Background: My client has a very extensive proprietary forms library which is effectively implemented in C (actually, it's a proprietary object-oriented language that basically wraps Windows controls and interacts with them with SendMessage(), SetStyle(), etc.)
Problem I want to solve: Whenever I drag/resize a top-level window (or drag a splitter) in an app implemented in the above framework, there is massive flicker. The top-level window is repainted, and any controls it contains repaint themselves.
Question 1: Is there a way to surgically introduce double-buffering into the forms library. In particular, I want to know if I can implement double-buffering using standard Windows GDI functions.
For example, if I could cause the top-level windows to be double-buffered such that all child windows of the top-level window are automatically drawn double-buffered as well. An even better alternative would be to be able to introduce double-buffering on any arbitrary window and have all its children inherit this.
The best solution would somehow cause the BeginPaint() function for child controls to return a handle to the DC of the offscreen back buffer so that I don't have to write special code for each individual control class.
Question 2: Is there a way (such as a set of flags) to cause generic Windows controls (EDIT, BUTTON, and so on) to draw themselves double-buffered? This would be a worse solution than a more generic approach that would just seamlessly give them the back buffer to draw on, but it might also be acceptable.
All help greatly appreciated. Please let me know if I can clarify anything for you.
