make MessageComposerInput (new and old) warn on unload

new needs binding due to class this ref being softer
couldn't do this nicely in MessageComposer/Input as
isTyping wasn't propagated.

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/views/rooms/MessageComposerInput.js

@@ -93,6 +93,7 @@ export default class MessageComposerInput extends React.Component {
         this.onEscape = this.onEscape.bind(this);
         this.setDisplayedCompletion = this.setDisplayedCompletion.bind(this);
         this.onMarkdownToggleClicked = this.onMarkdownToggleClicked.bind(this);
+        this.onPageUnload = this.onPageUnload.bind(this);
 
         const isRichtextEnabled = UserSettingsStore.getSyncedSetting('MessageComposerInput.isRichTextEnabled', false);
 
@@ -233,11 +234,13 @@ export default class MessageComposerInput extends React.Component {
             this.refs.editor,
             this.props.room.roomId
         );
+        window.addEventListener('beforeunload', this.onPageUnload);
     }
 
     componentWillUnmount() {
         dis.unregister(this.dispatcherRef);
         this.sentHistory.saveLastTextEntry();
+        window.removeEventListener('beforeunload', this.onPageUnload);
     }
 
     componentWillUpdate(nextProps, nextState) {
@@ -249,6 +252,13 @@ export default class MessageComposerInput extends React.Component {
         }
     }
 
+    onPageUnload(event) {
+        if (this.isTyping) {
+            return event.returnValue =
+                'You seem to be typing a message, are you sure you want to quit?';
+        }
+    }
+
     onAction(payload) {
         let editor = this.refs.editor;
         let contentState = this.state.editorState.getCurrentContent();

src/components/views/rooms/MessageComposerInputOld.js

@@ -177,11 +177,20 @@ export default React.createClass({
         if (this.props.tabComplete) {
             this.props.tabComplete.setTextArea(this.refs.textarea);
         }
+        window.addEventListener('beforeunload', this.onPageUnload);
     },
 
     componentWillUnmount: function() {
         dis.unregister(this.dispatcherRef);
         this.sentHistory.saveLastTextEntry();
+        window.removeEventListener('beforeunload', this.onPageUnload);
+    },
+
+    onPageUnload(event) {
+        if (this.isTyping) {
+            return event.returnValue =
+                'You seem to be typing a message, are you sure you want to quit?';
+        }
     },
 
     onAction: function(payload) {