How to change NSTableView header background color in MAC OS X app?

Create the NSTableHeaderCell like below and play with the header cell's frame sizes and origins:

#import <Cocoa/Cocoa.h>

@interface CustomTableHeaderCell : NSTableHeaderCell {
    NSMutableDictionary *attrs;
}

#import "CustomTableHeaderCell.h"

@implementation CustomTableHeaderCell

- (id)initTextCell:(NSString *)text
{
    if (self = [super initTextCell:text]) {

        if (text == nil || [text isEqualToString:@""]) {
            [self setTitle:@"One"];
        }

        /* old_
        self.textColor = [NSColor blackColor];
         */
        // new_
        self.textColor = [NSColor whiteColor];


        attrs = [[NSMutableDictionary dictionaryWithDictionary:
                  [[self attributedStringValue]
                   attributesAtIndex:0
                   effectiveRange:NULL]]
                 mutableCopy];
//        self.font = [NSFont fontWithName:appleeH8GhKr0 size:12];
        return self;
    }
    return nil;
}

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

    // sets the origin and frame for header's title
//    fillRect.size.height = 25;

    if (fillRect.origin.x == 0)
    {
//        fillRect.origin.y += 5;
       // for adding left margin to first column title try to add spaces in text of header title
       // try to play with the numbers of fillRect rect
    }
    else if (fillRect.origin.x == 239)
    {
//        fillRect.size.width  -= 80;
    }

    // setting the background color of tableview's header view
    NSGradient *gradient = [[NSGradient alloc]
                            initWithStartingColor:[NSColor greenColor]
                            endingColor:[NSColor greenColor]];
    [gradient drawInRect:NSRectFromCGRect(fillRect) angle:90.0];
    [self drawInteriorWithFrame:NSRectFromCGRect(CGRectInset(fillRect, 0.0, 1.0)) inView:view];
 }


- (NSRect)adjustedFrameToVerticallyCenterText:(NSRect)frame
{
    // super would normally draw text at the top of the cell
    NSInteger offsetY = floor((NSHeight(frame) -
                              ([[self font] ascender] - [[self font] descender])) / 2);
    return NSInsetRect(frame, 20, offsetY);
}

-(void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView{
    [super drawInteriorWithFrame:[self adjustedFrameToVerticallyCenterText:cellFrame]
                          inView:controlView];
}

- (void)drawWithFrame:(NSRect)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];
}

Set the header cell for column like below:

NSArray *columns = nil;
    if(self.tblVc)
        columns = [self.tblVc tableColumns];
    NSEnumerator *cols = [columns objectEnumerator];
    NSTableColumn *col = nil;
    CustomTableHeaderCell *headerCell;

    while (col = [cols nextObject]) {
        NSString *key = [[col headerCell] stringValue];
        headerCell = [[CustomTableHeaderCell alloc]
                      initTextCell:key];

        NSRect rectHeader =self.tblVc.headerView.frame;
        rectHeader.size.height = 25;
        self.tblVc.headerView.frame=rectHeader;

        [col setHeaderCell:headerCell];
    }

and use disclosure button on top of table view's header like below:

It will show the results like this:

I don't find other ways to do it, just have to draw everything. Hope it's helpful.

CGRect outCellFrame;

- (void) drawWithFrame:(NSRect)cellFrame inView:(NSView *)controlView;
   {
   // <C> this only sets the interior bgColor leaving the borders in standard       color
   outCellFrame = cellFrame;
   [super drawWithFrame:cellFrame inView:controlView];
      // <C> this draws the red bg as expected but doesn't show the interior;
   //

   // <C> this draws the red bg as expected but
   //     1) doesn't layout the interior well (I could fix this);
   //     2) doesn't show the sort controls (it's over-drawn with the code bellow);
   //
   //    [NSColor.redColor setFill];
  //    NSRectFill(cellFrame);
  //    CGRect titleRect = [self titleRectForBounds:cellFrame];
  //    [self.attributedStringValue drawInRect:titleRect];
}

 -(NSRect *) outer:(NSRect)rect fromInner: (NSRect)innerRect {
   NSRect * list =  (NSRect *)  malloc(sizeof(rect) * 4);
   NSRect rem;
  NSDivideRect(rect, &list[0], &rem,  innerRect.origin.x - rect.origin.x,    NSRectEdgeMinX);

