catch TOpenGLContext exceptions
lazarus / 70-OpenGL

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apeoperaio · 2016-02-19 10:45

I developed an application using TOpenGLcontext.
Some users have problems with opengl (especially on linux), missing
libraries, FB config missing and so on.

Actually if the system on which my application is running has problems
with opengl my app crashes.
e.g.:
"Could not find FB config"
Press OK to ignore and risk data corruption
Press Cancel to kill the program

I would like to catch these exceptions and if Topenglcontext cannot
work I would like to disable it and run my app wihout it.

How can I do it?
Thanks.
Andrea

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balazsszekely · 2016-02-19 11:04

You should debug the code and find out which line causing the
exception. To handle all exception on application level, switch do
release mode, then do this on the main form:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
//... TForm1 = class(TForm)    procedure FormCreate(Sender: TObject); 
private    procedure HandleExceptions(Sender: TObject; E: Exception); 
  { private declarations }  public    { public declarations }  end;  
     //...procedure TForm1.FormCreate(Sender: TObject);begin 
Application.OnException := @HandleExceptions;end; procedure
TForm1.HandleExceptions(Sender: TObject; E: Exception);begin  //handle
here --> show something or not, it's up to you 
ShowMessage(E.Message); end;

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apeoperaio · 2016-02-19 11:16

I cannot find where the exception is raised exactly since I am not
able to reproduce the problem.

Anyway I just want to not create the TOpenGLContext if OpenGL are not
working.
I have a TOpenGLContext on my main form (design time), I would like to
catch exceptions related ONLY to opengl and eventually disable in some
way the openglcontext and run my application without using
TOpenGLContext.
I can create TOpenGLContext at runtime after a test that guarantee me
that TOpenGLContext will run.
I want to avoid unexpected crash related to opengl.

Something like

try
  Ok:= TestIFTOpenGLContextCanRun;
except
  messageerror;
end;
if Ok then
  CreateTOpengLContext;
// run my app