I'm trying to manipulate the text on a button in my shell, but no matter what I try, I continue to get:

object.Exception: Access Violation

The code I'm attempting to run is attached. Can anyone take a look and shed some light on what I'm doing wrong? Thanks!

sleek schrieb:
> I'm trying to manipulate the text on a button in my shell, but no matter what I try, I continue to get:
> 
> object.Exception: Access Violation
> 
> The code I'm attempting to run is attached. Can anyone take a look and shed some light on what I'm doing wrong? Thanks! 
> 
> 

The documentation of SWT says for most widgets:
IMPORTANT: This class is not intended to be subclassed.

So do not subclass Shell, instead use it as a member variable.

But the access violation is caused by accessing a local variable from your startStopButton selection listener. The initComponents method is finished long before the listener is called. So the "startStopButton" variable do no more exist. Make this variable a member var of the MainWindow class.

Aha!  dgListener!!! I did not notice that this existed. Using it seems to have solved my problem. Is this documented somewhere on the DWT site?

"sleek" <cslush@gmail.com> wrote in message news:g75l5i$1i62$1@digitalmars.com...
> I'm trying to manipulate the text on a button in my shell, but no matter what I try, I continue to get:
>
> object.Exception: Access Violation
>
> The code I'm attempting to run is attached. Can anyone take a look and shed some light on what I'm doing wrong? Thanks!
>
> 

The startStopButton is a member variable. I am just initializing it in the initComponents method. Thanks for the info about not sub-classing Shell. I'm used to writing Swing code where normally you extend most widgets.

"Frank Benoit" <keinfarbton@googlemail.com> wrote in message news:g75m35$1jot$1@digitalmars.com...
> sleek schrieb:
>> I'm trying to manipulate the text on a button in my shell, but no matter what I try, I continue to get:
>>
>> object.Exception: Access Violation
>>
>> The code I'm attempting to run is attached. Can anyone take a look and shed some light on what I'm doing wrong? Thanks!
>
> The documentation of SWT says for most widgets:
> IMPORTANT: This class is not intended to be subclassed.
>
> So do not subclass Shell, instead use it as a member variable.
>
> But the access violation is caused by accessing a local variable from your startStopButton selection listener. The initComponents method is finished long before the listener is called. So the "startStopButton" variable do no more exist. Make this variable a member var of the MainWindow class.
>
>
> 

sleek schrieb:
> Aha!  dgListener!!! I did not notice that this existed. Using it seems to have solved my problem. Is this documented somewhere on the DWT site?
> 

Now it is mentioned here:
http://www.dsource.org/projects/dwt/wiki/DiffToOriginal#ThingsaddedorchangedinDWT:

sleek schrieb:
> The startStopButton is a member variable. 

hm, i missed that. I was too much expecting this problem :)
This looks like a compiler bug to me.

sleek schrieb:
> I'm trying to manipulate the text on a button in my shell, but no matter what I try, I continue to get:
> 
> object.Exception: Access Violation
> 
> The code I'm attempting to run is attached. Can anyone take a look and shed some light on what I'm doing wrong? Thanks! 
> 
> 
Hm, in the hope of locating a compiler bug, i tested your code. And it worked for me.

I'll definitely try and take another look at it. I'm using the compiler and libraries from the Easy-D install, so maybe that's the issue?

"Frank Benoit" <keinfarbton@googlemail.com> wrote in message news:g75scg$1v22$1@digitalmars.com...
> sleek schrieb:
>> I'm trying to manipulate the text on a button in my shell, but no matter what I try, I continue to get:
>>
>> object.Exception: Access Violation
>>
>> The code I'm attempting to run is attached. Can anyone take a look and shed some light on what I'm doing wrong? Thanks!
> Hm, in the hope of locating a compiler bug, i tested your code. And it worked for me.

sleek schrieb:
> I'll definitely try and take another look at it. I'm using the compiler and libraries from the Easy-D install, so maybe that's the issue?
> 

According to http://www.fsdev.net/versions/show/7
DMD 1.030 is included there.
This version has a bug with anonymous classes, like that one used in your code.
Using DMD 1.033 should solve this.

On http://www.dsource.org/projects/dwt/wiki/Requirements I have listed the current supported compiler(s).

To update, it is sufficient to overwrite the dmd.exe with the newer version.

Very cool. Thanks for the update. I'll upgrade now

"Frank Benoit" <keinfarbton@googlemail.com> wrote in message news:g773n1$12uu$1@digitalmars.com...
> sleek schrieb:
>> I'll definitely try and take another look at it. I'm using the compiler and libraries from the Easy-D install, so maybe that's the issue?
>>
>
> According to http://www.fsdev.net/versions/show/7
> DMD 1.030 is included there.
> This version has a bug with anonymous classes, like that one used in your
> code.
> Using DMD 1.033 should solve this.
>
> On http://www.dsource.org/projects/dwt/wiki/Requirements I have listed the current supported compiler(s).
>
> To update, it is sufficient to overwrite the dmd.exe with the newer version.
>