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

packages/excalidraw/textAutoResizeHandle.ts

@@ -0,0 +1,89 @@
+import { DEFAULT_TRANSFORM_HANDLE_SPACING } from "@excalidraw/common";
+import {
+  pointFrom,
+  pointRotateRads,
+  type GlobalPoint,
+  type Radians,
+} from "@excalidraw/math";
+
+import type { EditorInterface } from "@excalidraw/common";
+
+import type { ExcalidrawTextElement } from "@excalidraw/element/types";
+
+const TEXT_AUTO_RESIZE_HANDLE_GAP = 12;
+const TEXT_AUTO_RESIZE_HANDLE_LENGTH = 16;
+const TEXT_AUTO_RESIZE_HANDLE_HITBOX_WIDTH = 10;
+const TEXT_AUTO_RESIZE_HANDLE_HITBOX_HEIGHT =
+  TEXT_AUTO_RESIZE_HANDLE_LENGTH + 2;
+const MAX_HANDLE_HEIGHT_RATIO = 0.8;
+
+export const getTextBoxPadding = (zoomValue: number) =>
+  (DEFAULT_TRANSFORM_HANDLE_SPACING * 2) / zoomValue;
+
+export const getTextAutoResizeHandle = (
+  textElement: ExcalidrawTextElement,
+  zoomValue: number,
+  formFactor: EditorInterface["formFactor"],
+) => {
+  const padding = getTextBoxPadding(zoomValue);
+
+  if (
+    formFactor !== "desktop" ||
+    TEXT_AUTO_RESIZE_HANDLE_LENGTH >
+      (textElement.height + padding * 2) * zoomValue * MAX_HANDLE_HEIGHT_RATIO
+  ) {
+    return null;
+  }
+
+  const gap = TEXT_AUTO_RESIZE_HANDLE_GAP / zoomValue;
+  const length = TEXT_AUTO_RESIZE_HANDLE_LENGTH / zoomValue;
+  const center = pointFrom(
+    textElement.x + textElement.width / 2,
+    textElement.y + textElement.height / 2,
+  );
+  const handleCenter = pointRotateRads(
+    pointFrom(center[0] + textElement.width / 2 + padding + gap, center[1]),
+    center,
+    textElement.angle,
+  );
+
+  return {
+    center: handleCenter,
+    start: pointRotateRads(
+      pointFrom(handleCenter[0], handleCenter[1] - length / 2),
+      handleCenter,
+      textElement.angle,
+    ) as GlobalPoint,
+    end: pointRotateRads(
+      pointFrom(handleCenter[0], handleCenter[1] + length / 2),
+      handleCenter,
+      textElement.angle,
+    ) as GlobalPoint,
+    hitboxWidth: TEXT_AUTO_RESIZE_HANDLE_HITBOX_WIDTH / zoomValue,
+    hitboxHeight: TEXT_AUTO_RESIZE_HANDLE_HITBOX_HEIGHT / zoomValue,
+  };
+};
+
+export const isPointHittingTextAutoResizeHandle = (
+  point: Readonly<{ x: number; y: number }>,
+  textElement: ExcalidrawTextElement,
+  zoomValue: number,
+  formFactor: EditorInterface["formFactor"],
+) => {
+  const handle = getTextAutoResizeHandle(textElement, zoomValue, formFactor);
+
+  if (!handle) {
+    return false;
+  }
+
+  const unrotatedPoint = pointRotateRads(
+    pointFrom(point.x, point.y),
+    handle.center,
+    -textElement.angle as Radians,
+  );
+
+  return (
+    Math.abs(unrotatedPoint[0] - handle.center[0]) <= handle.hitboxWidth / 2 &&
+    Math.abs(unrotatedPoint[1] - handle.center[1]) <= handle.hitboxHeight / 2
+  );
+};