OpenEuphoria

1. Win32Lib: child window demo anomaly?

• Posted by Dan Moyer <danielmoyer at prodigy.net> Apr 25, 2007
• 562 views

This is not terribly important, but while looking at child windows
in the Win32Lib demos, I noticed a behavior that looks bad:

"child4.exw" makes a parent & a child window, with child just below titlebar
of parent & filling parent; the parent has a button which is initially hidden
by the child window.

If, and only before you MOVE the child, you move mouse to approx. where button
is under child & click, THE BUTTON IS *DRAWN* ONTO THE CHILD WINDOW!

(Moving the child around so that new "button" is off the parent will "erase"
those portions of it from the child.)

This can't be good??

Here's the demo's code:

--  code generated by Win32Lib IDE v0.17.0
include Win32Lib.ew
without warning

----------------------------------------------------------------------------
----
--  Window Window1
constant Window1 = createEx( Window, "Window1", 0, Default, Default, 400,
300, 0, 0 )
constant PushButton2 = createEx( Button, "PushButton2", Window1, 24, 28,
260, 104, 0, 0 )
---------------------------------------------------------
----------------------------------------------------------------------------
----
--  Window Window2
constant Window2 = createEx( Window, "Window 2", Window1, Default, Default,
400, 300, or_all({WS_CHILD}), 0)
---------------------------------------------------------
----------------------------------------------------------------------------
----
procedure Window1_onOpen (integer self, integer event, sequence params)--params
is ()
 openWindow(Window2,Normal) 
end procedure
setHandler( Window1, w32HOpen, routine_id("Window1_onOpen"))


WinMain( Window1,Normal )

Dan Moyer

3. Re: Win32Lib: child window demo anomaly?

• Posted by Chris McConnell <chris at mc-data.com> Apr 25, 2007
• 519 views
• Last edited Apr 26, 2007

CChris wrote:
> 
> Dan Moyer wrote:
> > 
> > This is not terribly important, but while looking at child windows
> > in the Win32Lib demos, I noticed a behavior that looks bad:
> > 
> > "child4.exw" makes a parent & a child window, with child just below titlebar
> > of parent & filling parent; the parent has a button which is initially
> > hidden
> > by the child window.
> > 
> > If, and only before you MOVE the child, you move mouse to approx. where
> > button
> > is under child & click, THE BUTTON IS *DRAWN* ONTO THE CHILD WINDOW!
> > 
> > (Moving the child around so that new "button" is off the parent will "erase"
> > those portions of it from the child.)
> > 
> > This can't be good??
> > 
> > Here's the demo's code:
> > }}}
<eucode>
> > --  code generated by Win32Lib IDE v0.17.0
> > include Win32Lib.ew
> > without warning
> > 
> > ----------------------------------------------------------------------------
> > ----
> > --  Window Window1
> > constant Window1 = createEx( Window, "Window1", 0, Default, Default, 400,
> > 300, 0, 0 )
> > constant PushButton2 = createEx( Button, "PushButton2", Window1, 24, 28,
> > 260, 104, 0, 0 )
> > ---------------------------------------------------------
> > ----------------------------------------------------------------------------
> > ----
> > --  Window Window2
> > constant Window2 = createEx( Window, "Window 2", Window1, Default, Default,
> > 400, 300, or_all({WS_CHILD}), 0)
> > ---------------------------------------------------------
> > ----------------------------------------------------------------------------
> > ----
> > procedure Window1_onOpen (integer self, integer event, sequence
> > params)--params is ()
> >  openWindow(Window2,Normal) 
> > end procedure
> > setHandler( Window1, w32HOpen, routine_id("Window1_onOpen"))
> > 
> > 
> > WinMain( Window1,Normal )
> > </eucode>
{{{

> > 
> > Dan Moyer
> 
> It's even worse than that.
> 
> Windows considers the button to be visible, and Window1 gets a WM_COMMAND
> message on clicking the button, even though Window2 is on top of it.
> 
> After the definition of Window2, add the following:
> }}}
<eucode>
> constant l2=create(ListBox,"",Window2,1,1,399,299,0)
> addItem(l2,"aaaaa")
> </eucode>
{{{

> The non empty list displays, and clicking it brings PushButton2 in the
> foreground. Child windows seem transparent, as well as their children.
> Same problem with a group instead of a list or a disabled label, but not
> with a button covering Window2.
> 
> Moving Window2 using the mouse disables this behaviour. Using setRect()
> or setCtlSize() right after opening Window2 doesn't.
> 
> I looked into openWindow(), since this behaviour was making it a candidate
> for the bug. Playing with the showWindow() parameter when the opened window
> is a child doesn't appear to help.
> 
> Can anyone with VC++ or similar available port this very simple code and see
> if the problem persists? I don't have it at office.
> 
> CChris

I was able to get around this problem by opening the child minimized and
imediately calling a showWindow(restore).