simple cursor controller

static/cursor.css

@@ -0,0 +1,3 @@
+.cursor_grabbing {
+    cursor: grabbing;
+}

static/javascript/cursor.js

@@ -6,3 +6,15 @@ document.addEventListener("mousemove", (e) => {
   currentX = e.clientX;
   currentY = e.clientY;
 });
+
+const CURSOR_NORMAL = "cursor_normal";
+const CURSOR_GRABBING = "cursor_grabbing";
+
+document.body.classList.remove(CURSOR_NORMAL);
+
+let current_cursor_state = CURSOR_NORMAL;
+function set_cursor_state(new_cursor_state) {
+  document.body.classList.remove(current_cursor_state);
+  document.body.classList.add(new_cursor_state);
+  current_cursor_state = new_cursor_state;
+}