feat(SwiftUI): Full-fledged SwiftUI support (#178)

SwiftUI support:
- Loading
- FilterToggle
- ClearFilters
- Stats
- QueryRuleCustomData
- SortBy
- RelevantSort
- FilterNumericRange
- CurrentFilters
- FiltersList

Implementation improvement:
- SearchBar
- Hits
- FacetList
- HierarchicalList

Author: VladislavFitz

Sources/InstantSearch/SwiftUI/FacetList.swift

@@ -34,17 +34,14 @@ public struct FacetList<Row: View, NoResults: View>: View {
     if let noResults = noResults?(), facetListObservableController.facets.isEmpty {
       noResults
     } else {
-      ScrollView(showsIndicators: true) {
-        VStack {
-          ForEach(facetListObservableController.facets, id: \.self) { facet in
-            row(facet, facetListObservableController.isSelected(facet))
-              .onTapGesture {
-                facetListObservableController.toggle(facet)
-              }
-          }
+      VStack {
+        ForEach(facetListObservableController.facets, id: \.self) { facet in
+          row(facet, facetListObservableController.isSelected(facet))
+            .onTapGesture {
+              facetListObservableController.toggle(facet)
+            }
         }
       }
-
     }
   }
 
@@ -86,17 +83,17 @@ struct Facets_Previews: PreviewProvider {
     }
   }()
 
-  static let controller: FacetListObservableController = {
-    let controller = FacetListObservableController(facets: test, selections: ["Samsung"])
-    controller.onClick = { facet in
-      controller.selections.formSymmetricDifference([facet.value])
+  static let demoController: FacetListObservableController = {
+    let demoController = FacetListObservableController(facets: test, selections: ["Samsung"])
+    demoController.onClick = { facet in
+      demoController.selections.formSymmetricDifference([facet.value])
     }
-    return controller
+    return demoController
   }()
 
   static var previews: some View {
     NavigationView {
-      FacetList(controller, row: FacetRow.init)
+      FacetList(demoController, row: FacetRow.init)
     }
   }
 

Sources/InstantSearch/SwiftUI/FacetRow.swift

@@ -35,7 +35,6 @@ public struct FacetRow: View {
       Spacer()
       if isSelected {
         Image(systemName: "checkmark")
-          .frame(maxHeight: .infinity, alignment: .trailing)
           .foregroundColor(.accentColor)
       }
     }

Sources/InstantSearch/SwiftUI/FilterList.swift

@@ -0,0 +1,62 @@
+//
+//  FilterList.swift
+//  
+//
+//  Created by Vladislav Fitc on 21/06/2021.
+//
+
+import Foundation
+#if canImport(Combine) && canImport(SwiftUI) && (os(iOS) || os(macOS))
+import Combine
+import SwiftUI
+
+/// A view presenting the list of filters
+@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
+public struct FilterList<Filter: FilterType & Hashable, Row: View, NoResults: View>: View {
+
+  @ObservedObject public var filtersListObservableController: FilterListObservableController<Filter>
+
+  /// Closure constructing a filter row view
+  public var row: (Filter, Bool) -> Row
+
+  /// Closure constructing a no results view
+  public var noResults: (() -> NoResults)?
+
+  public init(_ filtersListObservableController: FilterListObservableController<Filter>,
+              @ViewBuilder row: @escaping (Filter, Bool) -> Row,
+              @ViewBuilder noResults: @escaping () -> NoResults) {
+    self.filtersListObservableController = filtersListObservableController
+    self.row = row
+    self.noResults = noResults
+  }
+
+  public var body: some View {
+    if let noResults = noResults?(), filtersListObservableController.filters.isEmpty {
+      noResults
+    } else {
+      VStack {
+        ForEach(filtersListObservableController.filters, id: \.self) { filter in
+          row(filter, filtersListObservableController.isSelected(filter))
+            .onTapGesture {
+              filtersListObservableController.toggle(filter)
+            }
+        }
+      }
+    }
+  }
+
+}
+
+@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
+public extension FilterList where NoResults == Never {
+
+  init(_ filtersListObservableController: FilterListObservableController<Filter>,
+       @ViewBuilder row: @escaping(Filter, Bool) -> Row) {
+    self.filtersListObservableController = filtersListObservableController
+    self.row = row
+    self.noResults = nil
+  }
+
+}
+
+#endif

