Improved select performance.

Author: 5cript

nui-file-explorer/include/nui-file-explorer/item_with_internals.hpp

@@ -31,7 +31,8 @@ namespace NuiFileExplorer
 
         void isSelected(bool value)
         {
-            *selected_ = value;
+            if (selected_->value() != value)
+                *selected_ = value;
         }
 
         explicit ItemWithInternals(Item const& item)

nui-file-explorer/source/nui-file-explorer/side/selection_manager.cpp

@@ -134,7 +134,7 @@ namespace NuiFileExplorer
             const bool selected = (inRange(i) && ctrlRemove_.count(i) == 0) || ctrlAdd_.count(i) > 0;
             vec[i].isSelected(selected);
         }
-        items_->modifyNow();
+        Nui::globalEventContext.sync();
     }
 
     // =========================================================================
@@ -154,7 +154,7 @@ namespace NuiFileExplorer
         loseTrackToAllSelections();
         for (auto& item : items_->value())
             item.isSelected(false);
-        items_->modifyNow();
+        Nui::globalEventContext.sync();
     }
 
     void SelectionManager::selectAll()