Before any starts, I understand yourView.userInteractionEnabled = NO; is an option, but let me explain first the circumstance.
I have these 2 UIView objects, stoneOne and stoneTwo. I have 4 UISwipeGestureRecognizer objects attached to them for up, down, left and right. Imagine swiping these 'stones' around a 5x5 grid.
What I don't want is to be able to swipe both at the same time.
Currently, that bug is still an issue. I'll show you a method called swipeLeft: which represents the layout for all swipe directions.
- (IBAction)swipeLeft:(UISwipeGestureRecognizer *)recognizer {
_oldMove1 = _move1;
_oldMove2 = _move2;
if (recognizer.view == _oneStone
&& recognizer.direction == UISwipeGestureRecognizerDirectionLeft) {
_twoStone.userInteractionEnabled = NO;
_oneStone = recognizer.view;
[self moveOne:CGPointMake(-1, 0) withView:_oneStone];
self.move1++;
// 'causeADelay:' runs _twoStone.userInteractionEnabled = YES;
[self performSelector:#selector(causeADelay:) withObject:_twoStone afterDelay:1];
} else if (recognizer.view == _twoStone
&& recognizer.direction == UISwipeGestureRecognizerDirectionLeft) {
_oneStone.userInteractionEnabled = NO;
_twoStone = recognizer.view;
[self moveTwo:CGPointMake(-1, 0) withView:_twoStone];
self.move2++;
[self performSelector:#selector(causeADelay:) withObject:_oneStone afterDelay:1];
}
self.moveCount++;
}
One of the things I tried was creating a delay on when I can interact with my UIView objects. This worked ONLY IF I waited a split half-second to interact. The full delay would occur, and everything would work.
My bug is when you swipe them both at the same time. Is that because of the swipe gestures attached to them?
I also tried removing and reapplying the objects as subviews...didn't work, obviously. I really need this to work otherwise I have a dead-end game. I was very new to coding when I first started and never thought about Cocos2d or other game-driven platforms for development, so everything I have came from on-the-fly thinking.
There are several solutions, but here's a particularly easy one:
Remove the swipe gesture recognizers from the stones and attach them instead to the common superview of the stones. This solves the problem, because only one gesture recognizer on the same view will recognize at any one time.
Of course, you will now have to use hit-testing to find out which stone (if any) is being swiped. But that's an easy implementation detail, and is a small price to pay.
And of course another cool feature is that you now only need four gesture recognizers total!
Related
On iPhone's with 3D touch enabled, there is a feature where long pressing the left hand side of the screen with enough force opens lets you change which app is active. Because of this, when a non-moving touch happens on the left hand side of the screen, the touch event is delayed for a second or two until the iPhone verifies that the user is not trying to switch tasks and is interacting with the app.
This is a major problem when developing a game with SpriteKit, as these touches are delayed by a second every time a user taps/holds their finger on the left edge of the screen. I was able to solve this problem by registering a UILongPressGestureRecognizer in the main Scene of the game, thus disabling TouchesBegan and implementing a custom touches function (used as a selector by the gesture recognizer):
-(void)handleLongPressGesture:(UITapGestureRecognizer *)gesture {
CGPoint location = [gesture locationInView:self.view];
if (gesture.state == UIGestureRecognizerStateBegan)
{
//
}
else if (gesture.state == UIGestureRecognizerStateChanged)
{
//
}
else if (gesture.state == UIGestureRecognizerStateEnded)
{
//
}
else if (gesture.state == UIGestureRecognizerStateCancelled)
{
//
}
}
-(void)didMoveToView:(SKView *)view {
/* Setup your scene here */
UILongPressGestureRecognizer *longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(handleLongPressGesture:)];
longPressGestureRecognizer.delaysTouchesBegan = false;
longPressGestureRecognizer.minimumPressDuration = 0;
[view addGestureRecognizer:longPressGestureRecognizer];
// continue
}
The problem with this is that I would have to implement a gesture recognizer for every touch (including simultaneous ones) that I expect the user to enter. This interferes with any touchesBegan methods as subclasses of SKSpriteNode, SKScene, etc. and kills a lot of functionality.
Is there any way to disable this delay? When registering the gestureRecognizer, I was able to set delaysTouchesBegan property to false. Can I do the same somehow for my SKScene?
To see this issue in action, you can run the default SpriteKit project, and tap (hold for a second or two) near the left hand side of the screen. You will see that there is a delay between when you touch the screen and when the SKShapeNodes are rendered (as opposed to touching anywhere else on the screen).
