fix: stabilize mobile graph dragging and resize

ui/graph-renderer-utils.js

@@ -0,0 +1,46 @@
+function clampUnit(value) {
+  if (!Number.isFinite(Number(value))) return 0;
+  return Math.min(1, Math.max(0, Number(value)));
+}
+
+export function isUsableGraphCanvasSize(width = 0, height = 0, minDimension = 48) {
+  const normalizedWidth = Number(width);
+  const normalizedHeight = Number(height);
+  const threshold = Number.isFinite(Number(minDimension))
+    ? Math.max(1, Number(minDimension))
+    : 48;
+  return (
+    Number.isFinite(normalizedWidth) &&
+    Number.isFinite(normalizedHeight) &&
+    normalizedWidth >= threshold &&
+    normalizedHeight >= threshold
+  );
+}
+
+export function remapPositionBetweenRects(x = 0, y = 0, prevRect = null, nextRect = null) {
+  const pointX = Number.isFinite(Number(x)) ? Number(x) : 0;
+  const pointY = Number.isFinite(Number(y)) ? Number(y) : 0;
+  if (!prevRect || !nextRect) {
+    return {
+      x: pointX,
+      y: pointY,
+    };
+  }
+
+  const prevX = Number.isFinite(Number(prevRect.x)) ? Number(prevRect.x) : 0;
+  const prevY = Number.isFinite(Number(prevRect.y)) ? Number(prevRect.y) : 0;
+  const prevW = Math.max(1, Number.isFinite(Number(prevRect.w)) ? Number(prevRect.w) : 0);
+  const prevH = Math.max(1, Number.isFinite(Number(prevRect.h)) ? Number(prevRect.h) : 0);
+  const nextX = Number.isFinite(Number(nextRect.x)) ? Number(nextRect.x) : 0;
+  const nextY = Number.isFinite(Number(nextRect.y)) ? Number(nextRect.y) : 0;
+  const nextW = Math.max(1, Number.isFinite(Number(nextRect.w)) ? Number(nextRect.w) : 0);
+  const nextH = Math.max(1, Number.isFinite(Number(nextRect.h)) ? Number(nextRect.h) : 0);
+
+  const relX = clampUnit((pointX - prevX) / prevW);
+  const relY = clampUnit((pointY - prevY) / prevH);
+
+  return {
+    x: nextX + relX * nextW,
+    y: nextY + relY * nextH,
+  };
+}