pmacs3/application.py

#!/usr/bin/env python
import curses
from getpass import getpass
import locale
import os
import string
from subprocess import Popen, PIPE, STDOUT
import sys
import termios
import time
import traceback

import buffer
import buffer.about
import buffer.colors
import buffer.console
import buffer.data
import buffer.fs
import buffer.aes

from bufferlist import BufferList
import color
import completer
import keyinput
import method
from minibuffer import MiniBuffer, MiniBufferError
import mode
from point import Point
import util
from window import Window

class PmcError(Exception): pass
class RunError(PmcError): pass
class FileError(PmcError): pass
class DrawError(PmcError): pass

class Application(object):
    def __init__(self, stdscr, buffers=[], **kwargs):
        # initalize curses primitives
        self.stdscr = stdscr
        self.y, self.x = self.stdscr.getmaxyx()

        # we have to do this early so we can log errors
        self.log = buffer.LogBuffer()

        # initialize some basic stuff
        self.config             = {}
        self.highlighted_ranges = [] 
        self.highlight_mark     = False
        self.mini_active        = False
        self.mini_buffer        = None
        self.mini_prompt        = ""
        self.error_string       = ""
        self.error_timestamp    = None
        self.need_draw          = True
        self.input              = keyinput.Handler()
        
        # white is for delimiters, operators, numbers
        default = ('default', 'default')
        
        # magenta is for keywords/builtins, translation, globs
        lo_magenta = ('magenta202', 'default')
        hi_magenta = ('magenta505', 'default')
        
        # red is for comments, pods, endblocks
        lo_red = ('red300', 'default')
        hi_red = ('red511', 'default')
        
        # orange are for arrays and hashes
        hi_orange = ('yellow531', 'default')
        lo_orange = ('yellow520', 'default')
        
        # yellow is for scalars and prototypes
        hi_yellow = ('yellow551', 'default')
        lo_yellow = ('yellow330', 'default')
        
        # green is for strings and hash keys
        lo_green = ('green030', 'default')
        hi_green = ('green050', 'default')
        
        # cyan is for quotes, evals, regexes, subs
        lo_cyan = ('cyan033', 'default')
        hi_cyan = ('cyan155', 'default')
        
        # blue is unused
        lo_blue = ('blue113', 'default')
        hi_blue = ('blue225', 'default')

        # let's prepopulate some default token colors
        self.cached_colors = {}
        self.token_colors       = {
            'spaces':         default,
            'eol':            default,
            'comment':        hi_red,
            'comment.start':  hi_red,
            'comment.data':   hi_red,
            'comment.null':   hi_red,
            'comment.end':    hi_red,
            'continuation':   hi_red,
            'escaped':        hi_magenta,
            'string.start':   lo_green,
            'string.data':    hi_green,
            'string.null':    hi_green,
            'string.hex':     hi_magenta,
            'string.octal':   hi_magenta,
            'string.escaped': hi_magenta,
            'string.end':     lo_green,
            'char':           hi_green,
            #'integer':        ('white533', 'default'),
            #'float':          ('white533', 'default'),
            #'number':         ('white533', 'default'),
            'integer':        default,
            'float':          default,
            'number':         default,
            'label':          hi_magenta,
            'keyword':        hi_cyan,
            'reserved':       hi_cyan,
            'function':       hi_blue,
            'builtin':        hi_magenta,
            'method':         hi_cyan,
            'bareword':       default,
            'delimiter':      default,
            'operator':       default,
        }
        self.default_color = ('default', 'default',)

        # initialize configuration defaults
        self._load_config_defaults()

        # initialize our colors
        if curses.has_colors():
            curses.start_color()
            try:
                curses.use_default_colors()
                color.default_color = True
            except:
                color.default_color = False
        color.init()

        # initialize our modes
        # the first dict stores our modes by (lowercase) name, and the other
        # dicts all store various ways to "auto-detecting" the correct mode,
        # in the precedence with which they are used.
        self.modes           = {}
        self.mode_paths      = {}
        self.mode_basenames  = {}
        self.mode_extensions = {}
        self.mode_detection  = {}

        # initialize our methods
        self.methods = {}
        names = (
            'method', 'method.svn', 'method.cvs', 'method.search',
            'method.buffers', 'method.move', 'method.shell',
            'method.introspect', 'method.help', 'method.numbers',
            'method.spell', 'method.hg', 'method.utf8',
        )
        for name in names:
            exec("import %s" % name)
            mod = eval(name)
            for mname in dir(mod):
                if mname.startswith('_'):
                    continue
                cls = eval("%s.%s" % (name, mname))
                if hasattr(cls, '_is_method') and cls._is_method:
                    self.methods[cls._name()] = cls()

        # ok, now let's load all the "standard" modes
        mode.install(self)
        names = (
            'blame', 'c', 'console', 'consolemini', 'css', 'diff', 'dir',
            'elisp', 'hex', 'html', 'java', 'javascript', 'lisp', 'make',
            'mini', 'mutt', 'nasm', 'ocaml', 'perl', 'python', 'replace', 'rst',
            'scheme', 'search', 'sh', 'sql', 'tt', 'text', 'text2', 'which',
            'xml', 'cheetah', 'colortext', 'latex', 'insertmini', 'conf',
            'haskell', 'erlang', 'iperl', 'iperlmini', 'ipython', 'ipythonmini',
            'awk', 'shell', 'shellmini', 'fstab', 'yacc', 'pipe', 'mbox',
            'error', 'lua', 'lily', 'forth', 'ebnf', 'colortest',
        )
        for name in names:
            exec("import mode.%s; mode.%s.install(self)" % (name, name))