Sources/InstantSearch/SwiftUI/HierarchicalFacetRow.swift

@@ -0,0 +1,57 @@
+//
+//  HierarchicalFacetRow.swift
+//  
+//
+//  Created by Vladislav Fitc on 29/06/2021.
+//
+
+import Foundation
+#if canImport(Combine) && canImport(SwiftUI)
+import Combine
+import SwiftUI
+
+@available(iOS 13.0, OSX 11.00, tvOS 13.0, watchOS 6.0, *)
+public struct HierarchicalFacetRow: View {
+
+  /// Facet value
+  public var facet: Facet
+
+  /// Facet selection state
+  public var isSelected: Bool
+
+  /// Facet nesting level in the hierarchy
+  public var nestingLevel: Int
+
+  /// Character separating the facets in the hierarchical facet
+  ///
+  /// Default value: ">"
+  public var separator: Character
+
+  public var body: some View {
+    HStack(spacing: 10) {
+      Image(systemName: isSelected ? "chevron.down" : "chevron.right")
+        .font(.callout)
+      let displayFacetValue = facet
+        .value
+        .split(separator: separator)
+        .map { $0.trimmingCharacters(in: .whitespaces) }.last ?? ""
+      Text("\(displayFacetValue) (\(facet.count))")
+        .fontWeight(isSelected ? .semibold : .regular)
+        .contentShape(Rectangle())
+      Spacer()
+    }
+    .padding(.leading, CGFloat(nestingLevel * 20))
+  }
+
+  public init(facet: Facet,
+              nestingLevel: Int,
+              isSelected: Bool,
+              separator: Character = ">") {
+    self.facet = facet
+    self.nestingLevel = nestingLevel
+    self.isSelected = isSelected
+    self.separator = separator
+  }
+
+}
+#endif

Sources/InstantSearch/SwiftUI/HierarchicalList.swift

@@ -12,47 +12,50 @@ import SwiftUI
 
 /// A view presenting the list of hierarchical facets
 @available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
-public struct HierarchicalList: View {
+public struct HierarchicalList<Row: View, NoResults: View>: View {
 
-  @ObservedObject var hierarchicalController: HierarchicalObservableController
+  @ObservedObject public var hierarchicalObservableController: HierarchicalObservableController
+
+  /// Closure constructing a hierarchical facet row view
+  public var row: (Facet, Int, Bool) -> Row
+
+  /// Closure constructing a no results view
+  public var noResults: (() -> NoResults)?
+
+  public init(_ hierarchicalObservableController: HierarchicalObservableController,
+              @ViewBuilder row: @escaping (Facet, Int, Bool) -> Row,
+              @ViewBuilder noResults: @escaping () -> NoResults) {
+    self.hierarchicalObservableController = hierarchicalObservableController
+    self.row = row
+    self.noResults = noResults
+  }
 
   public var body: some View {
-    VStack(alignment: .leading, spacing: 5) {
-      ForEach(hierarchicalController.items.prefix(20), id: \.facet) { item in
-        let (_, level, isSelected) = item
-        let facet = self.facet(from: item)
-        HStack(spacing: 10) {
-          Image(systemName: isSelected ? "chevron.down" : "chevron.right")
-            .font(.callout)
-          Text("\(facet.value) (\(facet.count))")
-            .fontWeight(isSelected ? .semibold : .regular)
-        }
-        .padding(.leading, CGFloat(level * 15))
-        .onTapGesture {
-          hierarchicalController.toggle(item.facet.value)
+    if let noResults = noResults?(), hierarchicalObservableController.hierarchicalFacets.isEmpty {
+      noResults
+    } else {
+      VStack {
+        ForEach(hierarchicalObservableController.hierarchicalFacets, id: \.facet) { hierarchicalFacet in
+          let (facet, level, isSelected) = hierarchicalFacet
+          row(facet, level, isSelected)
+            .onTapGesture {
+              hierarchicalObservableController.toggle(facet.value)
+            }
         }
       }
     }
   }
 
-  private func maxSelectedLevel(_ hierarchicalFacets: [HierarchicalFacet]) -> Int? {
-    return hierarchicalFacets
-      .filter { $0.isSelected }
-      .max { $0.level < $1.level }?
-      .level
-  }
+}
 
-  private func facet(from hierarchicalFacet: HierarchicalFacet) -> Facet {
-    let value = hierarchicalFacet
-      .facet
-      .value
-      .split(separator: ">")
-      .map { $0.trimmingCharacters(in: .whitespaces) }[hierarchicalFacet.level]
-    return Facet(value: value, count: hierarchicalFacet.facet.count, highlighted: nil)
-  }
+@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
+public extension HierarchicalList where NoResults == Never {
 
-  public init(hierarchicalController: HierarchicalObservableController) {
-    self.hierarchicalController = hierarchicalController
+  init(_ hierarchicalObservableController: HierarchicalObservableController,
+       @ViewBuilder row: @escaping(Facet, Int, Bool) -> Row) {
+    self.hierarchicalObservableController = hierarchicalObservableController
+    self.row = row
+    self.noResults = nil
   }
 
