I'm using a UIGestureRecognizer to recognize a single tap, a double tap and a longpress.
What I would like to do is also recognize a longpress, then swipe to either left or right.
Would this be possible given that I'm already consuming a longpress? I'm confused on this one and would appreciate pointers on how to do.
Thanks
Just tried this out myself and it seems as if the UILongPressGestureRecognizer will transition to its end state as soon as the UISwipeGestureRecognizer begins. Just make sure shouldRecognizeSimultaneouslyWithGestureRecognizer: returns YES for this gesture combination.
You'd need to use two gesture recognisers and make sure you track the state of the long press one when you receive a callback to say it's ended, and then do something based on the swipe/pan gesture following it.
Related
Now I have implemented the fling feature in my ios app, but I want to stop the fling when a touch on screen happens, this does not only contain tap gesture, maybe other like long press or pinch, I have a BOOL value to indicate whether a touch happens, so should I add all kinds of gesture recognizers and set to BOOL value as true? Are there any simple solution? Thank you!
There are several methods in UIGestureRecognizerDelegate that will achieve what you want. gestureRecognizerShouldRegognizeSimultaneouslyWithGesture sounds like the best candidate. You will get passed two gesture recognizers. One will be your swipe gesture (the one you want to keep), the other will be the one you want to cancel (tap, long press, pinch) return NO in the correct scenario.
See docs: https://developer.apple.com/documentation/uikit/uigesturerecognizerdelegate
In my iPad project i have to make
1.Tap gesture
2.Swipe right and Swipe left Gesture
3.Single Finger Pan Gesture
4.Two finger Pan gesture.
5.Long press gesture
I don't know how to handle all these gestures.When Long press gesture is used only Swipe right gesture and two finger Pan gesture has to work. App gets confused at these many gestures in a single screen. How to Handle everything easily. Please help
Firstly i will say your question was little confusing and we can easily add multiple UITapGestures on a singleView without any prob. The OS automatically detects which gestures you are doing. There are many tutorials for that. Look at these links, if you still can find any solution, tell me may be i can try a code piece for u.
Link 1
Link 2
and lastly
Link 3
I'm making a game on the iPad where the player swipes up, down, left, or right to move the character. An attack is controlled by touchesBegan:withEvent:
My problem is that the character attacks whenever he moves.
Is there a way to set up a swipe gesture so the code doesn't run touchesBegan:withEvent: until it sees if the motion is the beginning of a swipe or not?
This is not too easy of a task. Without using some custom gestures I would suggest you to try the combination of UISwipeGestureRecognizer and UILongPressGestureRecognizer. I know this sound silly but it is not: An UILongPressGestureRecognizer acts pretty much the same as the pan gesture so even if the finger is dragged you will receive events. You need to set some proper minimum duration till it fires (depends on the swipe gesture) and some large minimum drag length so it doesn't get canceled for dragging. You need to remove the touch event methods then and move the code to long press gesture action.
To explain the result, your long press gesture will (if set correctly) work just the same as touch events except it will wait for specified duration. If in that duration a swipe is detected your long press gesture will not fire. Seems just what you need...
I am using a UIPanGestureRecogniser to implement drag and drop. When the drag starts I need to identify the object that is being dragged. However the objects are relatively small. And if the user doesn't hit the object right in the centre of the object it isn't getting dragged.
The problem is that when the gesture handler is first called with the state UIGestureRecognizerStateBegan, the finger has already moved several pixels, and so [UIPanGestureRecognizer locationInView:] returns that point, which is not where the gesture truly started. That makes sense as it can only recognize a pan after a few pixels of movement. However, I need the absolute start of the gesture, not the position after the gesture has first been recognized.
I'm thinking that maybe I need to implement a tap gesture recognizer as well, purely to capture the first touch. But that seems like a hack for what is not an unusual requirement. Is there no other way of getting that first touch from within the pan gesture recognizer?
UIGestureRecognizerDelegate protocol provides methods gestureRecognizerShouldBegin: and gestureRecognizer:shouldReceiveTouch: that can help you evaluate the touches before the pan has transitioned to state UIPanGestureRecognizerStateBegan
I working with UIGestureRecognizer atm creating some map alike program.
My work require me to listen to both long press gesture and pan gesture separate, so each of them can do their own task.
But in one case, i need to listen to long press first to know which object is chosen. After that, when i begin to move my finger (without lift it up), that object will be move too. It kind of like drag a marker around in google map. But because my long press recognizer already fired, pan gesture recognizer didn't get fire until i tab on the screen again.
I tried something like
recognizer.enabled = NO;
recignizer.enabled = YES;
But it didn't help at all.
So i wonder if there anyway to cancel long press after it recognized (UIGestureRecognizerStateBegan) so pan gesture recognizer will be fire immediately when i begin to move. Or i have to use UIResponder to make it work ?
Thank for your advice.
You can actually use UILongPressGestureRecognizer to detect the pan gesture after the long tap. The only caveat is that, since UILongPressGestureRecognizer is a subclass of UIGestureRecognizer it does not have the -translationInView: that is so handy in UIPanGestureRecognizer.
You can anyway do these calculations on your own by keeping track of where the touch has moved after the long press, as it will keep firing the action bound to the gesture recognizer.
Take a look at this question, it may help to calculate the translation with the long press gesture.