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..e6afac9b69377bcb034575ad011d9cbac727109f 100644
--- a/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
+++ b/chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.js
@@ -22,6 +22,16 @@
  *                  value="{{pinValue}}">
  *    </pin-keyboard>
  */
+
+(function() {
+
+/**
+ * How long the backspace button must be held down before clearing characters.
+ * @type {number}
+ * @const
+ */
+var repeatClearIntervalMs = 250;
+
 Polymer({
   is: 'pin-keyboard',
 
@@ -53,6 +63,15 @@ Polymer({
       notify: true,
       value: '',
       observer: 'onPinValueChange_'
+    },
+
+    /**
+     * The intervalID used for the backspace button set/clear interval.
+     * @private
+     */
+    repeatClearIntervalId_: {
+      type: Number,
+      value: 0
     }
   },
 
@@ -97,12 +116,38 @@ 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) {
+    this.onPinClear_();

[jdufault, 2016/09/02 22:58:53]

Buttons normally activate on up events, right? That way you can click the button
but cancel the click by moving the mouse away. I think the same thing should
work here too.

[sammiequon, 2016/09/03 00:53:49]

Done.

+    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_);
+    this.repeatClearIntervalId_ = 0;
+    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 +188,11 @@ 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.
@@ -201,3 +251,4 @@ Polymer({
     return (document.dir == 'rtl') && !Number.isInteger(+password);
   },
 });
+})();