Add MMMFlowLayoutContainer

MMMCommonUI.podspec

@@ -6,7 +6,7 @@
 Pod::Spec.new do |s|
 
 	s.name = "MMMCommonUI"
-	s.version = "3.11.2"
+	s.version = "3.12.0"
 	s.summary = "Small UI-related pieces reused in many components from MMMTemple"
 	s.description =	"#{s.summary}."
 	s.homepage = "https://github.com/mediamonks/#{s.name}"

Sources/MMMCommonUI/MMMFlowLayoutContainer.swift

@@ -0,0 +1,118 @@
+//
+// Starbucks App.
+// Copyright (c) 2024 MediaMonks. All rights reserved.
+// 
+
+import UIKit
+
+/// A container arranging subviews as words on a page.
+///
+/// Note that calling ``systemLayoutSizeFitting()`` won't work properly here as our height depends on width.
+///
+/// Things that could be improved:
+/// - recycle horizontal (row) stack views;
+/// - use UILayoutGuide's directly instead of stack views.
+public class MMMFlowLayoutContainer: NonStoryboardableView {
+
+	private let insets: UIEdgeInsets
+	private let horizontalSpacing: CGFloat
+	private let verticalAlignment: MMMLayoutVerticalAlignment
+	private let horizontalFittingPriority: UILayoutPriority
+	private let verticalStack: MMMVerticalStackContainer
+
+	public init(
+		horizontalSpacing: CGFloat,
+		verticalSpacing: CGFloat,
+		insets: UIEdgeInsets = .zero,
+		horizontalAlignment: MMMLayoutHorizontalAlignment = .left,
+		verticalAlignment: MMMLayoutVerticalAlignment = .center,
+		horizontalSizingPriority: UILayoutPriority = .defaultLow - 1
+	) {
+		self.insets = insets
+		self.verticalStack = .init(insets: insets, alignment: horizontalAlignment, spacing: verticalSpacing)
+		self.horizontalSpacing = horizontalSpacing
+		self.verticalAlignment = verticalAlignment
+		self.horizontalFittingPriority = horizontalSizingPriority
+
+		super.init()
+
+		addSubview(verticalStack)
+
+		mmm_addConstraintsAligningView(verticalStack, horizontally: .fill, vertically: .fill)
+	}
+
+	private var arrangedSubviews: [UIView] = []
+
+	public func setSubviews(_ subviews: [UIView]) {
+		guard self.arrangedSubviews != subviews else {
+			return
+		}
+		arrangedSubviews.forEach { $0.removeFromSuperview() }
+		self.arrangedSubviews = subviews
+		arrangedSubviews.forEach { addSubview($0) }
+		setNeedsUpdateConstraints()
+	}
+
+	private var lastConstrainedWidth: CGFloat = 0
+
+	public override func updateConstraints() {
+
+		super.updateConstraints()
+
+		lastConstrainedWidth = bounds.width
+
+		let totalWidth = bounds.inset(by: insets).width
+		guard totalWidth > 0 else {
+			verticalStack.setSubviews([])
+			return
+		}
+
+		var rows: [MMMHorizontalStackContainer] = []
+		var currentRow: [UIView] = []
+		var remainingWidth: CGFloat = 0
+
+		func flush() {
+			remainingWidth = totalWidth
+			guard !currentRow.isEmpty else {
+				return
+			}
+			let rowStack = MMMHorizontalStackContainer(insets: .zero, alignment: verticalAlignment, spacing: horizontalSpacing)
+			rowStack.setSubviews(currentRow)
+			rows.append(rowStack)
+			currentRow.removeAll()
+		}
+
+		func measure(_ subview: UIView) -> CGFloat {
+			ceil(subview.systemLayoutSizeFitting(
+				.init(remainingWidth, 0),
+				withHorizontalFittingPriority: horizontalFittingPriority, verticalFittingPriority: .fittingSizeLevel
+			).width)
+		}
+
+		flush()
+
+		for subview in arrangedSubviews {
+			var w = measure(subview)
+			if w > remainingWidth {
+				flush()
+				w = measure(subview)
+			}
+			currentRow.append(subview)
+			remainingWidth -= w + horizontalSpacing
+			if remainingWidth <= 0 {
+				flush()
+			}
+		}
+		flush()
+
+		verticalStack.setSubviews(rows)
+	}
+
+	public override func layoutSubviews() {
+		if lastConstrainedWidth != bounds.width {
+			setNeedsUpdateConstraints()
+			updateConstraintsIfNeeded()
+		}
+		super.layoutSubviews()
+	}
+}

Sources/MMMCommonUIObjC/MMMCommonUI.h

@@ -10,7 +10,6 @@
 #import "MMMAnimations.h"
 #import "MMMAutoLayoutScrollView.h"
 #import "MMMCollectionView.h"
-#import "MMMCommonUI.h"
 #import "MMMCommonUIMisc.h"
 #import "MMMContainerView.h"
 #import "MMMImageView.h"