate transformations and display list manipulation.

Articles and tips on this subject		updated
2211	Tcl/Tk - why does the canvas widget use a display list? "Tcl/Tk uses a display list when you draw on a canvas widget." OK - so what does that really mean? With most of the languages that we teach, any graphics you draw go straight into a frame buffer of a memory map that represents a frame buffer, so the earlier elements added to your graphic will be destructively ...	2009-06-01

can1	Drawing on a canvas
can2	Drawing shapes on a canvas and dragging them with the mouse
can3	Demo of different graphic objects
can4	Line styles on a Tk canvas
histo	Histogram drawn on a canvas - generalised code
imgoncanvas.tk	Placing a GIF on a canvas
tktext	text options in Tk - colour, font, size, centring

Using a Tcl/Tk canvas