diff --git a/src/scripts/controllers/task-detail.js b/src/scripts/controllers/task-detail.js
index ae40a4e..d2ed8e2 100644
--- a/src/scripts/controllers/task-detail.js
+++ b/src/scripts/controllers/task-detail.js
@@ -273,6 +273,10 @@
         };
 
         $scope.isAnyFileSelected = function () {
+            if (!$scope.task || !$scope.task.files) {
+                return false;
+            }
+
             for (var i = 0; i < $scope.task.files.length; i++) {
                 var file = $scope.task.files[i];
 
@@ -284,11 +288,35 @@
             return false;
         };
 
+        $scope.isAllFileSelected = function () {
+            if (!$scope.task || !$scope.task.files) {
+                return false;
+            }
+
+            for (var i = 0; i < $scope.task.files.length; i++) {
+                var file = $scope.task.files[i];
+
+                if (!file.isDir && !file.selected) {
+                    return false;
+                }
+            }
+
+            return true;
+        };
+
         $scope.selectFiles = function (type) {
             if (!$scope.task || !$scope.task.files) {
                 return;
             }
 
+            if (type === 'auto') {
+                if ($scope.isAllFileSelected()) {
+                    type = 'none';
+                } else {
+                    type = 'all';
+                }
+            }
+
             for (var i = 0; i < $scope.task.files.length; i++) {
                 var file = $scope.task.files[i];
 
diff --git a/src/views/task-detail.html b/src/views/task-detail.html
index 7d3bfc7..1473578 100644
--- a/src/views/task-detail.html
+++ b/src/views/task-detail.html
@@ -199,9 +199,18 @@
                     <div class="task-table-title" ng-if="context.showChooseFilesToolbar">
                         <div class="row">
                             <div class="col-sm-12">
-                                <button class="btn btn-xs btn-primary" ng-click="selectFiles('all')" translate>Select All</button>
-                                <button class="btn btn-xs btn-primary" ng-click="selectFiles('none')" translate>Select None</button>
-                                <button class="btn btn-xs btn-primary" ng-click="selectFiles('reverse')" translate>Select Invert</button>
+                                <div class="btn-group">
+                                    <button type="button" class="btn btn-primary btn-xs" ng-click="selectFiles('auto')"
+                                            ng-bind="(isAllFileSelected() ? 'Select None' : 'Select All') | translate">Select All</button>
+                                    <button type="button" class="btn btn-primary btn-xs dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+                                        <span class="caret"></span>
+                                    </button>
+                                    <ul class="dropdown-menu">
+                                        <li><a href="javascript:void(0);" ng-click="selectFiles('all')" translate>Select All</a></li>
+                                        <li><a href="javascript:void(0);" ng-click="selectFiles('none')" translate>Select None</a></li>
+                                        <li><a href="javascript:void(0);" ng-click="selectFiles('reverse')" translate>Select Invert</a></li>
+                                    </ul>
+                                </div>
                                 <button class="btn btn-xs btn-default" ng-click="chooseSpecifiedFiles('video')">
                                     <i class="fa fa-file-video-o"></i>
                                     <span translate>Videos</span>