Change CPPickerview selection programmatically? - ios

Question

So i have a switch and when it is "on" i would like the CPPickerView to switch to a particular value in an array. As well if the pickerview is moved again i would like the switch to move to the off position.
I know how to get the current day of the week and am trying to switch the pickerview selection to the current day of the week.
If i am way off base here asking such a generalised question just let me know or if you need any more information.
//CPPicker
self.daysOfWeekData = [[NSArray alloc] initWithObjects:#"Monday", #"Tuesday", #"Wednesday", #"Thursday", #"Friday", #"Saturday", #"Sunday", nil];
self.dayPickerView.allowSlowDeceleration = YES;
[self.dayPickerView reloadData];
#pragma mark - Horizontal pickerview
//DataSource
-(NSInteger)numberOfItemsInPickerView:(CPPickerView *)pickerView {
return 7;
}
-(NSString *)pickerView:(CPPickerView *)pickerView titleForItem:(NSInteger)item {
return daysOfWeekData[item];
}
//Delegate
-(void)pickerView:(CPPickerView *)pickerView didSelectItem:(NSInteger)item {
self.dayLabel.text = [NSString stringWithFormat:#"%#", daysOfWeekData[item]];
}
//Today's day date
- (IBAction)todaySwitchChange:(id)sender {
if (todaySwitch.on) {
NSLog(#"It is on");
} else {
NSLog(#"It is off");
}
}

Answer 1

This can be done by using CPPickerView's setSelectedItem:animated: method, along with the normal delegate methods.
In your todaySwitchChange: method when the switch is turned on, set the CPPickerView to your desired index:
//Today's day date
- (IBAction)todaySwitchChange:(id)sender {
if (todaySwitch.on) {
NSLog(#"It is on");
// This will cause the CPPickerView to select the item you choose
NSUInteger itemToSelect = someValue; //whatever logic you need to select the right index
[self.dayPickerView setSelectedItem:itemToSelect animated:YES]; // Or disable animation if desired
} else {
NSLog(#"It is off");
}
}
To toggle the switch off when the user scrolls on the CPPickerView, you'll need to hook into the delegate method which gives you notification that scrolling has occurred:
// Implement the following delegate method
- (void)pickerViewWillBeginChangingItem:(CPPickerView *)pickerView {
// Picker is going to change due to user scrolling, so turn the switch off
if (todaySwitch.on) {
todaySwitch.on = NO;
}
}
Hope this helps!