* Edit 1 *
For those trying to find a way to get around this for now, you can keep the gesture recognizer but set its cancelsTouchesInView to false. Use the gesture recognizer to do everything you need to do until TouchesBegan kicks in (touchesBegan will receive the same touch event about a second after the gesture recognizer recognizes the touch). Once touchesBegan kicks in, you can disable everything happening in the gesture recognizer. This seems like a sloppy fix to me, but it works for now.
Still trying to find a more-or-less formal solution.
I have experienced this as an user and it is really annoying. The only thing that worked for me was to disable the 3D touch. Otherwise the left side of the touchscreen is almost useless.
I'm writing a radial menu, where when you long press (UILongPressGestureRecognizer) on the screen, it pops out a menu of buttons, and I can drag my finger (which is already touching the screen) over one of the buttons, which selects, then when I let go, it performs an action specific to that button.
I currently have the radial menu as a UIControl subclass, and I'm trying to override beginTrackingWithTouch: and continueTrackingWithTouch:, but the long press that shows the menu (adds it to the superview), does not get transferred to a touch recognized by the UIControl.
Any ideas how I can "forward" this touch event from the UIControl's superview to it?
Thanks!
Not a direct answer, but you should really watch the WWDC session about scrollviews of this year. And then watch it again. It contains a fantastic amount of information, and most certainly an answer to your question. It is session 235: advanced scrollviews and touch handling techniques.
I would do this...
The long press handler:
-(IBAction)onLongPress:(UILongPressGestureRecognizer*)recognizer
{
CGPoint point = [recognizer locationInView:self.view];
if (recognizer.state == UIGestureRecognizerStateBegan) {
//create the radial view and add it to the view
CGSize radialViewSize = CGSizeMake(80, 80);
radialView = [[RadialView alloc] initWithFrame:CGRectMake(point.x - radialViewSize.width/2, point.y - radialViewSize.height/2, radialViewSize.width, radialViewSize.height)];
[self.view addSubview:radialView];
radialView.backgroundColor = [UIColor redColor];
} else if (recognizer.state == UIGestureRecognizerStateEnded) {
[radialView onTouchUp:[radialView convertPoint:point fromView:self.view]];
[radialView removeFromSuperview];
radialView = nil;
}
}
In your radial view: (I suppose that the radial view keeps the buttons in an array)
-(void)onTouchUp:(CGPoint)point
{
for (UIButton *button in buttons) {
if ([button pointInside:[self convertPoint:point toView:button] withEvent:nil]) {
//This button got clicked
//send button clicked event
[button sendActionsForControlEvents:UIControlEventTouchUpInside];
}
}
}
I know it's not perfect, since the touch events don't get forwarded to the radial view (as you asked), but it let's you click the buttons. Hope it helps!
I'm not sure if this is the same behavior you're looking for, but I recently had to overcome the exact same issue when developing my Concentric Radial Menu. The thing I discovered very quickly was that views added to the view hierarchy during the touch event do not get re-hit-tested and therefore seem unresponsive until the next event comes around.
The solution I used, which I can't say I love, was to implement a custom UIWindow subclass that intercepts - (void)sendEvent:(UIEvent *)event and forwards those events to the "active" radial menu.
That is, the menu registers with the window upon activation, then unregisters when being unloaded. If done atomically, this is actually a pretty safe technique, I just wish it were cleaner than it is.
Best of luck!
i have a problem with the UIPanGestureRecognizer behavior.
All works great unless I slide in from the top of my iPad. Top means here the side where the camera is located, no matter how the current device orientation is.
With the following code i debug the UIPanGestureRecognizer behavior:
- (void)viewDidLoad
{
[super viewDidLoad];
_pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panGesture:)];
[self.view addGestureRecognizer:_pan];
}
- (void)panGesture:(UIPanGestureRecognizer*)gesture
{
if (gesture.state == UIGestureRecognizerStateBegan) {
NSLog(#"BEGIN");
} else {
NSLog(#"GO");
}
}
So when i slide in from the top nothing happens.
It seems that iOS would catch that gesture, perhaps it is related to the notification center?
In principle it seems possible to get that gesture because i saw this on other apps.
What am I missing here?
Apple says in their transition guide that the existence of the notification center means that your touches at the very bottom and very top of the screen may be canceled. I think this is likely an example of that.
I have a view with four pan gestures attached. The first has both max and min number of touches set to 1, the second to 2, etc. This makes it so each will only recognize one touch while up to four fingers slide around on the screen.
That's working dandy. What isn't working is detecting when individual touches end. Anything I have set to happen when a gesture ends only happens when all gestures have ended completely.
