Programming Tool Box/SIMS_2.iso/vb_code1/clip_sib/read_me.txt

Text File | 1991-11-03 | 4KB | 66 lines

Hi,

It appears that the only reason VB doesn't support overlapping controls is
that the WS_CLIPSIBLINGS style bit is not set for VB controls. Setting this
style bit tells Win3 to clip overlapping child controls so that they are
displayed correctly and don't interfere with each other. The order in which
child windows are displayed is determined by their relative locations in the
Win3 Window Manager List. A window which is higher up on this list will appear
in front of any windows that are lower down in the list. CLIPSIB demonstrates
how to set the WS_CLIPSIBLINGS style bit for all of a Form's windows and
several API functions that you can use to access and manipulate the Window
Manager List.

I think you will be amazed at what you can do simply by setting this bit for
all of a Form's child windows (VB controls).

CLIPSIB contains three demonstrations of the added power that setting this bit
provides. In the upper left of the Form are a group of 4 overlapping list
boxes. Clicking any of the list boxes pops it in front of the other boxes so
you can make a selection. In the upper right of the Form are 3 small Picture
Controls that will be loaded with the Win3 bitmap named PYRAMID.BMP and a
larger Picture Control that will be loaded the the Win3 bitmap named
CHESS.BMP. The large Picture Control also has a Command Button on it. You can
use your mouse to move the small pictures on top of the large one and to
scroll the large picture -under- the small ones.

In the lower right of the Form is a simulation of a FIND Dialogue Box similar
to the ones found in VB and other Win3 programs. You can drag this box around
by its title bar. The special feature of this set of controls is that they
are *always* displayed on top of all other controls. Try dragging the Find box
on top of the group of list boxes and then click on the list boxes. Note that
even though the list boxes re-arrange themselves, they never pop-up in front
of the Find Box.

CLIPSIB runs in the VB environment, but the performance is *very* slow. You
should load the program into VB and then create and EXE file and run the EXE
file. The performance improvement is dramatic!!!

The credit for discovering the significance of WS_CLIPSIBLINGS must go
completely to Daniel Appleman, the owner of DesaWare and creator of the Custom
Control Factory VB Add-on Toolkit. Dan took the time to examine my first
attempt (in which I only manipulated the Window Manager List to get VB to
display overlapping controls correctly) and then very nicely explain that I
was out to lunch.<g> After Dan explained how things *really* work with Win3, I
was off to the races.

But Dan wasn't the only one who contributed to this program. Thanks must also
go to Ted Young and Jonathan Zuk who also took the time to look at my first
attempt. In fact, Jonathan mentioned WS_CLIPSIBLINGS, but his suggestion went
in one eye and out the other. So much for my powers of perception.<g>

This program requires the Win3 bitmaps PYRAMID.BMP and CHESS.BMP.  They come
with Win3 and should be in your Win3 directory.  The program also makes
extensive use of a custom DLL named CTLHWND.DLL which was written by Jonathan
Zuk.  Because the DLL is tiny, I've included it with the demo rather than make
you track it down in the MSBASIC Libraries.

Although Dan, Ted and Jonathan made significant contributions to this program,
I am solely responsible for any errors, omissions, bugs, etc. If you have any
problems with the program, I'm the guy you should jump on.<g>

CLIPSIB.BAS is FreeWare. Do what you like with it and have some fun.

Keith Funk (CIS 72240, 2020)
Nov. 3, 1991