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UIGestureRecognizer movements restrictions


I want to know if there is a way to restrict the size or movements of the UIViews in the GestureRecognizers. Sure I could write my own restriction code but wana know if we can set some property or something to have some bound limits.



For example in UIPanGestureRecognizer I want to restrict the movement of the view added to PanGesture within a particular CGRect, so is there any way I can set that bounding rect so on sensing PanGesture if the view is going out of my bounding frame it wont allow it.


Source: Tips4allCCNA FINAL EXAM

Comments

  1. as far as I am aware you have to write that yourself.

    tap gestures let you set how many taps you are responding to with how many fingers, but most of them do not provide a lot of helpers.

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  2. I think the simplest way to accomplish this is to create an invisible view in that rect and add the gesture to it.
    Example:
    You want to detect the movement in view X inside the rect {a,b,c,d}.
    Create a UIView Y in the {a,b,c,d} rect. Set it's background color to clearColor.
    Create the gesture recognizer and add it to the Y view.
    In the gesture's selector do something like this:

    - (void) selector:(UIPanGestureRecognizer *) gesture
    {
    UIView *viewX = [self.view viewWithTag:kTagViewX];
    //now you know that the gesture took place and you have access to your view
    }


    If you need to change the rect in which you want the gesture to be active , just move the Y view and voila!

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