[PYTHON] Make the OS X mouse pointer translucent

Since the mouse pointer usually only hits the tip, I thought it would be better to make it transparent. In particular, I make the pointer larger than usual, so when I put the pointer on a link etc., I sometimes have trouble seeing the letters below.

I thought that if the pointer was translucent, it would be comfortable to read the letters below even if the mouse pointer was made so huge.

The overall flow for making the mouse pointer translucent is as follows.

1. Dump the current mouse pointer data with Mousecape
2. Read the mouse pointer data with a Python script and make it translucent
3. Read the data processed by Python
4. Install Helper Tool to activate Mousecape at computer startup
5. Register AppleScript to start up to fill the Mousecape bug

Preparation

To carry out the content of this article, you will need the following:

• Mousecape
• Python

Mousecape is a tool for easily changing the mouse pointer. I will download and use the latest version 0.0.5.

Unzip the downloaded file and open the app file that appears, and the following window will appear.

Dump the current mouse pointer

Click ** Capes-> Dump Cusros .. ** on the toolbar to dump the current settings. When completed, it will look like this:

Right-click on this blue area and select ** Show in Finder ** to see the dumped cape file in the Finder, copy it to get the cape file. This becomes clear when you open it with a text editor, but inside it is a huge XML file that stores the image of the mouse pointer in Base64 encoding.

Make the mouse pointer translucent

Run the Python script that processes the cape file you just got. However, this Python script requires the following libraries:

• Pillow

$ pip install Pillow

You can install it with.

Then save the following script somewhere.

convert.py

from base64 import decodestring, encodestring
from xml.etree.ElementTree import ElementTree
import sys
import io
from PIL import Image

inputfile  = sys.argv[1].strip()
outputfile = sys.argv[2].strip()
opacity    = sys.argv[3].strip()

tree = ElementTree()
tree.parse(inputfile)

imagedata = tree.findall("dict/dict/dict/array/data")

for i in imagedata:
    img = decodestring(i.text)
   
    img  = Image.open(io.BytesIO(img))
    img  = img.convert('RGBA')
    data = img.getdata()

    new = []
    for p in data:
        new.append((p[0], p[1], p[2], int(p[3] * opacity)))

    img.putdata(new)
    img.save('temp.png', 'PNG')
    
    result = open('temp.png', 'r')
    base64 = encodestring(result.read())
    result.close()

    i.text = base64

tree.write(outputfile)

Execute as follows.

$ python convert.py /path/to/dumpfile.cape output.cape 0.5

This script takes command line arguments like this:

First argument

Dumped cape files

Second argument

Output destination file path

Third argument

Transmittance (0 to 1)

tell application "Mousecape"
	activate
end tell

delay 0.1

tell application "System Events" to tell application process "Mousecape"
	click (menu item 3 of menu 1 of menu bar item 2 of menu bar 1)
	set theSlider to slider 1 of window 1
	set value of theSlider to 3.0
end tell

quit application "Mousecape"