refactor: packages/

1 files changed, 341 insertions, 0 deletions

diff --git a/packages/excalidraw/element/transformHandles.ts b/packages/excalidraw/element/transformHandles.ts
new file mode 100644
index 0000000..d34eb32
--- /dev/null
+++ b/packages/excalidraw/element/transformHandles.ts
@@ -0,0 +1,341 @@
+import type {
+  ElementsMap,
+  ExcalidrawElement,
+  NonDeletedExcalidrawElement,
+  PointerType,
+} from "./types";
+
+import type { Bounds } from "./bounds";
+import { getElementAbsoluteCoords } from "./bounds";
+import type { Device, InteractiveCanvasAppState, Zoom } from "../types";
+import {
+  isElbowArrow,
+  isFrameLikeElement,
+  isImageElement,
+  isLinearElement,
+} from "./typeChecks";
+import {
+  DEFAULT_TRANSFORM_HANDLE_SPACING,
+  isAndroid,
+  isIOS,
+} from "../constants";
+import type { Radians } from "@excalidraw/math";
+import { pointFrom, pointRotateRads } from "@excalidraw/math";
+
+export type TransformHandleDirection =
+  | "n"
+  | "s"
+  | "w"
+  | "e"
+  | "nw"
+  | "ne"
+  | "sw"
+  | "se";
+
+export type TransformHandleType = TransformHandleDirection | "rotation";
+
+export type TransformHandle = Bounds;
+export type TransformHandles = Partial<{
+  [T in TransformHandleType]: TransformHandle;
+}>;
+export type MaybeTransformHandleType = TransformHandleType | false;
+
+const transformHandleSizes: { [k in PointerType]: number } = {
+  mouse: 8,
+  pen: 16,
+  touch: 28,
+};
+
+const ROTATION_RESIZE_HANDLE_GAP = 16;
+
+export const DEFAULT_OMIT_SIDES = {
+  e: true,
+  s: true,
+  n: true,
+  w: true,
+};
+
+export const OMIT_SIDES_FOR_MULTIPLE_ELEMENTS = {
+  e: true,
+  s: true,
+  n: true,
+  w: true,
+};
+
+export const OMIT_SIDES_FOR_FRAME = {
+  e: true,
+  s: true,
+  n: true,
+  w: true,
+  rotation: true,
+};
+
+const OMIT_SIDES_FOR_LINE_SLASH = {
+  e: true,
+  s: true,
+  n: true,
+  w: true,
+  nw: true,
+  se: true,
+};
+
+const OMIT_SIDES_FOR_LINE_BACKSLASH = {
+  e: true,
+  s: true,
+  n: true,
+  w: true,
+};
+
+const generateTransformHandle = (
+  x: number,
+  y: number,
+  width: number,
+  height: number,
+  cx: number,
+  cy: number,
+  angle: Radians,
+): TransformHandle => {
+  const [xx, yy] = pointRotateRads(
+    pointFrom(x + width / 2, y + height / 2),
+    pointFrom(cx, cy),
+    angle,
+  );
+  return [xx - width / 2, yy - height / 2, width, height];
+};
+
+export const canResizeFromSides = (device: Device) => {
+  if (device.viewport.isMobile) {
+    return false;
+  }
+
+  if (device.isTouchScreen && (isAndroid || isIOS)) {
+    return false;
+  }
+
+  return true;
+};
+
+export const getOmitSidesForDevice = (device: Device) => {
+  if (canResizeFromSides(device)) {
+    return DEFAULT_OMIT_SIDES;
+  }
+
+  return {};
+};
+
+export const getTransformHandlesFromCoords = (
+  [x1, y1, x2, y2, cx, cy]: [number, number, number, number, number, number],
+  angle: Radians,
+  zoom: Zoom,
+  pointerType: PointerType,
+  omitSides: { [T in TransformHandleType]?: boolean } = {},
+  margin = 4,
+  spacing = DEFAULT_TRANSFORM_HANDLE_SPACING,
+): TransformHandles => {
+  const size = transformHandleSizes[pointerType];
+  const handleWidth = size / zoom.value;
+  const handleHeight = size / zoom.value;
+
+  const handleMarginX = size / zoom.value;
+  const handleMarginY = size / zoom.value;
+
+  const width = x2 - x1;
+  const height = y2 - y1;
+  const dashedLineMargin = margin / zoom.value;
+  const centeringOffset = (size - spacing * 2) / (2 * zoom.value);
+
+  const transformHandles: TransformHandles = {
+    nw: omitSides.nw
+      ? undefined
+      : generateTransformHandle(
+          x1 - dashedLineMargin - handleMarginX + centeringOffset,
+          y1 - dashedLineMargin - handleMarginY + centeringOffset,
+          handleWidth,
+          handleHeight,
+          cx,
+          cy,
+          angle,
+        ),
+    ne: omitSides.ne
+      ? undefined
+      : generateTransformHandle(
+          x2 + dashedLineMargin - centeringOffset,
+          y1 - dashedLineMargin - handleMarginY + centeringOffset,
+          handleWidth,
+          handleHeight,
+          cx,
+          cy,
+          angle,
+        ),
+    sw: omitSides.sw
+      ? undefined
+      : generateTransformHandle(
+          x1 - dashedLineMargin - handleMarginX + centeringOffset,
+          y2 + dashedLineMargin - centeringOffset,
+          handleWidth,
+          handleHeight,
+          cx,
+          cy,
+          angle,
+        ),
+    se: omitSides.se
+      ? undefined