        # create all the insert methods for the character ranges we like
        for c in string.ascii_letters + string.digits + string.punctuation:
            obj = method.InsertString(c)
            self.methods[obj.name] = obj
            obj = method.OverwriteChar(c)
            self.methods[obj.name] = obj

        # buffer list stuff
        height             = self.y - 1
        width              = self.x
        self.bufferlist    = BufferList(height, width)
        self.active_slot   = 0
        self.complete_slot = None

        # run user custom code here
        self.rcerror = None
        self.loadrc()

        # initialize our buffers
        # note that only the first buffer will be initially visible
        buffers_ = list(buffers)
        buffers_.append(buffer.about.AboutBuffer())
        buffers_.append(self.log)
        if self.rcerror:
            buffers_.insert(0, buffer.data.DataBuffer('*RcError*', self.rcerror))

        # build windows for our buffers
        for b in buffers_:
            if b.modename:
                Window(b, self)
            else:
                Window(b, self, mode_name=kwargs.get('init_mode'))
            self.bufferlist.add_buffer(b)
        self.bufferlist.set_slot(self.active_slot, buffers_[0])

        # see if the user has requested that we go to a particular line
        jump_to_line = kwargs.get('jump_to_line')
        if not self.rcerror and jump_to_line:
            w = self.bufferlist.slots[0].window
            self.methods['goto-line'].execute(w, lineno=jump_to_line)

        # initialize our kill ring and last action
        self.kill_ring           = []
        self.kill_commands       = ['kill', 'kill-region']
        self.last_action         = None
        self.last_search         = None
        self.last_replace_before = None
        self.last_replace_after  = None
        self.registers           = {}
        self.arg_history         = {'default': []}

        # initialize tab handlers
        completer.set_completer('path', completer.FileCompleter(self))
        completer.set_completer('buffer', completer.BufferCompleter(self))
        completer.set_completer('command', completer.CommandCompleter(self))
        completer.set_completer('shell', completer.ShellCompleter(self))
        completer.set_completer('config', completer.ConfigCompleter(self))
        completer.set_completer('method', completer.MethodCompleter(self))
        completer.set_completer('register', completer.RegisterCompleter(self))
        completer.set_completer('mode', completer.ModeCompleter(self))
        completer.set_completer('token', completer.TokenCompleter(self))

        # set up curses
        self.win = curses.newwin(self.y, self.x, 0, 0)
        self.win.leaveok(0)
        curses.meta(1)
        curses.cbreak()
        curses.noecho()
        curses.nonl()
        curses.halfdelay(1)
        curses.def_prog_mode()

    def _load_config_defaults(self):
        self.config['ignore_suffix']    = ['~', '-', 'CVS', '.svn', '.git', '.hg']
        self.config['error_timeout']    = -1
        self.config['max_error_len']    = 192
        self.config['max_num_kills']    = 64
        self.config['word_letters']     = string.ascii_letters + string.digits
        self.config['default_color']    = ('default', 'default',)
        self.config['margin']           = 79
        self.config['margin_color']     = 'blue'
        self.config['use_last_replace'] = False

    def completion_window_is_open(self):
        n = self.complete_slot
        if n is None:
            pass
        elif n >= len(self.bufferlist.slots):
            self.complete_slot = None
        elif self.bufferlist.slots[n].window is None:
            self.complete_slot = None
        elif not hasattr(self.bufferlist.slots[n].window.buffer, '_completion'):
            self.complete_slot = None
        else:
            return True
        return False

    def get_completion_window(self):
        return self.bufferlist.slots[self.complete_slot].window

    def open_completion_buffer(self, s, candidates):
        opened   = False
        previous = None
        if len(self.bufferlist.slots) == 1:
            self.add_slot()
            opened = True

        n = len(self.bufferlist.slots) - 1
        if self.active_slot == n:
            n -= 1

        if not opened:
            previous = self.bufferlist.slots[n].window.buffer

        lines = []
        clen = len(candidates)
        if clen > self.bufferlist.slots[n].height:
            maxlen = 0
            for c in candidates:
                maxlen = max(maxlen, len(c))

            # NOTE: this is not an optimal packing, but it's fast and easy to
            # understand. i encourage someone else to write something better.
            numcols = max(self.bufferlist.slots[n].width // (maxlen + 2), 1)
            numrows = clen - ((clen // numcols) * (numcols - 1))
            for i in range(0, numrows):
                names = []
                index = i * numcols
                for j in range(0, numcols):
                    if index + j < clen:
                        names.append('%-*s' % (maxlen, candidates[index + j]))
                    else:
                        break
                lines.append('  '.join(names))
        else:
            lines = list(candidates)
        data = '\n'.join(lines)

        b             = self.data_buffer("*Completions*", data, switch_to=False)
        b._completion = s
        b._opened     = opened
        b._previous   = previous
        self.bufferlist.set_slot(n, b)
        self.complete_slot = n

    def close_completion_buffer(self):
        w = self.get_completion_window()
        opened = w.buffer._opened
        if opened:
            self.bufferlist.remove_slot(self.complete_slot)
        else:
            self.bufferlist.set_slot(self.complete_slot, w.buffer._previous)
        self.close_buffer(w.buffer)
        self.complete_slot = None

    def set_completer(self, datatype, comp):
        completer.set_completer(datatype, comp)

