snapshot of https://github.com/excalidraw/excalidraw.git (master, 2026-09-16; blobs > 131072B omitted)

packages/excalidraw/components/positionElementBesideCursor.ts

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+import { clamp } from "@excalidraw/math";
+
+const positionAxis = ({
+  cursorPosition,
+  elementSize,
+  containerSize,
+  gap,
+}: {
+  cursorPosition: number;
+  elementSize: number;
+  containerSize: number;
+  gap: number;
+}) => {
+  // flip to the other side of the cursor when overflowing the container
+  const position =
+    cursorPosition + gap + elementSize > containerSize
+      ? cursorPosition - gap - elementSize
+      : cursorPosition + gap;
+
+  // If the element does not fit on either side, keep as much of it within the
+  // container as possible.
+  return clamp(position, 0, Math.max(0, containerSize - elementSize));
+};
+
+/**
+ * Positions an element beside a cursor within a container, flipping the
+ * element to the other side of the cursor when it would overflow the
+ * container, resolved independently on each axis.
+ *
+ * Takes the cursor in client (viewport) coordinates and returns
+ * container-local coordinates.
+ */
+export const positionElementBesideCursor = ({
+  cursor,
+  element,
+  container,
+  gap,
+}: {
+  /** client (viewport) coordinates */
+  cursor: {
+    x: number;
+    y: number;
+  };
+  element: {
+    width: number;
+    height: number;
+  };
+  /** the container's bounding client rect */
+  container: Pick<DOMRect, "left" | "top" | "width" | "height">;
+  /** distance between the cursor and the positioned element */
+  gap: number;
+}) => ({
+  left: positionAxis({
+    cursorPosition: cursor.x - container.left,
+    elementSize: element.width,
+    containerSize: container.width,
+    gap,
+  }),
+  top: positionAxis({
+    cursorPosition: cursor.y - container.top,
+    elementSize: element.height,
+    containerSize: container.height,
+    gap,
+  }),
+});