I’ve made a sample program in which an NSTableView has two columns – one has sliders, and the other displays the value of the slider.

Here’s an example if my description isn’t clear http://home.earthlink.net/~zakariya/files/SliderTable.jpg

I’m using a custom NSTableColumn and have overridden the dataCellForRow: method to forward data cell requests to my dataSource, since eventually I’ll be using different types of cells on a per row basis, according to need. Right now I’m only using sliders, however.

• (id)dataCellForRow:(int)row { if (row >= 0) { return [self tableView] dataSource] tableView: [self tableView] objectValueForTableColumn: self row: row]; }

  return nil; }

the actual source for my controller and dataSource is as such: Note that the vars [[ValueID and CellID are global, static NSString pointers.

• (void) awakeFromNib { NSTableColumn *column;

  //create value display column column = [[NSTableColumn alloc] initWithIdentifier: ValueID]; [column setWidth: 50]; [column setResizable: NO]; column headerCell] setStringValue: [[ValueID]; [tableView addTableColumn: column];

  //create slider column column = [[MyTableColumn alloc] initWithIdentifier: CellID]; [column setWidth: [tableView bounds].size.width - 50]; [column setResizable: YES]; column headerCell] setStringValue: [[CellID]; [tableView addTableColumn: column];

  [tableView sizeLastColumnToFit];

  //create slider cell sliderCell = [[NSSliderCell alloc] init]; [sliderCell setMinValue: -5]; [sliderCell setMaxValue: 5]; [sliderCell setControlSize: NSSmallControlSize]; [sliderCell setNumberOfTickMarks: 20]; [sliderCell setContinuous: YES]; [sliderCell setAction: @selector( onSliderCell: )]; [sliderCell setTarget: self];

  //now make some fake values values = [[NSMutableArray alloc] init]; int i; for (i = 0; i < 10; i++) { [values addObject: [NSNumber numberWithFloat: ((float) i) - 5.0]]; }

}

• (void) dealloc { [values release]; }

/* Table Data Source Methods */

• (int)numberOfRowsInTableView: (NSTableView *)aTableView { return [values count]; }

• (id)tableView: (NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex { if (rowIndex < 0) return nil;

  NSString *identifier = [aTableColumn identifier]; if ([identifier isEqualToString: ValueID]) { return [values objectAtIndex: rowIndex]; } else if ([identifier isEqualToString: CellID]) { [sliderCell setFloatValue: values objectAtIndex: rowIndex] floatValue; return sliderCell; }

  return nil; }

• (void)tableView: (NSTableView *)aTableView setObjectValue:(id)anObject forTableColumn:(NSTableColumn *)aTableColumn row:(int)rowIndex { [values replaceObjectAtIndex: rowIndex withObject: anObject]; [tableView reloadData]; }

/* Cell callback */

• (void) onSliderCell: (id) sender { NSLog( @”sender: %@;\tslider floatValue: %.2f”, sender, [sliderCell floatValue]); }

Basically, this works. You drag the slider, and when you let go, the values column updates to show the change. BUT, the feedback isn’t live. E.g., the NSLog statement in onSliderCell: shows [sliderCell floatValue] as static – as whatever it was at mousedown. I need live feedback, since these sliders are meant to tune a realtime simulation.

It seems to me that the call to setContinuous on sliderCell should have fixed this, but it doesn’t.

Am I missing something obvious here?

–ShamylZakariya

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I hope this the proper way to respond (new member).

I’m just starting to use tableviews, and one of the things I want to do is very close to your code above. Question: what does the double bracket notation variable mean? Where does it come from? I have not seen it in objective C. Possible speedup suggestion: Would KVC bindings, perhaps to an ivar, help?

nnickk