Patch 1

Sources/FlowStack/FlowStack.swift

@@ -4,74 +4,84 @@
 //  Created by John Susek on 6/25/19.
 //  Copyright © 2019 John Susek. All rights reserved.
 //
-
+//  refactored by Alexander Voelz on 10/29/19
+//
 import SwiftUI
 
+/// arrange [content] in a grid
 @available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
 public struct FlowStack<Content>: View where Content: View {
-  // The number of columns we want to display
-  var columns: Int
-  // The total number of items in the stack
-  var numItems: Int
-  // The alignment of our columns in the last row
-  // when they don't fill all the column slots
-  var alignment: HorizontalAlignment
-
-  public let content: (Int, CGFloat) -> Content
-
-  public init(
-    columns: Int,
-    numItems: Int,
-    alignment: HorizontalAlignment?,
-    @ViewBuilder content: @escaping (Int, CGFloat) -> Content) {
-    self.content = content
-    self.columns = columns
-    self.numItems = numItems
-    self.alignment = alignment ?? HorizontalAlignment.leading
-  }
-
-  public var body : some View {
-    // A GeometryReader is required to size items in the scroll view
-    GeometryReader { geometry in
-
-      // Assume a vertical scrolling orientation for the grid
-      ScrollView(Axis.Set.vertical) {
-
-        // VStacks are our rows
-        VStack(alignment: self.alignment, spacing: 0) {
-          ForEach(0 ..< (self.numItems / self.columns)) { row in
-
-            // HStacks are our columns
-            HStack(spacing: 0) {
-              ForEach(0 ... (self.columns - 1)) { column in
-                self.content(
-                  // Pass the index to the content
-                  (row * self.columns) + column,
-                  // Pass the column width to the content
-                  (geometry.size.width/CGFloat(self.columns))
-                )
-                // Size the content to frame to fill the column
-                .frame(width: geometry.size.width/CGFloat(self.columns))
-              }
-            }
-          }
-
-          // Last row
-          // HStacks are our columns
-          HStack(spacing: 0) {
-            ForEach(0 ..< (self.numItems % self.columns)) { column in
-              self.content(
-                // Pass the index to the content
-                ((self.numItems / self.columns) * self.columns) + column,
-                // Pass the column width to the content
-                (geometry.size.width/CGFloat(self.columns))
-              )
-              // Size the content to frame to fill the column
-              .frame(width: geometry.size.width/CGFloat(self.columns))
-            }
-          }
-        }
-      }
-    }
-  }
+	/// - Parameter columns: The number of columns we want to display
+	var columns: Int
+	/// - Parameter numItems: The total number of items in the stack
+	var numItems: Int
+
+	/// - Parameter alignment: The alignment of our columns in the last row
+	var alignment = HorizontalAlignment.leading
+
+	public let content: (Int, CGFloat) -> Content
+
+	private func width(for size: CGSize)-> CGFloat {
+		return size.width/CGFloat(self.columns)
+	}
+
+	private func index(forRow row: Int, column: Int) -> Int {
+		return (row * self.columns) + column
+	}
+
+	private var lastRowColumns : Int { get { return numItems % columns }	}
+
+	private var rows : Int { get { return numItems / columns } }
+
+	public init(
+		columns: Int,
+		numItems: Int,
+		alignment: HorizontalAlignment? = HorizontalAlignment.leading,
+		@ViewBuilder content: @escaping (Int, CGFloat) -> Content) {
+		self.content = content
+		self.columns = columns
+		self.numItems = numItems
+		self.alignment = alignment ?? HorizontalAlignment.leading
+	}
+
+	public var body : some View {
+		// A GeometryReader is required to size items in the scroll view
+		GeometryReader { geometry in
+
+			// VStacks are our rows
+			VStack(alignment: self.alignment, spacing: 0) {
+				ForEach(0 ..< self.rows ) { row in
+
+					// HStacks are our columns
+					HStack(spacing: 0) {
+						ForEach(0 ..< self.columns) { column in
+							self.content(
+								// Pass the index to the content
+								self.index(forRow: row, column: column),
+								// Pass the column width to the content
+								self.width(for: geometry.size)
+							)
+								// Size the content to frame to fill the column
+								.frame(width: self.width(for: geometry.size))
+						}
+					}
+				}
+
+				// Last row
+				// HStacks are our columns
+				HStack(spacing: 0) {
+					ForEach(0 ..< self.lastRowColumns) { column in
+						self.content(
+							// Pass the index to the content
+							self.index(forRow: self.rows, column: column),
+							// Pass the column width to the content
+							self.width(for: geometry.size)
+						)
+							// Size the content to frame to fill the column
+							.frame(width: self.width(for: geometry.size))
+					}
+				}
+			}
+		}
+	}
 }