 }
@@ -61,23 +64,28 @@ public struct HierarchicalList: View {
 struct HierarchicalListPreview: PreviewProvider {
 
   static var previews: some View {
-    let controller: HierarchicalObservableController = .init()
-    HierarchicalList(hierarchicalController: controller)
-      .onAppear {
-        controller.setItem([
-          (Facet(value: "Category1", count: 10), 0, false),
-          (Facet(value: "Category1 > Category1-1", count: 7), 1, false),
-          (Facet(value: "Category1 > Category1-2", count: 2), 1, false),
-          (Facet(value: "Category1 > Category1-3", count: 1), 1, false),
-          (Facet(value: "Category2", count: 14), 0, true),
-          (Facet(value: "Category2 > Category2-1", count: 8), 1, false),
-          (Facet(value: "Category2 > Category2-2", count: 4), 1, true),
-          (Facet(value: "Category2 > Category2-2 > Category2-2-1", count: 2), 2, false),
-          (Facet(value: "Category2 > Category2-2 > Category2-2-2", count: 2), 2, true),
-          (Facet(value: "Category2 > Category2-3", count: 2), 1, false)
-        ])
-      }
+    let demoController: HierarchicalObservableController = .init()
+    HierarchicalList(demoController) { facet, nestingLevel, isSelected in
+      HierarchicalFacetRow(facet: facet,
+                           nestingLevel: nestingLevel,
+                           isSelected: isSelected)
+    }
+    .onAppear {
+      demoController.setItem([
+        (Facet(value: "Category1", count: 10), 0, false),
+        (Facet(value: "Category1 > Category1-1", count: 7), 1, false),
+        (Facet(value: "Category1 > Category1-2", count: 2), 1, false),
+        (Facet(value: "Category1 > Category1-3", count: 1), 1, false),
+        (Facet(value: "Category2", count: 14), 0, true),
+        (Facet(value: "Category2 > Category2-1", count: 8), 1, false),
+        (Facet(value: "Category2 > Category2-2", count: 4), 1, true),
+        (Facet(value: "Category2 > Category2-2 > Category2-2-1", count: 2), 2, false),
+        (Facet(value: "Category2 > Category2-2 > Category2-2-2", count: 2), 2, true),
+        (Facet(value: "Category2 > Category2-3", count: 2), 1, false)
+      ])
+    }
   }
 
 }
+
 #endif

Sources/InstantSearch/SwiftUI/SuggestionRow.swift

@@ -0,0 +1,68 @@
+//
+//  SuggestionRow.swift
+//  
+//
+//  Created by Vladislav Fitc on 01/04/2021.
+//
+
+import Foundation
+import SwiftUI
+
+/// A view presenting a search query suggestion
+@available(iOS 13.0, OSX 11.0, tvOS 13.0, watchOS 6.0, *)
+public struct SuggestionRow: View {
+
+  /// Suggestion
+  public let suggestion: QuerySuggestion
+
+  /// An action triggered when typeahead button (arrow) tapped
+  public var onTypeAhead: (String) -> Void
+
+  /// An action triggered when suggestion selected
+  public var onSelection: (String) -> Void
+
+  private func valueText(for suggestion: QuerySuggestion) -> Text {
+    if let highlightedValue = suggestion.highlighted {
+      let highlightedValueString = HighlightedString(string: highlightedValue)
+      return Text(highlightedString: highlightedValueString) { Text($0).bold() }
+    } else {
+      return Text(suggestion.query)
+    }
+  }
+
+  public init(suggestion: QuerySuggestion,
+              onSelection: @escaping (String) -> Void,
+              onTypeAhead: @escaping (String) -> Void) {
+    self.suggestion = suggestion
+    self.onSelection = onSelection
+    self.onTypeAhead = onTypeAhead
+  }
+
+  public var body: some View {
+    let stack =
+    HStack {
+      valueText(for: suggestion)
+        .padding(.vertical, 3)
+      Spacer()
+      Button(action: {
+              onTypeAhead(suggestion.query)
+             },
+             label: {
+              Image(systemName: "arrow.up.backward")
+                .foregroundColor(.gray)
+             })
+    }
+    .padding(.vertical, 4)
+    .padding(.horizontal, 20)
+    .contentShape(Rectangle())
+    #if os(tvOS)
+      return stack
+    #else
+      return stack
+        .onTapGesture {
+          onSelection(suggestion.query)
+        }
+    #endif
+  }
+
+}

Sources/InstantSearchCore/Common/Item/ItemController.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-public protocol ItemController: class {
+public protocol ItemController: AnyObject {
 
   associatedtype Item
 

Sources/InstantSearchCore/Common/Number/Boundable.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-public protocol Boundable: class {
+public protocol Boundable: AnyObject {
   associatedtype Number: Comparable & DoubleRepresentable
 
   func applyBounds(bounds: ClosedRange<Number>?)