IOS/Objective-C: Call Hit Test Method On View

Question

I cannot find in the documentation how you call the hit test method? Is it called automatically as a delegate method? Or how would you call it? When I put the following code in a VC, it does not fire when you load or tap on the view. Thanks for any suggestions.

  - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
    {
NSLog(@"hit test firing");
       return self.view;
    }

It is a `UIView` method, not a `UIViewController` method. You can call it whenever you like. — Paulw11, Jan 14 '18 at 22:19
You would call it via `[someUIViewObject hitTest:pointYouWantToTest, withEvent: nil]`, but as per my comment on the answer, explain what you are actually trying to do. — Paulw11, Jan 15 '18 at 00:44
This previous question explains goal in more detail. I thought first step would be just to get method to fire.https://stackoverflow.com/questions/48251450/ios-objective-c-pass-touch-event-on-scrollview-to-view-below-using-hittouch — user6631314, Jan 15 '18 at 03:32
It called automatically.To understand the working of Hit test go through this document: http://smnh.me/hit-testing-in-ios/ — Pallavi Srikhakollu, Jan 15 '18 at 07:06
Ok, if it is called automatically, where would I place above method so that it fires? - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event { NSLog(@"hit test firing"); return self.view; } I tried placing it in viewdidload of VC, view willappear and so forth and it did not fire. I want to add some additional code but first step is to get it to fire at all. — user6631314, Jan 15 '18 at 14:28

score 1 · Accepted Answer · answered Jan 14 '18 at 22:44

1

It is a method on UIView, here is the documentation: https://developer.apple.com/documentation/uikit/uiview/1622469-hittest

It will be called automatically by the system to determine which view has been tapped. You can override it if you want custom functionality.

answered Jan 14 '18 at 22:44

Ric Santos

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So if I put that method in a viewcontroller, it should get called automatically? Right now, it is not firing. – user6631314 Jan 14 '18 at 23:22
It will never be called for a UIViewController. It is a method on UIView, so it will only be called for UIView and its subclasses. – EricS Jan 14 '18 at 23:35
Where in the app should I place the code so that the NSLog statement will print out? I want to verify that it is getting called. – user6631314 Jan 14 '18 at 23:54
1

You would need to add it to a `UIView` subclass. If you haven't created any `UIView` subclasses that are in your view then there is nowhere you can add it. I think, perhaps, you have an X-Y problem here. What are you actually trying to achieve? If you want to record taps on your view controller's base view then you will need to add a tap gesture recogniser to it. – Paulw11 Jan 15 '18 at 00:43
I have a scrollview that is overlapping the bottom of a textview and absorbing touch events. There is a gesturerecognizer on both the scrollview for scrolling and the textview for touch events. Have already used canceltouchesinView = NO. I think I need to add hittest code so that the taps pass through to the textview. But have not been able to figure out where to put hittest code. I guess I have to create a category for scrollview? – user6631314 Jan 15 '18 at 03:25

IOS/Objective-C: Call Hit Test Method On View

1 Answers1