ITTabView.m

#import "ITTabView.h"

@interface NSTabViewItem (ITTabViewHacks)
- (NSRect)_tabRect;
@end

@implementation ITTabView

- (id)initWithFrame:(NSRect)frame {
	if ((self = [super initWithFrame:frame])) {
		_draggedTab = nil;
		_allowsDragging = NO;
		_requiredModifiers = NSCommandKeyMask;
	}
	return self;
}

- (void)setAllowsDragging:(BOOL)flag {
	_allowsDragging = flag;
}

- (BOOL)allowsDragging {
	return _allowsDragging;
}

- (void)setRequiredModifiers:(unsigned int)modifiers {
	_requiredModifiers = modifiers;
}

- (unsigned int)requiredModifiers {
	return _requiredModifiers;
}

- (void)moveTab:(NSTabViewItem *)tab toIndex:(int)index {
	int oldIndex = [self indexOfTabViewItem:tab];
	if ((oldIndex != NSNotFound) && (oldIndex != index)) {
		[tab retain];
		[self removeTabViewItem:tab];
		[self insertTabViewItem:tab atIndex:index];
		[self selectTabViewItem:tab];
		[tab release];
	}
}

- (void)mouseDown:(NSEvent *)event {
	if ((_requiredModifiers == 0 || ([[NSApp currentEvent] modifierFlags] & _requiredModifiers)) && [self allowsDragging]) {
		NSPoint clickedPoint;
		clickedPoint = [self convertPoint:[event locationInWindow] fromView:[[self window] contentView]];
		NSTabViewItem *clickedTab = [self tabViewItemAtPoint:clickedPoint];
		_draggedTab = clickedTab;
	}
	[super mouseDown:event];
}

- (void)mouseUp:(NSEvent *)event {
	if (_draggedTab && [self allowsDragging]) {
		NSPoint releasedPoint = [self convertPoint:[event locationInWindow] fromView:[[self window] contentView]];
		NSTabViewItem *releasedTab = [self tabViewItemAtPoint:releasedPoint];
		if (releasedTab && ![releasedTab isEqualTo:_draggedTab]) {
			[self moveTab:_draggedTab toIndex:[self indexOfTabViewItem:releasedTab]];
		}
		_draggedTab = nil;
	}
	[super mouseUp:event];
}

- (void)mouseDragged:(NSEvent *)event {
	if (_draggedTab && [self allowsDragging]) {
		NSPoint currentPoint = [self convertPoint:[event locationInWindow] fromView:[[self window] contentView]];
		NSTabViewItem *curTab = [self tabViewItemAtPoint:currentPoint];
		if (curTab && ![curTab isEqualTo:_draggedTab]) {
			[self moveTab:_draggedTab toIndex:[self indexOfTabViewItem:curTab]];
			[self selectTabViewItem:_draggedTab];
		}
	}
	[super mouseDragged:event];
}

@end