from Xlib import X, display, Xutil, Xatom
import struct

class Ratpoison:
    """The class allows programmatic access to the ratpoison window manager"""
    
    def __init__(self, display = display.Display()):
        self.dpy = display
        self.command = self.dpy.intern_atom ("RP_COMMAND");
        self.command_request = self.dpy.intern_atom ("RP_COMMAND_REQUEST");
        self.command_result = self.dpy.intern_atom ("RP_COMMAND_RESULT");
        screen = self.dpy.screen()
        self.root = screen.root
        self.w = self.root.create_window(0, 0, 1, 1, 0, 0,
                         event_mask = (X.PropertyChangeMask) )

    def _recieve_command_result(self, w):
        status = w.get_full_property (self.command_result, Xatom.STRING)
        assert status != None
        return status.value

    def send_command(self, cmd):
        done = 0
    
        self.w.change_property(self.command, Xatom.STRING, 8, chr(0) + cmd)

        self.root.change_property(self.command_request, Xatom.WINDOW, 8,
                                  struct.pack("l", self.w.id),
                                  mode=X.PropModeAppend)

        while not done:
            ev = self.dpy.next_event()
            if ev.atom == self.command_result and \
                   ev.state == X.PropertyNewValue:
                val = self._recieve_command_result(ev.window);
                done = 1;

        return val

    def echo(self, str):
        """Echo a string to the ratpoison bar"""
        self.send_command("echo %s" % str)

    def next(self):
        """Change to the next window"""
        self.send_command("next")

    def prev(self):
        """Change to the previous window"""
        self.send_command("prev")

    def windows(self):
        """Return a string listing the windows"""
        return self.send_command("windows")

    def select(self, win):
        """Select a specific window"""
        print "Selecting: ", win
        self.send_command("select %s" % win)

    def echo_windows(self):
        """Display a list of windows"""
        self.echo(self.windows())

    def other(self):
        """Jump to the other window"""
        self.send_command("other")

    def focus(self):
        self.send_command("focus")

if __name__ == "__main__":
    import sys
    import time
    
    rp  = Ratpoison()
    rp.echo(sys.argv[1])
    #print rp.send_command("windows")