Choose different UIPanGestureRecognizer touches - nsuserdefaults

Question

Ok so I have a app with a left menu and a right view controller which are controlled by the UIPanGestureRecognizer. So when a user swipes the bezel (20px) of the edge of the screen it navigates.
In a settings view controller I have UISwitches which control various other things, but one of them I want to control how many touches the UIPanGestureRecognizer will take.
The switch is set up properly and sends the user defaults to the other view controller, but on the receiving end of it, it won't read what the user has selected.
UIPanGestureRecognizer * pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panGestureCallback:)];
//Switch for SwipeNav
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
BOOL switchOn = [userDefaults boolForKey:#"SwipeNav"];
if (switchOn) {
// 2 Finger SwipeNav
[pan setMinimumNumberOfTouches:2];
[pan setMaximumNumberOfTouches:2];
}else{
[pan setMinimumNumberOfTouches:1];
[pan setMaximumNumberOfTouches:1];
}
[pan setDelegate:self];
[self.view addGestureRecognizer:pan];
How can I make it so when the switch is on, it uses 2 touches to navigate, and off it acts like normal?
Any assistance is always appreciated. Thank you.
UPDATED with settings sync code.
if (swipe){
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setBool:self.swipe.on forKey:#"SwipeNav"];
[userDefaults synchronize];
if ([swipe isOn]) {
[swipe setOn:YES animated:YES];
[self.tableView reloadData];
[[UIApplication sharedApplication] reloadInputViews];
} else {
[swipe setOn:NO animated:YES];
[self.tableView reloadData];
[[UIApplication sharedApplication] reloadInputViews];
}
}

Answer 1

I created a new project and tried to reproduce the problem that you are seeing and everything seems to work as expected. When switch is on the you need two buttons to pan and when switch is off you only need one. Let me know if that points you in the right direction. Your code seems to be correct.
I copy pasted the handlePan function from How to use UIPanGestureRecognizer to move object? iPhone/iPad
Created everything programmatically and copy pasted your code to save the state of the switch. Here is the code from two UIViewControllers
//
// ViewController.m
// StackOverflowSwitch
//
//
//
//
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic,strong) UIButton *myButton;
#property (nonatomic,strong) UISwitch *switchOn;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.myButton = [[UIButton alloc]initWithFrame:CGRectMake(10, 100, 150, 150)];
self.switchOn = [[UISwitch alloc]initWithFrame:CGRectMake(10, 300, 100, 100)];
self.myButton.backgroundColor =[UIColor grayColor];
[self.myButton setTitle:#"Click Me" forState:UIControlStateNormal];
[self.myButton addTarget:self action:#selector(click:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:self.switchOn];
[self.view addSubview:self.myButton];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)click:(UIButton *)sender
{
[self performSegueWithIdentifier:#"NextViewController" sender:self];
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if(self.switchOn.on){
NSLog(#"switch is on");
}else{
NSLog(#"switch is off");
}
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setBool:self.switchOn.on forKey:#"SwipeNav"];
[userDefaults synchronize];
}
#end
//////
#import "SecondViewController.h"
#interface SecondViewController() <UIGestureRecognizerDelegate>
#property (strong,nonatomic) UIView *myView;
#end
#implementation SecondViewController
-(void)viewDidLoad
{
[super viewDidLoad];
self.myView = [[UIView alloc]initWithFrame:CGRectMake(10, 10, 200, 200)];
self.myView.backgroundColor = [UIColor redColor];
[self.view addSubview:self.myView];
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
BOOL switchOn = [userDefaults boolForKey:#"SwipeNav"];
if (switchOn) {
// 2 Finger SwipeNav
[pan setMinimumNumberOfTouches:2];
[pan setMaximumNumberOfTouches:2];
}else{
[pan setMinimumNumberOfTouches:1];
[pan setMaximumNumberOfTouches:1];
}
[pan setDelegate:self];
[self.view addGestureRecognizer:pan];
[self.myView addGestureRecognizer:pan];
}
-(void)handlePan:(UIPanGestureRecognizer *)recognizer
{
CGPoint translation = [recognizer translationInView:self.view];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self.view];
if (recognizer.state == UIGestureRecognizerStateEnded) {
CGPoint velocity = [recognizer velocityInView:self.view];
CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y));
CGFloat slideMult = magnitude / 200;
NSLog(#"magnitude: %f, slideMult: %f", magnitude, slideMult);
float slideFactor = 0.1 * slideMult; // Increase for more of a slide
CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor),
recognizer.view.center.y + (velocity.y * slideFactor));
finalPoint.x = MIN(MAX(finalPoint.x, 0), self.view.bounds.size.width);
finalPoint.y = MIN(MAX(finalPoint.y, 0), self.view.bounds.size.height);
[UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
recognizer.view.center = finalPoint;
} completion:nil];
}
}
#end
///// Update
I am not exactly sure how [[UIApplication sharedApplication] reloadInputViews]; calls the function to update the UIPanGestureRecongizer in your code but i tried to recreate your functionality as close as possible by having the setupView method called every time i click the UISwitch
I created a custom view with UIPanGestureReconginzer in there and a method that I call from the UIViewController to update setNumberOfTouches. The view works as expected. The key here is not to initialize a new UIPanGuestureRecongizer but update the existing one. I assume in your app UIViewController or UIView which has the UIPanGuestureRecongizer is not being fully reloaded.
I created a property UIPanGuestureRecongizer which gets initialized the first time it's being accessed and then gets updated when switch is being pressed. Here is the custom UIView code. Let me know if you have any questions regarding the code.
#import "MyTestView.h"
#interface MyTestView() <UIGestureRecognizerDelegate>
#property(nonatomic,strong) UIPanGestureRecognizer *panGesture;
#end
#implementation MyTestView
-(instancetype)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
[self setupView];
}
return self;
}
-(UIPanGestureRecognizer *)panGesture
{
//lazy instantiation
if (!_panGesture) {
_panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
}
return _panGesture;
}
-(void)setupView
{
//this gets called everytime the UISwitch is being pressed.
NSLog(#"Setup views");
self.backgroundColor = [UIColor redColor];
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
BOOL switchOn = [userDefaults boolForKey:#"SwipeNav"];
if (switchOn) {
// 2 Finger SwipeNav
[self.panGesture setMinimumNumberOfTouches:2];
[self.panGesture setMaximumNumberOfTouches:2];
}else{
[self.panGesture setMinimumNumberOfTouches:1];
[self.panGesture setMaximumNumberOfTouches:1];
}
[self.panGesture setDelegate:self];
[self addGestureRecognizer:self.panGesture];
}
-(void)handlePan:(UIPanGestureRecognizer *)recognizer
{
CGPoint translation = [recognizer translationInView:self];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self];
if (recognizer.state == UIGestureRecognizerStateEnded) {
CGPoint velocity = [recognizer velocityInView:self];
CGFloat magnitude = sqrtf((velocity.x * velocity.x) + (velocity.y * velocity.y));
CGFloat slideMult = magnitude / 200;
NSLog(#"magnitude: %f, slideMult: %f", magnitude, slideMult);
float slideFactor = 0.1 * slideMult; // Increase for more of a slide
CGPoint finalPoint = CGPointMake(recognizer.view.center.x + (velocity.x * slideFactor),
recognizer.view.center.y + (velocity.y * slideFactor));
finalPoint.x = MIN(MAX(finalPoint.x, 0), self.bounds.size.width);
finalPoint.y = MIN(MAX(finalPoint.y, 0), self.bounds.size.height);
[UIView animateWithDuration:slideFactor*2 delay:0 options:UIViewAnimationOptionCurveEaseOut animations:^{
recognizer.view.center = finalPoint;
} completion:nil];
}
}
#end

