Any structures attached to the window_list *must* have a struct nsObject * as their
first entry, and handle events outside of gui.c.
svn path=/trunk/netsurf/; revision=10332
This is achieved through new function history_redraw_rectangle.
It takes the co-ordinates of the history area to plot as parameters 2-5
and the co-ordinates of the top-left position to draw this area as params 6,7
Added local history scrolling to Amiga port using the above function.
svn path=/trunk/netsurf/; revision=6740