+      : generateTransformHandle(
+          x2 + dashedLineMargin - centeringOffset,
+          y2 + dashedLineMargin - centeringOffset,
+          handleWidth,
+          handleHeight,
+          cx,
+          cy,
+          angle,
+        ),
+    rotation: omitSides.rotation
+      ? undefined
+      : generateTransformHandle(
+          x1 + width / 2 - handleWidth / 2,
+          y1 -
+            dashedLineMargin -
+            handleMarginY +
+            centeringOffset -
+            ROTATION_RESIZE_HANDLE_GAP / zoom.value,
+          handleWidth,
+          handleHeight,
+          cx,
+          cy,
+          angle,
+        ),
+  };
+
+  // We only want to show height handles (all cardinal directions)  above a certain size
+  // Note: we render using "mouse" size so we should also use "mouse" size for this check
+  const minimumSizeForEightHandles =
+    (5 * transformHandleSizes.mouse) / zoom.value;
+  if (Math.abs(width) > minimumSizeForEightHandles) {
+    if (!omitSides.n) {
+      transformHandles.n = generateTransformHandle(
+        x1 + width / 2 - handleWidth / 2,
+        y1 - dashedLineMargin - handleMarginY + centeringOffset,
+        handleWidth,
+        handleHeight,
+        cx,
+        cy,
+        angle,
+      );
+    }
+    if (!omitSides.s) {
+      transformHandles.s = generateTransformHandle(
+        x1 + width / 2 - handleWidth / 2,
+        y2 + dashedLineMargin - centeringOffset,
+        handleWidth,
+        handleHeight,
+        cx,
+        cy,
+        angle,
+      );
+    }
+  }
+  if (Math.abs(height) > minimumSizeForEightHandles) {
+    if (!omitSides.w) {
+      transformHandles.w = generateTransformHandle(
+        x1 - dashedLineMargin - handleMarginX + centeringOffset,
+        y1 + height / 2 - handleHeight / 2,
+        handleWidth,
+        handleHeight,
+        cx,
+        cy,
+        angle,
+      );
+    }
+    if (!omitSides.e) {
+      transformHandles.e = generateTransformHandle(
+        x2 + dashedLineMargin - centeringOffset,
+        y1 + height / 2 - handleHeight / 2,
+        handleWidth,
+        handleHeight,
+        cx,
+        cy,
+        angle,
+      );
+    }
+  }
+
+  return transformHandles;
+};
+
+export const getTransformHandles = (
+  element: ExcalidrawElement,
+  zoom: Zoom,
+  elementsMap: ElementsMap,
+  pointerType: PointerType = "mouse",
+  omitSides: { [T in TransformHandleType]?: boolean } = DEFAULT_OMIT_SIDES,
+): TransformHandles => {
+  // so that when locked element is selected (especially when you toggle lock
+  // via keyboard) the locked element is visually distinct, indicating
+  // you can't move/resize
+  if (
+    element.locked ||
+    // Elbow arrows cannot be rotated
+    isElbowArrow(element)
+  ) {
+    return {};
+  }
+
+  if (element.type === "freedraw" || isLinearElement(element)) {
+    if (element.points.length === 2) {
+      // only check the last point because starting point is always (0,0)
+      const [, p1] = element.points;
+      if (p1[0] === 0 || p1[1] === 0) {
+        omitSides = OMIT_SIDES_FOR_LINE_BACKSLASH;
+      } else if (p1[0] > 0 && p1[1] < 0) {
+        omitSides = OMIT_SIDES_FOR_LINE_SLASH;
+      } else if (p1[0] > 0 && p1[1] > 0) {
+        omitSides = OMIT_SIDES_FOR_LINE_BACKSLASH;
+      } else if (p1[0] < 0 && p1[1] > 0) {
+        omitSides = OMIT_SIDES_FOR_LINE_SLASH;
+      } else if (p1[0] < 0 && p1[1] < 0) {
+        omitSides = OMIT_SIDES_FOR_LINE_BACKSLASH;
+      }
+    }
+  } else if (isFrameLikeElement(element)) {
+    omitSides = {
+      ...omitSides,
+      rotation: true,
+    };
+  }
+  const margin = isLinearElement(element)
+    ? DEFAULT_TRANSFORM_HANDLE_SPACING + 8
+    : isImageElement(element)
+    ? 0
+    : DEFAULT_TRANSFORM_HANDLE_SPACING;
+  return getTransformHandlesFromCoords(
+    getElementAbsoluteCoords(element, elementsMap, true),
+    element.angle,
+    zoom,
+    pointerType,
+    omitSides,
+    margin,
+    isImageElement(element) ? 0 : undefined,
+  );
+};
+
+export const shouldShowBoundingBox = (
+  elements: readonly NonDeletedExcalidrawElement[],
+  appState: InteractiveCanvasAppState,
+) => {
+  if (appState.editingLinearElement) {
+    return false;
+  }
+  if (elements.length > 1) {
+    return true;
+  }
+  const element = elements[0];
+  if (isElbowArrow(element)) {
+    // Elbow arrows cannot be resized as single selected elements
+    return false;
+  }
+  if (!isLinearElement(element)) {
+    return true;
+  }
+
+  return element.points.length > 2;
+};