List printers managed by extensions in print preview

chrome/browser/resources/print_preview/data/destination_store.js

Index: chrome/browser/resources/print_preview/data/destination_store.js
diff --git a/chrome/browser/resources/print_preview/data/destination_store.js b/chrome/browser/resources/print_preview/data/destination_store.js
index b3249f2de77fb6faf13cfdbbdcd790c522f949c0..03c839445cad9fde84aa4fc45d9600a8a87baee5 100644
--- a/chrome/browser/resources/print_preview/data/destination_store.js
+++ b/chrome/browser/resources/print_preview/data/destination_store.js
@@ -154,6 +154,29 @@ cr.define('print_preview', function() {
     this.privetSearchTimeout_ = null;
 
     /**
+     * Whether a search for extension destinations is in progress.
+     * @type {boolean}
+     * @private
+     */
+    this.isExtensionDestinationSearchInProgress_ = false;
+
+    /**
+     * Whether the destination store has already loaded all extension
+     * destinations.
+     * @type {boolean}
+     * @private
+     */
+    this.hasLoadedAllExtensionDestinations_ = false;
+
+    /**
+     * ID of a timeout set at the start of an extension destination search. The
+     * timeout ends the search.
+     * @type {?number}
+     * @private
+     */
+    this.extensionSearchTimeout_ = null;
+
+    /**
      * MDNS service name of destination that we are waiting to register.
      * @type {?string}
      * @private
@@ -201,6 +224,15 @@ cr.define('print_preview', function() {
   DestinationStore.PRIVET_SEARCH_DURATION_ = 2000;
 
   /**
+   * Maximum amount of time spent searching for extension destinations, in
+   * milliseconds.
+   * @type {number}
+   * @const
+   * @private
+   */
+  DestinationStore.EXTENSION_SEARCH_DURATION_ = 2000;
+
+  /**
    * Localizes printer capabilities.
    * @param {!Object} capabilities Printer capabilities to localize.
    * @return {!Object} Localized capabilities.
@@ -267,7 +299,8 @@ cr.define('print_preview', function() {
      */
     get isLocalDestinationSearchInProgress() {
       return this.isLocalDestinationSearchInProgress_ ||
-        this.isPrivetDestinationSearchInProgress_;
+        this.isPrivetDestinationSearchInProgress_ ||
+        this.isExtensionDestinationSearchInProgress_;
     },
 
     /**
@@ -339,6 +372,31 @@ cr.define('print_preview', function() {
           cr.dispatchSimpleEvent(
             this,
             DestinationStore.EventType.CACHED_SELECTED_DESTINATION_INFO_READY);
+        } else if (this.appState_.selectedDestinationOrigin ==
+                   print_preview.Destination.Origin.EXTENSION) {
+          // TODO(tbarzic): Add support for requesting a single extension's
+          // printer list.
+          this.startLoadExtensionDestinations();
+
+          var parsedDestinationID =
+              print_preview.ExtensionDestinationParser.parseDestinationID(
+                  this.appState_.selectedDestinationId);
+          this.selectedDestination_ =
+              print_preview.ExtensionDestinationParser.parse({
+                extensionId: parsedDestinationID.extensionID,
+                id: parsedDestinationID.printerID,
+                name: this.appState_.selectedDestinationName_ || ''
+              });
+
+          if (this.appState_.selectedDestinationCapabilities) {
+            this.selectedDestination_.capabilities =
+                this.appState_.selectedDestinationCapabilities;
+
+            cr.dispatchSimpleEvent(
+                this,
+                DestinationStore.EventType
+                    .CACHED_SELECTED_DESTINATION_INFO_READY);
+          }
         } else {
           this.selectDefaultDestination_();
         }
@@ -437,8 +495,14 @@ cr.define('print_preview', function() {
         if (destination.isPrivet) {
           this.nativeLayer_.startGetPrivetDestinationCapabilities(
               destination.id);
-        }
-        else if (destination.isLocal) {
+        } else if (destination.isExtension) {
+          var parsedDestinationID =
+              print_preview.ExtensionDestinationParser.parseDestinationID(
+                  destination.id);
+          this.nativeLayer_.startGetExtensionDestinationCapabilities(
+              parsedDestinationID.extensionID,
+              parsedDestinationID.printerID);
+        } else if (destination.isLocal) {
           this.nativeLayer_.startGetLocalDestinationCapabilities(
               destination.id);
         } else {
@@ -481,18 +545,35 @@ cr.define('print_preview', function() {
     /** Initiates loading of privet print destinations. */
     startLoadPrivetDestinations: function() {
       if (!this.hasLoadedAllPrivetDestinations_) {
+        if (this.privetDestinationSearchInProgress_)
+          clearTimeout(this.privetSearchTimeout_);
         this.isPrivetDestinationSearchInProgress_ = true;
         this.nativeLayer_.startGetPrivetDestinations();
         cr.dispatchSimpleEvent(
             this, DestinationStore.EventType.DESTINATION_SEARCH_STARTED);
-        if (this.privetDestinationSearchInProgress_)
-          clearTimeout(this.privetSearchTimeout_);
         this.privetSearchTimeout_ = setTimeout(
             this.endPrivetPrinterSearch_.bind(this),
             DestinationStore.PRIVET_SEARCH_DURATION_);
       }
     },
 