Answer 2

Alright, so after much testing/code flipping, I think I have found my solution.
So a little more backstory, I use MMDrawerController, so the method above about placing [self setupView]; in (instancetype)initWithCoder didn't do anything. The setupView or in my case is called "setupGestureRecognizers" is loaded in the viewDidLoad. Anywhere else it wouldn't load the gesture's at all.
With my current switch code and gesture loading I have this:
-(UIPanGestureRecognizer *)panGestureNav {
if (!_panGesture) {
_panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(panGestureCallback:)];
}
return _panGesture;
}
-(void)setupGestureRecognizers{
switchOn = [[NSUserDefaults standardUserDefaults] boolForKey:#"SwipeNav"];
if (switchOn == YES) {
// 2 Finger SwipeNav
[self.panGestureNav setMinimumNumberOfTouches:2];
[self.panGestureNav setMaximumNumberOfTouches:2];
NSLog(#"2 Finger Nav");
}else {
[self.panGestureNav setMinimumNumberOfTouches:1];
[self.panGestureNav setMaximumNumberOfTouches:1];
NSLog(#"Normal Nav");
}
[self.panGestureNav setDelegate:self];
[self.view addGestureRecognizer:self.panGestureNav];
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapGestureCallback:)];
[tap setDelegate:self];
[self.view addGestureRecognizer:tap];
}
Which would normally work, but this library does things differently, so I have to look into their gesture calling and what I ended up doing was calling it here:
-(MMOpenDrawerGestureMode)possibleOpenGestureModesForGestureRecognizer:(UIGestureRecognizer*)gestureRecognizer withTouch:(UITouch*)touch{
CGPoint point = [touch locationInView:self.childControllerContainerView];
MMOpenDrawerGestureMode possibleOpenGestureModes = MMOpenDrawerGestureModeNone;
if([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]){
[self setupGestureRecognizers]; <------------
So now it loads and functions as I want.
Thank you Yan so all of your assistance. Hope this helps somebody.