    # this sets up a mode, as well as optionally adding information on when to
    # auto-load the mode
    def setmode(self, name, cls, paths=[], bases=[], exts=[], detection=[]):
        self.modes[name] = cls
        for p in paths: self.mode_paths[p] = name
        for b in bases: self.mode_basenames[b] = name
        for e in exts: self.mode_extensions[e] = name
        for d in detection: self.mode_detection[d] = name

    # we are evil
    def eval(self, s): return eval(s)
    def globals(self): return globals()
    def locals(self): return locals()

    # slots
    def add_slot(self):
        b = self.bufferlist.slots[self.active_slot].window.buffer
        n = self.bufferlist.add_slot()
        self.bufferlist.set_slot(n, b)
    def remove_slot(self, n):
        slots = self.bufferlist.slots
        assert len(slots) > 1, "oh no you didn't!"
        assert n >= 0 and n < len(slots), "invalid slot %r %r" % (n, len(slots))
        self.bufferlist.remove_slot(n)
        if self.active_slot > n:
            self.active_slot = max(0, self.active_slot - 1)
    def single_slot(self):
        while len(self.bufferlist.slots) > 1:
            if self.active_slot == 0:
                self.remove_slot(1)
            else:
                self.remove_slot(0)

    def get_window_height_width(self, i):
        slots = self.bufferlist.slots
        assert i >= 0 and i < len(slots), "invalid slot: %d" % i
        slot = slots[i]
        return (slot.height, slot.width)

    # files and stuff
    def close_buffer(self, b):
        blist = self.bufferlist
        blist.remove_buffer(b)
        b.close()
        active_slot = blist.slots[self.active_slot]
        for i in range(0, len(blist.slots)):
            if blist.slots[i].is_empty():
                if blist.hidden_buffers:
                    blist.set_slot(i, blist.hidden_buffers[0])
                elif active_slot.window:
                    blist.set_slot(i, active_slot.window.buffer)
                else:
                    blist.set_slot(i, None)
            assert blist.slots[i].window is not None
    def close_buffer_by_name(self, name):
        if self.has_buffer_name(name):
            self.close_buffer(self.get_buffer_by_name(name))

    def make_name(self, name):
        return util.make_name(name, self.has_buffer_name)
        #if self.has_buffer_name(name):
        #    i = 1
        #    auxname = '%s/%d' % (name, i)
        #    while self.has_buffer_name(auxname):
        #        i += 1
        #        auxname = '%s/%d' % (name, i)
        #    name = auxname
        #return name
    
    def open_path(self, path, binary=False, cipher=None, password=None):
        path = util.literal_path(path)
        b = self.get_buffer_by_path(path)
        if b is None:
            name = self.make_name(os.path.basename(path))

            mode_name = None
            if cipher is None:
                if not os.path.exists(path) or os.path.isfile(path):
                    if binary:
                        b = buffer.Binary32Buffer(path, name=name)
                    else:
                        b = buffer.FileBuffer(path, name=name)
                elif os.path.isdir(path):
                    b = buffer.fs.DirBuffer(path, name=name)
                    mode_name = 'dir'
                else:
                    raise FileError("not a file or dir: %r" % path)
            elif cipher == 'aes':
                if not password:
                    raise RunError("password is required")
                if not os.path.exists(path) or os.path.isfile(path):
                    b = buffer.aes.AesBuffer(path, password, name=name)
                else:
                    raise FileError("not a file or dir: %r" % path)
            try:
                b.open()
            except buffer.BinaryDataException:
                if binary:
                    raise
                else:
                    binary = True
                    b = buffer.Binary32Buffer(path, name=name)
                    b.open()
                    if mode_name is None:
                        mode_name = 'hex'
            Window(b, self, height=0, width=0, mode_name=mode_name)
            self.add_buffer(b)
        return b

    # mini buffer handling
    def get_mini_buffer(self):
        return self.mini_buffer
    def mini_buffer_is_open(self):
        return self.mini_buffer is not None
    def open_mini_buffer(self, prompt, cb, method=None, tabber=None,
                         modename=None, startvalue=None, queue='default'):
        parentw = self.bufferlist.slots[self.active_slot].window
        if self.mini_buffer_is_open():
            self.close_mini_buffer()
        self.mini_prompt = prompt
        self.mini_buffer = MiniBuffer(cb, self, method, tabber, modename, queue,
                                      parentw)
        try:
            w = self.x - 1 - len(self.mini_prompt) - 1
            Window(self.mini_buffer, self, height=1, width=w)
            if startvalue:
                self.mini_buffer.set_data(startvalue)
            self.arg_history.setdefault(queue, [])
            self.arg_history[queue].append(startvalue or '')
            self.mini_buffer.hindex = len(self.arg_history[queue]) - 1
                
            self.mini_active = True
        except MiniBufferError:
            self.mini_buffer = None
            self.mini_prompt = ''
    def exec_mini_buffer(self):
        self.mini_buffer.callback(self.mini_buffer.make_string())
        self.close_mini_buffer()
    def close_mini_buffer(self):
        self.mini_active = False
        if self.mini_buffer_is_open():
            self.mini_buffer.close()
        self.mini_buffer = None
        self.mini_prompt = ""
        assert not self.mini_active
    def get_mini_buffer_prompt(self):
        return self.mini_prompt
    def set_mini_buffer_prompt(self, p):
        self.mini_prompt = p

