⭐️ Impl: ViewPositionHorizontal

ios/Temp/ViewPositionHorizontal.swift

@@ -0,0 +1,359 @@
+//
+//  ViewPositionHorizontal.swift
+//  react-native-ios-modal
+//
+//  Created by Dominic Go on 10/4/24.
+//
+
+import Foundation
+
+
+public enum ViewPositionHorizontal {
+  case stretch;
+  case stretchPercent(percent: CGFloat);
+
+  case stretchWindow;
+  case stretchWindowPercent(percent: CGFloat);
+
+  case center;
+  case centerStretch(percent: CGFloat);
+  case centerFixedWidth(constant: CGFloat);
+
+  case leading;
+  case leadingStretch(percent: CGFloat);
+  case leadingFixedWidth(constant: CGFloat);
+
+  case trailing;
+  case trailingStretch(percent: CGFloat);
+  case trailingFixedWidth(constant: CGFloat);
+
+  // MARK: Computed Properties
+  // -------------------------
+
+  public var percentMultiplier: CGFloat?  {
+    switch self {
+      case let .stretchPercent(percent):
+        return percent;
+
+      case let .stretchWindowPercent(percent):
+        return percent;
+
+      case let .centerStretch(percent):
+        return percent;
+
+      case let .leadingStretch(percent):
+        return percent;
+
+      case let .trailingStretch(percent):
+        return percent;
+
+      default:
+        return nil;
+    };
+  };
+
+  public var constantWidth: CGFloat? {
+    switch self {
+      case let .centerFixedWidth(constant):
+        return constant;
+
+      case let .leadingFixedWidth(constant):
+        return constant;
+
+      case let .trailingFixedWidth(constant):
+        return constant;
+
+      default:
+        return nil;
+    };
+  };
+
+  public var hasImplicitWidth: Bool {
+    switch self {
+      case .stretch, .stretchPercent,
+           .stretchWindow, .stretchWindowPercent,
+           .centerStretch, .leadingStretch, .trailingStretch:
+        return true;
+
+      default:
+        return false;
+    };
+  };
+
+  public var hasExplicitWidth: Bool {
+    self.constantWidth != nil;
+  };
+
+  /// `false` if the width is ambiguous
+  public var willSatisfyWidthConstraint: Bool {
+       self.hasImplicitWidth
+    || self.hasExplicitWidth;
+  };
+
+  // MARK: Functions
+  // ---------------
+
+  public func createHorizontalConstraintsGrouped(
+    forView childView: UIView,
+    attachingTo parentView: UIView,
+    withWindow window: UIWindow?,
+    marginLeading: CGFloat = 0,
+    marginTrailing: CGFloat = 0,
+    preferToUseWidthConstraint: Bool = false
+  ) -> (
+    constraintLeading    : NSLayoutConstraint?,
+    constraintTrailing   : NSLayoutConstraint?,
+    constraintWidth      : NSLayoutConstraint?,
+    constraintCenterX    : NSLayoutConstraint?,
+    constraintLeadingMin : NSLayoutConstraint?,
+    constraintTrailingMin: NSLayoutConstraint?
