Проверить, развернут ли или свернут полностью TTreeView

function IsTreeviewFullyExpanded(tv: TTreeview): Boolean;
 var
   Node: TTreeNode;
 begin
   Assert(Assigned(tv));
   if tv.Items.Count > 0 then
   begin
     Node   := tv.Items[0];
     Result := True;
     while Result and Assigned(Node) do
     begin
       Result := Node.Expanded or not Node.HasChildren;
       Node   := Node.GetNext;
     end; {While}
   end {If}
   else
     Result := False
 end;
 
 function IsTreeviewFullyCollapsed(tv: TTreeview): Boolean;
 var
   Node: TTreeNode;
 begin
   Assert(Assigned(tv));
   if tv.Items.Count > 0 then
   begin
     Node   := tv.Items[0];
     Result := True;
     while Result and Assigned(Node) do
     begin
       Result := not (Node.Expanded and Node.HasChildren);
       Node   := Node.GetNext;
     end; {While}
   end {If}
   else
     Result := False
 end;

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