objective c - Modifying Table Headers on Mac

Question

I've been able to find tutorials on modifying the table headers on iOS using UITableView - but havent been able to find any info for mac development. Does anyone know of any good resources / steps to modify the appearance of tables?

Zach

Answer 1

To change how the table headers appear you need to subclass NSTableHeaderCell, perform your own custom drawing in one of its drawing methods, then replace the header cells of each column with an instance of your subclass.

You may also find that you need to subclass NSTableHeaderView to draw the any space where no header cells are visible, and to replace the cornerView of the table view.

This should get you started:

for (NSTableColumn *column in [tableView tableColumns]) {
   [column setHeaderCell:
      [[[MyHeaderCell alloc]
                      initTextCell:[[column headerCell] stringValue]]
                      autorelease]];
}

And here’s a starting point for a subclass of NSTableHeaderCell:

@interface MyHeaderCell : NSTableHeaderCell
{
}
- (void)drawWithFrame:(CGRect)cellFrame
          highlighted:(BOOL)isHighlighted
               inView:(NSView *)view;
@end

@implementation MyHeaderCell

- (void)drawWithFrame:(CGRect)cellFrame
          highlighted:(BOOL)isHighlighted
               inView:(NSView *)view
{
   CGRect fillRect, borderRect;
   CGRectDivide(cellFrame, &borderRect, &fillRect, 1.0, CGRectMaxYEdge);

   NSGradient *gradient = [[NSGradient alloc]
      initWithStartingColor:[NSColor whiteColor]
                endingColor:[NSColor colorWithDeviceWhite:0.9 alpha:1.0]];
   [gradient drawInRect:fillRect angle:90.0];
   [gradient release];

   if (isHighlighted) {
      [[NSColor colorWithDeviceWhite:0.0 alpha:0.1] set];
      NSRectFillUsingOperation(fillRect, NSCompositeSourceOver);
   }

   [[NSColor colorWithDeviceWhite:0.8 alpha:1.0] set];
   NSRectFill(borderRect);

   [self drawInteriorWithFrame:CGRectInset(fillRect, 0.0, 1.0) inView:view];
}

- (void)drawWithFrame:(CGRect)cellFrame inView:(NSView *)view
{
   [self drawWithFrame:cellFrame highlighted:NO inView:view];
}

- (void)highlight:(BOOL)isHighlighted
        withFrame:(NSRect)cellFrame
           inView:(NSView *)view
{
   [self drawWithFrame:cellFrame highlighted:isHighlighted inView:view];
}

@end