Question

I am trying to draw an image into a UIView subclass overriding drawRect. This image drawing class needs moving and zooming capabilities, so I made it a subview of a scrollview.

My problem is that my image seems to get cropped, either by the screen or the scrollView bounds (the image is larger than the screen). I don’t have a clue why, this seems to e pretty basic stuff.

The view hierarchy in my ViewController looks like this:

View Controller
  View
    ScrollView
      MapView

I’ve created outlets for the scroll view and the map view (which is the view implementing drawRect).

My ViewController initial setup code for configuring the scroll view looks like this:

- (void)viewDidLoad
{
    [super viewDidLoad];
    scrollView.delegate = self; 
    scrollView.contentSize = CGSizeMake(450, 476);
    scrollView.minimumZoomScale = 0.6;
    scrollView.maximumZoomScale = 6.0;
}

My drawRect implementation:

- (void)drawRect:(CGRect)rect
{ 
    UIImage *myImage = [UIImage imageNamed:@"map.jpg"];
    CGRect rectangle = CGRectMake(0,0,450,476);
    [myImage drawInRect:rectangle];
}

The image is draggable and zoomable within the scroll view, but it’s cropped at what seems to be the screen bounds.

Any help would be appreciated.

Answer 1

drawRect can’t draw outside the rect passed as a parameter to the drawRect method, which is determined by the view frame. Make your view 1200,1200 and make sure that clipToBounds is disabled on all the containing views.