Picker goes black, then crashes app (sometimes) - objective-c

Question

I have a number of text fields that offer a selection of pre defined values in the form of a picker view. Occasionally, usually after a lot of text boxes have been filled in, the picker goes black, then the app crashes.
I cant seem to reproduce the problem, it just happens occasionally...reported by some users. As ive picked up this code form someone else maybe I have missed something?
Here is the code for the custom class for the text box/pickers
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
self.touchEnabled = YES;
self.textField = nil;
self.editableTextField = nil;
__selectedValue = #"";
self.pickerView = nil;
self.button = nil;
self.textValue = nil;
self.otherSelected = NO;
self.backgroundColor = [UIColor clearColor];
self.userInteractionEnabled = YES;
self.values = [NSArray arrayWithObjects:#"Value1", #"Value2", #"Other", nil];
}
return self;
}
- (void)layoutSubviews
{
if (self.textField == nil) {
UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, 31.0f)];
textField.borderStyle = UITextBorderStyleRoundedRect;
textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
textField.font = [UIFont systemFontOfSize:12.0f];
UIPickerView *pickerView = [[UIPickerView alloc] init];
[pickerView sizeToFit];
pickerView.delegate = self;
pickerView.dataSource = self;
pickerView.showsSelectionIndicator = YES;
if (self.textValue != nil && ![self.textValue isEqualToString:#""]) {
textField.text = self.textValue;
int matchedIndex = -1;
int otherIndex = -1;
for (int i = 0; i < self.values.count; i++) {
NSString *value = [self.values objectAtIndex:i];
if ([value isEqualToString:#"Other"]) {
otherIndex = i;
}
if ([self.textValue isEqualToString:[self.values objectAtIndex:i]]) {
matchedIndex = i;
}
}
if (matchedIndex > -1) {
[pickerView selectRow:matchedIndex inComponent:0 animated:NO];
} else if (otherIndex > -1) {
[pickerView selectRow:otherIndex inComponent:0 animated:NO];
}
}
textField.inputView = pickerView;
self.pickerView = pickerView;
UIToolbar *accessoryView = [[UIToolbar alloc] init];
[accessoryView sizeToFit];
accessoryView.barStyle = UIBarStyleBlackOpaque;
accessoryView.tintColor = [UIColor grayColor];
UIBarButtonItem *spacer = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:#"Done" style:UIBarButtonItemStyleDone target:self action:#selector(pickerDone:)];
self.doneButton = doneButton;
accessoryView.items = [NSArray arrayWithObjects:spacer, doneButton, nil];
textField.inputAccessoryView = accessoryView;
[self addSubview:textField];
self.textField = textField;
}
if (self.button == nil) {
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.backgroundColor = [UIColor clearColor];
button.frame = self.bounds;
[button addTarget:self action:#selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:button];
self.button = button;
}
}
- (void)buttonPressed:(id)sender
{
if (self.fieldDelegate != nil) {
[self.fieldDelegate performSelector:#selector(fieldBeganEditing:) withObject:self];
}
if (self.otherSelected) {
self.doneButton.action = #selector(textFieldDone:);
self.textField.inputView = nil;
} else {
self.doneButton.action = #selector(pickerDone:);
self.textField.inputView = self.pickerView;
}
[self.textField becomeFirstResponder];
}
- (void)textFieldDone:(id)sender
{
LogCmd();
[self.textField resignFirstResponder];
self.textField.inputView = self.pickerView;
self.doneButton.action = #selector(pickerDone:);
[self.textField becomeFirstResponder];
}
- (void)pickerDone:(id)sender
{
LogCmd();
NSString *value = [self.values objectAtIndex:[self.pickerView selectedRowInComponent:0]];
if (!self.otherSelected) {
self.textField.text = value;
__selectedValue = value;
}
[self.textField resignFirstResponder];
}
/*- (void)setValues:(NSArray *)values
{
_values = values;
[self.pickerView reloadAllComponents];
}*/
#pragma mark - UITextFieldDelegate
- (void)textFieldDidEndEditing:(UITextField *)textField
{
LogCmd();
}
#pragma mark - UIPickerViewDelegate
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent: (NSInteger)component
{
NSString *value = [self.values objectAtIndex:row];
if ([value isEqualToString:#"Other"]) {
self.otherSelected = YES;
self.textField.text = #"";
__selectedValue = #"";
[self.doneButton setAction:#selector(textFieldDone:)];
self.textField.inputView = nil;
[self.textField resignFirstResponder];
[self.textField becomeFirstResponder];
//[self.textField performSelector:#selector(becomeFirstResponder) withObject:nil afterDelay:0.2];
} else {
self.otherSelected = NO;
self.textField.text = value;
__selectedValue = value;
}
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent: (NSInteger)component
{
return [self.values objectAtIndex:row];
}
#pragma mark - UIPickerViewDataSource
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return self.values.count;
}
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}