Generate Android App compliant iconography resources

android_drawables.sh

#!/bin/bash
########################################################################
# Script to generate Android standard iconography from an image file
# 
# Generated images comply with official iconography specifications.
# More at: http://www.androiddocs.com/design/style/iconography.html
# 
# This script relies on ImageMagik's 'convert' command and the awesome ffmpeg lib.
# Usage:
# 
# 	generate_icons IMG_SOURCE ICON_TYPE
# 	
# 		IMG_SOURCE: 	Path to a supported image from which icons will be generated
# 		ICON_TYPE: 		Can be 'launcher', 'action_bar', 'notification'
# 

SUPPORTED_EXT=( "png" )
# Get image from first parameter
img_path="$1"
if [ "$img_path" == "" ]; then echo "Please specify an image"; exit; fi
if [ ! -f "$img_path" ]; then echo "Image '$img_path' doesn't exist"; exit; fi
# Check extension
img_ext="${img_path#*.}"
img_ext="$(echo "$img_ext" | awk '{print tolower($0)}')"
echo "File extension: '$img_ext'"
if [[ ! " ${SUPPORTED_EXT[@]} " =~ " ${img_ext} " ]]; then echo "Extension '$img_ext' not supported (yet)"; exit; fi

# Get icon type
icon_type="$2"
SUPPORTED_TYPE=( "launcher" "action_bar" "notification" )
if [[ ! " ${SUPPORTED_TYPE[@]} " =~ " ${icon_type} " ]]; then echo "Unknown icon type: '$icon_type'. Must be one from: "; printf '\t%s\n' "${SUPPORTED_TYPE[@]}"; exit; fi



# print dpi
dpi="$(identify -format '%x,%y\n' -units PixelsPerInch "$img_path")"
echo "Original image density: $dpi"

MDPI_FOLDER="drawable-mdpi"
HDPI_FOLDER="drawable-hdpi"
XHDPI_FOLDER="drawable-xhdpi"
XXHDPI_FOLDER="drawable-xxhdpi"
XXXHDPI_FOLDER="drawable-xxxhdpi"

if [ -d "$MDPI_FOLDER" ] || [ -d "$HDPI_FOLDER" ] || [ -d "$XHDPI_FOLDER" ] || [ -d "$XXHDPI_FOLDER" ] || [ -d "$XXXHDPI_FOLDER" ]; then
	echo -n "WARNING: Some of the folders already exist. Continue? (y/n): "
	read user_response
	while [ "$user_response" != "y" ] && [ "$user_response" != "n" ]; do
		echo -n "Invalid answer '$user_response'. Continue? (y/n): "
		read user_response
	done
	if [ "$user_response" == "n" ]; then
		echo "Doing nothing then"
		exit
	fi
fi

OUT_IMG=""
TOTAL_CREATED="0"
function print_image_info(){
	if [ -f "$OUT_IMG" ]; then
		echo -e "\tCreated image: '$OUT_IMG'"
		density="$(identify -format '%x,%y' -units PixelsPerInch "$OUT_IMG")"
		echo -e "\t\tDensity: $density"
		size="$(ls -lh $OUT_IMG | awk '{print $5}')"
		echo -e "\t\tFile size: $size"
		img_size="$(identify -format '%wx%h' "$OUT_IMG")"
		echo -e "\t\tImage size: $img_size"
	else
		echo -e "\tImage could not be created!"
	fi
}

function create_icon(){
	IMG=$1
	DIR=$2
	MULT=$5
	SIZE="$(echo "$3 * $5" | bc -l )"
	DENSITY="$(echo "$4 * $5" | bc -l)"
	# Create folder
	if [ -d "$DIR" ]; then
		echo "WARNING: using already existent directory $DIR"
	else
		mkdir "$DIR"
	fi
	# Create image
	OUT_IMG="$DIR/$(basename $IMG)"
	# Warn if it already exists
	if [ -f "$OUT_IMG" ]; then
		echo -n "WARNING: Image '$OUT_IMG' already exists. Override? (y/n): "
		read user_responsee
		while [ "$user_responsee" != "y" ] && [ "$user_responsee" != "n" ]; do
			echo -n "Invalid answer '$user_responsee'. Override? (y/n): "
			read user_responsee
		done
		if [ "$user_responsee" == "n" ]; then
			echo "Skipping creation then"
			return 0
		fi
		echo "Overriding existing file"
	fi
	img_w="$(identify -format '%w' "$IMG")"
	img_h="$(identify -format '%h' "$IMG")"
	if [[ "$img_w" > "$img_h" ]]; then
		echo | ffmpeg -i "$IMG" -vf scale=$SIZE:-1:flags=lanczos -loglevel quiet "$OUT_IMG" 2> /dev/null
	else
		echo | ffmpeg -i "$IMG" -vf scale=-1:$SIZE:flags=lanczos -loglevel quiet "$OUT_IMG" 2> /dev/null
	fi
	# Change DPI metadata
	convert -density $DENSITY -units PixelsPerInch "$OUT_IMG" "$OUT_IMG"
	TOTAL_CREATED=$(($TOTAL_CREATED+1))
	print_image_info
}

echo -n "Will create icons for "
if [ "$icon_type" == "launcher" ]; then
	BASE_SIZE=48
	echo -n "Launcher"
elif [ "$icon_type" == "action_bar" ]; then
	echo -n "Action bar"
	BASE_SIZE=32
elif [ "$icon_type" == "notification" ]; then
	echo -n "Notifications"
	BASE_SIZE=24
fi
echo " (Base size: $BASE_SIZEx$BASE_SIZE dp)"

BASE_DPI=160
echo "Creating MDPI version..."
create_icon $img_path $MDPI_FOLDER $BASE_SIZE $BASE_DPI 1

echo "Creating HDPI version..."
create_icon $img_path $HDPI_FOLDER $BASE_SIZE $BASE_DPI 1.5

echo "Creating XHDPI version..."
create_icon $img_path $XHDPI_FOLDER $BASE_SIZE $BASE_DPI 2

echo "Creating XXHDPI version..."
create_icon $img_path $XXHDPI_FOLDER $BASE_SIZE $BASE_DPI 3

echo "Creating XXXHDPI version..."
create_icon $img_path $XXXHDPI_FOLDER $BASE_SIZE $BASE_DPI 4

echo "Finished! Created $TOTAL_CREATED images"