"""This file makes every other line read-only.
   This is an example of using overlays"""

from GPS import *

parse_xml ("""
  <action name="make lines readonly">
     <shell lang="python">readonly.make_readonly()</shell>
  </action>
  <menu action="make lines readonly">
     <title>/Tests/Make Lines Readonly</title>
  </menu>
""")

def make_readonly():
   """Make every other line readonly in the current file"""
   buffer = EditorBuffer.get ()
   loc = EditorLocation (buffer, 1, 1)

   overlay = buffer.create_overlay ("readonly")
   overlay.set_property ("editable", False)

   readonly = True
   while loc < buffer.end_of_buffer():
      eol = loc.end_of_line()
      buffer.apply_overlay (overlay, loc, eol - 1)
      loc = loc.forward_line (2)