You'll want to change this line:
if(SDL_PollEvent(&keyEvent_))
To this:
while(SDL_PollEvent(&keyEvent_))
As is, you're only processing one pending event per update, but in general you should process *all* pending events. (Otherwise, events will get 'backed up', and you may get noticeable lag or other similar problems.)
Also, you might check out
SDL_GetKeyState() (it looks like you're basically duplicating the functionality that it already offers).
As for the problem you describe, yes, you'll most likely want to use a timer. There are a couple of different ways to handle keyboard input with SDL: one is to check an 'is down' flag for each key as you're doing, and the other is to respond to individual 'key down' and 'key up' messages. In your case, for (e.g.) piece rotation, all you're really interested in is the corresponding 'key down' message; when the key is pressed, you rotated the piece, and assuming you've disabled 'key repeat', the piece won't rotate again until the player releases the key and presses it again.
For linear motion, you'll want to create and start an 'interval timer' when the key is pressed, and then allow it to continue to run as long as the key is down. Every time the timer 'trips', you move the piece. The timer should trip when it starts (so that the piece moves immediately), and at a regular interval of your choosing thereafter. The implementation details are somewhat incidental, but a fairly straightforward solution is to create a simple 'interval timer' class that manages the details of tracking elapsed time and sending a 'trip' signal at the appropriate intervals.
[Edit: Fixed copy-and-paste error.]
[Edited by - jyk on February 18, 2010 9:39:32 PM]
