I have a custom view class. Inside my view controller I add a Tap gesture recognizer on this view object. Now, in the handler of tap gesture I am setting up a property on my view object which I am trying to fetch in the drawRect of my view class. Now, surprisingly when I print view objects in my "handleGesture" & "drawRect", I get two different objects. Because of this my if condition inside drawRect do not get execute. What could be the reason?
It do not come in state UIGestureRecognizerStateBegan. It always coming inside UIGestureRecognizerStateEnded.
// Adding Gesture in my view
MyCustomView *customView= [[[MyCustomView alloc] init] autorelease];
UIGestureRecognizer *GestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleGesture:)];
[customView addGestureRecognizer:GestureRecognizer];
[GestureRecognizer release];
// Handling tap on my view
- (void)handleGesture:(UIGestureRecognizer *)GestureRecognizer; {
MyCustomView *aView= (MyCustomView *)GestureRecognizer.view;
switch (iGestureRecognizer.state) {
case UIGestureRecognizerStateBegan:
NSLog(#"Began");
[aView setNeedsDisplay];
aView.touchDown = YES;
break;
case UIGestureRecognizerStateEnded:
NSLog(#"Ended");
aView.touchDown = NO;
[aView setNeedsDisplay];
break;
default:
break;
}
}
// Inside my view class
- (void)drawRect:(CGRect)iRect {
if (self.touchDown) {
// Do something here
}
}
There is nothing calling the drawRect method. You don't want to do this directly, but in your handleGesture method, you could put in a call to [aView setNeedsDisplay] and your view's drawRect will get called in the next drawing cycle.
I want to be able to dismiss the iPhone keyboard when the user taps anywhere outside of the keyboard. How can I go about doing this? I know I need to dismiss the responder, but need to know how to implement it when a user taps out of the keyboard space.
You'll need to add an UITapGestureRecogniser and assign it to the view, and then call resign first responder on the textfield on it's selector.
The code:
In viewDidLoad
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(dismissKeyboard)];
[self.view addGestureRecognizer:tap];
In dismissKeyboard:
-(void)dismissKeyboard {
[aTextField resignFirstResponder];
}
(Where aTextField is the textfield that is responsible for the keyboard)
OPTION 2
If you can't afford to add a gestureRecognizer then you can try this
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch * touch = [touches anyObject];
if(touch.phase == UITouchPhaseBegan) {
[aTextField resignFirstResponder];
}
}
The simplest solution I have used is this:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.view endEditing:YES];
}
The endEditing command can be used on any view that contains your textfield as a subview. The other advantage of this method is that you don't need to know which textfield triggered the keyboard. So even if you have a multiple textfields, just add this line to the superview.
Based on the Apple documentation, I think this method exists specifically to solve this problem.
Add a tapGesture Recognizer but make sure cancelsTouchesInView = NO
UITapGestureRecognizer* tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(closeTextInput)];
tapGesture.cancelsTouchesInView = NO;
[self.view addGestureRecognizer:tapGesture];
[tapGesture release];
You'll need to add an UITapGestureRecogniser and assign it to the view, and then call resign first responder on the textfield on it's selector.
The code:
In viewDidLoad
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(dismissKeyboard)];
[self.view addGestureRecognizer:tap];
In dismissKeyboard:
-(void)dismissKeyboard {
[self.view endEditing:true];
}
You need to add a transparent UIVIew as a subview below the keyboard and handle touches there, to dismiss the keyboard. Below code is for your reference.
UITapGestureRecognizer* gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(overlayTouched:)];
gesture.delegate = self;
[(UITapGestureRecognizer *)gesture setNumberOfTouchesRequired:1];
UIView* trans = [[UIView alloc] initWithFrame:[[delegate view] bounds]];
[trans setOpaque:NO];
[trans setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin];
[trans setAlpha:0.3];
[trans setUserInteractionEnabled:YES];
trans.multipleTouchEnabled = YES;
[trans addGestureRecognizer:gesture];
[trans setBackgroundColor:[UIColor blackColor]];
[trans setTag:BLACK_SCREEN_VIEW];
This is a Swift 4 solution:
let tap = UITapGestureRecognizer(target: self, action: #selector(self.dismissKeyboard))
self.view.addGestureRecognizer(tap)
And the dismissKeyboard
#objc func dismissKeyboard() {
self.view.endEditing(true)
}
Other way to do is simple:
Makes your UIView as UIControl in custom class in the interface builder, then you can attach an IBAction method in Touch up inside event of your UIView : UIControl, then you put [yourTextField resignFirstResponder] inside the IBAction method, like this:
- (IBAction) hideKeyboard: (id) sender
{
// If you have more than one textfield to dismiss, of course only can be active 1, but here you can't know who is it, because sender will be the UIView : UIControl
[alias resignFirstResponder];
[password resignFirstResponder];
}
Then, you have other option and it's to put in your textfield the return key of the keyboard as Done (It can be any of those you want, but Done it's good for this, because return means to do an action with the form) in the interface builder, so you can press Done and hide the keyboard, but in that case you have to attach the previous IBAction method to the Did end on exit event.
