NSTableView subclass to handle being printed and paginated properly

PaginatedTable.m

#import <Cocoa/Cocoa.h>

@interface PaginatedTable : NSTableView {
  NSMutableArray *topBorderRows;
  NSMutableArray *bottomBorderRows;
}
@end

@implementation PaginatedTable

// Taken from here: http://lists.apple.com/archives/cocoa-dev/2002/Nov/msg01710.html
// Ensures rows in the table aren't cut off when printing
- (void)adjustPageHeightNew:(CGFloat *)newBottom top:(CGFloat)oldTop bottom:(CGFloat)oldBottom limit:(CGFloat)bottomLimit {
  if (!topBorderRows) {
    topBorderRows = [NSMutableArray array];
    bottomBorderRows = [NSMutableArray array];
  }
  
  int cutoffRow = [self rowAtPoint:NSMakePoint(0, oldBottom)];
  NSRect rowBounds;
  
  *newBottom = oldBottom;
  if (cutoffRow != -1) {
    rowBounds = [self rectOfRow:cutoffRow];
    if (oldBottom < NSMaxY(rowBounds)) {
      *newBottom = NSMinY(rowBounds);
      
      NSNumber *row = [NSNumber numberWithInt:cutoffRow];
      NSNumber *previousRow = [NSNumber numberWithInt:cutoffRow - 1];
      
      // Mark which rows need which border, ignore ones we've already seen, and adjust ones that need different borders
      if (![[topBorderRows lastObject] isEqual:row]) {
        if ([[bottomBorderRows lastObject] isEqual:row]) {
          [topBorderRows removeLastObject];
          [bottomBorderRows removeLastObject];
        }
        
        [topBorderRows addObject:row];
        [bottomBorderRows addObject:previousRow];
      }
    }
  }
}

// Draw the row as normal, and add any borders to cells that were pushed down due to pagination
- (void)drawRow:(NSInteger)rowIndex clipRect:(NSRect)clipRect {
  [super drawRow:rowIndex clipRect:clipRect];
  
  if ([topBorderRows count] == 0) return;
  
  NSRect rowRect = [self rectOfRow:rowIndex];
  NSBezierPath *gridPath = [NSBezierPath bezierPath];
  NSColor *color = [NSColor darkGrayColor];
  
  for (int i=0; i<[topBorderRows count]; i++) {
    int rowNeedingTopBorder = [(NSNumber *)[topBorderRows objectAtIndex:i] integerValue];
    if (rowNeedingTopBorder == rowIndex) {
      [gridPath moveToPoint:rowRect.origin];
      [gridPath lineToPoint:NSMakePoint(rowRect.origin.x + rowRect.size.width, rowRect.origin.y)];
      
      [color setStroke];
      [gridPath stroke];
    }
    
    int rowNeedingBottomBorder = [(NSNumber *)[bottomBorderRows objectAtIndex:i] integerValue];
    if (rowNeedingBottomBorder == rowIndex) {
      [gridPath moveToPoint:NSMakePoint(rowRect.origin.x, rowRect.origin.y + rowRect.size.height)];
      [gridPath lineToPoint:NSMakePoint(rowRect.origin.x + rowRect.size.width, rowRect.origin.y + rowRect.size.height)];
      
      [color setStroke];
      [gridPath stroke];
    }
  }
}
@end