[CUPS] Implement the local CUPS printer setup waiting UI.

chrome/browser/resources/print_preview/search/destination_list_item.js

Index: chrome/browser/resources/print_preview/search/destination_list_item.js
diff --git a/chrome/browser/resources/print_preview/search/destination_list_item.js b/chrome/browser/resources/print_preview/search/destination_list_item.js
index 8b529d45acc919b3f3d5aec44328569b9268b49c..feaa4e7b665b99b67eaed0d631b46de71af5eb1b 100644
--- a/chrome/browser/resources/print_preview/search/destination_list_item.js
+++ b/chrome/browser/resources/print_preview/search/destination_list_item.js
@@ -53,6 +53,8 @@ cr.define('print_preview', function() {
    * @enum {string}
    */
   DestinationListItem.EventType = {
+    // Dispatched to check the printer needs to be configured before activation.
+    CONFIGURE_REQUEST: 'print_preview.DestinationListItem.CONFIGURE_REQUEST',
     // Dispatched when the list item is activated.
     SELECT: 'print_preview.DestinationListItem.SELECT',
     REGISTER_PROMO_CLICKED:
@@ -99,6 +101,51 @@ cr.define('print_preview', function() {
     },
 
     /**
+     * Called if the printer configuration request is accepted. Show the waiting
+     * message to the user as the configuration might take longer than expected.
+     */
+    onConfigureRequestAccepted: function() {
+      // It must be a Chrome OS CUPS printer which hasn't been set up before.
+      assert(
+          this.destination_.origin == print_preview.Destination.Origin.CROS &&
+          !this.destination_.capabilities);
+      setIsVisible(
+          this.getChildElement('.configuring-in-progress-text'), true);
+    },
+
+    /**
+     * Called if the printer configuration request is rejected. The request is
+     * rejected if another printer is setting up in process or the current
+     * printer doesn't need to be setup.
+     * @param {bool} shouldIgnore If true, which indicates another printer is
+     *     setting up in process, the printer should not be activated.
+     */
+    onConfigureRequestRejected: function(shouldIgnore) {
+      if (!shouldIgnore)
+        this.onDestinationActivated_();
+    },
+
+    /**
+     * Called when the printer configuration request is resolved successful or
+     * failed.
+     * @param response {!print_preview.PrinterSetupResponse}
+     */
+    onConfigureResolved: function(response) {
+      assert(response.printerId == this.destination_.id);
+      if (response.success) {
+        setIsVisible(
+            this.getChildElement('.configuring-in-progress-text'), false);
+        this.destination_.capabilities = response.capabilities;
+        this.onDestinationActivated_();
+      } else {
+        setIsVisible(
+            this.getChildElement('.configuring-in-progress-text'), false);
+        setIsVisible(
+            this.getChildElement('.configuring-failed-text'), true);
+      }
+    },
+
+    /**
      * Initializes the element with destination's info.
      * @private
      */
@@ -171,6 +218,12 @@ cr.define('print_preview', function() {
           this.getChildElement('.register-promo'),
           this.destination_.connectionStatus ==
               print_preview.Destination.ConnectionStatus.UNREGISTERED);
+
+      // Reset the configuring messages for CUPS printers.
+      setIsVisible(
+        this.getChildElement('.configuring-in-progress-text'), false);
+      setIsVisible(
+        this.getChildElement('.configuring-failed-text'), false);
     },
 
     /**
@@ -195,11 +248,25 @@ cr.define('print_preview', function() {
     },
 
     /**
-     * Called when the destination item is activated. Dispatches a SELECT event
-     * on the given event target.
+     * Called when the destination item is activated. Check if the printer needs
+     * to be set up first before activation.
      * @private
      */
     onActivate_: function() {

[skau, 2017/03/29 20:17:11]

If we're not on ChromeOS, we don't need to check for resolution.  We should
check for cr.isChromeOS and activate the destination if we're not.

[xdai1, 2017/03/30 17:48:19]

If we're not on Chrome OS, the check in line 596 in destination_search.js should
fail and the configuration request should be rejected directly. But I agree with
you that it's better to do a early return here. The original behavior on other
OS doesn't change. 

+      // Check if the printer needs configuration before using. The user is only
+      // allowed to set up one printer at one time.
+      var configureEvt =
+          new Event(DestinationListItem.EventType.CONFIGURE_REQUEST);
+      configureEvt.destination = this.destination_;
+      this.eventTarget_.dispatchEvent(configureEvt);
+    },
+
+    /**
+     * Called when the destination has been resolved successfully and needs to
+     * be activated. Dispatches a SELECT event on the given event target.
+     * @private
+     */
+    onDestinationActivated_: function() {
       if (this.destination_.id ==
               print_preview.Destination.GooglePromotedId.FEDEX &&
           !this.destination_.isTosAccepted) {