feat: Initial commit

Assets/Cryville.Common/Unity/UI/AspectRatioLayoutElement.cs

@@ -0,0 +1,113 @@
+using UnityEngine;
+using UnityEngine.EventSystems;
+using UnityEngine.UI;
+
+namespace Cryville.Common.Unity.UI {
+	/// <summary>
+	/// A <see cref="ILayoutElement" /> that takes the length of one axis to compute the preferred length of the other axis with respect to a aspect ratio.
+	/// </summary>
+	[AddComponentMenu("Layout/Aspect Ratio Layout Element")]
+	[ExecuteAlways]
+	public class AspectRatioLayoutElement : UIBehaviour, ILayoutElement {
+		[SerializeField]
+		[Tooltip("The aspect ratio. Width divided by height.")]
+		private float m_aspectRatio = 1;
+		/// <summary>
+		/// The aspect ratio. Width divided by height.
+		/// </summary>
+		public float AspectRatio {
+			get { return m_aspectRatio; }
+			set { SetProperty(ref m_aspectRatio, value); }
+		}
+
+		[SerializeField]
+		[Tooltip("Whether to compute the length of the y axis.")]
+		private bool m_isVertical = false;
+		/// <summary>
+		/// Whether to compute the length of the y axis.
+		/// </summary>
+		public bool IsVertical {
+			get { return m_isVertical; }
+			set { SetProperty(ref m_isVertical, value); }
+		}
+
+		private void SetProperty<T>(ref T prop, T value) {
+			if (Equals(prop, value)) return;
+			prop = value;
+			SetDirty();
+		}
+
+		/// <inheritdoc />
+		public float minWidth {
+			get {
+				return m_isVertical ? -1 : (transform as RectTransform).rect.height * m_aspectRatio;
+			}
+		}
+		/// <inheritdoc />
+		public float preferredWidth { get { return minWidth; } }
+		/// <inheritdoc />
+		public float flexibleWidth { get { return -1; } }
+
+		/// <inheritdoc />
+		public float minHeight {
+			get {
+				return m_isVertical ? (transform as RectTransform).rect.width / m_aspectRatio : -1;
+			}
+		}
+		/// <inheritdoc />
+		public float preferredHeight { get { return minHeight; } }
+		/// <inheritdoc />
+		public float flexibleHeight { get { return -1; } }
+
+		/// <inheritdoc />
+		public int layoutPriority { get { return 1; } }
+
+		/// <inheritdoc />
+		public void CalculateLayoutInputHorizontal() { }
+
+		/// <inheritdoc />
+		public void CalculateLayoutInputVertical() { }
+
+		protected override void OnEnable() {
+			base.OnEnable();
+			SetDirty();
+		}
+		protected override void OnBeforeTransformParentChanged() {
+			base.OnBeforeTransformParentChanged();
+			SetDirty();
+		}
+		protected override void OnTransformParentChanged() {
+			base.OnTransformParentChanged();
+			SetDirty();
+		}
+		protected override void OnDidApplyAnimationProperties() {
+			base.OnDidApplyAnimationProperties();
+			SetDirty();
+		}
+#if UNITY_EDITOR
+		protected override void OnValidate() {
+			base.OnValidate();
+			SetDirty();
+		}
+#endif
+		protected override void OnDisable() {
+			SetDirty();
+			base.OnDisable();
+		}
+		protected override void OnRectTransformDimensionsChange() {
+			base.OnRectTransformDimensionsChange();
+			SetDirty();
+		}
+		bool _delayedSetDirty;
+		private void SetDirty() {
+			if (!IsActive()) return;
+			if (CanvasUpdateRegistry.IsRebuildingLayout()) _delayedSetDirty = true;
+			else LayoutRebuilder.MarkLayoutForRebuild(transform as RectTransform);
+		}
+		void Update() {
+			if (!_delayedSetDirty) return;
+			_delayedSetDirty = false;
+			LayoutRebuilder.MarkLayoutForRebuild(transform as RectTransform);
+		}
+	}
+}