How to disable/enable a UIPanGestureRecognizer with two separate UIBarButtonItems? - ios

Question

I am trying to turn off a UIPanGestureRecognizer with the click of a "Save" button. Then, I am trying to turn back on this UIPanGestureRecognizer with the click of an "Edit" button. I can figure out how to turn them off with the following code like this:
- (IBAction)saveButton:(id)sender {
buttonCount ++;
if (buttonCount > 0) {
for (_buttonField in self.view.subviews) {
_buttonField.gestureRecognizers = nil;
_buttonField.layer.borderColor = [UIColor blackColor].CGColor;
}
}
}
Yet, I have two problems. First of all, this is turning off all of the gesture recognizers, which I do not want to do. Secondly, I cannot figure out how to turn them back on. For this I have tried the following:
- (IBAction)editButton:(id)sender {
buttonCount ++;
if (buttonCount > 0) {
if ([[UIColor colorWithCGColor:_buttonField.layer.borderColor] isEqual:[UIColor whiteColor]]) {
for (_buttonField in self.view.subviews) {
_buttonField.gestureRecognizers = YES;
}
}
}
}
However, I receive an error on the line of code that is set to YES.
Here is my complete set of code for reference:
#implementation FieldGoalChartViewController
{
}
-(void)viewDidLoad{
[super viewDidLoad];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {
UITouch *aTouch = [touches anyObject];
CGRect buttonRect = self.buttonField.frame;
CGPoint point = [aTouch locationInView:self.buttonField.superview];
if (!CGRectContainsPoint(buttonRect, point)) {
_buttonField.layer.borderColor = [UIColor blackColor].CGColor;
_draggedView.layer.borderColor = [UIColor blackColor].CGColor;
for (_buttonField in self.view.subviews) {
_buttonField.layer.borderColor = [UIColor blackColor].CGColor;
}
}
}
- (void)longPress:(UILongPressGestureRecognizer*)gesture {
if ( gesture.state == UIGestureRecognizerStateBegan ) {
gesture.view.layer.borderColor = [UIColor whiteColor].CGColor;
UIAlertController * alert= [UIAlertController
alertControllerWithTitle:#"Would you like to delete the selected rep(s)?"
message:nil
preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction* deleteButton = [UIAlertAction
actionWithTitle:#"Delete"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction * action)
{
for (_buttonField in self.view.subviews) {
if ([[UIColor colorWithCGColor:_buttonField.layer.borderColor] isEqual:[UIColor whiteColor]]) {
[_buttonField removeFromSuperview];
}
}
[alert dismissViewControllerAnimated:YES completion:nil];
}];
UIAlertAction* cancelButton = [UIAlertAction
actionWithTitle:#"Cancel"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction * action)
{
[alert dismissViewControllerAnimated:YES completion:nil];
}];
[alert addAction:deleteButton];
[alert addAction:cancelButton];
[self presentViewController:alert animated:YES completion:nil];
}
}
- (void)panWasRecognized:(UIPanGestureRecognizer *)panner {
{
panner.view.layer.borderColor = [UIColor whiteColor].CGColor;
_draggedView = panner.view;
CGPoint offset = [panner translationInView:_draggedView.superview];
CGPoint center = _draggedView.center;
_draggedView.center = CGPointMake(center.x + offset.x, center.y + offset.y);
_draggedView.layer.masksToBounds =YES;
_buttonField.layer.borderWidth = 3.0f;
// Reset translation to zero so on the next `panWasRecognized:` message, the
// translation will just be the additional movement of the touch since now.
[panner setTranslation:CGPointZero inView:_draggedView.superview];
}
}
-(void)buttonTouched:(UIButton*)sender forEvent:(id)tap {
NSSet *touches = [tap allTouches];
UITouch *touch = [touches anyObject];
UITouchPhase *phase = touch.phase;
touch.view.layer.borderColor = [UIColor whiteColor
].CGColor;
}
-(void)doubleTapped:(UIButton*)sender forEvent:(id)twoTaps {
NSSet *touches = [twoTaps allTouches];
UITouch *touch = [touches anyObject];
UITouchPhase *phase = touch.phase;
touch.view.layer.borderColor = [UIColor blackColor].CGColor;
}
- (IBAction)saveButton:(id)sender {
buttonCount ++;
if (buttonCount > 0) {
for (_buttonField in self.view.subviews) {
_buttonField.gestureRecognizers = nil;
_buttonField.layer.borderColor = [UIColor blackColor].CGColor;
}
}
}
- (IBAction)editButton:(id)sender {
buttonCount ++;
if (buttonCount > 0) {
if ([[UIColor colorWithCGColor:_buttonField.layer.borderColor] isEqual:[UIColor whiteColor]]) {
for (_buttonField in self.view.subviews) {
_buttonField.gestureRecognizers = YES;
}
}
}
}
- (IBAction)addRepButton:(UIBarButtonItem *)newRep {
self.labelCounter++;
buttonCount ++;
if (buttonCount > 0 )
{
_buttonField = [[UIButton alloc]initWithFrame:CGRectMake(300, 300, 28, 28)];
[_buttonField setTitle:[NSString stringWithFormat:#"%i", self.labelCounter]forState:UIControlStateNormal];
[_buttonField setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
_buttonField.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
_buttonField.userInteractionEnabled = YES;
_buttonField.layer.cornerRadius = 14;
_buttonField.layer.borderColor = [UIColor blackColor].CGColor;
_buttonField.layer.borderWidth = 3.0f;
_buttonField.titleLabel.font = [UIFont boldSystemFontOfSize:13];
[_buttonField setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
_buttonField.layer.backgroundColor = [UIColor blackColor].CGColor;
_buttonField.layer.masksToBounds = YES;
//Pan gesture declared in button
UIPanGestureRecognizer *panner = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panWasRecognized:)];
[_buttonField addGestureRecognizer:panner];
//Long Press gesture declared in button
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPress:)];
[self.buttonField addGestureRecognizer:longPress];
//Touch down inside declared in button
[self.buttonField addTarget:self action:#selector(buttonTouched:forEvent:) forControlEvents:UIControlEventTouchDown];
//Double Tap inside declared in button
[self.buttonField addTarget:self action:#selector(doubleTapped:forEvent:) forControlEvents:UIControlEventTouchDownRepeat];
[self.view addSubview:(_buttonField)];
}
}
#end
I want to know how to specifically turn off the UIPanGestureRecognizer with the click of my "Save" UIBarButton, and then turn the UIPanGestureRecognizer with the click of my "Edit" UIBarButton.

Answer 1

If you added Pan gesture in IB then you can create outlet and use the enabled property on the instance of the gesture to enable and disable the gesture, simple.
panGestureRecognizer.enabled = NO; (or)
panGestureRecognizer.enabled = YES;