procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
DYNAMIC void __fastcall MouseDown(System::Uitypes::TMouseButton Button, System::Classes::TShiftState Shift, int X, int Y);
Dynamically locates the control that can be resized by the splitter.
After calling the parent class's method, MouseDown locates the control that it is about to resize. Because this control is located dynamically, an application can delete or add aligned controls beside a splitter at runtime and the splitter will resize whichever control is currently beside it.