NSScrollView doesn't scroll when adding NSSegmentedControl

Question

I have an empty NSScrollView created with Interface Builder.

And in my code I add, upon a user click, a NSSegmentedControl. For all the next clicks, I add a segment to it.

My problem is that, once I reach the visual limit of NSScrollView, it doesn't start to scroll and all the post-limit segments are never shown.

This is the NSScrollView from Interface Builder :

And here is the method :

- (IBAction)addSegment:(id)sender
{
    if (segCtrlColumns == nil) {
        segCtrlColumns = [[NSSegmentedControl alloc] initWithFrame:[self.viewColumns frame]]; //self.viewColumns is the NSScrollView from IBOutlet
        [segCtrlColumns setSegmentCount:1];
        [segCtrlColumns setLabel:@"Test" forSegment:0];
        [segCtrlColumns setTarget:self];
    } else {
        double increaseSegments = [segCtrlColumns segmentCount]+1;
        [segCtrlColumns setSegmentCount:increaseSegments];
        [segCtrlColumns setLabel:@"Test" forSegment:increaseSegments-1];
    }
    [self.viewColumns setDocumentView:segCtrlColumns];
}

And here is the problem :

(Well it is more likely "nothing to scroll" than "not scrollable")

Answer 1

Okay, I did a few tests and the problem is not the nsscrollview but the nssegmentedcontrol. It doesn't update its frame size at all. So it is stuck at the width I set in the initWithFrame - which was the size of the scrollView. (And this is why NSScrollView never started to scroll)

I never found an easy way on how to get the real size (updated size) of NSSegmentedControl as more segments are added, so I did this trick :

• I forced all my segments to be at the same size (100 points width)
• As I append segments, I update the NSSegmentedControl's frame by an other 100 points

here is the code :

-(IBAction)addColumn:(id)sender
{
    if (segCtrlColumns == nil) {
        //Init with a single segment with 100 points (pixels) width
        segCtrlColumns = [[NSSegmentedControl alloc] initWithFrame:NSMakeRect(0, 0, 100.0, 30.0)];
        [segCtrlColumns setSegmentCount:1];
        [segCtrlColumns setWidth:96.0 forSegment:0]; //The segment has some borders to concider in its size
        [segCtrlColumns setLabel:@"Testing" forSegment:0];
        [segCtrlColumns setTarget:self];
        //Tell the scrollview, the documentView is my segmented control
        [self.viewColumns setDocumentView:segCtrlColumns];
    } else {
        //Add a segment and update the frame size
        double increaseSegments = [segCtrlColumns segmentCount]+1;
        [segCtrlColumns setFrame:NSMakeRect(0, 0, segCtrlColumns.frame.size.width+100.0, 30.0)];
        [segCtrlColumns setSegmentCount:increaseSegments];
        [segCtrlColumns setWidth:96.0 forSegment:increaseSegments-1];
        [segCtrlColumns setLabel:@"Testing" forSegment:increaseSegments-1];
    }
}

The only problem here is that all the segments are at the same size and not dynamic...