(feat) now use md-on-demand for (hopefully) faster mailbox loading

UI/Templates/MailerUI/UIxMailFolderTemplate.wox

@@ -14,7 +14,8 @@
       </header>
       <md-virtual-repeat-container class="md-flex">
         <md-list class="sg-section-list">
-          <div md-virtual-repeat="currentMessage in mailbox.selectedFolder.$messages">
+          <div md-virtual-repeat="currentMessage in
+                                  mailbox.selectedFolder" md-on-demand="md-on-demand">
             <md-list-item
                 ng-class="{'sg-active': currentMessage.uid == mailbox.selectedFolder.selectedMessage, unread: !currentMessage.isread}"
                 ng-click="mailbox.selectMessage(currentMessage)"
@@ -33,8 +34,6 @@
                       ng-bind-html="currentMessage.relativedate"><!-- date --></span>
                 <div class="sg-md-subhead-multi">{{currentMessage.$shortAddress('from')}}</div>
                 <div class="sg-md-body-multi">{{currentMessage.subject}}</div>
-                <i class="icon-ion-refresh"
-                   ng-hide="mailbox.selectedFolder.$loadMessage(currentMessage.uid)"><!-- loading --></i>
               </div>
               <div class="sg-tile-icons">
                 <md-icon ng-show="currentMessage.priority == 'highest' || currentMessage.priority == 'high'">warning</md-icon>

UI/WebServerResources/js/Mailer/Mailbox.service.js

@@ -167,6 +167,35 @@
     }
   };
 
+  /**
+   * @function getLength
+   * @memberof Mailbox.prototype
+   * @desc Used by md-virtual-repeat / md-on-demand
+   * @returns the number of items in the mailbox
+   */
+  Mailbox.prototype.getLength = function() {
+    return this.$messages.length;
+  };
+
+  /**
+   * @function getItemAtIndex
+   * @memberof Mailbox.prototype
+   * @desc Used by md-virtual-repeat / md-on-demand
+   * @returns the message as the specified index
+   */
+  Mailbox.prototype.getItemAtIndex = function(index) {
+    var message;
+
+    if (index >= 0 && index < this.$messages.length) {
+      message = this.$messages[index];
+
+      if (this.$loadMessage(message.uid))
+        return message;
+    }
+
+    return null;
+  };
+
   /**
    * @function $id
    * @memberof Mailbox.prototype
@@ -588,7 +617,7 @@
 
         if (_this.uids) {
           Mailbox.$log.debug('unwrapping ' + data.uids.length + ' messages');
-          
+
           // First entry of 'headers' are keys
           headers = _.invoke(_this.headers[0], 'toLowerCase');
           _this.headers.splice(0, 1);