    # window handling
    def toggle_window(self):
        blist = self.bufferlist
        assert 0 <= self.active_slot and self.active_slot < len(blist.slots)
        self.active_slot = (self.active_slot + 1) % len(blist.slots)
    def window(self):
        return self.bufferlist.slots[self.active_slot].window
    def active_window(self):
        if self.mini_active:
            return self.mini_buffer.windows[0]
        else:
            slot = self.active_slot
            assert 0 <= slot and slot < len(self.bufferlist.slots), \
                "0 <= %d < %d" % (slot, len(self.bufferlist.slots))
            i = self.active_slot
            return self.bufferlist.slots[i].window

    # buffer handling
    def new_file_buffer(self, path, data, switch_to=True):
        assert not self.has_buffer_name(path), '%r is already open' % path
        # touch the file
        f = open(path, 'w')
        f.write(data)
        f.close()
        # create the buffer
        b = buffer.FileBuffer(path)
        try:
            b.open()
        except buffer.BinaryDataException:
            b = buffer.Binary32Buffer(path)
            b.open()
            b.modename = 'hex'
        Window(b, self, height=0, width=0)
        self.add_buffer(b)
        if switch_to:
            self.switch_buffer(b)
        return b
    def data_buffer(self, name, data, switch_to=True, modename=None):
        if self.has_buffer_name(name):
            b = self.bufferlist.buffer_names[name]
            self.remove_buffer(b)
        b = buffer.data.DataBuffer(name, data)
        if modename is not None:
            b.modename = modename
        Window(b, self, height=0, width=0)
        self.add_buffer(b)
        if switch_to:
            self.switch_buffer(b)
        return b

    # NOTE: make sure that data has escaped \, [, and ] properly, or else you
    #       will get undesirable results
    def color_data_buffer(self, name, data, switch_to=True, modename='colortext'):
        if self.has_buffer_name(name):
            b = self.bufferlist.buffer_names[name]
            self.remove_buffer(b)
        b = buffer.colors.ColorDataBuffer(name, data)
        if modename is not None:
            b.modename = modename
        Window(b, self, height=0, width=0)
        self.add_buffer(b)
        if switch_to:
            self.switch_buffer(b)
    def get_buffer_by_path(self, path):
        return self.bufferlist.get_buffer_by_path(path)
    def has_buffer_name(self, name):
        return self.bufferlist.has_buffer_name(name)
    def get_buffer_by_name(self, name):
        return self.bufferlist.get_buffer_by_name(name)
    def has_buffer(self, b):
        return self.bufferlist.has_buffer(b)
    def add_buffer(self, b):
        self.bufferlist.add_buffer(b)
    def remove_buffer(self, b):
        assert self.bufferlist.has_buffer(b), "can't kill what's not there"
        assert len(self.bufferlist.buffers) > 1, "can't kill with no other buffers"
        self.bufferlist.remove_buffer(b)
        b.close()
        if self.bufferlist.empty_slot(self.active_slot):
            b2 = self.bufferlist.hidden_buffers[0]
            self.bufferlist.set_slot(self.active_slot, b2)
    def switch_buffer(self, b):
        assert self.has_buffer_name(b.name()), "buffer %s does not exist" % (b.name())
        assert 0 <= self.active_slot and self.active_slot < len(self.bufferlist.slots)
        self.bufferlist.set_slot(self.active_slot, b)

    def add_window_to_buffer(self, b, slotname):
        if not b.has_window(slotname):
            slot = self.bufferlist.slots[slotname]
            Window(b, self, height=slot.height, width=slot.width)

    # error string handling
    def set_msg(self, s):
        self.error_string = s
        self.error_timestamp = time.time()
    def set_error(self, s):
        self.set_msg(s)
        self.log.append_lines([s, u""], act=buffer.ACT_NONE, force=True)
    def clear_error(self):
        self.error_string = u""
        self.error_timestamp = None
    def try_manual_resize(self):
        y, x = self.stdscr.getmaxyx()
        if y != self.y or x != self.x:
            self.y, self.x = y, x
            self.resize_slots()
    def resize_event(self):
        (self.y, self.x) = self.stdscr.getmaxyx()
        self.resize_slots()
    def resize_slots(self):
        n = len(self.bufferlist.slots)
        assert n > 0
        x = self.x - 1
        y_sum = self.y - n
        self.bufferlist.resize(y_sum, x)

