DSL for PlasticView Anchors and Values

Katana/Plastic/Anchor.swift

@@ -32,16 +32,21 @@ public struct Anchor: Equatable {
 
   /// the `PlasticView` to which the anchor is associated to
   let view: PlasticView
-
+
+  /// the offset at which this anchor will be set, with respect to the anchor it will be assigned to
+  var offset: Value
+
   /**
    Creates an anchor with a given type, related to a specific `PlasticView`
 
    - parameter kind: the kind of the anchor
    - parameter view: the view the anchor pertains to
+   - parameter offset: the offset at which this anchor will be set, with respect to the anchor it will be assigned to
   */
-  init(kind: Kind, view: PlasticView) {
+  init(kind: Kind, view: PlasticView, offset: Value = .zero) {
     self.kind = kind
     self.view = view
+    self.offset = offset
   }
 
   /**
@@ -51,27 +56,32 @@ public struct Anchor: Equatable {
   var coordinate: CGFloat {
     let absoluteOrigin = self.view.absoluteOrigin
     let size = self.view.frame
-
+    var coord: CGFloat
+
     switch self.kind {
     case .left:
-      return absoluteOrigin.x
+      coord = absoluteOrigin.x
 
     case .right:
-      return absoluteOrigin.x + size.width
+      coord = absoluteOrigin.x + size.width
 
     case .centerX:
-      return absoluteOrigin.x + size.width / 2.0
+      coord = absoluteOrigin.x + size.width / 2.0
 
     case .top:
-      return absoluteOrigin.y
+      coord = absoluteOrigin.y
 
     case .bottom:
-      return absoluteOrigin.y + size.height
+      coord = absoluteOrigin.y + size.height
 
     case .centerY:
-      return absoluteOrigin.y + size.height / 2.0
+      coord = absoluteOrigin.y + size.height / 2.0
 
     }
+
+    coord += view.scaleValue(offset)
+
+    return coord
   }
 
   /**
@@ -85,4 +95,18 @@ public struct Anchor: Equatable {
   public static func == (lhs: Anchor, rhs: Anchor) -> Bool {
     return lhs.kind == rhs.kind && lhs.view === rhs.view
   }
+
+  /**
+   Create an anchor equal to `lhs`, but with an offset equal to `lhs.offset + rhs`
+   */
+  public static func + (lhs: Anchor, rhs: Value) -> Anchor {
+    return Anchor(kind: lhs.kind, view: lhs.view, offset: lhs.offset + rhs)
+  }
+
+  /**
+   Create an anchor equal to `lhs`, but with an offset equal to `lhs.offset - rhs`
+   */
+  public static func - (lhs: Anchor, rhs: Value) -> Anchor {
+    return Anchor(kind: lhs.kind, view: lhs.view, offset: lhs.offset + -rhs)
+  }
 }

Katana/Plastic/Array+Plastic.swift

@@ -40,13 +40,13 @@ extension Array where Element: PlasticView {
     }
 
     let leftmostOffset = (right.coordinate - left.coordinate - totalWidth) / 2.0
-    firstView.setLeft(left, offset: Value.fixed(leftmostOffset))
+    firstView.left = left + .fixed(leftmostOffset)
 
     for (index, view) in otherViews.enumerated() {
       let leftwardView = self[index] // take prev view
       let scaledSpacing = scaledSpacings[index]
       let anchor = Anchor(kind: .right, view: leftwardView)
-      view.setLeft(anchor, offset: .fixed(scaledSpacing))
+      view.left = anchor + .fixed(scaledSpacing)
     }
   }
 
@@ -80,13 +80,13 @@ extension Array where Element: PlasticView {
     }
 
     let upmostOffset = (bottom.coordinate - top.coordinate - totalHeight) / 2.0
-    firstView.setTop(top, offset: .fixed(upmostOffset))
+    firstView.top = top + .fixed(upmostOffset)
 
     for (index, view) in otherViews.enumerated() {
       let upperView = self[index]
       let scaledSpacing = scaledSpacings[index]
       let anchor = Anchor(kind: .bottom, view: upperView)
-      view.setTop(anchor, offset: .fixed(scaledSpacing))
+      view.top = anchor + .fixed(scaledSpacing)
     }
   }
 
@@ -144,12 +144,12 @@ extension Array where Element: PlasticView {
       view.width = .fixed(width)
 
       if index == 0 {
-        view.setLeft(left, offset: insets.left)
+        view.left = left + insets.left
 
       } else {
         let leftwardView = self[index-1]
         let spacing = spacings[index-1]
-        view.setLeft(leftwardView.right, offset: spacing)
+        view.left = leftwardView.right + spacing
       }
     }
   }
@@ -207,12 +207,12 @@ extension Array where Element: PlasticView {
       view.height = .fixed(height)
 
       if index == 0 {
-        view.setTop(top, offset: insets.top)
+        view.top = top + insets.top
 
       } else {
         let upperView = self[index-1]
         let spacing = spacings[index - 1]
-        view.setTop(upperView.bottom, offset: spacing)
+        view.top = upperView.bottom + spacing
       }
     }
   }

