Implement rotated box.

Runtime/widgets/basic.cs

 using System;
 using System.Collections.Generic;
 using System.Linq;
+using UIWidgets.Runtime.rendering;
 using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.painting;
 using Unity.UIWidgets.rendering;
         public readonly float? stepHeight;
 
         float? _stepWidth {
-            get {
-                return this.stepWidth == 0.0f ? null : this.stepWidth;
-            }
+            get { return this.stepWidth == 0.0f ? null : this.stepWidth; }
-        
+
-            get {
-                return this.stepHeight == 0.0f ? null : this.stepHeight;
-            }
+            get { return this.stepHeight == 0.0f ? null : this.stepHeight; }
         }
 
         public override RenderObject createRenderObject(BuildContext context) {
             properties.add(new FloatProperty("elevation", this.elevation));
             properties.add(new DiagnosticsProperty<Color>("color", this.color));
             properties.add(new DiagnosticsProperty<Color>("shadowColor", this.shadowColor));
+        }
+    }
+
+    public class RotatedBox : SingleChildRenderObjectWidget {
+        public RotatedBox(
+            Key key = null,
+            int? quarterTurns = null,
+            Widget child = null
+        ) : base(key: key, child: child) {
+            D.assert(quarterTurns != null);
+            this.quarterTurns = quarterTurns;
+        }
+
+
+        public readonly int? quarterTurns;
+
+        public override RenderObject createRenderObject(BuildContext context) {
+            return new RenderRotatedBox(this.quarterTurns ?? 0);
+        }
+
+        public override void updateRenderObject(BuildContext context, RenderObject renderObject) {
+            (renderObject as RenderRotatedBox).quarterTurns = this.quarterTurns ?? 0;
         }
     }
 

Runtime/rendering/rotated_box.cs

+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.gestures;
+using Unity.UIWidgets.rendering;
+using Unity.UIWidgets.ui;
+using UnityEngine;
+
+namespace UIWidgets.Runtime.rendering {
+    class RotatedBoxUtils {
+        public const float _kQuarterTurnsInRadians = Mathf.PI / 2.0f;
+    }
+
+    public class RenderRotatedBox : RenderObjectWithChildMixinRenderBox<RenderBox> {
+        public RenderRotatedBox(
+            int quarterTurns,
+            RenderBox child = null
+        ) {
+            this.child = child;
+            this._quarterTurns = quarterTurns;
+        }
+
+        public int quarterTurns {
+            get { return this._quarterTurns; }
+            set {
+                if (this._quarterTurns == value) {
+                    return;
+                }
+
+                this._quarterTurns = value;
+                this.markNeedsLayout();
+            }
+        }
+
+        int _quarterTurns;
+
+        public bool _isVertical {
+            get { return this.quarterTurns % 2 == 1; }
+        }
+
+        protected override float computeMinIntrinsicWidth(float height) {
+            if (this.child == null) {
+                return 0.0f;
+            }
+
+            return this._isVertical
+                ? this.child.getMinIntrinsicHeight(height)
+                : this.child.getMinIntrinsicWidth(height);
+        }
+
+        protected override float computeMaxIntrinsicWidth(float height) {
+            if (this.child == null) {
+                return 0.0f;
+            }
+
+            return this._isVertical
+                ? this.child.getMaxIntrinsicHeight(height)
+                : this.child.getMaxIntrinsicWidth(height);
+        }
+
+        protected override float computeMinIntrinsicHeight(float width) {
+            if (this.child == null) {
+                return 0.0f;
+            }
+
+            return this._isVertical ? this.child.getMinIntrinsicWidth(width) : this.child.getMinIntrinsicHeight(width);
+        }
+
+        protected override float computeMaxIntrinsicHeight(float width) {
+            if (this.child == null) {
+                return 0.0f;
+            }
+
+            return this._isVertical ? this.child.getMaxIntrinsicWidth(width) : this.child.getMaxIntrinsicHeight(width);
+        }
+
+        Matrix3 _paintTransform;
+
+        protected override void performLayout() {
+            this._paintTransform = null;
+            if (this.child != null) {
+                this.child.layout(this._isVertical ? this.constraints.flipped : this.constraints, parentUsesSize: true);
+                this.size = this._isVertical
+                    ? new Size(this.child.size.height, this.child.size.width)
+                    : this.child.size;
+                this._paintTransform = Matrix3.I();
+                this._paintTransform.preTranslate(this.size.width / 2.0f, this.size.height / 2.0f);
+                this._paintTransform.preRotate(RotatedBoxUtils._kQuarterTurnsInRadians * (this.quarterTurns % 4));
+                this._paintTransform.preTranslate(-this.child.size.width / 2.0f, -this.child.size.height / 2.0f);
+            }
+            else {
+                this.performResize();
+            }
+        }
+
+        protected override bool hitTestChildren(
+            HitTestResult result,
+            Offset position = null
+        ) {
+            D.assert(this._paintTransform != null || this.debugNeedsLayout || this.child == null);
+            if (this.child == null || this._paintTransform == null) {
+                return false;
+            }
+
+
+            Matrix3 inverse = Matrix3.I();
+            this._paintTransform.invert(inverse);
+            return this.child.hitTest(result, position: inverse.mapPoint(position));
+        }
+
+        void _paintChild(PaintingContext context, Offset offset) {
+            context.paintChild(this.child, offset);
+        }
+
+        public override void paint(PaintingContext context, Offset offset) {
+            if (this.child != null) {
+                context.pushTransform(this.needsCompositing, offset, this._paintTransform, this._paintChild);
+            }
+        }
+
+        public override void applyPaintTransform(RenderObject child, Matrix3 transform) {
+            if (this._paintTransform != null) {
+                transform.preConcat(this._paintTransform);
+            }
+
+            base.applyPaintTransform(child, transform);
+        }
+    }
+}

Runtime/rendering/rotated_box.cs.meta

+fileFormatVersion: 2
+guid: 057a0f3b94794fce9f9f3aa7bb624256
+timeCreated: 1557210363