#!/bin/sh

# startx configuration file.

# Copyright (C) 2011-2014  Simon Ruderich
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


# Some systems don't set the LANG environment variable when starting xinitrc,
# this causes problems for rxvt-unicode-256color which fails to display UTF-8
# characters correctly when LANG is missing and for notify.py which also needs
# LANG set (for Python's decode() function). Therefore load my general shell
# environment which also includes $LANG.
if test -f "$HOME/.shell/env"; then
    . "$HOME/.shell/env"
fi


installed() {
    type "$1" >/dev/null 2>&1
}
error() {
    if installed xmessage; then
        xmessage "$@" &
    else
        # Log message to a file which is displayed by my Zsh setup on startup.
        printf '%s\n' "$*" >>"$HOME/.xinitrc.errors"
    fi
}
# Save PID of the most recently started background process. Used to terminate
# them when logging out to prevent unused background processes. On some
# systems this is only necessary for some programs (like ssh-agent), haven't
# yet figured out why.
save_background_pid() {
    background_pids="$background_pids $!"
}
background_pids=


# Options, can be modified in ~/.xinitrc.local. To disable a boolean option
# set it to an empty value.
#
# Default to use a background image.
set_background=yes
# Default to display a warning if no screen locker is not available.
screen_lock_force=yes
# Lock screen after x minutes of inactivity.
screen_lock_time=3
# Locker program to lock the screen (with xautolock).
screen_locker=xtrlock

# Load settings for the local system.
if test -f "$HOME/.xinitrc.local"; then
    . "$HOME/.xinitrc.local"
fi


# Start ssh-agent if no agent is running, thanks to
# http://code.haskell.org/XMonadContrib/scripts/xinitrc (read on 2011-06-19).
if test -z "$SSH_AGENT_PID" && test -x /usr/bin/ssh-agent; then
    # -s to force bourne shell output. This file is a bourne shell script even
    # if the environment might suggest otherwise.
    eval `/usr/bin/ssh-agent -s` >/dev/null
fi

# Use a black background for the root window.
xsetroot -solid black

# Force English keyboard layout.
if installed setxkbmap; then
    setxkbmap -option compose:menu us
fi

# Use the Caps lock as Ctrl because it's easier to reach and very useful for
# all programs. Caps lock is removed completely. Thanks to
# http://snarfed.org/space/switch%20control%20and%20caps%20lock
if xmodmap | grep -E '^lock.*Caps_Lock' >/dev/null; then
    xmodmap -e 'remove Lock = Caps_Lock'
    xmodmap -e 'remove Control = Control_L'
    xmodmap -e 'keysym Caps_Lock = Control_L'
    xmodmap -e 'add Control = Control_L'
fi
# Move grave and tilde next to left shift key. This setting may only be
# necessary because of my German keyboard which I use with an English layout.
xmodmap -e 'keycode 94 = grave asciitilde'

# Enable scrolling with trackpoint and middle mouse on Thinkpads, also disable
# touchpad. Thanks to DerRoteBaron.
if xinput 2>/dev/null | grep 'TPPS/2 IBM TrackPoint' >/dev/null; then
    xinput set-int-prop "TPPS/2 IBM TrackPoint" "Evdev Wheel Emulation" 8 1
    xinput set-int-prop "TPPS/2 IBM TrackPoint" "Evdev Wheel Emulation Button" 8 2
    xinput set-int-prop "TPPS/2 IBM TrackPoint" "Evdev Wheel Emulation Axes" 8 6 7 4 5
    xinput --disable "SynPS/2 Synaptics TouchPad"
fi

# Disable annoying audio bell. Thanks to Sebastian Rachuj.
xset b off

# Load settings for X programs. Xdefaults is deprecated.
xrdb "$HOME/.Xresources"

# Change the background if available.
if test -f "$HOME/.background" && test -n "$set_background"; then
    if installed hsetroot; then
        hsetroot -full "$HOME/.background"
    elif installed feh; then
        feh --bg-scale "$HOME/.background"
        # Remove the unnecessary ~/.fehbg file created by `feh`. I don't want
        # to restore the background, I just run `feh` on each startx run.
        # --no-fehbg is only available in recent feh releases.
        rm -f "$HOME/.fehbg"
    fi
fi

# Display timed reminders and recheck the file for changes every minute (-z1).
if installed remind && test -f "$HOME/.reminders"; then
    remind -z1 -k'.shell/bin/notify.py %s &' "$HOME/.reminders" &
    save_background_pid
fi

# Set color temperature of display according to time of day.
if installed redshift; then
    redshift -l 49.9:10.9 -t 5500:4500 >/dev/null &
fi


# Start best available screen locker.
xlockscreen=`"$HOME/.xlockscreen" start "$screen_lock_time" "$screen_locker"`
if test $? -ne 0 && test -n "$screen_lock_force"; then
    error "$xlockscreen"
fi


# Use compton to get transparent windows. See ~/.Xresources for configuration
# of urxvt.
if installed compton; then
    compton &
# xcompmgr as fallback.
elif installed xcompmgr; then
    xcompmgr &
fi


# My window manager doesn't start a terminal emulator on its own, start one
# when I login.
(urxvt || rxvt || xterm) &

# Start window manager.
failed=
if installed herbstluftwm; then
    herbstluftwm --locked || failed=1
elif installed xmonad; then
    xmonad || failed=1
elif installed stumpwm; then
    stumpwm || failed=1
else
    failed='no window manager found'
fi
# Fallback in case my window manager failed to start. Otherwise X terminates
# the session immediately (because xinitrc finishes).
if test -n "$failed"; then
    if test x"$failed" = x1; then
        failed='failed to start window manager'
    fi
    error "$failed (spawning fallback terminal)"
    urxvt || rxvt || xterm
fi


# Cleanup.
#
# Kill ssh-agent to prevent unused background processes.
if test -x /usr/bin/ssh-agent; then
    /usr/bin/ssh-agent -k >/dev/null
    # No `eval` necessary, we terminate anyway.
fi
# Kill remaining background processes.
if test -n "$background_pids"; then
    kill $background_pids
fi