How do I redeclare a property as read-write in UIResponder subclass with swift?

Question

I'm trying to follow this guide, but using swift: InputAccessoryView docked at bottom

I can't seem to set the inputAccessoryView for my ViewController, according to the documentation, I need to redeclare it:

The value of this read-only property is nil. If you want to attach custom controls to a system-supplied input view (such as the system keyboard) or to a custom input view (one you provide in the inputView property), redeclare this property as read-write in a UIResponder subclass. You can then use this property to manage a custom accessory view. When the receiver becomes the first responder, the responder infrastructure attaches the accessory view to the appropriate input view before displaying it.

I can't figure out how to do this using swift. Any help is greatly appreciated.

Answer 1

Old question but this may be of use to those not overly familiar with Objective-C.

I'm not sure how to achieve this with swift alone but it's easy enough to do the "dirty work" in objective c land and utilise the result in swift

Process

This approach requires 3 files to be added to your project.

1. Add an objective C class, copy and paste the following code into the two new files (.h, .m)
2. Add a bridging header and copy and paste into it the specified import
3. At this point you can extend any swift class from this Objective c class instead of UIView and et voila, you can change the inputAccessoryView.

Enjoy

.h file

#import <UIKit/UIKit.h>

/**
 * Starting point for subclasses that allow input accessorty view to be changed
 */
@interface YourBaseView : UIView

@property (readwrite,nonatomic) UIView*_Nullable inputAccessoryView;
@end

.m file

#import "YourBaseView.h"

@implementation YourBaseView

/*
 // Only override drawRect: if you perform custom drawing.
 // An empty implementation adversely affects performance during animation.
 - (void)drawRect:(CGRect)rect {
 // Drawing code
 }
 */

@end

Bridging Header

In the "YOUR_PROJECT_NAME-Bridging-Header.h" (or whatever its called in the Objective-C Bridging Header property in build settings of your project (SWIFT_OBJC_BRIDGING_HEADER)

#import "YourBaseView.h"

Swift Demo

class YourSwiftAccessoryInputView : YourBaseView
{
    //the rest is up to you
}

let instance = YourSwiftAccessoryInputView(frame: CGRect(x:0, y:0,width:100,height:100))
instance.inputAccessoryView = Some view

Answer 2

Try this.

private weak var _inputAccessoryViewController: UIInputViewController?
override var inputAccessoryViewController: UIInputViewController? {
    get {
        return _inputAccessoryViewController
    }
    set {
        _inputAccessoryViewController = newValue
    }
}

Anyway, I don't think this makes any differences.

Answer 3

Like this:

private let accessoryView = AccessoryView()
class MessagesViewController : UIViewController {
    override var inputAccessoryView: AccessoryView {
        return accessoryView
    }
}