allow message input textarea height to grow with more text

src/widgets/send-message.jsx

@@ -111,6 +111,10 @@ class SendMessage extends React.PureComponent {
         // Set focus on desktop, but not on mobile: focus causes soft keyboard to pop up.
         this.messageEditArea.focus();
       }
+
+      // Adjust height of the message area for the amount of text.
+      this.messageEditArea.style.height = '0px';
+      this.messageEditArea.style.height = this.messageEditArea.scrollHeight + 'px';
     }
 
     if (prevProps.topicName != this.props.topicName) {
@@ -276,7 +280,7 @@ class SendMessage extends React.PureComponent {
                   </Suspense>) :
                   <textarea id="send-message-input" placeholder={prompt}
                     value={this.state.message} onChange={this.handleMessageTyping}
-                    onKeyPress={this.handleKeyPress}
+                    onKeyDown={this.handleKeyPress}
                     ref={ref => {this.messageEditArea = ref;}} />)}
               {this.state.message || !audioEnabled ?
                 <a href="#" onClick={this.handleSend} title={formatMessage(messages.icon_title_send)}>