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..e301a175a11b176a9dfee927de67dba8d754cbe9 100644
--- a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
+++ b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
@@ -53,6 +53,23 @@ Polymer({
       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
     }
   },
 
@@ -97,12 +114,34 @@ 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 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
@@ -143,6 +182,11 @@ 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.