feat: add menu item Edit > Copy column names

Refs #2055

Author: ansgarbecker

source/main.lfm

@@ -3650,6 +3650,9 @@ object MainForm: TMainForm
       object CopyItem: TMenuItem
         Action = actCopy
       end
+      object MenuItem3: TMenuItem
+        Action = actCopyColumnNames
+      end
       object Copywithtabstospaces1: TMenuItem
         Action = actCopyTabsToSpaces
       end
@@ -5105,6 +5108,12 @@ object MainForm: TMainForm
       Caption = 'Tree filters'
       OnExecute = actDisplayTreeFiltersExecute
     end
+    object actCopyColumnNames: TAction
+      Category = 'Various'
+      Caption = 'Copy column names'
+      ImageIndex = 3
+      OnExecute = menuCopyColumnNamesClick
+    end
   end
   object ImageListMain: TImageList
     Scaled = True

source/main.pas

@@ -215,13 +215,15 @@   TQueryHistoryItemComparer = class(TComparer<TQueryHistoryItem>)
   { TMainForm }
 
   TMainForm = class(TExtForm)
+    actCopyColumnNames: TAction;
     actPreferencesSQL: TAction;
     MainMenu1: TMainMenu;
     MainMenuFile: TMenuItem;
     FileNewItem: TMenuItem;
     MainMenuHelp: TMenuItem;
     FollowForeignKey: TMenuItem;
     menuColorScheme: TMenuItem;
+    MenuItem3: TMenuItem;
     menuSQLpreferences: TMenuItem;
     menuQFdummy: TMenuItem;
     N1: TMenuItem;
@@ -10139,14 +10141,20 @@ procedure TMainForm.menuCopyColumnNamesClick(Sender: TObject);
   Col: TColumnIndex;
   List: TStringList;
 begin
-  Grid := PopupComponent(Sender) as TVirtualStringTree;
+  if Sender is TMenuItem then
+    Grid := PopupComponent(Sender) as TVirtualStringTree
+  else if Screen.ActiveControl is TVirtualStringTree then
+    Grid := Screen.ActiveControl as TVirtualStringTree
+  else
+    Exit;
+
   List := TStringList.Create;
   Col := Grid.Header.Columns.GetFirstVisibleColumn(True);
   while Col > NoColumn do begin
     List.Add(Grid.Header.Columns[Col].Text);
     Col := Grid.Header.Columns.GetNextVisibleColumn(Col);
   end;
-  Clipboard.TryAsText := List.CommaText;
+  Clipboard.TryAsText := List.Text;
   List.Free;
 end;