Katana/Plastic/EdgeInsets.swift

@@ -67,10 +67,10 @@ public struct EdgeInsets: Equatable {
    - warning: Always prefer the static method `scalable(_:_:_:_:)` instead of this constructor
   */
   public init(_ top: CGFloat, _ left: CGFloat, _ bottom: CGFloat, _ right: CGFloat) {
-    self.top = Value(top)
-    self.left = Value(left)
-    self.bottom = Value(bottom)
-    self.right = Value(right)
+    self.top = .scalable(top)
+    self.left = .scalable(left)
+    self.bottom = .scalable(bottom)
+    self.right = .scalable(right)
   }
 
 

Katana/Plastic/PlasticView+Convenience.swift

@@ -18,8 +18,8 @@ extension PlasticView {
    - parameter insets: the insets to use when filling the view frame. Only the left and right insets are used.
   */
   public func fillHorizontally(_ view: PlasticView, insets: EdgeInsets = .zero) {
-    self.setLeft(view.left, offset: insets.left)
-    self.setRight(view.right, offset: -insets.right)
+    self.left = view.left + insets.left
+    self.right = view.right - insets.right
   }
 
   /**
@@ -30,8 +30,8 @@ extension PlasticView {
    - parameter insets: the insets to use when filling the view frame. Only the left and right insets are used
   */
   public func fillVertically(_ view: PlasticView, insets: EdgeInsets = .zero) {
-    self.setTop(view.top, offset: insets.top)
-    self.setBottom(view.bottom, offset: -insets.bottom)
+    self.top = view.top + insets.top
+    self.bottom = view.bottom - insets.bottom
   }
 
   /**
@@ -81,10 +81,11 @@ extension PlasticView {
                 bottom: Anchor,
                  right: Anchor,
                 insets: EdgeInsets = .zero) {
-    self.setLeft(left, offset: insets.left)
-    self.setRight(right, offset: -insets.right)
-    self.setTop(top, offset: insets.top)
-    self.setBottom(bottom, offset: -insets.bottom)
+
+    self.left = left + insets.left
+    self.right = right - insets.right
+    self.top = top + insets.top
+    self.bottom = bottom - insets.bottom
   }
 
   /**
@@ -106,10 +107,7 @@ extension PlasticView {
                    aspectRatio: CGFloat = 1,
                    insets: EdgeInsets = .zero) {
 
-    self.setLeft(left, offset: insets.left)
-    self.setRight(right, offset: -insets.right)
-    self.setTop(top, offset: insets.top)
-    self.setBottom(bottom, offset: -insets.bottom)
+    self.fill(top: top, left: left, bottom: bottom, right: right, insets: insets)
 
     let width = self.width.unscaledValue
     let height = self.height.unscaledValue
@@ -133,7 +131,7 @@ extension PlasticView {
   */
   public func centerBetween(left: Anchor, right: Anchor) {
     let offset: Value = .fixed((right.coordinate - left.coordinate) / 2.0)
-    self.setCenterX(left, offset: offset)
+    self.centerX = left + offset
   }
 
   /**
@@ -145,7 +143,7 @@ extension PlasticView {
   */
   public func centerBetween(top: Anchor, bottom: Anchor) {
     let offset: Value = .fixed((bottom.coordinate - top.coordinate) / 2.0)
-    self.setCenterY(top, offset: offset)
+    self.centerY = top + offset
   }
 
   /**
@@ -167,9 +165,9 @@ extension PlasticView {
    - parameter insets: the insets to use when aligning edges
   */
   public func coverLeft(_ view: PlasticView, insets: EdgeInsets = .zero) {
-    self.setLeft(view.left, offset: insets.left)
-    self.setTop(view.top, offset: insets.top)
-    self.setBottom(view.bottom, offset: -insets.bottom)
+    self.left = view.left + insets.left
+    self.top = view.top + insets.top
+    self.bottom = view.bottom - insets.bottom
   }
 
   /**
@@ -180,9 +178,9 @@ extension PlasticView {
    - parameter insets: the insets to use when aligning edges
   */
   public func coverRight(_ view: PlasticView, insets: EdgeInsets = .zero) {
-    self.setRight(view.right, offset: -insets.right)
-    self.setTop(view.top, offset: insets.top)
-    self.setBottom(view.bottom, offset: -insets.bottom)
+    self.right = view.right - insets.right
+    self.top = view.top + insets.top
+    self.bottom = view.bottom - insets.bottom
   }
 
   /**
@@ -193,9 +191,9 @@ extension PlasticView {
    - parameter insets: the insets to use when aligning edges
   */
   public func asHeader(_ view: PlasticView, insets: EdgeInsets = EdgeInsets.zero) {
-    self.setLeft(view.left, offset: insets.left)
-    self.setRight(view.right, offset: -insets.right)
-    self.setTop(view.top, offset: insets.top)
+    self.left = view.left + insets.left
+    self.right = view.right - insets.right
+    self.top = view.top + insets.top
   }
 
   /**
@@ -206,8 +204,8 @@ extension PlasticView {
    - parameter insets: the insets to use when aligning edges
   */
   public func asFooter(_ view: PlasticView, insets: EdgeInsets = EdgeInsets.zero) {
-    self.setLeft(view.left, offset: insets.left)
-    self.setRight(view.right, offset: -insets.right)
-    self.setBottom(view.bottom, offset: -insets.bottom)
+    self.left = view.left + insets.left
+    self.right = view.right - insets.right
+    self.bottom = view.bottom - insets.bottom
   }
 }