    # exit
    def exit(self):
        self.done = True

    # kill stack manipulation
    def push_kill(self, s):
        if s is not None:
            if self.last_action in self.kill_commands and \
                len(self.kill_ring):
                self.kill_ring[-1] = self.kill_ring[-1] + s
            else:
                self.kill_ring.append(s)
        maxnum = self.config.get('max_num_kills')
        if maxnum and len(self.kill_ring) > maxnum:
            self.kill_ring.pop(0)
    def pop_kill(self):
        return self.kill_ring.pop(-1)
    def has_kill(self, i=-1):
        return len(self.kill_ring) >= abs(i)
    def get_kill(self, i=-1):
        return self.kill_ring[i]

    # undo/redo
    def undo(self):
        try:
            self.window().undo()
        except Exception, e:
            self.set_error("%s" % (e))
    def redo(self):
        try:
            self.window().redo()
        except Exception, e:
            self.set_error("%s" % (e))

    # action creating methods
    def make_insert_action(self, c):
        return lambda: self.window().insert_string(c)
    def make_window_action(self, methodname):
        f = getattr(self.window(), methodname)
        f()

    # load user configuration NOW
    def loadrc(self):
        path = os.path.join(os.getenv('HOME'), '.pmc', 'conf')
        if not os.path.exists(path):
            return
        try:
            f = open(path, 'r')
            exec(f)
            f.close()
        except:
            s = traceback.format_exc()
            self.rcerror = 'There was an error during startup:\n\n' + s

    # after actions get handled, do some stuff
    def post_action_hook(self, act):
        self.last_action = act.name
        if self.highlight_mark:
            if act.name == 'set-mark' or act.metadata.get('is_move'):
                pass
            else:
                self.highlight_mark = False

    # UTF-8 aware way to write to the screen
    def addstr(self, y, x, s, attr=curses.A_NORMAL):
        self.win.addstr(y, x, s.encode('utf-8'), attr)

    # the mighty run-loop!
    def run(self):
        self.done = False
        self.draw()
        if os.getenv('PMC_EARLY_OUT'):
            return
        while not self.done:
            i = self.win.getch()

            # if we get a resize event, wait for things to stabilize
            if i == curses.KEY_RESIZE:
                while i == curses.KEY_RESIZE: i = self.win.getch()
                self.resize_event()
                self.need_draw = True

            # add the keycodes to our input handler
            try:
                self.input.parse(i)
            except Exception, e:
                self.set_error(str(e))

            # if the mode has parsed keycodes into a key, we (possibly) handle
            # some actions, and refresh the screen
            while self.input.tokens:
                self.need_draw = True
                t = self.input.tokens.pop(0)
                self.active_window().mode.handle_token(t)

            if self.need_draw:
                self.draw()
                self.need_draw = False

        # clean up, clean up
        for b in self.bufferlist.buffers:
            b.close()

        # clear the error line; it might look confusing to the user
        try:
            self.addstr(self.y-1, 0, ' ' * self.x)
        except:
            pass
        self.win.refresh()
        return

    # highlighting
    def add_highlighted_range(self, hr):
        self.highlighted_ranges.append(hr)
    def clear_highlighted_ranges(self, name=None):
        if name is None:
            self.highlighted_ranges = []
        else:
            i = 0
            while i < len(self.highlighted_ranges):
                if self.highlighted_ranges[i].name == name:
                    del self.highlighted_ranges[i]
                else:
                    i += 1

    # running external programs
    def run_pipe(self, args, b, name='*Output*', switch=True, modename=None):
        pipe = Popen(args=args, stdin=PIPE, stdout=PIPE, stderr=STDOUT)
        data = b.make_string().encode('utf-8')
        pipe.stdin.write(data)
        pipe.stdin.close()
        output = pipe.stdout.read()
        status = pipe.wait()
        if callable(switch):
            switch_to = switch(status)
        else:
            switch_to = bool(switch)
        self.data_buffer(name, output, switch_to=switch_to, modename=modename)
        return status
    def run_external(self, *args):
        curses.reset_shell_mode()
        try:
            pipe = Popen(args)
            pipe.wait()
        except OSError, e:
            self.set_error("%s: %s" % (args[0], e))
        curses.reset_prog_mode()
        self.win.redrawwin()
        self.draw()

    # full screen drawer
    def draw(self):
        try:
            n = len(self.get_minibuffer_lines())
            assert n > 0
            if n != self.bufferlist.mini_height:
                self.bufferlist.resize_mini(n)
            self.draw_slots()
            self.draw_minibuffer()
            self.draw_cursor()
            self.win.refresh()
        except:
            raise #XYZ
            # ok, so there was a problem...
            # let's see if the screen changed sizes and if so, resize our slots
            self.resize_event()

        # clear the error message if appropriate
        tout   = self.config.get('error_timeout', 0)
        tstamp = self.error_timestamp
        if tstamp and tout and time.time() - tstamp > tout:
            self.clear_error()

        self.try_manual_resize()

