Move client/{base, observable, layout, touch, util, view} to samples/ui_lib .

client/touch/EventUtil.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * Common events related helpers.
- */
-class EventUtil {
-
-  /**
-   * Add an event listener to an element.
-   * The event callback is specified by [handler].
-   * If [capture] is true, the listener gets events on the capture phase.
-   * If [removeHandlerOnFocus] is true the handler is removed when there is any
-   * focus event, and added back on blur events.
-   */
-  static void observe(Element element,
-                      EventListenerList listenerList, Function handler,
-                      [bool capture = false, bool removeHandlerOnFocus = false]) {
-    listenerList.add(handler, capture);
-    // TODO(jacobr): this remove on focus behavior seems really ugly.
-    if (removeHandlerOnFocus) {
-      element.on.focus.add((e) { listenerList.remove(handler, capture); });
-      element.on.blur.add((e) { listenerList.add(handler, capture); });
-    }
-  }
-
-  /**
-   * Clear the keyboard focus of the currently focused element (if there is
-   * one). If there is no currently focused element then this function will do
-   * nothing. For most browsers this will cause the keyboard to be dismissed.
-   */
-  static void blurFocusedElement() {
-    Element focusedEl = document.query("*:focus");
-    if (focusedEl != null) {
-      focusedEl.blur();
-    }
-  }
-}