Windows' drivers have a focus problem.

[maynardGK]

With new coding in GDL it has been possible to nearly replicate the desirable behavior of
keyboard focus without patching the plplot drivers, wingcc,c or wingdi.c.
Previously, keyboard focus was controlled solely by returning focus to the foreground
window. The foreground window was however changed in the original wingcc driver and so
un-doing this change via a patch in plplot allowed for a correct behavior:

--- /f/plplot/plplot-5.13.0/drivers/wingcc.c	Fri Aug 25 19:43:25 2017
+++ /f/tarball/plplot-5.13.0/drivers/wingcc.c	Sat Jun 09 12:44:28 2018
@@ -636,7 +634,7 @@
     // sort of thing).
     //
     ShowWindow( dev->hwnd, SW_SHOWDEFAULT );
-    SetForegroundWindow( dev->hwnd );
+    BringWindowToTop( dev->hwnd );

(this patch was proposed and rejected by the plplot group)

The new interface to wingcc #864 works around this but it is somehow inadequate, failing the following test with multiple windows (can be .RUN or just executed with "@").

fs=findgen(40) & !prompt="" & iw=-1
iw++&window,iw,xs=512,ys=512,xp=128*iw,yp=128*iw&plot,fs,chars=iw,thi=iw
iw++&window,iw,xs=512,ys=512,xp=128*iw,yp=128*iw&plot,fs,chars=iw,thi=iw
iw++&window,iw,xs=512,ys=512,xp=128*iw,yp=128*iw&plot,fs,chars=iw,thi=iw
iw++&window,iw,xs=512,ys=512,xp=128*iw,yp=128*iw&plot,fs,chars=iw,thi=iw
iw++&window,iw,xs=512,ys=512,xp=128*iw,yp=128*iw&plot,fs,chars=iw,thi=iw
iw++&window,iw,xs=512,ys=512,xp=128*iw,yp=128*iw&plot,fs,chars=iw,thi=iw
wshow,iw,0
wshow,iw-1,0
wshow,iw-2,0
wshow,iw-2,/icon
wshow,iw-2,0
wshow,iw-3,0
wshow,0,0,/icon
wshow,0
end

[pjb7687]

I suspect below picks up a wrong handle.

gdl/src/gdlwinstream.hpp

Line 195 in 4e34157

refocus = GetForegroundWindow();

This is okay.

[pjb7687]

Also, this seems to be raising the previous plot:

gdl/src/gdlwinstream.cpp

Line 462 in 4e34157

Raise(); // Brings again the plot window on top, but not focused

[pjb7687]

Tried to fix it: 3eb16a4
Two things are fixed:

1. The plot is not properly repainted when I run the suggested code using GDL Workbench.
2. The code works when I replace the third argument of wshow function (show) to be 1.

I simply removed the UnsetFocus function from devicewin. I have searched for how IDL behaves on Windows on Youtube, seems like the Windows IDL also doesn't do this...

I found that when the third argument (show) is 0, then actually the window should be hidden, according to this:
https://www.l3harrisgeospatial.com/docs/WSHOW_Procedure.html

But instead, it seems like the current implementation tries to bring the window bottom (in the z-order). I don't know which one is the right behavior of IDL, so postponed fixing it...

[pjb7687]

When the third argument is 1:

[pjb7687]

Having no ideas about IDL behavior, I'll make it behave the same as ubuntu GDL... Makes sense?

[pjb7687]

Another fix: 77c3f03
This is when the third argument is 0:

[pjb7687]

Is this okay now?

[GillesDuvert]

wshow,3,0 puts window 3 below all others.
wshow,3,1 put it above.
wshow,3,/icon iconize the window. It cannot be shown again unless a wshow,3,icon=0 is issued, and the window appears above all the others, even after a command like 'wshow,3,0,icon=0 .
GDL is apparently not completely OK with this with the X11 driver on unix.
Concerning the focus, IDL always disable passing the focus to a plot window, which is IMHO more than clever, but the plplot windows (so, the GDL ones, example: the X11 window) somehow obey the desktop behaviour on 'focus stealing' and are not declared 'no focus at all'. One can instruct the window manager (KDE in my case) to disable focus always on windows named 'GDL*' but this is too system dependent. There must be a magic call to have all plplot windows to never get focus.

[pjb7687]

@GillesDuvert Thank you so much for clarifying this! Then the patched Windows driver behaves correctly. It never steals the focus from the GDL command line.

[pjb7687]

One exception is when you fire up a new plot window using 'plot'. However at least wshow seems to work okay.. I will further investigate it.

[GillesDuvert]

obsolete since #882 has been merged