    # NOTE: this is taken from the cursor code
    def map_point(self, slot, p):
        w = slot.window
        swidth = slot.width - w.mode.lmargin - w.mode.rmargin
        blen = len(w.buffer.lines)
        count = w.mode.header
        (x, y) = w.first.xy()
        (vy, vx) = (None, None)
        while count < slot.height:
            if p.y == y and p.x >= x and p.x <= x + swidth:
                vy, vx = slot.y_offset + count, p.x - x + w.mode.lmargin
                if vx == swidth and p.x < len(w.buffer.lines[y]):
                    vx = 0
                    vy += 1
                break
                    
            if y >= blen or x + swidth >= len(w.buffer.lines[y]):
                x = 0
                y += 1
            else:
                x += swidth
            count += 1
        return vx, vy

    def draw_cursor(self):
        if self.mini_active:
            b = self.mini_buffer
            w = b.windows[0]
            p = w.logical_cursor()
            x = p.x + len(self.mini_prompt)
            y = p.y
            if y >= len(b.lines):
                return

            lines = self.get_minibuffer_lines()
            while x > self.x - 1:
                y += 1
                x -= self.x - 1
            vy, vx = self.y - len(lines) + y, x
        else:
            slot = self.bufferlist.slots[self.active_slot]
            w = slot.window
            #swidth = slot.width - w.mode.lmargin - w.mode.rmargin
            if w.active_point is not None and w.point_is_visible(w.active_point):
                p = w.active_point
            else:
                p = w.logical_cursor()

            vx, vy = self.map_point(slot, p)
        if vy is None or vx is None:
            return
        try:
            self.win.move(vy, vx)
        except:
            raise DrawError("(%r=%r) no (%r)" % ((vx, vy), p, (self.x, self.y)))

    # sub-drawing methods
    def draw_slots(self):
        self.win.erase()
        for i in range(0, len(self.bufferlist.slots)):
            #slot = self.bufferlist.slots[i]
            self.draw_slot(i)
            self.draw_status_bar(i)
            
    def highlight_char(self, sy, sx, fg='default', bg='default'):
        junk = self.win.inch(sy, sx)
        char = chr(junk & 255)
        attr = color.build(fg, bg)
        try:
            #self.win.addstr(sy, sx, char, attr)
            self.addstr(sy + 1000, sx, char, attr)
        except curses.error:
            raise DrawError("(%d, %d, %r, %r) v. (%d, %d)" %
                            (sy, sx, fg, bg, self.y, self.x))

    def highlight_chars(self, sy, sx1, sx2, fg='default', bg='default'):
        assert sx2 < self.x, "%d < %d" % (sx2, self.x)
        for x in range(sx1, sx2):
            self.highlight_char(sy, x, fg, bg)

    def highlight_simple_range(self, slot, y1, x1, x2, fg, bg):
        count    = slot.window.mode.header
        tx1, tx2 = slot.window.mode.lmargin, slot.width - 1
        x, y     = slot.window.first.xy()
        while count < slot.height:
            if y1 == y and x1 < slot.width + x:
                sy  = slot.y_offset + count
                sx1 = x1 - x + slot.window.mode.lmargin
                sx2 = x2 - x + slot.window.mode.lmargin
                if x1 <= x:
                    if x2 < slot.width + x:
                        self.highlight_chars(sy, tx1, sx2, fg, bg)
                        break
                    else:
                        self.highlight_chars(sy, tx1, tx2, fg, bg)
                else:
                    if x2 < slot.width + x:
                        self.highlight_chars(sy, sx1, sx2, fg, bg)
                        break
                    else:
                        self.highlight_chars(sy, sx1, tx2, fg, bg)

            if x + slot.width > len(slot.window.buffer.lines[y]):
                x = 0
                y += 1
            else:
                x += slot.width - 1
            count += 1

    def highlight_complex_range(self, slot, p1, p2, fg, bg):
        count    = slot.window.mode.header
        tx1, tx2 = slot.window.mode.lmargin, slot.width - 1
        x, y     = slot.window.first.xy()
        while count < slot.height:
            if p1.y <= y:
                sy  = slot.y_offset + count
                if p1.y == y:
                    if p1.x > slot.width + x:
                        pass
                    elif p1.x > x:
                        self.highlight_chars(sy, p1.x - x + tx1, tx2, fg, bg)
                    else:
                        self.highlight_chars(sy, tx1, tx2, fg, bg)
                elif p2.y > y:
                    self.highlight_chars(sy, tx1, tx2, fg, bg)
                elif p2.y == y and p2.x >= x and p2.x < slot.width + x:
                    if slot.width > p2.x - x:
                        self.highlight_chars(sy, tx1, p2.x - x + tx1, fg, bg)
                        break
                    else:
                        self.highlight_chars(sy, tx1, tx2, fg, bg)

            if x + slot.width > len(slot.window.buffer.lines[y]):
                x = 0
                y += 1
            else:
                x += slot.width - 1
            count += 1

    def highlight_range(self, slot, p1, p2, fg, bg):
        if p1.y == p2.y:
            return self.highlight_simple_range(slot, p1.y, p1.x, p2.x, fg, bg)
        else:
            return self.highlight_complex_range(slot, p1, p2, fg, bg)

    def draw_slot(self, i):
        assert self.active_slot < len(self.bufferlist.slots), \
            "strange: %d < %d" % (self.active_slot, len(self.bufferlist.slots))
        assert i < len(self.bufferlist.slots), \
            "puzzling: %d < %d" % (i, len(self.bufferlist.slots))
        slot = self.bufferlist.slots[i]
        if slot.window is None:
            return
        w = slot.window