+  ) {
+
+    var constraintLeading    : NSLayoutConstraint?;
+    var constraintTrailing   : NSLayoutConstraint?;
+    var constraintWidth      : NSLayoutConstraint?;
+    var constraintCenterX    : NSLayoutConstraint?;
+    var constraintLeadingMin : NSLayoutConstraint?;
+    var constraintTrailingMin: NSLayoutConstraint?;
+
+    let marginTotal = marginLeading + marginTrailing;
+
+    switch (self, preferToUseWidthConstraint) {
+      case (.stretch, false):
+        constraintLeading = childView.leadingAnchor.constraint(
+          equalTo: parentView.leadingAnchor,
+          constant: marginLeading
+        );
+
+        constraintTrailing = childView.trailingAnchor.constraint(
+          equalTo: parentView.trailingAnchor,
+          constant: -marginTrailing
+        );
+
+      case (.stretch, true):
+        constraintWidth = childView.widthAnchor.constraint(
+          equalTo: parentView.widthAnchor,
+          constant: -marginTotal
+        );
+
+        constraintCenterX = childView.centerXAnchor.constraint(
+          equalTo: parentView.centerXAnchor
+        );
+
+      case (let .stretchPercent(percent), _):
+        if marginTotal == 0 {
+          constraintWidth = childView.widthAnchor.constraint(
+            equalTo: parentView.widthAnchor,
+            multiplier: percent
+          );
+
+          constraintCenterX = childView.centerXAnchor.constraint(
+            equalTo: parentView.centerXAnchor
+          );
+
+        } else {
+          constraintWidth = childView.widthAnchor.constraint(
+            equalTo: parentView.widthAnchor,
+            multiplier: percent
+          );
+
+          constraintLeadingMin = childView.leadingAnchor.constraint(
+            greaterThanOrEqualTo: parentView.leadingAnchor,
+            constant: marginLeading
+          );
+
+          constraintTrailingMin = childView.trailingAnchor.constraint(
+            greaterThanOrEqualTo: parentView.trailingAnchor,
+            constant: marginTrailing
+          );
+
+          constraintWidth!.priority = .required;
+          constraintLeadingMin!.priority = .defaultHigh;
+          constraintTrailingMin!.priority = .defaultHigh;
+        };
+
+      case (.stretchWindow, false):
+        let parentViewAdj = window ?? parentView;
+
+        constraintLeading = childView.leadingAnchor.constraint(
+          equalTo: parentViewAdj.leadingAnchor,
+          constant: marginLeading
+        );
+
+        constraintTrailing = childView.trailingAnchor.constraint(
+          equalTo: parentViewAdj.trailingAnchor,
+          constant: marginTrailing
+        );
+
+      case (.stretchWindow, true):
+        let parentViewAdj = window ?? parentView;
+
+        constraintWidth = childView.widthAnchor.constraint(
+          equalTo: parentViewAdj.widthAnchor,
+          constant: -marginTotal
+        );
+
+        constraintCenterX = childView.centerXAnchor.constraint(
+          equalTo: parentViewAdj.centerXAnchor
+        );
+
+      case (let .stretchWindowPercent(percent), _):
+        let parentViewAdj = window ?? parentView;
+
+        if marginTotal == 0 {
+          constraintWidth = childView.widthAnchor.constraint(
+            equalTo: parentViewAdj.widthAnchor,
+            multiplier: percent
+          );
+
+          constraintCenterX = childView.centerXAnchor.constraint(
+            equalTo: parentViewAdj.centerXAnchor
+          );
+
+        } else {
+          constraintWidth = childView.widthAnchor.constraint(
+            equalTo: parentViewAdj.widthAnchor,
+            multiplier: percent
+          );
+
+          constraintLeadingMin = childView.leadingAnchor.constraint(
+            greaterThanOrEqualTo: parentViewAdj.leadingAnchor,
+            constant: marginLeading
+          );
+
+          constraintTrailingMin = childView.trailingAnchor.constraint(
+            greaterThanOrEqualTo: parentViewAdj.trailingAnchor,
+            constant: marginTrailing
+          );
+
+          constraintWidth!.priority = .required;
+          constraintLeadingMin!.priority = .defaultHigh;
+          constraintTrailingMin!.priority = .defaultHigh;
