Question

I’d like a custom gesture so that if the user slides his/her finger up from the bottom of the screen it displays a scroll view that occupies the bottom fourth of the screen. Similarly, to close the view, the user slides his/her finger downwards off the screen. I am mostly having trouble figuring out how to connect the gesture with the animation so that the view slides up and down as the user moves his/her finger.

Answer 1

Assume you have two views, self.view and self.scrollView. self.scrollView is a sub-view inside self.view.

Then place self.scrollView offscreen.

Register drag events for both views:

[self.view addTarget:self action:@selector(mainViewMoved:withEvent:) forControlEvents:UIControlEventTouchDragInside];
[self.scrollView addTarget:self action:@selector(scrollViewMoved:withEvent:) forControlEvents:UIControlEventTouchDragInside];

Do whether view movement required in mainViewMoved:withEvent (bring up scrollView) and scrollViewMoved:withEvent (move itself up/down) handlers based on the touch movements.

More info in this question.