Example delegate method:
- (void) handlePan:(UIPanGestureRecognizer*)recognizer {
//Setting what happens when a gesture is recognized as beginning
if (recognizer.state == UIGestureRecognizerStateBegan) {
//...whatever happens, bunnies follow your finger or whatever
} else
//Setting what happens when a gesture ends
if ((recognizer.state == UIGestureRecognizerStateEnded) |
(recognizer.state == UIGestureRecognizerStateCancelled) |
(recognizer.state == UIGestureRecognizerStateFailed)) {
NSLog(#"end");
}
}
What should be happening is that I see "end" in the console whenever any finger is lifted. Instead, I see nothing until all fingers are lifted, at which point I see "end" repeated four times (or as many times as fingers that were on the screen).
Is there any way I can make this work the way I intend?
edit After fiddling I see that I may not be analyzing my problem correctly. The whole reason I want to detect when a gesture's touch ends is that I want to have gestures able to become active when there is more than one touch on screen, but I want each gesture to only track one touch itself. I was setting an "active" flag on gestures that were tracking touches, and then toggling that flag off after touches ended, and that wasn't working, because touch-end-detection was hard to implement well.
But if there's a different way to achieve the same thing, that's the real thing I'm looking for: among many overlapping touches, have each gesture recognizer track one and only one.
You may want to do something like - it catches the change in fingers on the screen for the given gesture; you may need to add some more logic surrounding which gesture you're working with:
switch( recognizer.numberOfTouches ) {
case 1: {
NSLog(#"1 ");
break;
}
case 2: {
NSLog(#"2");
break;
}
case 3: {
NSLog(#"3");
break;
}
case 4: {
NSLog(#"4");
break;
}
default: {
NSLog(#"0");
}
}
This is what eventually worked.
In short, I made a flag that flipped whenever a gesture recognizer was assigned a touch, ensuring no other recognizers accepted that touch. I also tested each recognizer to make sure it only accepted a touch when it wasn't already following a touch. So I made each touch only get assigned once, and each recognizer only accept one touch. Worked like a charm.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
//set this to no every time a new touch happens, meaning it isn't taken yet.
touchTaken = NO;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
//If the touch is taken or the gesture's already following a touch, say no.
if (touchTaken | ([gestureRecognizer numberOfTouches] > 0)) {
return NO;
}
else {
touchTaken = YES;
return YES;
}
}
This may have been posted here somewhere but I can't find it. I am writing a simple iOS app with two UIViews. The user will first press and hold a certain area of the screen then release their touch on it then quickly touching a second view below.
The first UIView has a UILongPressGestureRecognizer attached to it and works fine. The second UIView has a UITapGestureRecognizer attached to it and also works fine. I cannot however, get either of these gesture recognizers to return anything that states that the user released their touch.
I have tried this code to no avail:
- (void)holdAction:(UILongPressGestureRecognizer *)holdRecognizer
{
if (UIGestureRecognizerStateRecognized) {
holdLabel.text = #"Holding Correctly. Release Touch when ready.";
holdView.backgroundColor = [UIColor greenColor];
} else if (UIGestureRecognizerStateCancelled){
holdLabel.text = #"Ended";
holdView.backgroundColor = [UIColor redColor];
}
Any suggestions would be great and especially if someone knows how to implement a call that returns the state of a user touching the device. I've looked over the developer docs and have come up empty.
After tinkering for a couple hours, I found a way that is working, not sure if its the best way to do it. Turns out I need to be writing it like the code below. I wasn't calling the specific UIGestureRecognizer I was declaring in the viewDidLoad() method.
- (void)holdAction:(UILongPressGestureRecognizer *)holdRecognizer
{
if (holdRecognizer.state == UIGestureRecognizerStateBegan) {
holdLabel.text = #"Holding Correctly. Release when ready.";
holdView.backgroundColor = [UIColor greenColor];
} else if (holdRecognizer.state == UIGestureRecognizerStateEnded)
{
holdLabel.text = #"You let go!";
holdView.backgroundColor = [UIColor redColor];
}
}
You need to use manual touch handling here (as opposed to using a gesture recognizer). Any UIResponder subclass can implement the following four methods:
– touchesBegan:withEvent:
– touchesMoved:withEvent:
– touchesEnded:withEvent:
– touchesCancelled:withEvent:
By using these methods, you get access to every phase of the touch events. You might have to implement your own logic to detect the long press, but you have full access to all touches.
For more information on touch handling, this session from WWDC 2011 is golden (requires dev account):
https://developer.apple.com/itunes/?destination=adc.apple.com.8270634034.08270634040.8367260921?i=1527940296
Swift 4+
let gesture = UILongPressGestureRecognizer(target: self, action: #selector(self.checkAction))
self.view.addGestureRecognizer(gesture)
#objc func checkAction(sender : UILongPressGestureRecognizer) {
if sender.state == .ended || sender.state == .cancelled || sender.state == .failed {
}
}