Question

I am using a swipe gesture recognizer to for an IBAction in my iPhone app. I have an image in the middle of the view, and when I swipe to the left, I want the image to move to the left a little bit and then bounce back to its original position, like it is being forced back with a rubber band. Can anyone help me with this? Thanks!

Answer 1

I have used UIView animateWithDuration. I had to nest them in order to have the bouncing, and provided a start and end frame for each.

Here is some hideously ugly code, which may be the best way to do it, but I’m not sure:

CGRect bounceUpFrameFirst = [[UIScreen mainScreen] bounds];
bounceUpFrameFirst.origin.y = bounceUpFrameFirst.origin.y - 30.0;
CGRect bounceUpFrameSecond = [[UIScreen mainScreen] bounds];
bounceUpFrameSecond.origin.y = bounceUpFrameFirst.origin.y - 15.0;
CGRect bounceUpFrameThird = [[UIScreen mainScreen] bounds];
bounceUpFrameThird.origin.y = bounceUpFrameFirst.origin.y - 10.0;
CGRect bounceDownFrame = [[UIScreen mainScreen] bounds];

[UIView animateWithDuration:0.1 animations:^{[wakeView setFrame:bounceUpFrameFirst]; [sleepView setFrame:bounceUpFrameFirst];} completion:^(BOOL finished){[UIView animateWithDuration:0.1 animations:^{[wakeView setFrame:bounceDownFrame]; [sleepView setFrame:bounceDownFrame];} completion:^(BOOL finished){[UIView animateWithDuration:0.1 animations:^{[wakeView setFrame:bounceUpFrameSecond]; [sleepView setFrame:bounceUpFrameSecond];} completion:^(BOOL finished){[UIView animateWithDuration:0.1 animations:^{[wakeView setFrame:bounceDownFrame]; [sleepView setFrame:bounceDownFrame];} completion:^(BOOL finished){[UIView animateWithDuration:0.1 animations:^{[wakeView setFrame:bounceUpFrameThird]; [sleepView setFrame:bounceUpFrameThird];} completion:^(BOOL finished){[UIView animateWithDuration:0.1 animations:^{[wakeView setFrame:bounceDownFrame]; [sleepView setFrame:bounceDownFrame];}];}];}];}];}];}];