🚀 go-pugleaf

chris@chrism.demon.co.uk (Chris Marriott) writes:
: In article <1993Jan9.011837.22185@delfin.com> dan@delfin.com writes:
: 
: >I have created an owner draw listbox.  Is there any way to prevent
: >the listbox from redrawing all visible items when it scrolls one line 
: >after receiving an LB_ADDSTRING message?  Without the LB_ADDSTRING,
: >scrolling only redraws the newly visible item, doing a quick bitmap
: >shift of the other items.
: >
: >I have tried everything I could think of.  At this point, it seems
: >to me that there is no way to avoid it.
: >
: >
: 
: Send the listbox a WM_SETREDRAW, FALSE message.  Add all the strings
: except the last one.  Send WM_SETREDRAW, TRUE.  Add the last string.
: -- 
:  

I appreciate the responses, but my question is actually much more
sophisticated.  I know all about WM_SETREDRAW.  I want to append one
line to the listbox and have it visible.  No matter how I get it 
to be visible (SCROLL,SETPOS,etc.), all my visible owner draw lines
receive WM_DRAWITEM messages --- this is not necessary!  In fact,
when repositioning using the WM_VSCROLL message, Windows does what I
want (no owner draw requests except for the newly added item at the
bottom), but then repaints the entire listbox (sending many draw item
requests).

For most people, this activity is so fast it is invisible (you can only
catch Windows in the act by overloading your system (say, by running Spy),
or by tracing messages.  I like to really optimize my code, however.