Detect tap on UIView's "empty space" - ios

I've got a view hierarchy that looks like that
UIScrollView
|
+- UIView
|
+- UITextField
+- UITextField
+- UIButton
What I want is for user which tapped one of the text fields and sees the keyboard on the screen to be able to tap on an "empty space" of UIView to hide keyboard. So, I don't want, for instance, an event from UIButton to bubble up to UIView (that's exactly what happens if I add UITapGestureRecognizer to UIView).
How can I achieve the desired functionality?

In your viewDidLoad method add this gesture recognizer:
UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(dismissKeyboard)];
gestureRecognizer.cancelsTouchesInView = NO;
[self.view addGestureRecognizer:gestureRecognizer];
Then add the dismissKeyboard method:
- (void) dismissKeyboard{
[YOURFIELDHERE resignFirstResponder];
}
You also need to add this to make it so the buttons are still clickable and not overridden by the gesture recognizer:
gestureRecognizer.delegate = self; // in viewDidLoad
<UIGestureRecognizerDelegate> //in your header file
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
if ([touch.view isKindOfClass:[UIButton class]]){
return NO;
}
return YES; // handle the touch
}

I encounter this same problem and solve it with a naive solution.
Change the View from an instance of UIView to an instance of UIControl so that it can handle touch events.
Create an IBAction method in the View Controller that handles the touch event. In this case, we will resign any first responder from the view's subviews.
- (IBAction)backgroundTapped:(id)sender
{
[contentView endEditing:YES];
}
contentView is just the instance variable pointing to the View. You can name it anything you want. When you passed the message endEditing to the View, it essentially tells its subviews to resign first responder, thus dismissing the keyboard.
Connect the target (View) and action (IBAction method you just created) via Interface Builder, by opening the connection inspector of the View, select Touch Up Inside and drag it to the File's Owner object, then select the name of the method.
Hopefully it helps.

I know it's a little late, but a quick, simple solution is the following:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
[self.view endEditing:YES];
}
It gets called if you tap on any empty space.

Mike Z's answer is good. But I think the "if condition" below would be easier and simple in UIGestureRecognizerDelegate when you use Mike Z's answer.
Especially when the subviews are not only a button type, they may also be UITableViewCell, Custom View, etc.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
return touch.view == yourEmptySpaceView;
}

Related

Enabling touch event on Objects In a UIScrollview

I've a scrollview that has a UIView on it and on those Views, there's a UIImageView on it, three UILabel on it, I want to enable user Interaction on it, but wouldn't work. I've enabled setUserInteraction for both the UIView, UIScrollView, UILabels, UIImageView none is Responding to click actions at all. The layout look like the Image Below....
implement
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
so the gestures of the uiscroll view won't conflict with the subview's recognisers
basically what happens is that the UIScrollView won't pass the events to its subviews because the default of the above method is to return NO
This sounds too easy to be the problem, but I've made the following mistake: Everything is set just right, but I did not drag out one of the SentEvents like TouchUpInside to an action in the implementation.
check this way,
1> first check whether your view controller respond to UIGestureRecognizerDelegate this way
#interface RootViewController : UIViewController<UIGestureRecognizerDelegate>
2> then in design check you map scrollview property and delegate properly
3> apply this code in viewDidload
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapditected)];
tapGesture.delegate = self;
// prevents the scroll view from swallowing up the touch event of child buttons
tapGesture.cancelsTouchesInView = NO;
[self.scroller addGestureRecognizer:tapGesture];
4> check you apply this code
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
5> if all goes wll then this method should detected
-(void)tapditected{
}

Disable Touches on a view

Hi I have a UIView who's alpha is 0.7 and below it are some UITextFields. I don't want it to call touches events while keeping touches events. I tried using
[lightBoxView setUserInteractionEnabled:NO];
But now the UITextFields can become active or first responder. How can I disable it from calling touch events as well as not passing touches to others?
You also need to set the userInteractionEnabled = NO for all the subviews as well.
Try this,
[[lightBoxView subviews] makeObjectsPerformSelector:#selector(setUserInteractionEnabled:)
withObject:[NSNumber numberWithBool:NO]];
This will call setUserInteractionEnabled: on all direct subviews of lightBoxView and set it to NO. For a more complex subview hierarchy you will have to recursively loop through all the child views and disable the user interaction on each one. For this you can write a recursive method in a UIView category. For more details about this category method take a look at this answer.
Hope that helps!
You can remove those control from tough gesture delegate method.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if ([touch.view isKindOfClass:[UITextFiled class]])
{
return NO;
}
else
{
return YES;
}
}

How do I ignore the tap if the user tapped on a UIBarButtonItem?