    NSDivideRect(rect, &list[1], &rem, - innerRect.origin.x - innerRect.size.width + rect.origin.x + rect.size.width , NSRectEdgeMaxX);
    NSDivideRect(rect, &list[2], &rem, innerRect.origin.y - rect.origin.y, NSRectEdgeMinY);
    NSDivideRect(rect, &list[3], &rem,  -innerRect.origin.y - innerRect.size.height + rect.origin.y + rect.size.height  , NSRectEdgeMaxY);
    return list;
 }

  -(void) updateBackground:(CGRect) cellFrame and:(CGRect) innerCellFrame{
  [self.backgroundColor set];
  NSRect * list = [self outer:cellFrame fromInner:innerCellFrame];
  NSRectFillListUsingOperation(list, 4, NSCompositingOperationSourceOver);
 free(list);}



  - (void) drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView;
   {

      [self updateBackground:outCellFrame and:cellFrame];
     [super drawInteriorWithFrame:cellFrame inView:controlView];


    }






  - (void) drawSortIndicatorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView ascending:(BOOL)ascending priority:(NSInteger)priority;
  {
      [self.backgroundColor set];


     NSImage * image = ascending ?  [NSImage imageNamed:@"NSDescendingSortIndicator"]:[NSImage imageNamed:@"NSAscendingSortIndicator"] ;
     // use your image here.  If you need to change color, try to make a colored templated image here.

     CGRect frame = [self sortIndicatorRectForBounds:cellFrame];
    [self.backgroundColor set];
    CGRect res = NSMakeRect(frame.origin.x, cellFrame.origin.y,  cellFrame.size.width - frame.origin.x, cellFrame.size.height);
    NSRectFillUsingOperation(res , NSCompositingOperationSourceOver);

    [NSColor.blueColor setFill];
    [NSColor.blueColor setStroke];
    [image drawInRect: [self sortIndicatorRectForBounds:frame]];

 }

Thanks guys for your help. I've ended up with this simple solution which also solves the sort indicators. I've gave up on custom NSHeaderCell and resolved everything in single custom NSTableHeaderRowView method:

- (void)drawRect:(NSRect)dirtyRect
{
    [NSGraphicsContext saveGraphicsState];

    // Row: Fill the background
    //
    [NSColor.whiteColor setFill];
    const CGRect headerRect = CGRectMake(0.0, 1.0, self.bounds.size.width, self.bounds.size.height-1.0);
    [[NSBezierPath bezierPathWithRect:headerRect] fill];

    // Columns
    //
    for (NSUInteger i = 0; i < self.tableView.numberOfColumns; ++i) {
        NSRect rect = [self headerRectOfColumn:i];

        // separator on left
        //
        if (i != 0) {
            [[NSColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.35] setFill];
            [[NSBezierPath bezierPathWithRect:NSMakeRect(rect.origin.x, rect.origin.y+4.0, 1.0, rect.size.height-8.0)] fill];
        }

        NSTableColumn *tableColumn = self.tableView.tableColumns[i];
        NSSortDescriptor *col_sd = tableColumn.sortDescriptorPrototype;
        NSTableHeaderCell *tableHeaderCell = tableColumn.headerCell;

        // text
        //
        NSString *columnText = tableHeaderCell.stringValue;
        [columnText drawInRect:NSInsetRect(rect, 5.0, 4.0) withAttributes:nil];

        // sort indicator
        //
        for (NSInteger priority = 0; priority < self.tableView.sortDescriptors.count; ++priority) {
            NSSortDescriptor *sortDesciptor = self.tableView.sortDescriptors[priority];
            // <C> there is no way to get column from sortDesciptor so I use this trick comparing sortDesciptor with current column.sortDescriptorPrototype;
            // <C> not sure why sel_isEqual() dosn't work so I compare its string representation;
            if ([NSStringFromSelector(sortDesciptor.selector) isEqualToString:NSStringFromSelector(col_sd.selector)] == YES && [sortDesciptor.key isEqualToString:col_sd.key] == YES) {
                SDEBUG(LEVEL_DEBUG, @"sort-hdr", @"MATCH: sel=%@", NSStringFromSelector(sortDesciptor.selector));
                // <C> default implementation draws indicator ONLY for priority 0; Otherwise the indicator would have to graphically show the prio;
                // <C> it is a support for multi-column sorting;
                // <REF> shall you need it: https://stackoverflow.com/questions/46611972/sorting-a-viewbased-tableview-with-multiple-sort-descriptors-doesnt-work
                [tableHeaderCell drawSortIndicatorWithFrame:rect inView:self ascending:sortDesciptor.ascending priority:priority];
            }
        }
    }

    [NSGraphicsContext restoreGraphicsState];
}