Detect when user taps the selection indicator in a UIDatePicker? - iphone

Question

How can I detect when the user taps the selection indicator in a UIDatePicker?
Without this the user has to scroll to some other date and then back again to pick the date which is displayed under the selection indicator when the date picker slides up.
Thanks a lot,
Stine
UPDATE: This is the only solution I could come up with myself:
UIDatePicker *aDatePicker = [[UIDatePicker alloc] init];
self.datePicker = aDatePicker;
[aDatePicker release];
[self.datePicker addTarget:self action:#selector(datePicked:) forControlEvents:UIControlEventValueChanged];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(datePicked:)];
[self.datePicker addGestureRecognizer:tap];
[tap release];
Which means that datePicked will be called twice when the user actually rotates the wheel.
UPDATE: The above mentioned solution does not work for UIPickerViews though. I do not know how to achieve the wanted behavior in those cases.

Answer 1

You can do some tweak in this way:-
Conform delegate <UIGestureRecognizerDelegate>in your .h file
UITapGestureRecognizer* gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(pickerViewTapGestureRecognized:)];
[yourDatePicker addGestureRecognizer:gestureRecognizer];
gestureRecognizer.delegate=self;
gestureRecognizer.numberOfTapsRequired=2;//Whenever you do double tap it will called. So allow user to do double tap on selected date.
//Below is the Delegate method
-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
//Below method will trigger when do the double tap
-(void)pickerViewTapGestureRecognized:(UITapGestureRecognizer*)recognizer
{
UIDatePicker *datePicker=(UIDatePicker*)[[recognizer view] viewWithTag:101];
NSLog(#"datePicker=%#", datePicker.date);
}

Answer 2

Try this code:
UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(pickerViewTapped:)];
[recognizer setNumberOfTapsRequired:2];
[recognizer setCancelsTouchesInView:NO];
[recognizer setDelaysTouchesEnded:NO];
[recognizer setDelaysTouchesBegan:NO];
[self.answerPicker addGestureRecognizer:recognizer];
// ....
- (IBAction)pickerViewTapped:(UITapGestureRecognizer *)sender {
CGPoint coord = [sender locationInView:self.answerPicker];
if(coord.y <= 126 && coord.y >= 90) {
//do something
}
}

Answer 3

This is an old question but here's what I did in order to grab the selection bar rect on the UIDatePicker. With this, you could just add a button/view with a gesture recognizer to detect taps. It's a bit of a hack but it seems to be working well in iOS6 and iOS7.
+ (CGRect)getSelectionBarRectFromPicker:(UIDatePicker *)picker
{
int counter = 0;
CGRect selectionBarRect;
for(UIView *datePickerView in picker.subviews){
for(UIView *subview in datePickerView.subviews){
if([[[UIDevice currentDevice] systemVersion] floatValue] < 7.0){
if([NSStringFromClass([subview class]) isEqualToString:#"_UIPickerViewSelectionBar"]){
if(counter == 0){
selectionBarRect.origin = subview.frame.origin;
selectionBarRect.size.height = subview.frame.size.height;
}
selectionBarRect.size.width += subview.frame.size.width;
counter++;
}
} else {
if(subview.frame.size.height < 1){
if(counter == 0){
selectionBarRect.origin = subview.frame.origin;
selectionBarRect.size.width = subview.frame.size.width;
} else {
selectionBarRect.size.height = subview.frame.origin.y - selectionBarRect.origin.y;
}
counter++;
}
}
}
}
return selectionBarRect;
}