Added ScrollStack.ControllerSize to manage fitToLayout and fixed size for axis

Author: malcommac

ScrollStackController.xcodeproj/project.xcworkspace/xcuserdata/daniele.xcuserdatad/UserInterfaceState.xcuserstate

@@ -26,8 +26,8 @@ public class GalleryVC: UIViewController, ScrollStackContainableController {
         return vc
     }
 
-    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> CGFloat? {
-        return 300
+    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> ScrollStack.ControllerSize? {
+        return .fixed(300)
     }
 
     public override func viewDidAppear(_ animated: Bool) {

ScrollStackControllerDemo/Child View Controllers/GalleryVC.swift

@@ -23,12 +23,14 @@ public class NotesVC: UIViewController, ScrollStackContainableController {
         return vc
     }
 
-    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> CGFloat? {
+    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> ScrollStack.ControllerSize? {
         let size = CGSize(width: stackView.bounds.size.width, height: 9000)
         var best = self.view.systemLayoutSizeFitting(size, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
-        best.height += 20
-        // it's important to set both the height constraint and bottom safe area for table bottom
-        return best.height
+        best.height += 20 // just some offset for UITextView insets
+        // NOTE:
+        // it's important to set both the height constraint and bottom safe constraints to safe area for textview,
+        // otherwise growing does not work.
+        return .fixed(best.height)
     }
 
 

ScrollStackControllerDemo/Child View Controllers/NotesVC.swift

@@ -32,11 +32,14 @@ public class PricingVC: UIViewController, ScrollStackContainableController {
         return vc
     }
 
-    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> CGFloat? {
-        let size = CGSize(width: stackView.bounds.size.width, height: 9000)
-        let best = self.view.systemLayoutSizeFitting(size, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
-        // it's important to set both the height constraint and bottom safe area for table bottom
-        return best.height
+    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> ScrollStack.ControllerSize? {
+        return .fitLayoutForAxis
+//        let size = CGSize(width: stackView.bounds.size.width, height: 9000)
+//        let best = self.view.systemLayoutSizeFitting(size, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
+//        // NOTE:
+//        // it's important to set both the height constraint and bottom safe constraints to safe area for tableview,
+//        // otherwise growing does not work.
+//        return best.height
     }
 
     override public func updateViewConstraints() {

ScrollStackControllerDemo/Child View Controllers/PricingVC.swift

@@ -48,8 +48,8 @@ public class TagsVC: UIViewController, ScrollStackContainableController {
         return vc
     }
 
-    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> CGFloat? {
-        return (isExpanded == false ? 170 : 170 + collectionView.contentSize.height + 20)
+    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> ScrollStack.ControllerSize? {
+        return (isExpanded == false ? .fixed(170) : .fixed(170 + collectionView.contentSize.height + 20))
     }
 
     public func reloadContentFromStackViewRow() {

ScrollStackControllerDemo/Child View Controllers/TagsVC.swift

@@ -16,10 +16,11 @@ public class WelcomeVC: UIViewController, ScrollStackContainableController {
         return vc
     }
 
-    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> CGFloat? {
-        let size = CGSize(width: stackView.bounds.size.width, height: 9000)
-        let best = self.view.systemLayoutSizeFitting(size, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
-        return best.height
+    public func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> ScrollStack.ControllerSize? {
+       // let size = CGSize(width: stackView.bounds.size.width, height: 9000)
+       // let best = self.view.systemLayoutSizeFitting(size, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
+       // return best.height
+        return .fitLayoutForAxis
     }
 
     public func reloadContentFromStackViewRow() {

ScrollStackControllerDemo/Child View Controllers/WelcomeVC.swift

@@ -245,6 +245,8 @@ open class ScrollStackRow: UIView, UIGestureRecognizerDelegate {
         separatorConstraints?.trailing.constant = (separatorAxis == .vertical ? 0 : -separatorInsets.right)
     }
 
+    // MARK: - Sizing the Controller
+    
     internal func askForCutomizedSizeOfContentView() {
         guard let customizableController = controller as? ScrollStackContainableController else {
             return // ignore, it's not implemented, use autolayout.
@@ -255,20 +257,40 @@ open class ScrollStackRow: UIView, UIGestureRecognizerDelegate {
             return // ignore, use autolayout in place for content view.
         }
 
-        switch currentAxis {
-        case .horizontal:
-            contentView.width(constant: bestSize)
-            contentView.height(constant: nil)
+        switch bestSize {
+        case .fixed(let value):
+            setupRowToFixedValue(value)
 
-        case .vertical:
+        case .fitLayoutForAxis:
+            setupRowSizeToFitLayout()
+        }
+    }
+    
+    private func setupRowToFixedValue(_ value: CGFloat) {
+        guard let stackView = stackView else { return }
+
+        if stackView.axis == .vertical {
             contentView.width(constant: nil)
-            contentView.height(constant: bestSize)
-            
-        default:
-            break
+            contentView.height(constant: value)
+        } else {
+            contentView.width(constant: value)
+            contentView.height(constant: nil)
+        }
+    }
+    
+    private func setupRowSizeToFitLayout()  {
+        guard let stackView = stackView else { return }
+        
+        var bestSize: CGSize!
+        if stackView.axis == .vertical {
+            let maxAllowedSize = CGSize(width: stackView.bounds.size.width, height: CGFloat.greatestFiniteMagnitude)
+            bestSize = contentView.systemLayoutSizeFitting(maxAllowedSize, withHorizontalFittingPriority: .required, verticalFittingPriority: .defaultLow)
+        } else {
+            let maxAllowedSize = CGSize(width: CGFloat.greatestFiniteMagnitude, height: stackView.bounds.size.height)
+            bestSize = contentView.systemLayoutSizeFitting(maxAllowedSize, withHorizontalFittingPriority: .defaultLow, verticalFittingPriority: .required)
         }
 
-        print("")
+        setupRowToFixedValue(bestSize.height)
     }
 
     // MARK: - Handle Touch

Sources/ScrollStackController/ScrollStackRow.swift

@@ -49,7 +49,7 @@ public protocol ScrollStackContainableController: UIViewController {
     /// - Parameter axis: axis of the stackview.
     /// - Parameter row: row where the controller is placed.
     /// - Parameter stackView: stackview where the row is placed.
-    func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> CGFloat?
+    func scrollStackRowSizeForAxis(_ axis: NSLayoutConstraint.Axis, row: ScrollStackRow, in stackView: ScrollStack) -> ScrollStack.ControllerSize?
 
     /// Method is called when you call a `reloadRow` function on a row where this controller is contained in.
     func reloadContentFromStackViewRow()
@@ -122,6 +122,14 @@ extension ScrollStackRowHighlightable where Self: UIView {
 
 public extension ScrollStack {
 
+    /// Define the controller size.
+    /// - `fixed`: fixed size in points.
+    /// - `fitLayoutForAxis`: attempt to size the controller to fits its content set with autolayout.
+    enum ControllerSize {
+        case fixed(CGFloat)
+        case fitLayoutForAxis
+    }
+    
     /// Insertion of the new row.
     /// - `top`: insert row at the top of the stack.
     /// - `bottom`: append the row at the end of the stack rows.