NSScrollview not scrolling programmatically?

Question

Note:Both Horizontal and vertical scrollers are visible on the screen and work fine.But I cant make them move Programatically.

I am working on a cocoa desktop application.I am using the NSScrollview in my Mainmenu.xib file and I am creating an outlet in its owner which is Appdelegate.h . Here is the outlet

@property(nonatomic,retain) IBOutlet NSScrollView* scrollview;

When I try to set a new referencing outlet of my NSScrollview from the interface builder and take the line to file's owner I only see one option "delegate".I dont see the outlet scrollview. So I connect the scrollview to the delegate in file's owner (As I cant see the scrollview outlet).

Now I am trying to do auto scrolling in my code.Here is the code

for(int a=0;a<10000;a++)
{
    NSPoint pointToScrollTo = NSMakePoint ( 100+a,100+a );  // Any point you like.
    [[self.scrollview contentView] scrollToPoint: pointToScrollTo];
    [self.scrollview reflectScrolledClipView: [self.scrollview contentView]];
}

This code does not work and The scroller does not scroll automatically.

I am trying to make a slow scrolling animation with this code.

Answer 1

NSClipView has a scrollToPoint: method which can be used to scroll programmatically:

- (IBAction)scrollToMid:(id)sender
{
    CGFloat midYPoint = [self.scrollView contentView].frame.size.height/2.0;
    [[self.scrollView contentView] scrollToPoint:NSMakePoint(0.0, midYPoint)];
    [self.scrollView reflectScrolledClipView:[self.scrollView contentView]];
}

If you want animated scrolling, you have to set the boundsOrigin via animator proxy. (Because neither NSScrollView nor NSClipView expose an animatable scroll point property)

- (IBAction)scrollToMidAnimated:(id)sender
{
    [NSAnimationContext beginGrouping];
    [[NSAnimationContext currentContext] setDuration:2.0];
    NSClipView* clipView = [self.scrollView contentView];
    NSPoint newOrigin = [clipView bounds].origin;
    newOrigin.y = [self.scrollView contentView].frame.size.height/2.0;
    [[clipView animator] setBoundsOrigin:newOrigin];
    [NSAnimationContext endGrouping];
}

Answer 2

Better way to get this, flip the view. I have worked on this to get the scroll view to top.

-(void)scrollToTop:(NSScrollView *)scrollView
{
    NSPoint newScrollOrigin;
    if ([[scrollView documentView] isFlipped]) {
        newScrollOrigin=NSMakePoint(0.0,0.0);
    } else {
        newScrollOrigin=NSMakePoint(0.0,NSMaxY([[scrollView documentView] frame]) -NSHeight([[scrollView contentView] bounds]));
    }

    [[scrollView documentView] scrollPoint:newScrollOrigin];
}

That should be called in windowDidLoad to get the position .

-(void)windowDidLoad
{
    [super windowDidLoad];
    [self scrollToTop:_myScroll];
}