+        };
+
+      case (.center, _):
+        // TODO: handle margins
+        constraintCenterX = childView.centerXAnchor.constraint(
+          equalTo: parentView.centerXAnchor
+        );
+
+      case (let .centerStretch(percent), _):
+        // TODO: handle margins
+        constraintWidth = childView.widthAnchor.constraint(
+          equalTo: parentView.widthAnchor,
+          multiplier: percent,
+          constant: -marginTotal
+        );
+
+        constraintCenterX = childView.centerXAnchor.constraint(
+          equalTo: parentView.centerXAnchor
+        );
+
+      case (let .centerFixedWidth(constant), _):
+        // TODO: handle margins
+        constraintWidth = childView.widthAnchor.constraint(
+          equalToConstant: constant
+        );
+
+        constraintCenterX = childView.centerXAnchor.constraint(
+          equalTo: parentView.centerXAnchor
+        );
+
+      case (.leading, _):
+        constraintLeading = childView.leadingAnchor.constraint(
+          equalTo: parentView.leadingAnchor,
+          constant: marginLeading
+        );
+
+      case (let .leadingStretch(percent), _):
+        // TODO: handle trailing margins
+        constraintWidth = childView.widthAnchor.constraint(
+          equalTo: parentView.widthAnchor,
+          multiplier: percent
+        );
+
+        constraintLeading = childView.leadingAnchor.constraint(
+          equalTo: parentView.leadingAnchor,
+          constant: marginLeading
+        );
+
+      case (let .leadingFixedWidth(constant), _):
+        // TODO: handle trailing margin
+        constraintWidth = childView.widthAnchor.constraint(
+          equalToConstant: constant
+        );
+
+        constraintLeading = childView.leadingAnchor.constraint(
+          equalTo: parentView.leadingAnchor,
+          constant: marginLeading
+        );
+
+      case (.trailing, _):
+        constraintTrailing = childView.trailingAnchor.constraint(
+          equalTo: parentView.trailingAnchor,
+          constant: -marginTrailing
+        );
+
+      case (let .trailingStretch(percent), _):
+        // TODO: handle leading margin
+        constraintWidth = childView.widthAnchor.constraint(
+          equalTo: parentView.widthAnchor,
+          multiplier: percent
+        );
+
+        constraintTrailing = childView.trailingAnchor.constraint(
+          equalTo: parentView.trailingAnchor,
+          constant: -marginTrailing
+        );
+
+      case (let .trailingFixedWidth(constant), _):
+        // TODO: handle leading margin
+        constraintWidth = childView.widthAnchor.constraint(
+          equalToConstant: constant
+        );
+
+        constraintTrailing = childView.trailingAnchor.constraint(
+          equalTo: parentView.trailingAnchor,
+          constant: -marginTrailing
+        );
+    };
+
+    return (
+      constraintLeading,
+      constraintTrailing,
+      constraintWidth,
+      constraintCenterX,
+      constraintLeadingMin,
+      constraintTrailingMin
+    );
+  };
+
+  public func createHorizontalConstraints(
+    forView childView: UIView,
+    attachingTo parentView: UIView,
+    withWindow window: UIWindow?,
+    marginLeading: CGFloat = 0,
+    marginTrailing: CGFloat = 0,
+    preferToUseWidthConstraint: Bool = false
+  ) -> [NSLayoutConstraint] {
+
+    let groupedConstraints = self.createHorizontalConstraintsGrouped(
+      forView: childView,
+      attachingTo: parentView,
+      withWindow: window,
+      marginLeading: marginLeading,
+      marginTrailing: marginTrailing,
+      preferToUseWidthConstraint: preferToUseWidthConstraint
+    );
+
+    var constraints: [NSLayoutConstraint] = [];
+    constraints.unwrapThenAppend(groupedConstraints.constraintLeading);
+    constraints.unwrapThenAppend(groupedConstraints.constraintTrailing);
+    constraints.unwrapThenAppend(groupedConstraints.constraintWidth);
+    constraints.unwrapThenAppend(groupedConstraints.constraintCenterX);
+    constraints.unwrapThenAppend(groupedConstraints.constraintLeadingMin);
+    constraints.unwrapThenAppend(groupedConstraints.constraintTrailingMin);
+
+    return constraints;
+  };
+};