        # draw the header
        if w.mode.header:
            rstrs = w.mode.get_header()
            assert len(rstrs) >= w.mode.header
            for j in range(0, w.mode.header):
                k = 0
                for rstr in rstrs[j]:
                    rstr.draw(self.win, slot.y_offset + j, slot.x_offset + k, slot.width)
                    k += len(rstr.string)

        # draw the actual slot
        self._draw_slot(i)

        # highlighted regions
        for hr in self.highlighted_ranges:
            (high_w, p1, p2, fg, bg) = hr
            if w is high_w and p2 >= w.first and p1 <= w.last:
                self.highlight_range(slot, p1, p2, fg, bg)

        if (self.active_slot == i and not self.highlighted_ranges and self.highlight_mark):
            fg, bg = 'black', 'cyan'
            cursor = w.logical_cursor()
            mark   = w.mark
            if mark is None:
                return

            if mark <= cursor:
                p1, p2 = mark, cursor
            else:
                p1, p2 = cursor, mark

            if p1 < w.first: p1 = w.first
            if p2 > w.last: p2 = w.last
            self.highlight_range(slot, p1, p2, fg, bg)

        if w.margins_visible:
            shade = util.get_margin_color(w, 'blue')
            limit = util.get_margin_limit(w, 80)
            if limit < self.x:
                for j in range(0, slot.height):
                    char = chr(self.win.inch(j + slot.y_offset, limit) & 255)
                    attr = color.build('default', shade, 'bold')
                    self.addstr(j + slot.y_offset, limit + w.mode.lmargin, char, attr)
        
    def _draw_slot(self, i):
        slot     = self.bufferlist.slots[i]
        w        = slot.window
        x, y     = w.first.xy()
        lm, rm   = w.mode.lmargin, w.mode.rmargin
        count    = w.mode.header
        swidth   = slot.width - lm - rm
        lit      = w.mode.name in w.buffer.highlights
        ended    = False

        # figure out which "physical line" is the first to be shown. note that
        # the cursor shouldn't be in the last column unless it's the end of a
        # line.
        k = x // swidth

        while count < slot.height:
            if lit:
                rlines = w.render_line_lit(y, swidth)
            else:
                rlines = w.render_line_raw(y, swidth)
            for j in range(k, len(rlines)):
                y2 = slot.y_offset + count
                if lm:
                    lcont = j > 0
                    rstrs = slot.window.mode.get_lmargin(w, y, x, ended, lcont)
                    for rstr in rstrs:
                        rstr.draw(self.win, y2, 0)
                for rstr in rlines[j]:
                    rstr.draw(self.win, y2, 0 + lm)
                if rm:
                    rcont = j < len(rlines) - 1
                    rstrs = slot.window.mode.get_rmargin(w, y, x, ended, rcont)
                    for rstr in rstrs:
                        rstr.draw(self.win, y2, slot.width - rm)
                count += 1
                if count >= slot.height:
                    break
            k = 0
            y += 1
            ended = ended or y >= len(w.buffer.lines)

    def draw_status_bar(self, slotname):
        slot = self.bufferlist.slots[slotname]
        if slot.window is None:
            return
        status = slot.window.mode.get_status_bar()
        status = status.ljust(slot.width)[:slot.width]
        self.addstr(slot.height + slot.y_offset, 0, status, curses.A_REVERSE)

    # input bar drawing
    def draw_minibuffer(self):
        lines = self.get_minibuffer_lines()
        attr = color.build('default', 'default')
        if self.error_string:
            attr = color.build('default', 'default')
        for i in range(0, len(lines)):
            line = lines[i]
            try:
                self.addstr(self.y - len(lines) + i, 0, line, attr)
            except:
                raise
        if self.error_string or not self.mini_buffer_is_open():
            return
        pattr = color.build('cyan', 'default', 'bold')
        plines = self.get_minibuffer_x_lines(self.mini_prompt)
        for i in range(0, len(plines)):
            pline = plines[i]
            try:
                self.addstr(self.y - len(lines) + i, 0, pline, pattr)
            except:
                pass

    def get_minibuffer_x_lines(self, s):
        i     = 0
        lines = []
        while i < len(s):
            lines.append(s[i:i + self.x - 1])
            i += self.x - 1
        return lines

    def get_minibuffer_lines(self):
        lines2 = []
        if self.error_string:
            maxlen = self.config['max_error_len']
            if len(self.error_string) < maxlen:
                s = self.error_string
            else:
                s = self.error_string[:maxlen] + '...'
        elif self.mini_buffer_is_open():
            s = self.mini_prompt + self.mini_buffer.lines[0]
            lines2 = self.mini_buffer.lines[1:]
        else:
            return [' ' * (self.x - 1)]
        lines = self.get_minibuffer_x_lines(s)
        lines.extend(lines2)
        return lines

def open_aes_file(path, name=None, binary=False):
    if os.path.isfile(path) or not os.path.exists(path):
        p = getpass("Please enter the AES password: ")
        return buffer.aes.AesBuffer(path, p, name)
    else:
        raise Exception, "can't open %r; unsupported file type" % path

