I really wanted to process ENTER, DELETE, LEFT and RIGHT keyboard events at the callback level

header file:

#ifndef FL_BROWSER2_
#define FL_BROWSER2_

#include <FL/Fl_Browser.H>

class Fl_Browser2 : public Fl_Browser
{
public:
    Fl_Browser2(int x, int y, int w, int h, const char* l = 0);
    int handle(int event);
};

#endif // FL_BROWSER2_

class implementation:

Fl_Browser2::Fl_Browser2(int x, int y, int w, int h, const char* l)
: Fl_Browser(x, y, w, h, l)
{
}

int Fl_Browser2::handle(int event)
{
    int key = Fl::event_key();
    if (event == FL_KEYUP &&
        ( key == FL_Enter ||
          key == FL_Left ||
          key == FL_Right ||
          key == FL_Delete ) ) {
        do_callback();
        return 1;
    }
    return Fl_Browser::handle(event);
}