For some reason my UITapGestureRecognizer is blocking my toolbar buttons from being pressed when the recognizer is added to self.view and I don't want it to. In shouldReceiveTouch I want to return NO if the item is the toolbar button.
How do I do this, however? The items aren't UIBarButtonItems apparently, because when I put an if statement to check if touch.view is of that class, it ignores it. If I put a breakpoint there and inspect touch.view its class is UIToolbarTextButton. But [UIToolbarTextButton class] I get a "use of undeclared identifier UIToolbarTextButton" error.
Can I say if it's a subview of UIToolBar? What should I do?
Without any code, this is a hard question to answer... However it sounds like you are adding the Tapgesture recognizer to the same view as your toolbar... You could check the coordinates to see if they are within the CGrect of the uitoolbar... but really what I would recommend is creating a view which contains 2 subviews: one is your toolbar, the other is the main part of your view... then add the tapGesture only to the mainView. Good luck
The better solution is not to add the UITapGestureRecognizer to the self.view.
Add a new view with Interface Builder that covers all the area but the toolbar area.
Put all your controls inside it and add the tap gesture to it.
Alternative: Add this to your ViewDidLoad function or somewhere you find more appropriate.
for (UIView *v in [toolbar items])
{
v.tag = 5; // tag tool bar items
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
if (touch.view.tag == 5)
return NO;
return YES;
}

Tap on UIBarButtonItem is not ignored by TapGestureRecognizer

I have a view with a UIToolbar with a few UIBarButtonItems and a UITableView containing some UITextFields.
I would like to dismiss the keyboard for a textfield with a tap anywhere. Therefore I added a TapGestureRecognizer to the view. To avoid that the TapgestureRecognizer handles taps on the UIBarButtonItems I added the following method (delegate is set).
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
UIView *view = touch.view;
while (view) {
NSLog(#"Class of view: %#", NSStringFromClass([view class]));
view = view.superview;
}
// Disallow recognition of tap gestures in the toolbar
if ([touch.view isKindOfClass:[UIToolbar class]]) {
return NO;
}
if ([touch.view.superview isMemberOfClass:[UIToolbar class]]) {
return NO;
}
return YES;
}
A UIBarButtonItem is not a view itself, but it has UIToolbar as its superview. When I use the above method, the check for isKindOfClass:[UIToolbar class] does not seem to work for all taps on the toolbar. However the check for the superview with isMemberOfClass:[UIToolbar class] works.
I don't understand this. Maybe someone can explain this behavior?
You shouldn't rely on the view hierarchy around private view classes. It could change at any time.
A better approach is to add the gesture to the table view (or other appropriate view which represents the area you're interested in). Just be sure to enable and disable the gesture at appropriate times so as not to block the usual table operation.

UITextfield's clear button hides keyboard when its inside UIScrollView

I have a textfield inside a UIScrollView and i want to show a clear button when user starts editing. Also i need to hide keyboard when user taps the background of UIScrollview (but not the textfield). Displaying that clear button isn't a problem, the problem is that when clear button is tapped keyboard gets hidden and the text field doesn't get cleared. Obviously the problem is with the gesture recognizer, because method dealing with this gets fired when the clear button is clicked (but it's not fired when the text field is tapped). Here's my code :
//adding gesture recognizer so i can hide keyboard when user taps scrollview
- (void) textFieldDidBeginEditing:(UITextField *)textField
{
if (self.tapOutside == nil) self.tapOutside = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(textFieldTouchOutSide:)];
[self.scrollView addGestureRecognizer:self.tapOutside];
}
//This hides keyboard BUT IS ALSO CALLED WHEN CLEAR BUTTON IS TAPPED
- (void)textFieldTouchOutSide:(id)sender
{
[self.textfield resignFirstResponder];
}
//NEVER GETS CALLED
- (BOOL) textFieldShouldClear:(UITextField *)textField {
return YES;
}
Any ideas how to solve this? Maybe better way to add gesture recognizer? I can't think of no elegant solution ... Thanks a lot in advance...
I had the same problem and solved it implementing the following method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
// Disallow recognition of gestures in unwanted elements
if ([touch.view isMemberOfClass:[UIButton class]]) { // The "clear text" icon is a UIButton
return NO;
}
return YES;
}
Don't forget to conform to the "UIGestureRecognizerDelegate" protocol and set the delegate (using your vars):
self.tapOutside.delegate = self;
Cheers
I was just having this issue and this solution worked, however if you do have other buttons on the view that you allow the user to tap while filling out the form you can do the following:
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
// Disallow recognition of gestures in unwanted elements
if ([touch.view isMemberOfClass:[UIButton class]] && [touch.view.superview isMemberOfClass:[UITextField class]]) {
// The "clear text" icon is a UIButton
return NO;
}
return YES;
}
This will narrow down the case to only return No if the button is a subview of a UITextField, as is the case with the clear button, but still hide the keyboard if they touch a normal button that would normally execute your gesture code.

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