PluginMeasure: use selected unit system

src/PluginMeasure.js

@@ -1,7 +1,24 @@
+const formatUnits = require('./formatUnits')
+
+let control
+let unitSystems = {
+  si: 'metres',
+  imp: 'landmiles',
+  nautical: 'nauticalmiles',
+  m: 'metres'
+}
+
 register_hook('init', function () {
   // Measurement plugin
   if (L.control.polylineMeasure) {
-    L.control.polylineMeasure({
+    control = L.control.polylineMeasure({
+      unit: unitSystems[formatUnits.settings.system]
     }).addTo(map)
   }
 })
+
+register_hook('format-units-refresh', () => {
+  if (control) {
+    control.options.unit = unitSystems[formatUnits.settings.system]
+  }
+})