Gtkmm - "Gtk :: DrawingArea" in "Gtk :: ScrolledWindow"?

Question

I am making a GUI program using "gtkmm". I would like to draw some graphics for the widget "Gtk :: DrawingArea", but I want this widget to be "resizable", so when I draw, let it say a line from "(0, 0)" to "(50 , 50) "pixel - the drawing area should be resized to a square of size" (50, 50) "; and when I, for example, draw a line from "(0, 0)" to say "(100, 70)" pixel - the drawing area should be changed to a rectangle with the size "(100, 70)".

And for this I put the widget "Gtk :: DrawingArea" in the container "Gtk :: ScrolledWindow".

Therefore, when I put an image with the size "(100, 100)" in the drawing area →, I will call the corresponding member function "Gtk :: DrawingArea :: set ___ size_request (100, 100)", which will set the size of the drawing area to ( 100, 100) pixels. Therefore, if "Gtk :: ScrolledWindow" is "smaller" than the "Gtk :: DrawingArea" inside it, the scrollable window should change to "scrollable" - BUT THE PROBLEM THAT IT DOES NOT WORK !!!!!

So can someone explain to me how I can do this?

Thanks.

Answer 1

Add GTK :: Viewport between your ScrolledWindow and DrawingArea.

Answer 2

- , Gtk:: Viewport,

Gtk::DrawingArea::set_size_request(width,height);