Extended NibDesignable Version

NibDesignable.swift

@@ -23,6 +23,16 @@
 
 import UIKit
 
+
+/**
+    Protocol for `NibDesignable` pattern (related to `@IBDesignable`) for loading xib-based views for `UIView` subclasses in an `@IBDesignable`-compatible way.  Views which are `NibDesignable` may typically be rendered in Interface Builder.
+
+    ## See also
+
+    [NibDesignable](https://github.com/mbogh/NibDesignable) project on github.com (MIT License)
+
+     - authors: [@mbogh](https://github.com/mbogh), *et al*.
+    */
 public protocol NibDesignableProtocol: NSObjectProtocol {
     /**
      Identifies the view that will be the superview of the contents loaded from
@@ -31,165 +41,248 @@ public protocol NibDesignableProtocol: NSObjectProtocol {
      - returns: Superview for Nib contents.
      */
     var nibContainerView: UIView { get }
-    // MARK: - Nib loading
-
-    /**
-     Called to load the nib in setupNib().
-
-     - returns: UIView instance loaded from a nib file.
-     */
-    func loadNib() -> UIView
+
     /**
      Called in the default implementation of loadNib(). Default is class name.
 
      - returns: Name of a single view nib file.
      */
-    func nibName() -> String
+    var nibName: String { get }
+
+    /**
+     Called in the default implementation of loadNib(). Default is the bundle of the custom view class.
+
+     - returns: the bundle of the NibDesigable to look for the Nib for.
+     */
+    var bundle: Bundle { get }
+
+    /**
+     Specifies which class should be responsible for loading the nib of this NibDesignable.
+     Defaults to the class that implements the NibDesignable protocol.
+     However, if subclasses of NibDesignable views (i.e. subclasses of subclasses of NibDesignable) don't want to
+     handle their own Nib but rely on that of their superclass, they should override this variable and return the
+     super class. This will make sure the superclass handles nib loading and will result in the same nib being used
+     for the sub class as was used by the superclass.
+
+     - returns: the class that handles the nib loading. This class needs to be implementing NibDesignableProtocol.
+     */
+    var nibLoadingClass: AnyClass { get }
 }
 
-extension NibDesignableProtocol {
-    // MARK: - Nib loading
-
+extension NibDesignableProtocol where Self: UIView {
+
     /**
      Called to load the nib in setupNib().
 
      - returns: UIView instance loaded from a nib file.
      */
-    public func loadNib() -> UIView {
-        let bundle = Bundle(for: type(of: self))
-        let nib = UINib(nibName: self.nibName(), bundle: bundle)
-        return nib.instantiate(withOwner: self, options: nil)[0] as! UIView // swiftlint:disable:this force_cast
+    internal func loadNib() -> UIView {
+        let bundle = self.bundle
+        let nib = UINib(nibName: self.nibName, bundle: bundle)
+        let m_view = nib.instantiate(withOwner: self, options: nil)[0] as! UIView // swiftlint:disable:this force_cast
+        return m_view
     }
 
     // MARK: - Nib loading
 
     /**
      Called in init(frame:) and init(aDecoder:) to load the nib and add it as a subview.
      */
-    fileprivate func setupNib() {
+    internal func setupNib() {
         let view = self.loadNib()
         self.nibContainerView.addSubview(view)
         view.translatesAutoresizingMaskIntoConstraints = false
         let bindings = ["view": view]
         self.nibContainerView.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[view]|", options:[], metrics:nil, views: bindings))
         self.nibContainerView.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[view]|", options:[], metrics:nil, views: bindings))
+        self.nibContainerView.preservesSuperviewLayoutMargins = true
+
+        if #available(iOS 11.0, *) {
+            // do nothing, because it works ok
+        } else {
+            // add the preservesSuperviewLayoutMargins workaround
+            // will be executed for anything < 11.0
+            view.preservesSuperviewLayoutMargins = true
+        }
     }
-}
 
-extension UIView {
+    /// The nib container view of nib designable view.
+    /// Defaults to the view itself.
     public var nibContainerView: UIView {
         return self
     }
-    /**
-     Called in the default implementation of loadNib(). Default is class name.
 
