Implement refreshing logic in Files app.

ui/file_manager/file_manager/foreground/js/spinner_controller.js

 // Copyright 2014 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.
 
 /**
  * Controller for spinner.
  * @param {!HTMLElement} element
- * @param {!DirectoryModel} directoryModel
  * @constructor
  * @extends {cr.EventTarget}
  */
-function SpinnerController(element, directoryModel) {
+function SpinnerController(element) {
   /**
    * The container element of the file list.
    * @type {!HTMLElement}
    * @const
    * @private
    */
   this.element_ = element;
 
   /**
-   * Directory model.
-   * @type {!DirectoryModel}
-   * @const
-   * @private
-   */
-  this.directoryModel_ = directoryModel;
-
-  /**
    * @type {number}
    * @private
    */
   this.timeoutId_ = 0;
 }
 
 SpinnerController.prototype.__proto__ = cr.EventTarget.prototype;
 
 /**
- * Shows the spinner.
+ * Blinks the spinner for a short period of time.
+ */
+SpinnerController.prototype.blink = function() {

[hirono, 2015/07/06 04:52:38]

Can we hide blinking spinner when the current directory is changed?

[mtomasz, 2015/07/06 08:48:48]

Do we need to hide it? Blinking is only one second. The code would be more
complicated (dependency on DirectoryModel).

[hirono, 2015/07/06 09:39:27]

I think it is worth to handle it. I'm guessing the spinner is not designed for
laying on files. e.g. We hide the spinner at the first scan update event.
Let's ask UX.

[mtomasz, 2015/07/07 03:42:10]

Sebastien said he's fine with blinking the spinner for 1s on top, so I guess
it's OK to keep it. Also, I find it very unlikely that a user will click the
refresh button and within one second navigate to other directory. But I can add
the hiding on dir change logic if you feel strong about it. WDYT?

[hirono, 2015/07/07 03:58:22]

SGTM. Thank you for confirming!

+  this.element_.hidden = false;
+  clearTimeout(this.blinkHideTimeoutId_);
+  this.blinkHideTimeoutId_ = 0;

[hirono, 2015/07/06 04:52:38]

Is this line needed?

[mtomasz, 2015/07/06 08:48:48]

Done.

+  this.blinkHideTimeoutId_ = setTimeout(this.hide.bind(this), 1000);
+};
+
+/**
+ * Shows the spinner until hide is called.
  */
 SpinnerController.prototype.show = function() {
-  if (!this.directoryModel_.isScanning())
-    return;
   this.element_.hidden = false;
+  clearTimeout(this.blinkHideTimeoutId_);
+  this.blinkHideTimeoutId_ = 0;
   clearTimeout(this.timeoutId_);
   this.timeoutId_ = 0;
   var spinnerShownEvent = new Event('spinner-shown');
   this.dispatchEvent(spinnerShownEvent);
 };
 
 /**
  * Hides the spinner.
  */
 SpinnerController.prototype.hide = function() {
-  if (this.directoryModel_.isScanning() &&
-      this.directoryModel_.getFileList().length == 0) {
-    return;
-  }
   this.element_.hidden = true;
   clearTimeout(this.timeoutId_);
   this.timeoutId_ = 0;
+  clearTimeout(this.blinkHideTimeoutId_);
+  this.blinkHideTimeoutId_ = 0;
 };
 
 /**
- * Shows the spinner after 500ms.
+ * Shows the spinner after 500ms (unless it's already visible).
  */
 SpinnerController.prototype.showLater = function() {
   if (!this.element_.hidden)

[hirono, 2015/07/06 09:39:27]

I think we should clear blinkHideTimeout here.

blink() -> showLater(), means the client code expect the spinner eventually is
shown.

[mtomasz, 2015/07/07 03:42:11]

Good point. Done.

     return;
   clearTimeout(this.timeoutId_);
   this.timeoutId_ = setTimeout(this.show.bind(this), 500);
 };