This script generates the Papiwaita icon theme, which is an icon theme based upon Adwaita with the addition of Papirus' application icons.

papiwaita.sh

#! /usr/bin/env bash

if [[ $UID != 0 ]]; then
	echo "This script must be run as root."
	exit 1
fi

if [[ $# -gt 1 ]]; then
	echo "Only one argument may be used at a time. Use -h or --help to see valid arguments."
	exit 1
fi

copyFlag=false

case "$1" in
	"-c" | "--copy")
		copyFlag=true
		;;
	"-h" | "--help")
		echo "This script generates the Papiwaita icon theme, which is an icon theme based upon Adwaita with the addition of Papirus' application icons."
		echo ""
		echo "The following are valid arguments:"
		echo ""
		echo "-c | --copy : Copy Papirus' icons over to Papiwaita rather than creating symbolic links."
		echo "-h | --help : View this message."
		exit 0
		;;
	"*")
		echo "The argument passed was unrecognised. Use --help to see valid arguments."
		exit 1
		;;
esac

appSizes=("16" "22" "24" "32" "42" "48" "64" "84" "96" "128")
appSymSizes=("16" "22" "24" "32" "48" "64")
themeDir="/usr/share/icons"

# Adjust Umask
oldUmask="$(umask | tr -d "\n")"
umask "022"

# Remove Old Theme
rm -rf "$themeDir/Papiwaita"

# Create Directory Structure
for i in "${appSizes[@]}"; do
	mkdir -p "$themeDir/Papiwaita/${i}x${i}/apps"
done
mkdir -p "$themeDir/Papiwaita/symbolic/apps"

# Create Symbolic Links for @2x Size Icons
for i in "${appSymSizes[@]}"; do
	ln -rs "$themeDir/Papiwaita/${i}x${i}" "$themeDir/Papiwaita/${i}x${i}@2x"
done

# Create Symbolic Links for Papirus Icons
for i in "${appSizes[@]}"; do
	for j in "$themeDir/Papirus/${i}x${i}/apps/"*; do
		if $copyFlag; then
			cp --preserve=links --reflink=auto "$j" "$themeDir/Papiwaita/${i}x${i}/apps/$(basename $j)"
		else
			ln -s "$j" "$themeDir/Papiwaita/${i}x${i}/apps/$(basename $j)"
		fi
	done
done
for i in "$themeDir/Papirus/symbolic/apps/"*; do
	if $copyFlag; then
		cp --preserve=links --reflink=auto "$i" "$themeDir/Papiwaita/symbolic/apps/$(basename $i)"
	else
		ln -s "$i" "$themeDir/Papiwaita/symbolic/apps/$(basename $i)"
	fi
done

# Write Theme Index
cat > "$themeDir/Papiwaita/index.theme" << EOL
[Icon Theme]
Name=Papiwaita
Comment=Adwaita, but with Papirus' application icons.
Example=folder
Inherits=Adwaita,hicolor

Directories=16x16/apps,16x16@2x/apps,22x22/apps,22x22@2x/apps,24x24/apps,24x24@2x/apps,32x32/apps,32x32@2x/apps,42x42/apps,48x48/apps,48x48@2x/apps,64x64/apps,64x64@2x/apps,84x84/apps,96x96/apps,128x128/apps,symbolic/apps

[16x16/apps]
Context=Applications
Size=16
Type=Fixed

[16x16@2x/apps]
Context=Applications
Size=16
Scale=2
Type=Fixed

[22x22/apps]
Context=Applications
Size=22
Type=Fixed

[22x22@2x/apps]
Context=Applications
Size=22
Scale=2
Type=Fixed

[24x24/apps]
Context=Applications
Size=24
Type=Fixed

[24x24@2x/apps]
Context=Applications
Size=24
Scale=2
Type=Fixed

[32x32/apps]
Context=Applications
Size=32
Type=Fixed

[32x32@2x/apps]
Context=Applications
Size=32
Scale=2
Type=Fixed

[42x42/apps]
Context=Applications
Size=42
Type=Fixed

[48x48/apps]
Context=Applications
Size=48
Type=Fixed

[48x48@2x/apps]
Context=Applications
Size=48
Scale=2
Type=Fixed

[64x64/apps]
Context=Applications
Size=64
Type=Fixed

[64x64@2x/apps]
Context=Applications
Size=64
Scale=2
Type=Fixed

[84x84/apps]
Context=Applications
Size=84
Type=Fixed

[96x96/apps]
Context=Applications
Size=96
Type=Fixed

[128x128/apps]
Context=Applications
Size=128
MinSize=128
MaxSize=512
Type=Scalable

[symbolic/apps]
Context=Applications
Size=16
MinSize=16
MaxSize=512
Type=Scalable
EOL

# Generate Theme Cache
if [[ -x $(which gtk-update-icon-cache) ]]; then
	gtk-update-icon-cache -q "$themeDir/Papiwaita"
fi

# Restore Umask
umask "$oldUmask"