prevent panning beyound the RHS of superview
calculate maximum x pan
calculate minimum x pan
DraggableView - Restrict movement within parent bounds
add explanation for restricting pan to parent bounds,
panWithTransform - buggy
try removing constraints
Creating a view which pans by adjusting its transform in the storyboard causes constraints to interfere and make it jump back to the original position on pan end.
tidy
drag, pinch-zoom and rotate a view. Three taps resets it
add drawing view