-     - returns: Name of a single view nib file.
-     */
-    open func nibName() -> String {
-        return type(of: self).description().components(separatedBy: ".").last!
+    /// The name of the nib that the contents of this view is loaded from.
+    public var nibName: String {
+        return self.nibLoadingClass.description().components(separatedBy: ".").last!
+    }
+    /// The name of the bundle to look for the nib in. Defaults to the bundle
+    /// that contains the nibLoadingClass.
+    public var bundle: Bundle {
+        return Bundle(for: self.nibLoadingClass)
+    }
+
+    /// The class that is responsible for loading the nib. Defaults to the UIView's (sub)class itself.
+    public var nibLoadingClass: AnyClass {
+        return type(of: self)
     }
 }
 
+/**
+    `NibDesignableProtocol`-compliant implementation of `UIView`
+
+    ## See also
+    `NibDesignableProtocol`
+ */
 @IBDesignable
 open class NibDesignable: UIView, NibDesignableProtocol {
 
     // MARK: - Initializer
+    /// :nodoc:
     override public init(frame: CGRect) {
         super.init(frame: frame)
         self.setupNib()
     }
 
     // MARK: - NSCoding
+    /// :nodoc:
     required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
         self.setupNib()
     }
 }
 
+/**
+ `NibDesignableProtocol`-compliant implementation of `UITableViewCell`
+
+ ## See also
+ `NibDesignableProtocol`
+ */
 @IBDesignable
 open class NibDesignableTableViewCell: UITableViewCell, NibDesignableProtocol {
-    public override var nibContainerView: UIView {
+
+    /// The nib container view of this TableView cell.
+    open var nibContainerView: UIView {
         return self.contentView
     }
 
     // MARK: - Initializer
+    /// :nodoc:
     override public init(style: UITableViewCellStyle, reuseIdentifier: String?) {
         super.init(style: style, reuseIdentifier: reuseIdentifier)
+        self.preservesSuperviewLayoutMargins = true
+        self.setupNib()
+    }
+
+    // MARK: - NSCoding
+    /// :nodoc:
+    required public init?(coder aDecoder: NSCoder) {
+        super.init(coder: aDecoder)
+        self.preservesSuperviewLayoutMargins = true
         self.setupNib()
     }
+}
 
+/**
+ `NibDesignableProtocol`-compliant implementation of `UIControl`
+
+ ## See also
+ `NibDesignableProtocol`
+ */
+@IBDesignable
+open class NibDesignableControl: UIControl, NibDesignableProtocol {
+
+    // MARK: - Initializer
+    /// :nodoc:
+    override public init(frame: CGRect) {
+        super.init(frame: frame)
+        self.setupNib()
+    }
+
     // MARK: - NSCoding
+    /// :nodoc:
     required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
         self.setupNib()
     }
 }
 
+/**
+ `NibDesignableProtocol`-compliant implementation of `UITableViewHeaderFooterView`
+
+ ## See also
+ `NibDesignableProtocol`
+ */
 @IBDesignable
 open class NibDesignableTableViewHeaderFooterView: UITableViewHeaderFooterView, NibDesignableProtocol {
 
-	public override var nibContainerView: UIView {
+    /// The nib container view of this TableView header footer view.
+	open var nibContainerView: UIView {
 			return self.contentView
 	}
 
-	// MARK: - Initializer
+    // MARK: - Initializer
+    /// :nodoc:
 	override public init(reuseIdentifier: String?) {
 		super.init(reuseIdentifier: reuseIdentifier)
 		self.setupNib()
 	}
 
-	// MARK: - NSCoding
+    // MARK: - NSCoding
+    /// :nodoc:
 	required public init?(coder aDecoder: NSCoder) {
 		super.init(coder: aDecoder)
 		self.setupNib()
 	}
 }
 
-@IBDesignable
-open class NibDesignableControl: UIControl, NibDesignableProtocol {
-
-    // MARK: - Initializer
-    override public init(frame: CGRect) {
-        super.init(frame: frame)
-        self.setupNib()
-    }
-
-    // MARK: - NSCoding
-    required public init?(coder aDecoder: NSCoder) {
-        super.init(coder: aDecoder)
-        self.setupNib()
-    }
-}
-
+/**
+ `NibDesignableProtocol`-compliant implementation of `UICollectionReusableView`
+
+ ## See also
+ `NibDesignableProtocol`
+ */
 @IBDesignable
 open class NibDesignableCollectionReusableView: UICollectionReusableView, NibDesignableProtocol {
 
     // MARK: - Initializer
+    /// :nodoc:
     override public init(frame: CGRect) {
         super.init(frame: frame)
         self.setupNib()
     }
 
     // MARK: - NSCoding
+    /// :nodoc:
     required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
         self.setupNib()
     }
 }
 
+/**
+ `NibDesignableProtocol`-compliant implementation of `UICollectionViewCell`
+
+ ## See also
+ `NibDesignableProtocol`
+ */
 @IBDesignable
 open class NibDesignableCollectionViewCell: UICollectionViewCell, NibDesignableProtocol {
-    public override var nibContainerView: UIView {
+
+    /// The nib container view of this collection view cell.
+    open var nibContainerView: UIView {
         return self.contentView
     }
 
     // MARK: - Initializer
+    /// :nodoc:
     override public init(frame: CGRect) {
         super.init(frame: frame)
         self.setupNib()
     }
 
     // MARK: - NSCoding
+    /// :nodoc:
     required public init?(coder aDecoder: NSCoder) {
         super.init(coder: aDecoder)
         self.setupNib()