Enable UIPanGestureRecognizer when did longPress - ios

Question

I'd like to enable UIPanGestureRecognizer on customView when the customView did longPress.
(I wish when you longPress customView, the customView will switch to "move mode", and you can move the customView by drag.)
But in this code, only longPressAction: called. panAction: did not called.
How do I fix it to enable PanAction:?
- (void)viewDidLoad
{
[self.view addSubview:customView];
UILongPressGestureRecognizer *longPressRecognizer = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:#selector(longPressAction:)];
[customView addGestureRecognizer:longPressRecognizer];
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc]initWithTarget:self action:#selector(panAction:)];
[customView addGestureRecognizer:panRecognizer];
}
- (void)longPressAction:(UILongPressGestureRecognizer *)recognizer
{
if ([recognizer state] == UIGestureRecognizerStateBegan) {
CustomView *customView = (CustomView *)recognizer.view;
customView.panRecongnizerEnabled = YES; //panRecongnizerEnabled is CustomView's property
}
if ([recognizer state] == UIGestureRecognizerStateEnded) {
CustomView *customView = (CustomView *)recognizer.view;
customView.panRecongnizerEnabled = NO;
}
}
- (void)panAction:(UIPanGestureRecognizer *)recognizer
{
CustomView *customView = (CustomView *)recognizer.view;
if (customCell.panRecongnizerEnabled == NO) return;
NSLog(#"running panAction");
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}

Answer 1

Your ViewController needs to conform to the UIGestureRecognizerDelegate. I suspect you either already did that or otherwise the shouldRecognizeSimultaneouslyWithGestureRecognizer would not make any sense. But what you are definitely missing is setting the gestureRecognizer´s delegate to your viewController:
longPressRecognizer.delegate = self;
panRecognizer.delegate = self;
Now you should be receiving both long press and pan simultaneous.
Note: I tested without any customView, just added them to self.view. At least in that case, the code above worked as expected.

Answer 2

I know this question has been closed for a while, but I recently had to do something similar, and there is a much cleaner solution. The UILongPressGestureRecognizer is all you need to do this.
Long-press gestures are continuous. The gesture begins
(UIGestureRecognizerStateBegan) when the number of allowable fingers
(numberOfTouchesRequired) have been pressed for the specified period
(minimumPressDuration) and the touches do not move beyond the
allowable range of movement (allowableMovement). The gesture
recognizer transitions to the Change state whenever a finger moves,
and it ends (UIGestureRecognizerStateEnded) when any of the fingers
are lifted.
Because of this, for what you need, there is no need for the UIPanGestureRecognizer. Simply add the UILongPressGestureRecognizer and attach it to your main view.
- (void)viewDidLoad {
[super viewDidLoad];
UILongPressGestureRecognizer *longPressRecognizer = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:#selector(longPressAction:)];
// set this to your desired delay before the pan action will start.
longPressRecognizer.minimumPressDuration = 0.5;
[self.view addGestureRecognizer:longPressRecognizer];
}
Then, implement the longPressAction method to look at not just UIGestureRecognizerStateBegan or UIGestureRecognizerStateEnded states, but also the UIGestureRecognizerStateChanged state:
- (void)longPressAction:(UIGestureRecognizer *)recognizer
{
if ([recognizer state] == UIGestureRecognizerStateBegan || [recognizer state] == UIGestureRecognizerStateChanged ) {
CGPoint touchPoint = [recognizer locationInView:self.view];
[self.viewToMove setCenter: touchPoint];
NSLog(#"running panAction");
}
}
In my example, I simply move a dummy view to track the center of the user's finger, but you can put any logic you would have put in the UIPanGestureRecognizer's code. Simply put it inside the if block and it greatly simplifies your code and you don't need to deal with interactions between the two gesture recognizers. Your code would also result in many needless calls to the panAction method when the user is simply moving their finger around the screen (but hasn't done a long press).

Answer 3

You can do it by enabling the pan after the long press. Anyhow you will have to save a flag to know if the longPress was called. And in order to enable the pan gesture after the longPress, you can play with the pan gesture delegate, as following:
let previewLongPress = UILongPressGestureRecognizer(target: self, action: #selector(onLongPressed(sender:)))
let previewPanGesture = UIPanGestureRecognizer(target: self, action: #selector(onPanGesture(sender:)))
previewPanGesture?.delegate = self
Your delegate should seems like this:
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return gestureRecognizer == previewPanGesture && otherGestureRecognizer == previewLongPress
}
And now you're able to have a pan gesture after a long press gesture.
Hope it helps other people.