Pin keyboard improvements.

chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js

 // Copyright 2016 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.
 
 /**
  * @fileoverview
  * 'pin-keyboard' is a keyboard that can be used to enter PINs or more generally
  * numeric values.
  *
  * Properties:
  *    value: The value of the PIN keyboard. Writing to this property will adjust
  *           the PIN keyboard's value.
  *
  * Events:
  *    pin-change: Fired when the PIN value has changed. The pin is available at
  *                event.detail.pin.
  *    submit: Fired when the PIN is submitted. The pin is available at
  *            event.detail.pin.
  *
  * Example:
  *    <pin-keyboard on-pin-change="onPinChange" on-submit="onPinSubmit"
  *                  value="{{pinValue}}">
  *    </pin-keyboard>
  */
+
+/**
+ * Time in milliseconds for which the backspace button clears a character when

[jdufault, 2016/09/02 20:03:43]

What about:

  How long the backspace button must be held down before clearing characters.

I don't think you need to say milliseconds in the comment since it is in the
variable name.

[sammiequon, 2016/09/02 22:47:39]

Done.

+ * held down.
+ * @type {number}
+ * @const
+ */
+var repeatClearIntervalMs = 250;
+

[jdufault, 2016/09/02 20:03:44]

Make sure to wrap this all in a function to avoid introducing a global.

(function() {

// ...

})();

[sammiequon, 2016/09/02 22:47:39]

Done.

 Polymer({
   is: 'pin-keyboard',
 
   behaviors: [
     I18nBehavior,
   ],
 
   properties: {
     /**
      * Whether or not the keyboard's input element should be numerical
@@ skipping 11 matching lines @@
       type: Boolean,
       value: false
     },
 
     /** The value stored in the keyboard's input element. */
     value: {
       type: String,
       notify: true,
       value: '',
       observer: 'onPinValueChange_'
+    },
+
+    /**
+     * The intervalID used for the backspace button set/clear interval.

[jdufault, 2016/09/02 20:03:43]

Please add @private

[sammiequon, 2016/09/02 22:47:39]

Done.

+     */
+    repeatClearIntervalId_: {
+      type: Number,
+      value: 0
     }
   },
 
   /**
    * Gets the container holding the password field.
    * @type {!HTMLInputElement}
    */
   get inputElement() {
     return this.$$('#pin-input');
   },
@@ skipping 24 matching lines @@
    * @param {string} value
    * @param {string} previous
    */
   onPinValueChange_: function(value, previous) {
     if (value != previous)
       this.fire('pin-change', { pin: value });
   },
 
   /**
    * Called when the user wants to erase the last character of the entered
-   *  PIN value.
+   * PIN value.
    */
   onPinClear_: function() {
     this.value = this.value.substring(0, this.value.length - 1);
   },
 
+  /**
+   * Called when the user presses or touches the backspace button. Starts an
+   * interval callback to repeatedly clear the last pin value until the interval
+   * is cleared.
+   * @param {Event} event The event object.
+   * @private
+   */
+  onBackspaceGetFocus_: function(event) {

[jdufault, 2016/09/02 20:03:43]

Is there an actual "on-focus" event this could listen for?

[sammiequon, 2016/09/02 22:47:39]

on-blur and on-foucsout don't seem to trigger on-mouseup.

+    this.onPinClear_();
+    this.repeatClearIntervalId_ = setInterval(
+        this.onPinClear_.bind(this), repeatClearIntervalMs);
+    event.preventDefault();
+  },
+
+  /**
+   * Called when the user unpresses or untouches the backspace button. Stops the
+   * interval callback.
+   * @param {Event} event The event object.
+   * @private
+   */
+  onBackspaceLoseFocus_: function(event) {
+    clearInterval(this.repeatClearIntervalId_);

[jdufault, 2016/09/02 20:03:43]

reset repeatClearIntervalId_ value to 0?

[sammiequon, 2016/09/02 22:47:39]

Done.

+    event.preventDefault();
+  },
+
   /** Called when a key event is pressed while the input element has focus. */
   onInputKeyDown_: function(event) {
     // Up/down pressed, swallow the event to prevent the input value from
     // being incremented or decremented.
     if (event.keyCode == 38 || event.keyCode == 40) {
       event.preventDefault();
       return;
     }
 
     // Enter pressed.
@@ skipping 20 matching lines @@
   },
 
   /**
    * Called when a key press event is fired while the number button is focused.
    * Ideally we would want to pass focus back to the input element, but the we
    * cannot or the virtual keyboard will keep poping up.
    * @param {Event} event Keypress Event object.
    * @private
    */
   onKeyPress_: function(event) {
+    // If the active element is the input element, the input element itself will
+    // handle the keypresses, so we do not handle them here.
+    if (this.shadowRoot.activeElement == this.inputElement)
+      return;
+
     var code = event.keyCode;
 
     // Enter pressed.
     if (code == 13) {
       this.firePinSubmitEvent_();
       event.preventDefault();
       return;
     }
 
     this.value += String.fromCharCode(code);
@@ skipping 38 matching lines @@
     // possible. Number.isInteger will verify the value is not a NaN and that it
     // does not contain decimals.
     // This heuristic will fail for inputs like '1.0'.
     //
     // Since we still support users entering their passwords through the PIN
     // keyboard, we swap the input box to rtl when we think it is a password
     // (just numbers), if the document direction is rtl.
     return (document.dir == 'rtl') && !Number.isInteger(+password);
   },
 });