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:
@@ skipping 35 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.
+     */
+    intervalId_: {

[jdufault, 2016/09/01 16:40:11]

repeatClearIntervalId_?

[sammiequon, 2016/09/02 17:24:55]

Done.

+      type: Number,
+      value: 0
+    },
+
+    /**
+     * When the backspace button is held down, it repeatly clears the last
+     * character of the input value every intervalMs.
+     */
+    intervalMs_: {

[jdufault, 2016/09/01 16:40:11]

Make this a constant value defined at the top of the file.

[sammiequon, 2016/09/02 17:24:55]

Done.

+      type: Number,
+      value: 250
     }
   },
 
   /**
    * 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 the backspace button. Starts a interval
+   * callback to repeatedly clear the last pin value until the interval is
+   * cleared.
+   * @private
+   */
+  onBackspaceMouseDown_: function() {
+    this.onPinClear_();
+    this.intervalId_ = setInterval(function() {
+      this.async(function() { this.onPinClear_(); }, 1);

[jdufault, 2016/09/01 16:40:11]

Remove the this.async call if you're still using setInterval.

Also, what about removing the helper function?

this.intervalId_ = setInterval(this.onPinClear_.bind(this), this.intervalMs_)

[sammiequon, 2016/09/02 17:24:55]

Done.

+    }.bind(this), this.intervalMs_);
+  },
+
+  /**
+   * Called when the user unpresses the backspace button. Stops the interval
+   * callback.
+   * @private
+   */
+  onBackspaceMouseUpLeave_: function() {
+    clearInterval(this.intervalId_);
+  },
+
   /** 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);
   },
 });