gistfile1.m

/**
 * Allow hiding of disclosure triangles.
 * Taken from:
 *
 * http://blog.petecallaway.net/?p=11
 */
- (NSRect)frameOfOutlineCellAtRow:(NSInteger)row;
{
    BOOL showTriangle = YES;
    
    SEL selector = @selector(bm_outlineView:shouldShowDisclosureTriangleForItem:);
    if ([[self delegate] respondsToSelector: selector])
    {
        id item = [self itemAtRow: row];
        showTriangle = [[self delegate] bm_outlineView: self
                   shouldShowDisclosureTriangleForItem: item];
    }
    
    if (showTriangle)
        return [super frameOfOutlineCellAtRow: row];
    else
        return NSZeroRect;
}