UIPicker detect tap on currently selected row
Solution 1:
First, conform the class to the UIGestureRecognizerDelegate
protocol
Then, in the view setup:
UITapGestureRecognizer *tapToSelect = [[UITapGestureRecognizer alloc]initWithTarget:self
action:@selector(tappedToSelectRow:)];
tapToSelect.delegate = self;
[self.pickerView addGestureRecognizer:tapToSelect];
And elsewhere:
#pragma mark - Actions
- (IBAction)tappedToSelectRow:(UITapGestureRecognizer *)tapRecognizer
{
if (tapRecognizer.state == UIGestureRecognizerStateEnded) {
CGFloat rowHeight = [self.pickerView rowSizeForComponent:0].height;
CGRect selectedRowFrame = CGRectInset(self.pickerView.bounds, 0.0, (CGRectGetHeight(self.pickerView.frame) - rowHeight) / 2.0 );
BOOL userTappedOnSelectedRow = (CGRectContainsPoint(selectedRowFrame, [tapRecognizer locationInView:self.pickerView]));
if (userTappedOnSelectedRow) {
NSInteger selectedRow = [self.pickerView selectedRowInComponent:0];
[self pickerView:self.pickerView didSelectRow:selectedRow inComponent:0];
}
}
}
#pragma mark - UIGestureRecognizerDelegate
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return true;
}
Solution 2:
Nikolay's answer in Swift 4:
First, add a UITapGestureRecognizer
to your UIPickerView
in viewDidLoad()
and let your UIViewController
conform to the UIGestureRecognizerDelegate
.
let tap = UITapGestureRecognizer(target: self, action: #selector(pickerTapped))
tap.delegate = self
self.pickerView.addGestureRecognizer(tap)
Add this function which calls your UIPickerViewDelegate when a tap on a row has been detected:
@objc func pickerTapped(tapRecognizer: UITapGestureRecognizer) {
if tapRecognizer.state == .ended {
let rowHeight = self.pickerView.rowSize(forComponent: 0).height
let selectedRowFrame = self.pickerView.bounds.insetBy(dx: 0, dy: (self.pickerView.frame.height - rowHeight) / 2)
let userTappedOnSelectedRow = selectedRowFrame.contains(tapRecognizer.location(in: self.pickerView))
if userTappedOnSelectedRow {
let selectedRow = self.pickerView.selectedRow(inComponent: 0)
pickerView(self.pickerView, didSelectRow: selectedRow, inComponent: 0)
}
}
}
Add the shouldRecognizeSimultaneouslyWith
method from UIGestureRecognizerDelegate
:
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
Solution 3:
Nikolay's Answer with Swift:
let tap = UITapGestureRecognizer(target: self, action: #selector(OCAccountSettingsViewController.pickerTapped(_:)))
tap.cancelsTouchesInView = false
tap.delegate = self
pickerView.addGestureRecognizer(tap)
important let your viewController confirm the UIGestureRecognizerDelegate otherwise handler won't fire:
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true}
the last step will be the handler for tap event:
func pickerTapped(tapRecognizer:UITapGestureRecognizer)
{
if (tapRecognizer.state == UIGestureRecognizerState.Ended)
{
let rowHeight : CGFloat = self.pickerView.rowSizeForComponent(0).height
let selectedRowFrame: CGRect = CGRectInset(self.pickerView.bounds, 0.0, (CGRectGetHeight(self.pickerView.frame) - rowHeight) / 2.0 )
let userTappedOnSelectedRow = (CGRectContainsPoint(selectedRowFrame, tapRecognizer.locationInView(pickerView)))
if (userTappedOnSelectedRow)
{
let selectedRow = self.pickerView.selectedRowInComponent(0)
//do whatever you want here
}
}
}