UITap gesture only works on one view - ios

Question

I have the following code in a view controller:
#interface QuizController ()
#property (weak, nonatomic) IBOutlet UITextView *questionText;
#property (weak, nonatomic) IBOutlet UITextView *one;
#property (weak, nonatomic) IBOutlet UITextView *two;
#property (weak, nonatomic) IBOutlet UITextView *three;
#property (weak, nonatomic) IBOutlet UITextView *four;
#property(strong, nonatomic) NSMutableArray* possAnswers;
#end
#implementation QuizController
- (void)viewDidLoad {
[super viewDidLoad];
[self.manager setupGame];
self.possAnswers = [[NSMutableArray alloc] initWithObjects:#"a", #"b", #"c", #"d", nil];
}
//This listens for a tap on any of the TextViews and sets the background to Blue
- (IBAction)fourTapped:(id)sender {
NSLog(#"There's been a tap!");
[self blankBoxes];
if( [sender isKindOfClass:[UITapGestureRecognizer class]] )
{
UITapGestureRecognizer* tgr = (UITapGestureRecognizer*)sender;
UIView* view = tgr.view;
if( [view isKindOfClass:[UITextView class]]){
UITextView* tv = (UITextView*)view;
NSLog([tv text]);
[tv setBackgroundColor:[UIColor blueColor]];
}
}
}
-(void)blankBoxes
{
[_one setBackgroundColor:[UIColor whiteColor]];
[_two setBackgroundColor:[UIColor whiteColor]];
[_three setBackgroundColor:[UIColor whiteColor]];
[_four setBackgroundColor:[UIColor whiteColor]];
}
However, the only UITextView that gets highlighted is _one, no matter which view is tapped. I don't understand why this is. I'd be really grateful if anyone could point this out to me.

Answer 1

Gesture recognizers attach to one and only one view. That's by design. If you want a single gesture recognizer that lets you recognize taps on multiple views, you have to attach it to a common, enclosing superview, then look at the tap coordinates and figure out which view was tapped.
Normally you just create a different gesture recognizer for each view that needs to responds to taps.

Answer 2

Add the UIGestureRecognizer to a UIView that contains your subviews. After that use CGRectContainsPoint() to check if the tap location is in one of the subviews, then continue from there.
CGPoint *touchLocation = [gesture locationInView:self];
for(UIView *view in self.subviews){
if(CGRectContainsPoint(view.frame, touchLocation))
//Your code here
}