Issue appgrafics

John,

I can't replicate this behavior.  Do you have a simple code sample that causes this crash?

I will set up a source and send it to you!

The issue in the example is that you're checking for keys pressed after the window is closed.  The keyboard routines are tied to an AppGraphics window.  The call to kbhit after the window closes causes an exception because a non-existent window keyboard queue is queried.

It probably shouldn't outright crash, though it might be hard to modify the library to avoid that.  However, the fix would simply cause kbhit to return .FALSE., leaving this example in an infinite loop.

Basically, if all the AppGraphics windows are closed, it is extremely dangerous to continue making calls to the library.

John,

I see what you're asking now.  You want to disable the Windows "close" button?  If that ever did work in AppGraphics, it was a bug.  The closeflag only means that the program won't terminate, not that the window won't close.  If you click the close button, the window and its resources will be destroyed, but the program will keep running.

Overriding Windows' WM_CLOSE is going to be messy.  I would have to add a new API to block it.  The better way to handle this would be to assign a callback using setwindowclosecallback that will trigger safe shutdown in the main thread.  I'll see about cancelling the WM_CLOSE message, though.  It will take a bit of time to add.

Hi Jeff,
First of all thanks for the new update version 3.19
I'm trying to use the new "setwindowsystemclosecallback" routine
As described in the documentation, I created a callback-Function and after creating a window, I added the following line to my fortran source:       call setwindowsystemclosecallback( noclosewin() )
Noclosewin() is the function I created and compiles without any errors!
When I then try to compile the main-source I get an error at the line with the call to the new subroutine as mentioned above:
    Error: Expected a procedure for argument 'f' at (1)

I defined noclosewin as "integer"
Am I doing something wrong?

Hi Jeff,
If I remove the parentheses as you mention I get the same error when trying to compile the source!
I enabled the visibility of warnings in the editor. And the editor already shows the mentioned error before I even can start the compiler.

To do a simple test I kept it simple and created almost exactly the same function as You did! Only the "print" statement is not in there.
      function noclosewin()
!
      implicit none
!
!      procedure als window wordt geclosed
!
!
      INTEGER::noclosewin
!
      noclosewin = 0
!
      return
!
      END function noclosewin

But I don't think the function is the issue.
The main source holding the call to the new subroutine gives the error!

The following lines are amongst others in my mainsource:

      subroutine GRAF()
.
      use appgraphics
      implicit none
.
.
      integer:: noclosewin, ipixxx, ipixyy, winx, winy, iiwin
      character::(20) mnubuf
.
.
.
      iiwin = initwindow(ipixxx,ipixyy,mnubuf,winx,winy,dbflag=.false.,closeflag=.false.)
.
.
      call setwindowsystemclosecallback(noclosewin)
(here the editor presents the error-message!!!)
.
.
      end subroutine GRAF