And in this way the keyboard will hide touching outside or touching Done from the keyboard.
If you want to improve the code, if only will hide the keyboard touching Done from the keyboard the method should be:
// Attach all textFields here on Did end on exit event, will not work if touch outside the keyboard
- (IBAction) hideKeyboard: (id) sender
{
[sender resignFirstResponder];
}
If you are on a UITableViewController or have a UITableView that the user will be interacting with, in your ViewDidLoad you can simply do:
tableView.KeyboardDismissMode = UIScrollViewKeyboardDismissMode.OnDrag;
Note: this is Xamarin.iOS syntax.
If you don't want to add a gesture recognizer you can also use the touchesBegin method
Code in Swift 4
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
view.endEditing(true)
}
You don't even need a gesture recogniser. Views can detect touches without gesture recognisers. All you need is literally this in your view controller....
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.view endEditing:YES];
}
I have a UITextField that is the subview of UIScrollView
I have there exist a single tap gesture (or perhaps the older touch) as part of UITextField that makes it the first responder. I wanted to add a double tap Gesture to the UITextField. In order to make the two Gesture's mutually exclusive I needed to overload (though this is not quite the right word because I'm not using the same name) the single tap Gesture. When I do it works fine so long as the function that it calls doesn't make the UITextField the first responder. If it does make the textfield the first responder it fails the second time it's called.... wtf. So stack, a little help would go a long way.
this is where I add the gesture
UITapGestureRecognizer * singleTextTap = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(handleSingleTextTap:)];
singleTextTap.numberOfTapsRequired = 1;
[aTextField addGestureRecognizer:singleTextTap];
and this is where it is called
//single tap text
- (void) handleSingleTextTap:(UITapGestureRecognizer *)gestureRecognizer{
NSLog(#"handling single tap");
NSLog(#"textField gestures %#",
[gestureRecognizer.view.gestureRecognizers descriptionWithLocale:nil]);
[(UITextField *)gestureRecognizer.view becomeFirstResponder];
}
you may notice the NSLog that out puts the gestuers registered to the textField this was to check the state of my singleTextTap gesture. which is 'ended' the first time and all next times this code is never reached
The behaviour you're seeing is due to each time you send a becomeFirstResponder message to a UITextField it sets it's own gesture recognizers up. If you do a log on [textField gestureRecognizers] you'll see it sets up a lot of them. These are to deal with text editing functions such as long press for cursor movement and such. By way of adding these it cancels the ones you have setup. Easiest way to deal with this is something like this.
- (void) singleTap:(UITapGestureRecognizer*)singleTap {
if (![self.textField isFirstResponder]) {
[self.textField becomeFirstResponder];
self.label.text = #"Single Tap -> Make First Responder";
[self.label setNeedsDisplay];
}
}
- (void) doubleTap:(UITapGestureRecognizer*)doubleTap {
if (![self.textField isFirstResponder]) {
[self.textField becomeFirstResponder];
self.label.text = #"Double Tap -> Make First Responder";
[self.label setNeedsDisplay];
}
}
- (void) setupTextGestureRecognizers {
for (UIGestureRecognizer *rec in self.textField.gestureRecognizers) {
[self.textField removeGestureRecognizer:rec];
}
UITapGestureRecognizer *singleTap = [[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTap:)] autorelease];
UITapGestureRecognizer *doubleTap = [[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doubleTap:)] autorelease];
[singleTap setNumberOfTapsRequired:1];
[doubleTap setNumberOfTapsRequired:2];
[singleTap setCancelsTouchesInView:YES];
[doubleTap setCancelsTouchesInView:YES];
[singleTap requireGestureRecognizerToFail:doubleTap];
[self.textField addGestureRecognizer:singleTap];
[self.textField addGestureRecognizer:doubleTap];
}
- (void)viewDidLoad {
[super viewDidLoad];
[self setupTextGestureRecognizers];
self.textField.delegate = self;
}
- (BOOL) textFieldShouldReturn:(UITextField *)tf {
[tf resignFirstResponder];
if (tf == self.textField) {
[self setupTextGestureRecognizers];
}
return YES;
}
Here is an example project demonstrating this code in use.
What you're doing seems really strange, but whatever. I'll assume you know what you're doing.
