feat: basic window resizing

Packages/AppWindowUtility/Runtime/WindowResizer.cs

@@ -0,0 +1,49 @@
+using UnityEngine;
+using UnityEngine.EventSystems;
+
+namespace SatorImaging.AppWindowUtility {
+	public class WindowResizer : MonoBehaviour {
+		public MouseButton mouseButton;
+
+		private bool _isResizing;
+		private Vector2 _targetPosition = Vector2.zero;
+		private Vector2 _resizeDirection = Vector2.zero;
+
+		[SerializeField] private Vector2 aspectRatio = new(10, 15);
+
+		private void Update() {
+#if UNITY_EDITOR
+			if (_isResizing.Equals(_isResizing)) return; // to avoid CS0162 warning
+#endif
+
+			if (EventSystem.current?.currentSelectedGameObject) return;
+
+			if (Input.GetMouseButtonUp((int)mouseButton)) _isResizing = false;
+
+			if (Input.GetMouseButtonDown((int)mouseButton)) {
+				_targetPosition = Event.current.mousePosition;
+				_resizeDirection =
+					ResizeHelper.GetDirection(_targetPosition, new Vector2(Screen.width, Screen.height));
+				_isResizing = true;
+			}
+
+			if (_isResizing && Input.GetMouseButton((int)mouseButton) && _resizeDirection != Vector2.zero) {
+				float ratio = aspectRatio.x / aspectRatio.y;
+
+				Vector2 delta = new(
+					Event.current.mousePosition.x - _targetPosition.x,
+					Event.current.mousePosition.y - _targetPosition.y
+				);
+
+				AppWindowUtility.ResizeWindowRelative(delta.x, delta.y, _resizeDirection, ratio);
+
+				_targetPosition = Event.current.mousePosition;
+
+				if (_resizeDirection.x < 0)
+					_targetPosition.x -= delta.x;
+				if (_resizeDirection.y < 0)
+					_targetPosition.y -= delta.y;
+			}
+		}
+	}
+}