button(State, 'link', {x=State.left+lo, y=y, w=hi-lo, h=State.line_height, bg={r=1,g=1,b=1},
            icon = icon.hyperlink_decoration,
            onpress1 = function()
                         if file_exists(filename) then
                           source.switch_to_file(filename)
                         end
                       end,
          })

        button(State, 'draw', {x=buttonx, y=y+4, w=12,h=12, bg={r=1,g=1,b=0},
          icon = icon.insert_drawing,
          onpress1 = function()
                       Drawing.before = snapshot(State, line_index-1, line_index)
                       table.insert(State.lines, line_index, {mode='drawing', y=y, h=256/2, points={}, shapes={}, pending={}})
                       table.insert(State.line_cache, line_index, {})
                       if State.cursor1.line >= line_index then
                         State.cursor1.line = State.cursor1.line+1
                       end
                       schedule_save(State)
                       record_undo_event(State, {before=Drawing.before, after=snapshot(State, line_index-1, line_index+1)})
                     end,
        })

  button(Editor_state, 'menu', {x=x-5, y=y-2, w=width+5*2, h=Editor_state.line_height+2*2, bg=color,
    onpress1 = function()