gitignore

Author: ay42

Sources/Grid/Grid.swift

@@ -2,38 +2,61 @@ import SwiftUI
 
 /// A view that arranges its children in a grid.
 @available(iOS 13.0, OSX 10.15, *)
-public struct Grid<Data, Content> : View where Data: RandomAccessCollection, Data.Element: Identifiable, Content : View {
-    public typealias Item = Data.Element.IdentifiedValue
-    private let data: [Item]
-    private let minimumItemWidth: Length
-    private let spacing: Length
-    private let content: (Item) -> Content
+public struct Grid<Data, Content> : View where Data: RandomAccessCollection, Content : View {
+    private let data: [Data.Element]
+    private let minimumItemWidth: CGFloat
+    private let spacing: CGFloat
+    private let content: (Data.Element) -> Content
 
     public var body: some View {
         GeometryReader { geometry in
             ScrollView {
-                VStack(spacing: self.spacing) {
-                    ForEach(0..<Int((Length(self.data.count) / max(1.0, geometry.size.width / self.minimumItemWidth).rounded(.down)).rounded(.up))) { rowIndex in
+                VStack(alignment: .leading, spacing: self.spacing) {
+                    ForEach(0..<self.rowCount(with: geometry), id: \.self) { rowIndex in
                         HStack(spacing: self.spacing) {
-                            ForEach(0..<Int(geometry.size.width / self.minimumItemWidth)) { columnIndex in
-                                if rowIndex * max(1, Int(geometry.size.width / self.minimumItemWidth)) + columnIndex <= self.data.count - 1 {
-                                    self.content(self.data[rowIndex * max(1, Int(geometry.size.width / self.minimumItemWidth)) + columnIndex])
-                                } else {
-                                    Rectangle().foregroundColor(.clear)
-                                }
+                            ForEach(0..<self.columnCount(with: geometry), id: \.self) { (columnIndex: Int) -> Content? in
+                                self.item(with: geometry, rowIndex: rowIndex, columnIndex: columnIndex)
+                            }
+                            ForEach(0..<self.emptyElementsCount(geometry: geometry, row: rowIndex), id: \.self) { _ in
+                                Spacer()
                             }
                         }
                     }
-                    .clipped()
                 }
                 .padding()
             }
+            
         }
-        
     }
 
-    public init(_ data: Data, minimumItemWidth: Length = 300, spacing: Length = 8, content: @escaping (Item) -> Content) {
-        self.data = data.map { $0.identifiedValue }
+    func emptyElementsCount(geometry:GeometryProxy, row: Int) -> Int {
+        let isLastRow = rowCount(with: geometry) - 1 == row
+        let possibleItemsCount = rowCount(with: geometry) * columnCount(with: geometry)
+        return isLastRow ? possibleItemsCount % data.count : 0
+    }
+    
+    func rowCount(with geometry: GeometryProxy) -> Int {
+        Int((CGFloat(self.data.count) / max(1.0, geometry.size.width / self.minimumItemWidth).rounded(.down)).rounded(.up))
+    }
+    
+    func columnCount(with geometry: GeometryProxy) -> Int {
+        Int(geometry.size.width / self.minimumItemWidth)
+    }
+    
+    func itemIndex(with geometry: GeometryProxy, rowIndex: Int, columnIndex: Int) -> Int {
+        rowIndex * max(1, Int(geometry.size.width / self.minimumItemWidth)) + columnIndex
+    }
+    
+    func item(with geometry: GeometryProxy, rowIndex: Int, columnIndex: Int) -> Content? {
+        if self.itemIndex(with: geometry, rowIndex: rowIndex, columnIndex: columnIndex) <= self.data.count - 1 {
+            return self.content(self.data[self.itemIndex(with: geometry, rowIndex: rowIndex, columnIndex: columnIndex)])
+        } else {
+            return nil
+        }
+    }
+    
+    public init(_ data: Data, minimumItemWidth: CGFloat = 300, spacing: CGFloat = 8, content: @escaping (Data.Element) -> Content) {
+        self.data = data.map { $0 }
         self.content = content
         self.spacing = spacing
         self.minimumItemWidth = minimumItemWidth
@@ -43,7 +66,9 @@ public struct Grid<Data, Content> : View where Data: RandomAccessCollection, Dat
 #if DEBUG
 struct Grid_Previews: PreviewProvider {
     static var previews: some View {
-        Text("123")
+        Grid(0...100) {
+            Text("\($0)")
+        }
     }
 }
 #endif