powerline-shell.py.template

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import argparse
import os
import sys

def warn(msg):
    print '[powerline-bash] ', msg

class Powerline:
    symbols = {
        'compatible': {
            'separator': u'\u25B6',
            'separator_thin': u'\u276F'
        },
        'patched': {
            'separator': u'\u2B80',
            'separator_thin': u'\u2B81'
        },
        'flat': {
            'separator': '',
            'separator_thin': ''
        },
    }

    color_templates = {
        'bash': '\\[\\e%s\\]',
        'zsh': '%%{%s%%}',
        'bare': '%s',
    }

    def __init__(self, args, cwd):
        self.args = args
        self.cwd = cwd
        mode, shell = args.mode, args.shell
        self.color_template = self.color_templates[shell]
        self.reset = self.color_template % '[0m'
        self.separator = Powerline.symbols[mode]['separator']
        self.separator_thin = Powerline.symbols[mode]['separator_thin']
        self.segments = []

    def color(self, prefix, code):
        return self.color_template % ('[%s;5;%sm' % (prefix, code))

    def fgcolor(self, code):
        return self.color('38', code)

    def bgcolor(self, code):
        return self.color('48', code)

    def append(self, content, fg, bg, separator=None, separator_fg=None):
        self.segments.append((content, fg, bg, separator or self.separator,
            separator_fg or bg))

    def draw(self):
        return (''.join(self.draw_segment(i) for i in range(len(self.segments)))
                + self.reset).encode('utf-8')

    def draw_segment(self, idx):
        segment = self.segments[idx]
        next_segment = self.segments[idx + 1] if idx < len(self.segments)-1 else None

        return ''.join((
            self.fgcolor(segment[1]),
            self.bgcolor(segment[2]),
            segment[0],
            self.bgcolor(next_segment[2]) if next_segment else self.reset,
            self.fgcolor(segment[4]),
            segment[3]))

def get_valid_cwd():
    """ We check if the current working directory is valid or not. Typically
        happens when you checkout a different branch on git that doesn't have
        this directory.
        We return the original cwd because the shell still considers that to be
        the working directory, so returning our guess will confuse people
    """
    try:
        cwd = os.getcwd()
    except:
        cwd = os.getenv('PWD')  # This is where the OS thinks we are
        parts = cwd.split(os.sep)
        up = cwd
        while parts and not os.path.exists(up):
            parts.pop()
            up = os.sep.join(parts)
        try:
            os.chdir(up)
        except:
            warn("Your current directory is invalid.")
            sys.exit(1)
        warn("Your current directory is invalid. Lowest valid directory: " + up)
    return cwd


if __name__ == "__main__":
    arg_parser = argparse.ArgumentParser()
    arg_parser.add_argument('--cwd-only', action='store_true',
            help='Only show the current directory')
    arg_parser.add_argument('--cwd-max-depth', action='store', type=int,
            default=5, help='Maximum number of directories to show in path')
    arg_parser.add_argument('--mode', action='store', default='patched',
            help='The characters used to make separators between segments',
            choices=['patched', 'compatible', 'flat'])
    arg_parser.add_argument('--shell', action='store', default='bash',
            help='Set this to your shell type', choices=['bash', 'zsh', 'bare'])
    arg_parser.add_argument('prev_error', nargs='?', type=int, default=0,
            help='Error code returned by the last command')
    args = arg_parser.parse_args()

    powerline = Powerline(args, get_valid_cwd())