feat: setup window using the api

Packages/AppWindowUtility/Runtime/WindowGrabber.cs

@@ -0,0 +1,66 @@
+using UnityEngine;
+using UnityEngine.EventSystems;
+
+
+
+namespace SatorImaging.AppWindowUtility
+{
+    public class WindowGrabber : MonoBehaviour
+    {
+        public enum MouseButton
+        {
+            Left = 0,
+            Right = 1,
+            Middle = 2,
+        }
+        public MouseButton mouseButton;
+        public KeyCode modifierKey = KeyCode.None;
+        public KeyCode[] temporarilyDisableIfKeyPressed;
+
+
+        private bool isDragging = false;
+        Vector2 targetPosition = Vector2.zero;
+
+
+        void Update()
+        {
+#if UNITY_EDITOR
+            if(isDragging.Equals(isDragging)) return; // to avoid CS0162 warning
+#endif
+
+            // do nothing if any uGUI is in use.
+            if (EventSystem.current?.currentSelectedGameObject) return;
+
+
+            // initialize dragging state. don't check modifier key.
+            if (Input.GetMouseButtonUp((int)mouseButton)) isDragging = false;
+
+            // key check.
+            foreach (var k in temporarilyDisableIfKeyPressed) if (Input.GetKey(k)) return;
+            if (modifierKey != KeyCode.None && !Input.GetKey(modifierKey)) return;
+
+
+
+            if (Input.GetMouseButtonDown((int)mouseButton))
+            {
+                targetPosition = Event.current.mousePosition;
+                isDragging = true;
+            }
+
+            if (isDragging && Input.GetMouseButton((int)mouseButton))
+            {
+                // do NOT use Event.current.delta. it's sampled in local window coordinate.
+                // and moving window while mouse dragging changes coordinate sample by sample.
+                // just remove the gap between current mouse position and drag starting position.
+                AppWindowUtility.MoveWindowRelative(
+                    (int)(Event.current.mousePosition.x - targetPosition.x),
+                    (int)(Event.current.mousePosition.y - targetPosition.y)
+                );
+
+            }
+
+        }//
+
+
+    }//class
+}//namespace