Custom Clear Button

Question

I want to create custom clear button on UITextField, that is to use rightView and put image there, the problem is attaching the original clear button event to that custom rightView.

In Objective-C i can do that this way:

SEL clearButtonSelector = NSSelectorFromString(@"clearButton");
// Reference clearButton getter
IMP clearButtonImplementation = [self methodForSelector:clearButtonSelector];
// Create function pointer that returns UIButton from implementation of method that contains clearButtonSelector
UIButton * (* clearButtonFunctionPointer)(id, SEL) = (void *)clearButtonImplementation;
// Set clearTextFieldButton reference to “clearButton” from clearButtonSelector
UIButton *_clearTextFieldButton = clearButtonFunctionPointer(self, clearButtonSelector);
[_clearTextFieldButton setImage:[UIImage imageNamed:@"icon_remove"] forState:UIControlStateNormal];
self.hasClearButtonAsRightView = YES;

now how to convert this to Swift? or any ideas to workaround it?

Answer 1

You can add a custom button as right view of the UITextField like this

class CustomTextField : UITextField
{
    override init(frame: CGRect) {
        super.init(frame: frame)

        let clearButton = UIButton(frame: CGRect(origin: .zero, size: CGSize(width: 15, height: 15))
        clearButton.setImage(UIImage(named: "clear.png")!, forState: UIControlState.Normal)

        self.rightView = clearButton
        clearButton.addTarget(self, action: "clearClicked:", forControlEvents: .touchUpInside)

        self.clearButtonMode = .never
        self.rightViewMode = .always
    }

    func clearClicked(sender: UIButton)
    {
        self.text = ""
    }

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
}

Answer 2

Implementing a custom text field as suggested in the other answers is not a good idea. You should try to use extensions rather than inheritance if at all possible, because with inheritance you are much more likely to need to make major changes to your codebase in response to changes, whereas using extensions you are much more flexible to change.

I strongly suggest that instead of implementing a custom text field, you extend the UITextField class like this:

extension UITextField {
    func applyCustomClearButton() {
        clearButtonMode = .Never
        rightViewMode   = .WhileEditing

        let clearButton = UIButton(frame: CGRectMake(0, 0, 16, 16))
        clearButton.setImage(UIImage(name: "iCFieldClear")!, forState: .Normal)
        clearButton.addTarget(self, action: "clearClicked:", forControlEvents: .TouchUpInside)

        rightView = clearButton
    }

    func clearClicked(sender:UIButton) {
        text = ""
    }
}

Then to use it you just do this:

yourTextField.applyCustomClearButton()