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How enable and disable buttons using event in SWT. [message #1006467]

Thu, 31 January 2013 07:16

sumit singh
Messages: 73
Registered: October 2012
Location: Bangalore

Member

I'm creating one swt project . In that i have 1 dialog with 4 buttons.
What i need:
With one Button which is enable if i click then other will enable and this will disable.
And again from other button if i click all other should disable and 1st one should enable.

How I'm doing
Simple way to do this is create one function which invert the visibility. and call that method from widget Selection event.

What i want
Is there is any other way (Standard) to do this like using fireevent.

Thanks

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Re: How enable and disable buttons using event in SWT. [message #1006475 is a reply to message #1006467]

Thu, 31 January 2013 07:45

Simon SSC
Messages: 56
Registered: April 2012
Location: Germany

Member

Hi sumit,

the JFace Databinding might be an alternative :

DataBindingContext dbc = new DataBindingContext();
        Button button1 = new Button(parent, SWT.PUSH);
        Button button2 = new Button(parent, SWT.PUSH);
        ISWTObservableValue observeEnabledButton1 = SWTObservables.observeEnabled(button1);
        ISWTObservableValue observeEnabledButton2 = SWTObservables.observeEnabled(button2);
        
        UpdateValueStrategy updateValueStrategy = new UpdateValueStrategy();
        updateValueStrategy.setConverter(new IConverter() {
            
            @Override
            public Object getToType() {
                return Boolean.TYPE;
            }
            
            @Override
            public Object getFromType() {
                return Boolean.TYPE;
            }
            
            @Override
            public Object convert(Object fromObject) {
                if(fromObject instanceof Boolean){
                    // return inverse to disable the other button
                    return ((Boolean) fromObject).booleanValue() ? Boolean.FALSE : Boolean.TRUE;
                }
                return Boolean.FALSE;
            }
        });
        
        dbc.bindValue(observeEnabledButton1, observeEnabledButton2, updateValueStrategy, updateValueStrategy);

With that solution the enabled state of button1 is always the oppisite of the enabled state of button2 and the other way round.
So with that binding you only need to disable the button you just clicked and the other button will be enabled automatically by the binding.

@see JFace Databinding

Hope that helps and it is what you have asked for.

Best regards,

Simon

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Re: How enable and disable buttons using event in SWT. [message #1006480 is a reply to message #1006475]

Thu, 31 January 2013 08:07

sumit singh
Messages: 73
Registered: October 2012
Location: Bangalore

Member

Thnaks Simon,

I'll try it.

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Re: How enable and disable buttons using event in SWT. [message #1006586 is a reply to message #1006467]

Thu, 31 January 2013 18:43

Simon SSC
Messages: 56
Registered: April 2012
Location: Germany

Member

Hey sumit,

you´re welcome.

If you have any further questions do not hesitate to ask Wink

Best regards,

Simon

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Re: How enable and disable buttons using event in SWT. [message #1006653 is a reply to message #1006586]

Fri, 01 February 2013 05:34

sumit singh
Messages: 73
Registered: October 2012
Location: Bangalore

Member

Hi Simon,
Sorry for asking you again.
I tried your code, at starting time it works means button1 is disable and button2 is enable. But if i click button2 and its listener am disabling it but other button is still in disable mode . I'm putting my code:

Button button1 = new Button(parent, SWT.NONE);
button1.setText("hello");
final Button button2 = new Button(parent, SWT.NONE);
button2.addSelectionListener(new SelectionAdapter() {
		@Override
		public void widgetSelected(SelectionEvent e) {
		     button2.setEnabled(false);
		}
	});
button2.setText("world");
ISWTObservableValue observeEnabledButton1 = SWTObservables.observeEnabled(button1);
ISWTObservableValue observeEnabledButton2 = SWTObservables.observeEnabled(button2);
UpdateValueStrategy updateValueStrategy = new UpdateValueStrategy();
updateValueStrategy.setConverter(new IConverter() {
	@Override
	public Object getToType() {
 	    return Boolean.TYPE;
	}
       @Override
	public Object getFromType() {
	    return Boolean.TYPE;
	}
	@Override
        public Object convert(Object fromObject) {
	    if (fromObject instanceof Boolean) {
	   // return inverse to disable the other button
	        return ((Boolean) fromObject).booleanValue() ? Boolean.FALSE : Boolean.TRUE;
            }
	  return Boolean.FALSE;
	}
});
dbc.bindValue(observeEnabledButton1, observeEnabledButton2, updateValueStrategy, updateValueStrategy);

[Updated on: Fri, 01 February 2013 05:34]

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Re: How enable and disable buttons using event in SWT. [message #1007235 is a reply to message #1006653]

Tue, 05 February 2013 03:16

Simon SSC
Messages: 56
Registered: April 2012
Location: Germany

Member

Hi sumit,

Quote:

Sorry for asking you again.

It is my fault.
Actually there is no enabled listener available for controls, so that you need to bind the selection of the button to the other´s enabled observable.

So this code should do the job Wink

Button button1 = new Button(parent, SWT.NONE);
button1.setText("hello");
Button button2 = new Button(parent, SWT.NONE);
button2.setText("world");
ISWTObservableValue observeSelectionButton1 = SWTObservables.observeSelection(button1);
ISWTObservableValue observeEnabledButton2 = SWTObservables.observeEnabled(button2);
dbc.bindValue(observeSelectionButton1, observeEnabledButton2);

Best regards,

Simon

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