Merge pull request #1034 from n-gist/crosshair-selPoints-error-fix

Crosshair plugin runtime error on moving cursor out fix
danvk · Jan 11, 2025 · 09252ae · 09252ae
2 parents 3a5403a + 0b31994
commit 09252ae
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/src/extras/crosshair.js b/src/extras/crosshair.js
@@ -66,12 +66,14 @@ Dygraph.Plugins.Crosshair = (function _extras_crosshair_closure() {
     ctx.clearRect(0, 0, width, height);
     ctx.strokeStyle = this.strokeStyle_;
     ctx.beginPath();
-
-    var canvasx = Math.floor(e.dygraph.selPoints_[0].canvasx) + 0.5; // crisper rendering
-
-    if (this.direction_ === "vertical" || this.direction_ === "both") {
-      ctx.moveTo(canvasx, 0);
-      ctx.lineTo(canvasx, height);
+
+    if (e.dygraph.selPoints_.length !== 0) {
+      var canvasx = Math.floor(e.dygraph.selPoints_[0].canvasx) + 0.5; // crisper rendering
+
+      if (this.direction_ === "vertical" || this.direction_ === "both") {
+        ctx.moveTo(canvasx, 0);
+        ctx.lineTo(canvasx, height);
+      }
     }
 
     if (this.direction_ === "horizontal" || this.direction_ === "both") {