Question

I’m building a custom control, and I need it to be able to respond when it gets resized. I need the old dimensions and the new dimensions available in order to do some calculations.

Unfortunately, the SetWidth and SetHeight methods are private to TControl, not protected, and so I can’t override them. Is there any other way to know that my control’s about to be resized, and to have the old size and the new size both available?

Answer 1

Override the SetBounds public method. It passes in the new size, and you can use the Width and Height properties to get the current width/height.

procedure SetBounds(ALeft, ATop, AWidth, AHeight: Integer); override;