bestview

#!/bin/bash

# XXX showanddelete hacked to show best view by default and to
# change the image every five seconds if no key pressed.

# Maximum number of seconds to wait for a response from the terminal
# after a an escape sequence query. Usually, terminals respond much
# faster than 0.1 seconds, but may need to be increased for slow links
# (e.g., RS232C, ssh).
TIMEOUT=0.1

# Default sixel geometry if terminal does not respond to queries.
DEFAULT_WIDTH=800; DEFAULT_HEIGHT=480


cleanup() {
    # If the user hits ^C, we don't want them stuck in SIXEL mode
    echo -n $'\e[?80h'		# Reenable sixel scrolling
    echo -n $'\e\\'		# Escape sequence to stop SIXEL
    tput el
    exit 0
}
trap cleanup SIGINT SIGHUP SIGABRT


getwindowsize() {
    # Send control sequences to find how large of a sixel image can be shown.
    # Prints geometry as width then height. 

    local -i x y 		# for reading width and height integers
    local d			# dummy variable

    # Before querying the terminal, wait for it to be ready.
    waitforterminal

    # Send control sequence to query the sixel graphics geometry.
    IFS=";"  read -s -t ${TIMEOUT} -d "S" -p $'\e[?2;1;0S' d d x y d >&2
    if [[ $? -ne 0 ]]; then
	# Fall back to dtterm WindowOps to approximate sixel geometry.
	IFS=";"  read -s -t ${TIMEOUT} -d "t" -p $'\e[14t' d x y d >&2
    fi

    # Return the results (or the default if querying didn't work)
    [[ x -gt 0 ]]  ||  x=${DEFAULT_WIDTH}
    [[ y -gt 0 ]]  ||  y=${DEFAULT_HEIGHT}
    echo $x $y
    return
}


waitforterminal() {
    # Send an escape sequence and wait for a response from the terminal.
    # This routine will let us know when an image transfer has finished
    # and it's okay to send escape sequences that request results.
    # This is important if sixcat is run multiple times in a row, 
    # or if we want to run resetnumcolors at the end of the program.
    # WARNING. While this should work with any terminal, but if it fails
    # it'll end up waiting for approximately *forever* (i.e., 60 seconds).
    read -s -t ${1:-60} -d "c" -p $'\e[c'
}


flushstdin() {
    # flush stdin in case a key was hit twice by accident
    while read -s -n1 -t .001; do :; done
}

e() {
    # Clear current line and print text on it without a formfeed
    echo -en "\r"
    tput el
    echo -en "$*"
}

E() {
    # Clear current line and print text on it with a formfeed
    echo -en "\r"
    tput el
    echo -e "$*"
}

rename() {
    # Maybe rename an image file.
    local file="$1"
    local ext=${f##*.}
    local base=$(basename "$file" ".$ext")
    e "New name for $base? "
    read newname
    if [ "$newname" ]; then
	newname="$(dirname "$file")/$newname"
	newname="${newname#./}"	# Remove dotslash from "./foo.jpg"
	if [[ "$newname" != *$ext ]]; then
	    newname="$newname.$ext"
	fi

        e "Rename $file to $newname (y/N)? "
        read -s -n 1
        case $REPLY in
            y|Y)
		mv -i "$file" "$newname" &&
		    E "Renamed $file to $newname" &&
		    # If rename successful, write to outerscope variable "f"!!!
		    f="$newname"
		;;
	    *)
		E "Rename cancelled."
		;;
	esac
    else
	E "Rename cancelled."
    fi
}

editcomment() {
    # Retrieve the current image comment/caption and let the user edit it.
    local file="$1"
    comment=$(rdjpgcom "$1")

    read -e -i "$comment" -p "New comment? " newcomment

    if [ "$newcomment" == "$comment" ]; then
	E "Comment editing cancelled."
	return
    fi
    
    mv "$file" "$file.old"
    wrjpgcom -replace -comment "$newcomment" "$file.old" > "$file"
    gio trash "$file.old"
}

doit () {
    # For every file, show it and ask what is to be done.
    for f; do
	waitforterminal		# Wait for the terminal to be ready.

	if [[ -d "$f" ]]; then
	    echo "recursing on $f";
	    doit "$f"/*
	    continue
	fi
	[[ -f "$f" ]] || continue;

	# If the current file isn't an image, just skip it.
	if ! identify "$f" 2>/dev/null 1>&2; then
	    continue
	fi

	# Show a quick preview
	E "$f"
	e "preparing best fit view\r"
	convert -rotate '-90>' -rotate '+90' -gravity center \
		-geometry ">${WIDTH}x>${HEIGHT}"  "$f" sixel:-


	# Read a key loop
	while true; do
	    e "Press space to keep, 'd' to delete, 'v' to view, 'h' for help, 'q' to quit.\r";
	    flushstdin
	    if read -s -n1 -t 5 </dev/tty; then
		tput el
		case $REPLY in
		    s|" ") continue 2   # Nothing to do, just skip the image.
			   ;;
		    d|t) gio trash "$f" && echo "trashed $f"
		       sleep 0.25; flushstdin # Slow down deletes
		       continue 2
		       ;;
		    D) rm "$f" && echo "deleted $f"
		       sleep 0.25; flushstdin # Slow down deletes
		       continue 2
		       ;;
		    v) e "preparing high quality view\r"	# About 1 second
		       convert -geometry ">${WIDTH}x>${HEIGHT}" "$f" sixel:-
		       ;;
		    b) # Rotate to fit screen. Double rotate for square images.
			e "preparing best fit view\r"
			convert -rotate '-90>' -rotate '+90' -gravity center \
				-geometry ">${WIDTH}x>${HEIGHT}"  "$f" sixel:-
			;;
		    c|i) identify "$f"
		       rdjpgcom "$f" 2>/dev/null
		       ;;
		    r) rename "$f"
		       ;;
		    C) editcomment "$f"
		       ;;
		    w) e "preparing wide view\r"
		       convert -geometry ">${WIDTH}x" \
			       -crop ${WIDTH}x${HEIGHT} \
			       "$f" sixel:-
		       ;;
		    e) e "preparing enhanced view\r"
		       convert -geometry ">${WIDTH}x>${HEIGHT}" "$f" \
			       -channel rgb -auto-level -gamma 1.5 sixel:-
		       ;;
		    p) e "Paused. Hit any key.\r"
		       read -n1
		       ;;
		    h|'?') E "$(basename $0): Rapidly browse and delete image files"
		       cat <<- "EOF"
			For each image in a directory, a low quality preview will be shown.
			You can then hit one of these keys: 

			    space (or s): skip to next image.
			    d: trash image (also try 'gio list trash:' and 'gio trash --empty')
			    D: delete image immediately (no confirmation!)
			    v: view image in higher quality (can take a second).
			    b: best fit view (same as v, but image rotated to landscape).
			    w: wide view, show image full width 
			    e: enhanced view (auto-level + gamma 1.5)
			    c: display comments and image size.
			    r: rename image.
			    C: edit image comment.
			    h: help (looks like you found it).
			    q: quit

			EOF
		       ;;
		    q) exit;;
		esac;
	    else
		continue 2
	    fi;
	done
    done
    e
}


### MAIN

# # Set global variables to hold the window size. 
declare -i -g WIDTH HEIGHT	
read WIDTH HEIGHT <  <(getwindowsize)
HEIGHT=HEIGHT-32		# Trim some space for a line of text.


if [[ $# -gt 0 ]]; then
    doit "$@"
else
    doit *
fi