Bugfix: SectionFooterView AutoDimension Support (#110)

* Revert "fixes footer and header heights on ios 11 to be automatic dimension if the view returns as 0 (#109)"

This reverts commit 319a8b8.

* Revert "Merge pull request #108 from nealyoung/extremity-height-fix"

This reverts commit 2071110, reversing
changes made to e002d86.

* Bugfix: SectionFooterView AutoDimension Support

Problem:
1. I noticed our app was manually laying out subviews in our sectionFooters when I didn't see the need to.

2. After recent changes, Group tableView's which had nil section extremity defaulted to zero, which drops the standard spacing between sections. Note in attatchment.

Notable info:
Statics currently has deploy target of iOS8, which did not yet support automatic sectionFooterView dimensioning.

Solution:
- Offer autosizing option which uses UITableViewAutomaticDimension rather than view's original bounds height. Retain original .view(_) case in the event some clients were already sizing beforehand limiting integration breaks. This also offers automatic margin adherence.
- Bump deploy target to iOS9 for clean integration.
- Revert 2 previous PRs
- Default height for plain/grouped styles to play friendly with tableView's defaults.

* Example: AutoSized Extremity

Example/ViewController.swift

@@ -28,6 +28,11 @@ class ViewController: TableViewController {
 
         tableView.rowHeight = 50
 
+        // Note:
+        // Required to be set pre iOS11, to support autosizing
+        tableView.estimatedSectionHeaderHeight = 13.5
+        tableView.estimatedSectionFooterHeight = 13.5
+
         dataSource.sections = [
             Section(header: "Styles", rows: [
                 Row(text: "Value 1", detailText: "Detail", cellClass: Value1Cell.self),
@@ -69,7 +74,8 @@ class ViewController: TableViewController {
                         self.showAlert(title: "Deleted.")
                     })
                 ])
-            ])
+            ]),
+            Section(header: "AutoSized SectionFooterView", rows: [], footer: Section.Extremity.autoLayoutView(LargeAutoSizedExtremityView()))
         ]
     }
 
@@ -82,3 +88,28 @@ class ViewController: TableViewController {
         present(alert, animated: true, completion: nil)
     }
 }
+
+class LargeAutoSizedExtremityView: UIView {
+    lazy var label: UILabel = {
+        let label = UILabel()
+        label.numberOfLines = 0
+        label.translatesAutoresizingMaskIntoConstraints = false
+        label.text = "Is this the real life?\nIs this just fantasy?\nCaught in a landslide,\nNo escape from reality."
+        return label
+    }()
+
+    init() {
+        super.init(frame: .zero)
+
+        layoutMargins = UIEdgeInsets(top: 0, left: 16, bottom: 0, right: 16)
+        addSubview(label)
+        label.leadingAnchor.constraint(equalTo: layoutMarginsGuide.leadingAnchor).isActive = true
+        label.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor).isActive = true
+        label.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor).isActive = true
+        label.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor).isActive = true
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+}

Static.xcodeproj/project.pbxproj

@@ -442,7 +442,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -493,7 +493,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SWIFT_VERSION = 3.0.1;

Static/DataSource.swift

@@ -204,13 +204,7 @@ extension DataSource: UITableViewDataSource {
     }
 
     public func tableView(_ tableView: UITableView, heightForHeaderInSection sectionIndex: Int) -> CGFloat {
-        guard let headerView = section(at: sectionIndex)?.header else { return 0 }
-
-        var headerHeight = headerView.viewHeight
-        if headerHeight == 0 {
-            headerHeight = UITableViewAutomaticDimension
-        }
-        return headerHeight
+        return section(at: sectionIndex)?.header?.viewHeight ?? tableView.style.defaultSectionExtremityHeight
     }
 
     public func tableView(_ tableView: UITableView, titleForFooterInSection sectionIndex: Int) -> String? {
@@ -222,13 +216,7 @@ extension DataSource: UITableViewDataSource {
     }
 
     public func tableView(_ tableView: UITableView, heightForFooterInSection sectionIndex: Int) -> CGFloat {
-        guard let footerView = section(at: sectionIndex)?.footer else { return 0 }
-
-        var footerHeight = footerView.viewHeight
-        if footerHeight == 0 {
-            footerHeight = UITableViewAutomaticDimension
-        }
-        return footerHeight
+        return section(at: sectionIndex)?.footer?.viewHeight ?? tableView.style.defaultSectionExtremityHeight
     }
 
     public func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
@@ -295,3 +283,12 @@ extension DataSource: UITableViewDelegate {
         }
     }
 }
+
+extension UITableViewStyle {
+    var defaultSectionExtremityHeight: CGFloat {
+        switch self {
+        case .plain: return 0
+        case .grouped: return UITableViewAutomaticDimension
+        }
+    }
+}

Static/Section.swift

@@ -13,6 +13,10 @@ public struct Section: Hashable, Equatable {
         /// Custom view for the header or footer. The height will be the view's `bounds.height`.
         case view(UIView)
 
+        // View Sized with autolayout
+        // If Pre iOS11: Requires tableview estimatedSectionHeader/FooterHeight to be > 0
+        case autoLayoutView(UIView)
+
         var _title: String? {
             switch self {
             case .title(let extremityTitle): return extremityTitle
@@ -23,14 +27,15 @@ public struct Section: Hashable, Equatable {
         var _view: UIView? {
             switch self {
             case .view(let extremityView): return extremityView
+            case .autoLayoutView(let extremityView): return extremityView
             default: return nil
             }
         }
 
         var viewHeight: CGFloat {
             switch self {
-            case .title: return UITableViewAutomaticDimension
-            case .view(let extremityView): return extremityView.bounds.height
+            case .title(_), .autoLayoutView(_): return UITableViewAutomaticDimension
+            case .view(let view): return view.bounds.height
             }
         }
     }