Fix #148: Improve UX, delete is only enabled if all selected cells can be cleared.

Author: tom-englert

ResXManager.View/Tools/ExtensionMethods.cs

@@ -132,7 +132,10 @@ public static bool IsItemInvariant(this DataGridCellInfo info)
         public static bool IsOfColumnType(this DataGridCellInfo cell, [NotNull] params ColumnType[] columnTypes)
         {
             Contract.Requires(columnTypes != null);
-            return columnTypes.Any(columnType => columnType == (cell.Column?.Header as ILanguageColumnHeader)?.ColumnType);
+
+            var cellColumnType = (cell.Column?.Header as ILanguageColumnHeader)?.ColumnType;
+
+            return columnTypes.Any(columnType => columnType == cellColumnType);
         }
 
     }

ResXManager.View/Visuals/ResourceViewModel.cs

@@ -223,8 +223,10 @@ private bool CanDelete([CanBeNull] DataGrid dataGrid)
             if (dataGrid == null)
                 return false;
 
-            return (dataGrid.SelectionUnit == DataGridSelectionUnit.CellOrRowHeader) && dataGrid.SelectedCells.Any(cellInfo => cellInfo.IsOfColumnType(ColumnType.Comment, ColumnType.Language))
-                || SelectedTableEntries.Any();
+            if (dataGrid.SelectionUnit == DataGridSelectionUnit.CellOrRowHeader)
+                return dataGrid.SelectedCells.All(cellInfo => cellInfo.IsOfColumnType(ColumnType.Comment, ColumnType.Language));
+
+            return SelectedTableEntries.Any();
         }
 
         private bool CanCut()