Re: ScrolledWindow - how to allow scrolling only in one direction?

["Paul Davis" <pjdavis engineering uiowa edu>]

On 4/1/07, Tom Bachmann <e_mc_h2 web de> wrote:
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>
> Hi,
>
> [Please cc me, I'm not registered to the list. Also, I'm unsure if I'm
> better advised to ask on the gtk list, please tell me if this is indeed
> the case.]
>
> I'm trying to create a ScrolledWindow (or something comparable) that
> behaves like a normal container horizontally. That is, I don't want it
> to display a scrollbar, I don't want it to allow resizing smaller (in x
> direction) than the wrapped widget, and, most important, I want it to
> create a size request (in x direction) that depends on the size of the
> wrapped widget, where the last is most important. The reason is that I
> want to stuff multiple such ScrolledWindows into a hbox, and I want them
> to get space allocated (in x direction) proportional to the size of the
> wrapped widgets, as would be the case when there's no wrapping
> ScrolledWindow.
[snip]

You can inherit from Gtk::ScrolledWindow and override its
on_size_request function.

This seems to work:

#include <iostream>
#include <gtkmm.h>

class VScrolledWindow : public Gtk::ScrolledWindow
{
	public:
		VScrolledWindow()
		{
			set_policy( Gtk::POLICY_NEVER, Gtk::POLICY_ALWAYS ) ;
		}

		virtual ~VScrolledWindow() {}

	protected:

		virtual void
		on_size_request( Gtk::Requisition* requisition )
		{
			Gtk::ScrolledWindow::on_size_request( requisition ) ;

			Gtk::Widget* child = get_child() ;
			Gtk::Widget* vsb = get_vscrollbar() ;

			Gtk::Requisition c_req = { 0, 0 } ;
			Gtk::Requisition sb_req = { 0, 0 } ;

			if( child && child->is_visible() )
			{
				c_req = child->size_request() ;
			}

			if( vsb && vsb->is_visible() )
			{
				sb_req = vsb->size_request() ;
			}
		}
} ;

class window1
: public Gtk::Window
{
private:
Gtk::HBox box;
  Gtk::Button b1;
  Gtk::Button b2;
  Gtk::Button b3;

public:
window1 ()
  : b1 ("foo"), b2 ("foobarbazoo"), b3 ("foobar")
{
  add (box);
  box.add (b1);
  box.add (b2);
  box.add (b3);

  show_all_children ();
}
};

class window2
: public Gtk::Window
{
private:
Gtk::HBox box;
  VScrolledWindow s1, s2, s3;
  Gtk::Button b1, b2, b3;

public:
window2 ()
  : b1 ("foo"), b2 ("foobarbazoo"), b3 ("foobar")
{
  add (box);

	int w, h ;

  box.add (s1);
  s1.add (b1);

  box.add (s2);
  s2.add (b2);

  box.add (s3);
  s3.add (b3);

  show_all_children ();
}
};

int
main (int argc, char** argv)
{
Gtk::Main kit (argc, argv);

window1 w1;
window2 w2;
w2.show ();

Gtk::Main::run (w1);

return 0;
}

I based this on the example here:
http://svn.gnome.org/viewcvs/gtkmm/trunk/examples/book/custom/custom_container/

HTH,
Paul Davis