Resize multiple elements (rectangles, diamonds and ellipses onl… (#1193)

* experiment resizing multiple elements

* hack common component

* calculate scale properly (still se only)fg

* prioritize multi selection

* take handle offset into calculation

* fix master merge

* refactor resizeElements out from App

* wip: handlerRectanglesFromCoords

* fix test with type assertion

* properly show handles wip

* revert previous one and do a tweak

* remove unnecessary assignments

* replace hack code with good one

* refactor coords in arg

* resize NW

* resize from sw,ne

* fix with setResizeHandle

* do not show hint while resizing multiple elements

* empty commit

* fix format

src/element/resizeTest.ts

@@ -1,6 +1,10 @@
 import { ExcalidrawElement, PointerType } from "./types";
 
-import { handlerRectangles } from "./handlerRectangles";
+import {
+  OMIT_SIDES_FOR_MULTIPLE_ELEMENTS,
+  handlerRectanglesFromCoords,
+  handlerRectangles,
+} from "./handlerRectangles";
 import { AppState } from "../types";
 import { isLinearElement } from "./typeChecks";
 
@@ -77,16 +81,37 @@ export function getElementWithResizeHandler(
   }, null as { element: ExcalidrawElement; resizeHandle: ReturnType<typeof resizeTest> } | null);
 }
 
+export function getResizeHandlerFromCoords(
+  [x1, y1, x2, y2]: readonly [number, number, number, number],
+  { x, y }: { x: number; y: number },
+  zoom: number,
+  pointerType: PointerType,
+) {
+  const handlers = handlerRectanglesFromCoords(
+    [x1, y1, x2, y2],
+    0,
+    zoom,
+    pointerType,
+    OMIT_SIDES_FOR_MULTIPLE_ELEMENTS,
+  );
+
+  const found = Object.keys(handlers).find((key) => {
+    const handler = handlers[key as Exclude<HandlerRectanglesRet, "rotation">]!;
+    return handler && isInHandlerRect(handler, x, y);
+  });
+  return (found || false) as HandlerRectanglesRet;
+}
+
 /*
  * Returns bi-directional cursor for the element being resized
  */
 export function getCursorForResizingElement(resizingElement: {
-  element: ExcalidrawElement;
+  element?: ExcalidrawElement;
   resizeHandle: ReturnType<typeof resizeTest>;
 }): string {
   const { element, resizeHandle } = resizingElement;
   const shouldSwapCursors =
-    Math.sign(element.height) * Math.sign(element.width) === -1;
+    element && Math.sign(element.height) * Math.sign(element.width) === -1;
   let cursor = null;
 
   switch (resizeHandle) {