NSCollectionView scroll to origin fix

As you know Leopard has this new amazing facility to present complex data on screen. NSCollectionView allows you to lay out some NSViews each representing your data, whereas NSTableView supports only NSCells out of the box.

Anyway if you are thinking about using a NSCollectionView you will be disappointed to discover that the current implementation is very buggy. As pointed out in the linked posts whenever you resize a containing NSWindow the contained NSCollectionView will scroll to its origins (provided that you actually have springed the NSCollectionView to the window).

Fortunately, fixing the “scroll to origin” misbehavior is pretty easy. All you need to do is a NSWindow subclass implementing two delegate methods.

In the definition define an outlet that you will bind to the NSScrollView containing the NSCollectionView you want to resize properly. Moreover define an NSPoint to store the original position of the NSCollectionView in the NSScrollView.

@interface PGZWindow : NSWindow {

	IBOutlet NSScrollView * scrollView;
	NSPoint pos;


@property (retain) IBOutlet NSScrollView * scrollView;
- (void)windowDidResize:(NSNotification *)notification;
- (NSSize)windowWillResize:(NSWindow *) window toSize:(NSSize)newSize;


In the implementation you just store the position before the resize, and set it after the resize is completed. Note that you need to set the delegate to self or windowDidResize: will not be called (the mysteries of cocoa…).

@implementation PGZWindow
@synthesize scrollView;

- (void) awakeFromNib
	[self setDelegate:self];

- (NSSize)windowWillResize:(NSWindow *) window toSize:(NSSize)newSize
	NSPoint new_pos = [[scrollView contentView] bounds].origin;
	if(new_pos.x > 0.0 || new_pos.y > 0.0){
		self->pos = new_pos;

- (void)windowDidResize:(NSNotification *)notification
	NSPoint new_pos = [[scrollView contentView] bounds].origin;
	if(new_pos.x > 0.0 || new_pos.y > 0.0){
		self->pos = new_pos;
	} else {
		[[scrollView contentView] scrollToPoint:self->pos];
		[scrollView reflectScrolledClipView: [scrollView contentView]];
	self->pos = NSMakePoint(0.0, 0.0);


Thank you for reading and enjoy your resizing NSCollectionView. Cheers :)



  1. jay said

    nahi ye galat hai

RSS feed for comments on this post · TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: