#uigesturerecognizer

The base class is abstract, we only actually use concrete subclasses.

1. Need to add a gesture recognizer to a UI View. (this is usually done by controller —> when should we do this?, but sometimes we can do this in the storyboard)

2. Provide a method to “handle” the gesture. Callback given to gesture. (Provided by the UIView or the Controller, depends). If gesture modifies model, then controller. If gesture only modifies UI, then the callback is in the view.

Add this in didSet for an outlet of a view. 

Fixed UILongPressGestureRecognizer gets called twice when pressing down #dev #it #asnwer

UILongPressGestureRecognizer gets called twice when pressing down

I am detecting if the user has pressed down for 2 seconds:

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)]; longPress.minimumPressDuration = 2.0; [self addGestureRecognizer:longPress]; [longPress release];

This is how I handle the long press:

How to: Can you attach a UIGestureRecognizer to multiple views?

Can you attach a UIGestureRecognizer to multiple views?

UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapTapTap:)]; [self.view1 addGestureRecognizer:tapGesture]; [self.view2 addGestureRecognizer:tapGesture]; [tapGesture release];

In the above code only taps on view2 are recognized. If I comment out the third line then taps on view1are…

How to: UIGestureRecognizer on UIImageView

UIGestureRecognizer on UIImageView

I have a UIImageView, which I want to be able to resize and rotate etc.

Can a UIGestureRecognizer be added to the UIImageView?

I would want to add a rotate and pinch recognizer to a UIImageView which would be created at runtime.

How does one add these recognizers?

Answer: UIGestureRecognizer on UIImageView

Check that userInteractionEnabled is YES on the…

How to: How to disable back swipe gesture in UINavigationController on iOS 7

How to disable back swipe gesture in UINavigationController on iOS 7

In iOS 7 Apple add new default navigation behavior. You can swipe from left border of the screen to go back on navigation stack. But in my app, this behavior conflict with my custom left menu. So, is it possible to disable this new gesture in UINavigationController?

Answer: How to disable back swipe gesture in…

How to: UILongPressGestureRecognizer gets called twice when pressing down

UILongPressGestureRecognizer gets called twice when pressing down

I am detecting if the user has pressed down for 2 seconds:

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)]; longPress.minimumPressDuration = 2.0; [self addGestureRecognizer:longPress]; [longPress release];

This is how I handle the long press: