maximumZoomScale

MaximumZoomScale is a numeric property that defines the largest zoom factor allowed for zoomable content in many user interface toolkits. It sets an upper bound on the current zoom level, typically used with scrollable or pan-zoom containers. When a user performs pinch-zoom gestures or when code changes the zoom level programmatically, the resulting zoom scale will be clamped to the range between minimumZoomScale and maximumZoomScale.

In iOS, maximumZoomScale is a property of UIScrollView (type CGFloat). The default is 1.0. It should be greater than or equal to minimumZoomScale, otherwise zooming behavior is undefined or disabled. The complementary property minimumZoomScale defines the lower bound. If maximumZoomScale equals 1.0, the view cannot be zoomed beyond its original size.

Setting maximumZoomScale to a value larger than the content can effectively zoom in until the content size or constraints stop further zooming. Practically, ensure contentSize is appropriate and that the view for zooming is configured; in iOS, the delegate method viewForZoomingInScrollView must be implemented to enable zooming.

Programmatically, use setZoomScale:animated: with a value within the allowed range to change the zoom without user gestures.

Example: a scroll view with minimumZoomScale = 0.5 and maximumZoomScale = 4.0 allows zoom from half size to four times the original.

Interaction considerations: zooming is often constrained by the content size and the layout of subviews; extremely high maximumZoomScale values can hurt performance.