Sync panel props to editing element (#470)

* ensure panel props are sync to editing elem

* ensure we don't create empty-text elements (fixes #468)

* remove dead code

Co-authored-by: Christopher Chedeau <vjeuxx@gmail.com>

src/element/newElement.ts

@@ -2,6 +2,9 @@ import { randomSeed } from "roughjs/bin/math";
 import nanoid from "nanoid";
 import { Drawable } from "roughjs/bin/core";
 
+import { ExcalidrawElement, ExcalidrawTextElement } from "../element/types";
+import { measureText } from "../utils";
+
 export function newElement(
   type: string,
   x: number,
@@ -35,6 +38,28 @@ export function newElement(
   return element;
 }
 
+export function newTextElement(
+  element: ExcalidrawElement,
+  text: string,
+  font: string
+) {
+  const metrics = measureText(text, font);
+  const textElement: ExcalidrawTextElement = {
+    ...element,
+    type: "text",
+    text: text,
+    font: font,
+    // Center the text
+    x: element.x - metrics.width / 2,
+    y: element.y - metrics.height / 2,
+    width: metrics.width,
+    height: metrics.height,
+    baseline: metrics.baseline
+  };
+
+  return textElement;
+}
+
 export function duplicateElement(element: ReturnType<typeof newElement>) {
   const copy = { ...element };
   delete copy.shape;