Pin keyboard improvements.

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

Index: chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
diff --git a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
index d6c28711b4d28f8981da2fa4aa487e02dafc6e40..24211fc28b842437fbd1fe6f00082abb23a3bdad 100644
--- a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
+++ b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
@@ -22,6 +22,15 @@
  *                  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',
 
@@ -53,6 +62,14 @@ Polymer({
       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
     }
   },
 
@@ -97,12 +114,37 @@ Polymer({
 
   /**
    * 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
@@ -143,6 +185,11 @@ Polymer({
    * @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.