Using arrow keys with drawing windows

["Bobby T. Yee" <yeester+@CMU.EDU>]

I'm writing a program in which I need to go up and down a tree.  Is
there an easy way to do this using arrow keys?  (For example, pressing
the up arrow key will go up one level, pressing the down arrow key will
go down one level, and pressing the left or right arrow key will go to a
sibling of the current node.)  Or would I have to write a key-handler
for the drawing window (which could be troublesome becuase I've never
really understood how a key-handler works or how to write one...)?


|----------------------|----------------------------------------------|
|Bobby Yee             |  We're not fat, we're white, we're Catholic, |
|by0b@andrew.cmu.edu   |  And we are sick about it!                   |
|yeester@cmu.edu       |                            -- Don & Mike     |
|----------------------|----------------------------------------------|
|Ain't they jerks                                                     |
|I listen to 'em on the way home from work                            |
|Don & Mike on WJFK                                                   |
|Ain't they jerks                                                     |
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