Scrollbars, part 3: Optimizing the paint cycle

Raymond Chen July 29, 2003 Jul 29, 2003 07/29/03

Observe that we paint all 100 lines in our paint handler, even though most of them aren't visible. This is a problem if there are a large number of items, or if painting an item is time-consuming. So instead, we optimize our paint cycle so as to paint only the elements which intersect the...

Scrollbars, part 2

Raymond Chen July 25, 2003 Jul 25, 2003 07/25/03

Managing scrollbars is not hard in principle. The basic idea is not that difficult, but there are a lot of small details that need to be ironed out. If you don't get the details just right, your program will feel odd in a strange way that you often can't pinpoint, much like a subtle background hum that ...

The scratch program

Raymond Chen July 23, 2003 Jul 23, 2003 07/23/03

Occasionally, there is need to illustrate a point with a full program. To avoid reproducing the boring parts of the program, let's agree on using the following template for our sample programs. For expository purposes, I won't use a C++ class. I'll just keep all my variables global. In a real program, of course, instance data would be ...