CGPoint relative to view

Question

Consider a screen point (CGPoint) and a view (UIView), which is somewhere inside the view hierarchy (it can be a subview of other views).

How can you convert the point to a point relative to the view's coordinates?

Answer 1

First, convert the point from screen coordinates to the coordinates of your main window:

UIWindow *mainWindow = [[UIApplication sharedApplication] keyWindow]; CGPoint pointInWindowCoords = [mainWindow convertPoint:pointInScreenCoords fromWindow:nil]; 

Second, convert the point from window coords to view coords:

CGPoint pointInViewCoords = [myView convertPoint:pointInWindowCoords fromView:mainWindow];