fix(switch): trigger when on empty editable

Author: gabrielhase

src/core.js

@@ -217,6 +217,15 @@ export default class Editable {
     return new Cursor($host[0], range)
   }
 
+  createRangyRange () {
+    return rangy.createRange()
+  }
+
+  createCursor (element, range) {
+    const $host = $(element).closest(this.editableSelector)
+    return new Cursor($host[0], range)
+  }
+
   createCursorAtBeginning (element) {
     return this.createCursor(element, 'beginning')
   }

src/dispatcher.js

@@ -6,6 +6,7 @@ import eventable from './eventable'
 import SelectionWatcher from './selection-watcher'
 import config from './config'
 import Keyboard from './keyboard'
+import {getTotalCharCount} from './util/element'
 
 // This will be set to true once we detect the input event is working.
 // Input event description on MDN:
@@ -165,17 +166,17 @@ export default class Dispatcher {
 
   dispatchSwitchEvent (event, element, direction) {
     if (event.altKey || event.ctrlKey || event.metaKey || event.shiftKey) return
-
     const cursor = this.selectionWatcher.getSelection()
     if (!cursor || cursor.isSelection) return
-
-    if (direction === 'up' && cursor.isAtFirstLine()) {
+    
+    const totalCharCount = getTotalCharCount(element)
+    if (direction === 'up' && (cursor.isAtFirstLine() || totalCharCount === 0)) {
       event.preventDefault()
       event.stopPropagation()
       this.notify('switch', element, direction, cursor)
     }
 
-    if (direction === 'down' && cursor.isAtLastLine()) {
+    if (direction === 'down' && (cursor.isAtLastLine() || totalCharCount === 0)) {
       event.preventDefault()
       event.stopPropagation()
       this.notify('switch', element, direction, cursor)

src/util/element.js

@@ -0,0 +1,20 @@
+'use strict'
+function textNodesUnder (node) {
+  let all = []
+  for (node = node.firstChild; node; node = node.nextSibling) {
+      if (node.nodeType === 3) {
+      all.push(node)
+      } else {
+      all = all.concat(textNodesUnder(node))
+      }
+  }
+  return all
+}
+
+function getTotalCharCount (element) {
+  const textNodes = textNodesUnder(element)
+  const reducer = (acc, node) => acc + node.textContent.length
+  return textNodes.reduce(reducer, 0)
+}
+
+module.exports = {getTotalCharCount}