Media Library: Add button to select all items, fixes #6518 (#6610)

src/Orchard.Web/Modules/Orchard.MediaLibrary/Scripts/media-library.js

@@ -221,6 +221,12 @@ $(function () {
                 });
             };
 
+            self.selectAll = function () {
+                self.results().forEach(function (item) {
+                    viewModel.toggleSelect(item, true);
+                });
+            }
+
             self.clearSelection = function() {
                 this.focus(null);
                 // unselect previous elements
@@ -520,6 +526,10 @@ $(function () {
         	pickAndClose();
         });
 
+        $("#media-library-toolbar > .button-select-all").on('click', function () {
+            viewModel.selectAll();
+        });
+
         $("#media-library-main-list").on('dblclick', function () {
         	pickAndClose();
         });

src/Orchard.Web/Modules/Orchard.MediaLibrary/Views/Admin/Index.cshtml

@@ -22,6 +22,7 @@
         <a href="#" data-bind="attr: { href: '@HttpUtility.JavaScriptStringEncode(Url.Action("Create", "Folder", new { area = "Orchard.MediaLibrary"}))?folderPath=' + encodeURIComponent(displayed() ? displayed() : '') }" class="button"  id="button-create-folder">@T("Create Folder")</a>
         
         @Display(Model.CustomActionsShapes)
+        <button class="button-select-all">@T("Select All")</button>
     </div>
     <div id="media-library-main">
         <div id="media-library-main-navigation">