def open_plain_file(path, name=None, binary=False):
    if os.path.isfile(path) or not os.path.exists(path):
        if binary:
            return buffer.Binary32Buffer(path, name)
        else:
            return buffer.FileBuffer(path, name)
    elif os.path.isdir(path):
        return buffer.fs.DirBuffer(path, name)
    else:
        raise Exception, "can't open %r; unsupported file type" % path

def run_app(stdscr, buffers, **kwargs):
    curses.def_shell_mode()
    a = Application(stdscr, buffers, **kwargs)
    metax = a.methods['meta-x']
    for cmd in kwargs.get('init_cmds', []):
        metax.execute(a.active_window(), method=cmd)
    a.run()
    return 0

if __name__ == "__main__":
    ciphers   = {'none': open_plain_file,
                 'aes':  open_aes_file}

    locale.setlocale(locale.LC_ALL, '')

    # preprocess args
    argv = list(sys.argv[1:])
    goto_line = None
    i = 0
    while i < len(argv):
        if argv[i] == '-nw':
            del argv[i]
        elif argv[i].startswith('+'):
            goto_line = int(argv.pop(i))
        else:
            i += 1

    # set up the option parser, and set some defaults
    import optparse
    parser = optparse.OptionParser()
    parser.set_defaults(debug=False)
    parser.set_defaults(goto=None)
    parser.set_defaults(mode=None)
    parser.set_defaults(cipher='none')
    parser.set_defaults(linetype='unix')
    parser.set_defaults(pipe=False)
    parser.set_defaults(binary=False)
    parser.set_defaults(cmds=[])

    def exec_cb(option, opt, value, parser):
        parser.values.cmds.append(value)

    parser.add_option('-b', '--binary', dest='binary', action='store_true',
                      help='open file(s) in hex binary mode')
    parser.add_option('-p', '--pipe', dest='pipe', action='store_true',
                      help='read data from STDIN into buffer')
    parser.add_option('-d', '--debug', dest='debug', action='store_true',
                      help='run in debug mode')
    parser.add_option('-e', '--encrypt', dest='cipher', metavar='CIPHER',
                      help='decrypt and encrypt with CIPHER (default: none)')
    parser.add_option('-g', '--goto', dest='goto', metavar='NUM', type='int',
                      help='jump to line NUM of the first argument')
    parser.add_option('-m', '--mode', dest='mode', metavar='MODE',
                      help='open arguments in MODE')
    parser.add_option('-x', '--exec', action='callback', callback=exec_cb,
                      type='string', metavar='CMD', help='run CMD after launching')

    (opts, args) = parser.parse_args(argv)

    # if debugging, disable error handling to produce backtraces
    if opts.debug:
        mode.DEBUG = True

    # override $TERM if we need to
    if os.getenv('PMC_TERM'):
        os.putenv('TERM', os.getenv('PMC_TERM'))

    # load an optional init file
    try:
        exec(open(os.path.join(os.getenv('HOME'), '.pmc', 'init'), 'r'))
    except:
        pass

    # if -b but no -m, then use -m hex
    if opts.binary and not opts.mode:
        opts.mode = 'hex'

    # we will support using +19 as the first argument to indicate opening the
    # first file on line 19 (same as -g 19 or --goto 19)
    if goto_line:
        opts.goto = goto_line

    # figure out what kind of file open function to use
    if opts.cipher not in ciphers:
        sys.stderr.write('invalid cipher: %r' % opts.cipher)
        sys.exit(2)
    f = ciphers[opts.cipher]

    # open each path using our callback to get a buffer, open that buffer, etc.
    buffers = []
    names   = set()
    paths   = set()

    # if we used a pipe to read some data, that will be our first buffer
    if opts.pipe:
        data = sys.stdin.read()
        # since we just read until EOF from stdin, we need to reset STDIN using
        # the TTY.
        tty = open('/dev/tty', 'r')
        os.dup2(tty.fileno(), sys.stdin.fileno())

        # ok, so now create the actual buffer
        b = buffer.data.DataBuffer('*Pipe*', data)
        b.open()
        buffers.append(b)

    for path in args:
        path = os.path.abspath(os.path.realpath(util.expand_tilde(path)))
        if path in paths:
            continue

        # find a free name that doesn't conflict with any others
        name = util.make_name(os.path.basename(path), lambda x: x in names)

        try:
            b = f(path, name, opts.binary)
            b.open()
        except buffer.BinaryDataException, e:
            if not opts.mode:
                opts.mode = 'hex'
            b = f(path, name, True)
            b.open()

        buffers.append(b)
        paths.add(path)
        names.add(name)

    # save terminal state so we can restore it when the program exits
    attr = termios.tcgetattr(sys.stdin)
    keyinput.disable_control_chars()

    # ok, now run our app
    try:
        curses.wrapper(run_app, buffers, jump_to_line=opts.goto,
                       init_mode=opts.mode, init_cmds=opts.cmds)
        err = 0
    except:
        # restore terminal state before printing an error
        termios.tcsetattr(sys.stdin, termios.TCSANOW, attr)
        traceback.print_exc()
        err = 1

    # restore terminal state before exiting
    termios.tcsetattr(sys.stdin, termios.TCSANOW, attr)
    sys.exit(err)