Make the terminal demo able (to try) to connect to anything.

sky/examples/terminal/terminal.sky

 <!--
 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 -->
 <import src="/sky/framework/elements/sky-element.sky" />
 <import src="/sky/framework/elements/sky-scrollable.sky" />
 <sky-element>
 <template>
   <style>
     #control {
       height: -webkit-fill-available;
       background-color: black;
       color: rgb(255, 191, 0);
       font-family: 'Courier', 'monospace';
+      font-size: small;
     }
     .line {
-      white-space: pre;
+      white-space: nowrap;
     }
   </style>
   <sky-scrollable id="control" contenteditable />
 </template>
 <script>
 import 'dart:async';
 import 'dart:core';
 import 'dart:sky';
 import 'package:mojo/services/terminal/public/interfaces/terminal_client.mojom.dart' as terminal;
 import 'package:sky/framework/embedder.dart';
@@ skipping 24 matching lines @@
   }
 
   void shadowRootReady() {
     _control = shadowRoot.getElementById('control');
     _control.addEventListener('keydown', _handleKeyDown);
     _control.addEventListener('keypress', _handleKeyPress);
 
     // Initialize with the first line.
     _newLine();
 
-    _connect(getAttribute('url'));
+    var url = getAttribute('url');
+    if (url != null) {
+      connect(url);
+    }
   }
 
   void _handleKeyDown(KeyboardEvent event) {
     // TODO(vtl): In general, our key handling is a total hack (due in part to
     // sky's keyboard support being incomplete) -- e.g., we shouldn't have to
     // make our div contenteditable. We have to intercept backspace (^H) here,
     // since we won't actually get a keypress event for it. (Possibly, we should
     // only handle keydown instead of keypress, but then we'd have to handle
     // shift, etc. ourselves.)
     if (event.key == 8) {
@@ skipping 30 matching lines @@
     _control.appendChild(line);
   }
 
   void _clear() {
     while (_control.firstChild != null) {
       _control.firstChild.remove();
     }
     _newLine();
   }
 
-  // TODO(vtl): Should we always auto-connect? Should there be facilities for
-  // programmatically connecting? (What if the |url| attribute isn't set?)
-  void _connect(String url) {
+  void connect(String url) {
     var terminalClient = new terminal.TerminalClientProxy.unbound();
     embedder.connectToService(url, terminalClient);
     terminalClient.ptr.connectToTerminal(new TerminalFileImpl(this).stub);
     terminalClient.close();
   }
 
+  void putString(String s) {
+    for (var i = 0; i < s.length; i++) {
+      putChar(s.codeUnitAt(i));
+    }
+  }
+
   // |TerminalDisplay| implementation:
 
   @override
   void putChar(int byte) {
     // Fast-path for printable chars.
     if (byte >= 32) {
       _control.lastChild.textContent += new String.fromCharCode(byte);
       return;
     }
 
@@ skipping 24 matching lines @@
 
     var completer = new Completer<int>();
     _readerQueue.add(completer);
     return completer.future;
   }
 }
 
 _init(script) => register(script, TerminalDisplayImpl);
 </script>
 </sky-element>