offset Support

Author: iwecon

Sources/StackKit/HStackView.swift

@@ -172,6 +172,12 @@ extension HStackView {
                     subview.frame.origin.x = previousView.frame.maxX + spacing
                 }
             }
+            
+            guard let offset = subview._stackKit_offset else {
+                continue
+            }
+            subview.frame.origin.x += offset.x
+            subview.frame.origin.y += offset.y
         }
     }
 

Sources/StackKit/UIView+StackKit/UIView+StackKitCompatibleProvider.swift

@@ -13,6 +13,12 @@ extension UIView: StackKitCompatibleProvider { }
 
 extension StackKitCompatible where Base: UIView {
 
+    @discardableResult
+    public func offset(_ value: CGPoint?) -> Self {
+        view._stackKit_offset = value
+        return self
+    }
+    
     @discardableResult
     public func width(_ value: CGFloat?) -> Self {
         view._stackKit_width = value

Sources/StackKit/UIView+StackKit/_UIView_StackKitProvider.swift

@@ -1,6 +1,8 @@
 import UIKit
 
 struct _UIView_StackKitKeys {
+    static var offsetKey = "StackKit_offsetKey"
+    
     static var widthKey = "StackKit_widthKey"
     static var heightKey = "StackKit_heightKey"
 
@@ -12,6 +14,8 @@ struct _UIView_StackKitKeys {
 }
 
 protocol _UIView_StackKitProvider {
+    var _stackKit_offset: CGPoint? { get set }
+    
     var _stackKit_width: CGFloat? { get set }
     var _stackKit_height: CGFloat? { get set }
 
@@ -24,6 +28,22 @@ protocol _UIView_StackKitProvider {
 
 extension UIView: _UIView_StackKitProvider {
 
+    var _stackKit_offset: CGPoint? {
+        get {
+            guard let value = Runtime.getProperty(self, key: &_UIView_StackKitKeys.offsetKey) as? NSValue else {
+                return nil
+            }
+            return value.cgPointValue
+        }
+        set {
+            guard let newValue else {
+                Runtime.setProperty(self, key: &_UIView_StackKitKeys.offsetKey, value: nil, policy: .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+                return
+            }
+            Runtime.setProperty(self, key: &_UIView_StackKitKeys.offsetKey, value: NSValue(cgPoint: newValue), policy: .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+        }
+    }
+    
     var _stackKit_width: CGFloat? {
         get {
             Runtime.getCGFloatProperty(self, key: &_UIView_StackKitKeys.widthKey)

Sources/StackKit/VStackView.swift

@@ -164,6 +164,12 @@ extension VStackView {
                     subview.frame.origin.y = previousView.frame.maxY + spacing
                 }
             }
+            
+            guard let offset = subview._stackKit_offset else {
+                continue
+            }
+            subview.frame.origin.x += offset.x
+            subview.frame.origin.y += offset.y
         }
     }