+    /** Initializes loading of extension managed print destinations. */
+    startLoadExtensionDestinations: function() {
+      if (this.hasLoadedAllExtensionDestinations_)
+        return;
+
+      if (this.isExtensionDestinationSearchInProgress_)
+        clearTimeout(this.extensionSearchTimeout_);
+
+      this.isExtensionDestinationSearchInProgress_ = true;
+      this.nativeLayer_.startGetExtensionDestinations();
+      cr.dispatchSimpleEvent(
+          this, DestinationStore.EventType.DESTINATION_SEARCH_STARTED);
+      this.extensionSearchTimeout_ = setTimeout(
+          this.endExtensionPrinterSearch_.bind(this),
+          DestinationStore.EXTENSION_SEARCH_DURATION_);
+    },
+
     /**
      * Initiates loading of cloud destinations.
      * @param {print_preview.Destination.Origin=} opt_origin Search destinations
@@ -528,6 +609,7 @@ cr.define('print_preview', function() {
       this.startLoadCloudDestinations();
       this.startLoadLocalDestinations();
       this.startLoadPrivetDestinations();
+      this.startLoadExtensionDestinations();
     },
 
     /**
@@ -632,6 +714,21 @@ cr.define('print_preview', function() {
     },
 
     /**
+     * Called when loading of extension managed printers is done.
+     * @private
+     */
+    endExtensionPrinterSearch_: function() {
+      this.isExtensionDestinationSearchInProgress_ = false;
+      this.hasLoadedAllExtensionDestinations_ = true;
+      cr.dispatchSimpleEvent(
+          this, DestinationStore.EventType.DESTINATION_SEARCH_DONE);
+      // Clear initially selected (cached) extension destination if it hasn't
+      // been found among reported extension destinations.
+      if (this.isInAutoSelectMode_ && this.selectedDestination_.isExtension)
+        this.selectDefaultDestination_();
+    },
+
+    /**
      * Inserts a destination into the store without dispatching any events.
      * @return {boolean} Whether the inserted destination was not already in the
      *     store.
@@ -684,6 +781,14 @@ cr.define('print_preview', function() {
           this.nativeLayer_,
           print_preview.NativeLayer.EventType.PRIVET_CAPABILITIES_SET,
           this.onPrivetCapabilitiesSet_.bind(this));
+      this.tracker_.add(
+          this.nativeLayer_,
+          print_preview.NativeLayer.EventType.EXTENSION_PRINTERS_ADDED,
+          this.onExtensionPrintersAdded_.bind(this));
+      this.tracker_.add(
+          this.nativeLayer_,
+          print_preview.NativeLayer.EventType.EXTENSION_CAPABILITIES_SET,
+          this.onExtensionCapabilitiesSet_.bind(this));
     },
 
     /**
@@ -716,6 +821,7 @@ cr.define('print_preview', function() {
       this.loadedCloudOrigins_ = {};
       this.hasLoadedAllLocalDestinations_ = false;
       this.hasLoadedAllPrivetDestinations_ = false;
+      this.hasLoadedAllExtensionDestinations_ = false;
 
       clearTimeout(this.autoSelectTimeout_);
       this.autoSelectTimeout_ = setTimeout(
@@ -891,7 +997,6 @@ cr.define('print_preview', function() {
      * @private
      */
     onPrivetCapabilitiesSet_: function(event) {
-      var destinationId = event.printerId;
       var destinations =
           print_preview.PrivetDestinationParser.parse(event.printer);
       destinations.forEach(function(dest) {
@@ -901,6 +1006,47 @@ cr.define('print_preview', function() {
     },
 
     /**
+     * Called when an extension responds to a getExtensionDestinations
+     * request.
+     * @param {Object} event Contains information about list of printers
+     *     reported by the extension.
+     *     {@code done} parameter is set iff this is the final list of printers
+     *     returned as part of getExtensionDestinations request.
+     * @private
+     */
+    onExtensionPrintersAdded_: function(event) {
+      this.insertDestinations_(event.printers.map(function(printer) {
+        return print_preview.ExtensionDestinationParser.parse(printer);
+      }));
+
+      if (event.done && this.isExtensionDestinationSearchInProgress_) {
+        clearTimeout(this.extensionSearchTimeout_);
+        this.endExtensionPrinterSearch_();
+      }
+    },
+
+    /**
+     * Called when capabilities for an extension managed printer are set.
+     * @param {Object} event Contains the printer capabilities and ID, and the
+     *     ID of extension that manages the printer.
+     * @private
+     */
+    onExtensionCapabilitiesSet_: function(event) {
+      var destinationID =
+          print_preview.ExtensionDestinationParser.generateDestinationID(
+              event.extensionID, event.printerID);
+      var destinationKey = this.getDestinationKey_(
+          print_preview.Destination.Origin.EXTENSION,
+          destinationID,
+          '' /* account */);
+      var destination = this.destinationMap_[destinationKey];
+      if (!destination)
+        return;
+      destination.capabilities = event.capabilities;
+      this.updateDestination_(destination);
+    },
+
+    /**
      * Called from native layer after the user was requested to sign in, and did
      * so successfully.
      * @private