My_Widget.h

#ifndef MY_WIDGET_H
#define MY_WIDGET_H

#define MY_WIDGET(w) ((My_Widget *)w)

typedef struct My_Widget My_Widget;
struct My_Widget
{
        Ewl_Widget widget;
};

Ewl_Widget *my_widget_new(void);
int my_widget_init(My_Widget *w);

#endif

-----------------------------
My_Widget.c

Ewl_Widget *
my_widget_new(void)
{
        Ewl_Widget *w;

        w = NEW(My_Widget, 1);
        if (!w) return NULL;

        if (!my_widget_init(MY_WIDGET(w)))
                return NULL;

        return w;
}


int
my_widget_init(My_Widget *w)
{
        if (!ewl_widget_init(EWL_WIDGET(w)))
                return 0;

        ewl_widget_appearance_set(EWL_WIDGET(w), "custom_edje");
        ewl_theme_data_str_set(EWL_WIDGET(w),
                                "/custom_edje/file",
                                path_to_edje);
        ewl_theme_data_str_set(EWL_WIDGET(w),
                                "/custom_edje/group",
                                group_in_edje);

        return 1;
}