got insertion working!

lib/components/content.js

@@ -90,6 +90,27 @@ class Content extends React.Component {
     this.onChange(state)
   }
 
+  /**
+   * On before input, add the character to the state.
+   *
+   * @param {Event} e
+   */
+
+  onBeforeInput(e) {
+    let { state } = this.props
+    const { data }  = e
+
+    // If there is no data to input, there's nothing to do.
+    if (!data) return
+    e.preventDefault()
+
+    // If the state is expanded, we will have to re-render.
+    if (state.isExpanded) state = state.delete()
+
+    state = state.insert(data)
+    this.onChange(state)
+  }
+
   /**
    * Render the editor content.
    *
@@ -113,8 +134,9 @@ class Content extends React.Component {
         suppressContentEditableWarning
         spellCheck={false}
         data-type='content'
-        onKeyDown={(e) => this.onKeyDown(e)}
-        onSelect={(e) => this.onSelect(e)}
+        onKeyDown={e => this.onKeyDown(e)}
+        onSelect={e => this.onSelect(e)}
+        onBeforeInput={e => this.onBeforeInput(e)}
         style={style}
       >
         {children}

lib/models/state.js

@@ -2,6 +2,7 @@
 import Selection from './selection'
 import Node from './node'
 import Text from './text'
+import convertRangesToCharacters from '../utils/convert-ranges-to-characters'
 import toCamel from 'to-camel-case'
 import { OrderedMap, Record } from 'immutable'
 
@@ -281,6 +282,41 @@ class State extends StateRecord {
     const { startOffset } = state
     const endOffset = startOffset + 1
     state = state.removeCharacters(startNode.key, startOffset, endOffset)
+
+    return state
+  }
+
+  /**
+   * Insert a `text` string at the current cursor position.
+   *
+   * @param {String} text
+   * @return {State} state
+   */
+
+  insert(text) {
+    let state = this
+
+    // When still expanded, remove the current range first.
+    if (state.isExpanded) {
+      state = state.delete()
+    }
+
+    // Insert text at the current cursor.
+    const ranges = [{ text }]
+    let { startNode, startOffset } = state
+    let { characters } = startNode
+    let newCharacters = convertRangesToCharacters(ranges)
+    const { size } = newCharacters
+
+    // Splice in the new characters.
+    characters = characters.slice(0, startOffset)
+      .concat(newCharacters)
+      .concat(characters.slice(startOffset + size - 1, Infinity))
+
+    // Update the existing text node and the selection.
+    startNode = startNode.merge({ characters })
+    state = state.updateNode(startNode)
+    state = state.moveForward(size)
     return state
   }