CODEWITHSUNDEEP
objective-cswiftdelegatesprotocols
user3329412
user3329412

Reputation: 51

Convert Objective-C code to Swift: delegate

I'm now learning a function which is written in Objective-C. But I don't know Objective-C language. When I'm converting the code to Swift, I got stuck at the delegate functions.

The code in .h file is:

#import <UIKit/UIKit.h>

@protocol SCPopViewDelegate <NSObject>

@optional
- (void)viewHeight:(CGFloat)height;
- (void)itemPressedWithIndex:(NSInteger)index;

@end

@interface SCPopView : UIView

@property (nonatomic, weak)     id      <SCPopViewDelegate>delegate;
@property (nonatomic, strong)   NSArray *itemNames;

@end

and I'm trying to convert the code as:

protocol popViewDelegate: class {
    func itemPressedWithIndex(index: Int)
    func viewHeight(height: CGFloat)
}

but for the three last sentences, i don’t know how to deal with them, especially the one with id and delegate.

Can I get any help, please? I will do more effort to learn Swift. Thank you very much!

Upvotes: 0

Views: 765

Answers (3)

Md. Ibrahim Hassan
Md. Ibrahim Hassan

Reputation: 5467

Swift 4.2

Converted Code for Swift 4.2

protocol SCPopViewDelegate: class {
    func viewHeight(_ height: CGFloat)
    func itemPressed(with index: Int)
}

extension SCPopViewDelegate {
    func viewHeight(_ height: CGFloat) {}
    func itemPressed(with index: Int) {}
}

class SCPopView: UIView {
    weak var delegate: SCPopViewDelegate?
    var itemNames: [Any] = []
}

This code is based on code converted by an online code conversion tool, the link to the original generated code.

Upvotes: 1

Dare
Dare

Reputation: 2587

import UIKit

@objc protocol SCPopViewDelegate{
    optional func viewHeight(height: Float)
    optional func itemPressedWithIndex(index : Int)
}

class DGViewController: UIViewController {

    var delegate:SCPopViewDelegate! = nil

    override func viewDidLoad() {
        super.viewDidLoad()
        delegate?.viewHeight?(Float(self.view.frame.size.height))
    }

And in the class that implements the delegate 

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    var vc = DGViewController()
    vc.delegate = self
    vc.view.frame = self.view.frame;
    vc.view.backgroundColor = (UIColor.redColor())
    self.presentViewController(vc, animated: true) { () -> Void in}
}

func viewHeight(height: Float) {
    println(height)
}

Upvotes: 0

Duncan C
Duncan C

Reputation: 131408

The definition of the protocol ends with the first @end statement.

The @interface after that is the definition of an Objective-C class, SCPopView.

You don't need to care about the latter part if you're just trying to define the protocol in Swift.

FYI:

@interface someClass: NSObject

is equivalent to

class someClass: NSObject

In Swift.

Upvotes: 0

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