Virtual Windows

Virtual windows can be created in the Designer. The function dl_wnget() reads either basic or virtual windows from the library, and allocates a memory screen of the appropriate size.

If you wish to allow the user to scroll through the contents of the virtual window, you must:

• nInclude the header file vv_wnkt.h to enable scrolling.
  
  
• nReplace the calls to wn_up(), ki(), and wn_dn() with a single call to the window processing function, wn_proc().

To process a window, use the window process function, wn_proc():

int wn_proc(wnp)

WINDOWPTR wnp;        /* Pointer to window        */

wn_proc() calls the processing function for the window. The processing function places the window on the screen, if it is not already up. It then passes control to the user. If the window is a basic window, the processing function simply waits for the user to press any key, and then returns. If the window is virtual, or if it has a memory file that can be scrolled, the processing function allows the user to browse the contents of the window's buffer. When the user presses the Quit key or the Exit key, the processing function takes the window down if the window was not up when wn_proc() was called.