You might try the following:
UITapGestureRecognizer *doubleTap = ...;
UITapGestureRecognizer *singleTap = ...;
[singleTap requireGestureRecognizerToFail:doubleTap];
This means that the single tap recognizer will only fire if the double tap one doesn't fire, effectively making them mutually exclusive.
I need to do something like this:
UISCrollView with UIImageViews as its subviews. When user taps on UIImageViews an action occurs. But when user want to scroll UIScrollView should scroll even if scrolling started at UIImageView (at location where UIImage of UIImageView is displayed).
Basicly I can get one of two scenarios:
I can get that if user taps on UIImageView (which is subview of UIScrollView) an action occur, but when you try to scroll by draging finger from UIImageView the action also occurs (and I want a scroll to occur).
I can make that regardles where user taps the view will scroll but if user taps UIImageView the action will NOT occur.
I can't get you any of my code because I'm testing a lot of aprroches here and there and it's bit messy so it would be no use at all (without a tons of commenting).
Is there a clean and simple solution for doing this?
Ok here is some code:
-(UIView*) hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
if(isDragging == NO)
{
return [super hitTest:point withEvent:event];
}
NSLog(#"dragging ><><><><><>>><><><><>");
return nil;
}
Now if I return nil then I can scroll but I can't get to tap my UIImageView for an action. If I return [super hitTest:point withEvent:event] I can't scroll over my UIIMageView.
isDragging is test code to determine if I'm trying to scroll or just tap. But hit test occurs before I can set isDragging property accordingly to event that is happening.
Here is my init
-(id) initWithCoder:(NSCoder *)aDecoder
{
if(self = [super initWithCoder:aDecoder])
{
[self setUserInteractionEnabled:YES];
UISwipeGestureRecognizer *swipeRecLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipe)];
swipeRecLeft.direction = UISwipeGestureRecognizerDirectionDown;
UISwipeGestureRecognizer *swipeRecRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipe)];
swipeRecRight.direction = UISwipeGestureRecognizerDirectionUp;
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapSingle)];
[self addGestureRecognizer:swipeRecRight];
[self addGestureRecognizer:swipeRecLeft];
[self addGestureRecognizer:singleTap];
[swipeRecLeft release];
[swipeRecRight release];
[singleTap release];
isDragging = NO;
}
else {
self = nil;
}
return self;
}
Here are the rest of actions
-(void) tapSingle
{
[self.delegate hitOccur];
}
-(void) swipe
{
isDragging = YES;
}
And on top of it in my UIScrollView I've setted delegate and when scrolling ends I set isDragging property manualy to NO on each subview of my UIScrollView.
It's working... but it's not perfect. To actually scroll content I must swipe TWICE in UIImageView (first one is to set isDragging to YES and then we can scroll...). How to this right and proper?
LATEST UPDATE:
Ok I've managed to solve this problem. However I'm dead sure my way isn't clean or good one (but regardles it works).
In my UIScrollView subclass I've overided hitTest method with this:
-(UIView*) hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
if(!self.dragging)
{
if([[super hitTest:point withEvent:event] class] == [ResponsiveBookView class])
{
container = [super hitTest:point withEvent:event];
}
}
return self;
}
Where the container is id container and it holds my UIView subclass. So I can recognize if the touch was on my image or on scroll view itself. Now I need to detec if it is scrolling or just touching and I do this here:
-(void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event
{
if (!self.dragging) {
NSLog(#"touch touch touch");
[container tapSingle];
[self.nextResponder touchesEnded: touches withEvent:event];
}
[super touchesEnded: touches withEvent: event];
}
As you see if self.dragging (scrolling) the default behaviour will apply. If !self.dragging I will manually call tapSingle on my container (which will then make an action "occur"). It works!
Yeah—use gesture recognizers. If you add a UITapGestureRecognizer to each UIImageView (using the UIVIew -addGestureRecognizer: method), you should get both recognition of the taps and the default scrolling behavior.
How would I detect a long tap (tap and hold) within a UIScrollView?
In view's touchesBegan: you can call your "long tap" handle with some delay.
[touchHandler performSelector:#selector(longTap:) withObject:nil afterDelay:1.5];
Then in view's touchesEnded: you can cancel that call if not enough time has passed:
[NSObject cancelPreviousPerformRequestsWithTarget:touchHandler selector:#selector(longTap:) object:nil];
//Add gesture to a method where the view is being created. In this example long tap is added to tile (a subclass of UIView):
// Add long tap for the main tiles
UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longTap:)];
[tile addGestureRecognizer:longPressGesture];
[longPressGesture release];
-(void) longTap:(UILongPressGestureRecognizer *)gestureRecognizer{
NSLog(#"gestureRecognizer= %#",gestureRecognizer);
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
NSLog(#"longTap began");
}
}