Re: Setting checkbox with keyboard

[Andreas Höschler]

Hoi,

> Andreas Höschler wrote:
> > Hi all,
> >
> > I want to have a checkbox in a tableview and be able to tab into it
> > > from the column to its left with the TAB key and then set its state
> > with the keyboard (e.g. the space key, any other would be fine as 
> > well).
> > This is to avoid the need to use the mouse for very efficient data
> > entry. I did
> >
> >               NSButtonCell *buttonCell = [[NSButtonCell alloc]
> > initTextCell:@""];
> >               [buttonCell setButtonType:NSSwitchButton];
> >               [buttonCell setImagePosition:NSImageOnly];
> >               [buttonCell setSelectable:YES];
> >               [buttonCell setEditable:YES];
> >               [tableColumn setDataCell:buttonCell];
> >               [_displayObjects addObject:buttonCell];
> >               [buttonCell release];
> >
> > This allows me to tab into and over the checkbox column on the Mac. 
> > This
> > does not work under GNUstep! Why? I subclasses NSButtonCell
> >
> > @implementation GSButtonCell
> >
> > - (BOOL)acceptsFirstResponder
> > {
> >    BOOL result = [super acceptsFirstResponder];
> >    NSLog(@"%@ acceptsFirstResponder %d", self, result);
> >    return result;
> > }
> >
> > @end
> >
> > and expected acceptsFirstResponder to be called when I try to tab into
> > the column. However, this does not happen under GNUstep!?
>
> Is this method called under Cocoa? What GNUstep currently does when the
> tab key is pressed is to check whether the next cell is editable and if
> so the table view starts to edit that cell.
> I agree that this is not the best behaviour. But what would be correct?
> Check if the cell is selectable? Check the accepts first responder
> state? And then just select the cell? Or edit it, if it is editable and
> just select it if not? Your cell is editable. What sort of editing
> behaviour do you expect from an NSSwitchButton?

I expect anObject in

- (void)tableView:(NSTableView *)aTableView setObjectValue:anObject 
forTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex
{
}

to be [NSNumber numberWithInt:1] when the checkbox is checked and 
either [NSNumber numberWithInt:0] or nil when the checkbox is 
dechecked. On GNUstep I get an NSString that can be interpreted like an 
NSNumber, on the Mac I get an NSCFBoolean instance. I suppose this is 
an NSNumber sublcass. Whatever it is, I need to be able to decide in 
the above method whether the checkbox got checked or dechecked. This 
works on both platforms for mouseclicks. But it works on neither 
platform for key events. On the Mac I get an NSCFBoolean (true) when on 
the switch cell and pressing the space bar. Good so far. However, when 
I tab into the checkbox column with a previously set checkbox, then

- (void)tableView:(NSTableView *)aTableView setObjectValue:anObject 
forTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex

is called with NSCFBoolean (false). I consider this is a bug in Cocoa. 
On GNUstep I currently cannot even tab into the checkbox column. It 
would be great if we could get something sorted out in GNUstep that is 
not correctly implemented in GNUstep. :-)

> And who would get the space key? Normally the NSButton turns that key
> into a click. Should the table view do the same? If so for all cells or
> only for specific ones?
> For the correct behaviour we will need a lot of tests with Cocoa. If 
> you
> are willing to do this test and send in the result, it would be fairly
> easy to implement the correct behaviour.

What exactly do you want me to test?

Until this has been sorted out correctly it would already help a lot, 
if the not selectable checkbox column was simply jumped over when 
tabbing through the row. Currently editing of the row (cells) stops 
when the checkbox column is reached which is not appreciated by users. 
:-)

Regards,

  Andreas