Raise an Emacs window or run Emacs

emacs-raise-or-run.sh

#!/bin/bash

# ** Vars

# *** Emacs version
emacs="emacs"
emacsclient="emacsclient"
emacsWindowClass="Emacs"

# ** Functions

function findEmacsWindows {

    # Searching by window class or classname is not enough, because it
    # also finds Emacs' invisible windows. But the invisible windows
    # do not have WM_HINTS (although they do have
    # WM_NORMAL_HINTS...sigh). So to find the regular Emacs windows,
    # find the ones that have WM_HINTS.  ...  But sometimes Emacs
    # opens more than one invisible window (?!).  And one of those
    # windows may have WM_HINTS!  But it seems that only the real,
    # usable window has "_NET_WM_WINDOW_TYPE(ATOM) = _NET_WM_WINDOW_TYPE_NORMAL".
    # So grep for that to find the One True Window.
    #
    # ...the next day...
    #
    # Unbelievable.  24 hours later and I haven't changed anything but
    # it is picking up one of the TWO invisible windows since now one
    # of those invisible windows now has "_NET_WM_WINDOW_TYPE(ATOM) =
    # _NET_WM_WINDOW_TYPE_NORMAL" even though it didn't before.  So
    # now I have to try something like the FOURTH different method of
    # determining which Emacs window is the ACTUAL WINDOW...
    #
    # Ok, let's try looking for "window state:" which SHOULD only be
    # listed for an actual, usable window...

    for windowID in $(xdotool search --class $emacsWindowClass)
    do
        if [[ $(xprop -id $windowID WM_STATE) =~ "window state:" ]]
        then
            # Test against excludes
            if ! [[ $(xprop -id $windowID WM_ICON_NAME) =~ "Matrix" ]]
            then
                # No excludes match: return window ID
                echo $windowID
            fi
        fi
    done
}

function ifset {
    # Call like: if ifset command varname
    #            then
    #                for i in $varname

    declare -n ref=$2

    ref=$($1)

    [[ $ref ]] && return 0 || return 1
}

# ** Main

# *** Check for xdotool

if ! type xdotool &>/dev/null  # type works and is a bash builtin
then
    message="Install xdotool."
    echo "$message"
    notify-send "$message"
    exit 1
fi

# *** Get current window

currentWindow=$(xdotool getwindowfocus)

# Get current window class (not classname)
currentWindowClass=$(xprop -id $currentWindow WM_CLASS | awk '{ print $4 }' | tr -d '"')

# *** Minimize, raise, or run Emacs

if [[ $currentWindowClass = $emacsWindowClass ]]
then
    # Emacs is the active window.  Minimize it.
    $emacsclient -e "(switch-to-buffer \"*scratch*\")"
    xdotool windowminimize $currentWindow &>/dev/null

else
    # Emacs is not the active window.  Try to raise an Emacs window.
    if ifset findEmacsWindows emacsWindows
    then
	# Emacs windows found
	for window in $emacsWindows
	do
	    # Restore/unminimize, raise to top, and activate/focus
	    xdotool windowmap --sync $window windowraise $window windowactivate $window &>/dev/null
	done

    else
	# No Emacs windows found.  Run Emacs.
        if pgrep -f "emacs --daemon"
        then
            $emacsclient -c -n
        else
            $emacs # NOTE: [2017-12-06 Wed 09:03] Launching the daemon directly causes theme issues, so don't for now: --daemon
            #$emacsclient -c -n
        fi
    fi
fi