#374 Polygon number-of-sides cannot be edited after placed

src/editor/extensions/ext-polystar/ext-polystar.js

@@ -145,6 +145,35 @@ export default {
         });
         $id("polySides").addEventListener("change", (event) => {
           setAttr("sides", event.target.value);
+          const sides = event.target.value;
+          let i = selElems.length;
+          while (i--) {
+            const elem = selElems[i];
+            let xpos = 0;
+            let ypos = 0;
+            if (elem.points) {
+              const list = elem.points;
+              const len = list.numberOfItems;
+              for (let i = 0; i < len; ++i) {
+                const pt = list.getItem(i);
+                xpos += parseFloat(pt.x);
+                ypos += parseFloat(pt.y);
+              }
+              const cx = xpos / len;
+              const cy = ypos / len;
+              const edg = elem.getAttribute('edge');
+              const inradius = (edg / 2) * cot(Math.PI / sides);
+              const circumradius = inradius * sec(Math.PI / sides);
+              let points = "";
+              for (let s = 0; sides >= s; s++) {
+                const angle = (2.0 * Math.PI * s) / sides;
+                const x = circumradius * Math.cos(angle) + cx;
+                const y = circumradius * Math.sin(angle) + cy;
+                points += x + "," + y + " ";
+              }
+              elem.setAttribute("points", points);
+            }
+          }
         });
       },
       mouseDown(opts) {