show message about ClipboardItem support #50

for Firefox

src/lib/utils/clipboardIo.js

@@ -1,7 +1,7 @@
 import Lib from 'plotly.js/src/lib'
 import dataUrlToBlob from 'dataurl-to-blob'
 
-async function _copyBlob(blob) {
+async function _copyBlob (blob) {
   await navigator.clipboard.write([
     new ClipboardItem({
       [blob.type]: blob

src/views/Main/Workspace/Tabs/Tab/DataView/Pivot/index.vue

@@ -176,8 +176,7 @@ export default {
         const canvas = await getPivotCanvas(this.$refs.pivotOutput)
         cIo.copyCanvas(canvas)
       }
-    },
-
+    }
   }
 }
 </script>

src/views/Main/Workspace/Tabs/Tab/DataView/index.vue

@@ -107,7 +107,11 @@ export default {
       return this.$refs.viewComponent.getOptionsForSave()
     },
     copyToClipboard () {
-      this.$refs.viewComponent.copyPngToClipboard()
+      if ('ClipboardItem' in window) {
+        this.$refs.viewComponent.copyPngToClipboard()
+      } else {
+        alert ("Your browser doesn't support copying images into the clipboard. If you use Firefox you can enable it by setting dom.events.asyncClipboard.clipboardItem to true.")
+      }
     }
   }
 }