Ff pheno fix (#543)

Closes #541 

Tried to find a workaround, could not (in a reasonable time). Instead,
just turn off scroll feature in FF.

This was one of the known cons of switching to svg over table:
#372

frontend/src/components/ThePhenogrid.vue

@@ -495,17 +495,24 @@ const scrollInfo = useScroll(scroll);
 const scrollCoords = ref({ x: 0, y: 0, w: 0, h: 0 });
 function updateScroll() {
   if (!svg.value || !scroll.value) return;
-  const { x, y } = screenToSvgCoords(
+  const position = screenToSvgCoords(
     svg.value,
     scrollInfo.x.value,
     scrollInfo.y.value,
   );
-  const { x: w, y: h } = screenToSvgCoords(
+  if (!position) return;
+  const dimensions = screenToSvgCoords(
     svg.value,
     scroll.value.clientWidth,
     scroll.value.clientHeight,
   );
-  scrollCoords.value = { x: x + marginLeft, y: y + marginTop, w, h };
+  if (!dimensions) return;
+  scrollCoords.value = {
+    x: position.x + marginLeft,
+    y: position.y + marginTop,
+    w: dimensions.x,
+    h: dimensions.y,
+  };
 }
 watch(() => scrollInfo, updateScroll, { deep: true });
 useResizeObserver(scroll, updateScroll);

frontend/src/util/dom.ts

@@ -38,8 +38,11 @@ export const firstInView = (elements: HTMLElement[]): number => {
 
 /** convert screen coordinates to svg coordinates */
 export const screenToSvgCoords = (svg: SVGSVGElement, x: number, y: number) => {
-  /** https://bugzilla.mozilla.org/show_bug.cgi?id=543965 */
-  if (!svg || !svg.getCTM()) return new DOMPoint(0, 0);
+  /**
+   * https://bugzilla.mozilla.org/show_bug.cgi?id=543965 no viable workarounds
+   * found
+   */
+  if (!svg.getCTM()) return;
   let point = svg.createSVGPoint();
   point.x = x;
   point.y = y;