February 25, 2017 at 12:55 PM by Dr. Drang
I’ve been writing and rewriting this screenshot script/workflow/thingsince 2006. Every now and then I have an idea of how to improve it, and I inflict the update on you. Usually, instead of describing the whole thing, I refer you back to one or more of the earlier posts and only explain what’s new. That makes for convoluted reading (assuming you’re reading at all), so I decided to write three posts on the topic that cover everything:
This one, which describes a Keyboard Maestro macro, SnapClip, that takes a screenshot, puts it on the clipboard, and optionally saves it to the Desktop. Second, another Keyboard Maestro macro, SnapSCP, which takes a screenshot, saves it locally, uploads it to a server via scp , and puts an HTML link to the file on the clipboard for pasting into a blog post. Finally, a set of instructions for setting up login credentials on your Mac and the server so you don’t have to enter a password or passphrase when you run SnapSCP (or when you run scp or ssh from the command line).I’ll put links to the latter two post in the list above once they’re written.
SnapClip is modeled on the builtin macOS 4 keyboard shortcut for taking a screenshot of a portion of the screen. (As we’ll see in a bit, it uses macOS’s screencapture command.) Like 4, it starts by changing your pointer to a crosshair, which you can drag across the screen to select an arbitrary rectangle for capturing.
Alternately, if you want to select an entire window, tap the spacebar. The pointer will change to a camera, and whatever window the camera is over will turn blue, indicating that it will be what’s captured when you click.
It’s at this point that SnapClip diverges from 4. A window pops up on your screen with a couple of choices.
If you select “Background border”, SnapClip will put a blue border around the screenshot, just like you see in the screenshot above. Although this option appears for both arbitrary rectangle and window screenshots, it’s intended to be used only for the latter.
The second option, “Save file to Desktop,” does exactly what you think. In some cases, you want to save the screenshot in addition to having it on your clipboard. Like 4, the filename is based on the date and time at which the screenshot was taken, but it isn’t as verbose. The format is simply
yyyymmdd-HHMMSS.pngThe default action button is labeled “Clipboard” as a reminder that the purpose here is to get the screenshot onto the clipboard, even if a copy is also saved to a file.
The blue background border is my attempt to strike a happy medium between the two types of window screenshots 4 and screencapture can produce: a window with a big dropshadow border,
or a bare window with no edges,
The dropshadow border is way too big and lots of people in the Mac world hate it, but the edgeless window gives me vertigo; I feel as if I’ll walk off the edge and fall to my death. It doesn’t even look like a window. SnapClip’s blue border is relatively narrow but gives the sense of a window with the Desktop behind it, which is what I’m looking for in a screenshot.
The color of the border is Solid Aqua Dark Blue, which is, by an amazing coincidence, the color I use for my Desktop.
Now that we know how SnapClip works and what it looks like in action, let’s see how it’s built. It’s a Keyboard Maestro macro with a hot key of 4:
The macro has only one step, but that step is a doozy. It’s this python script:
python: 1: #!/usr/bin/env python 2: 3: import Pashua 4: import tempfile 5: from PIL import Image 6: import sys, os 7: import subprocess 8: import shutil 9: from datetime import datetime 10: 11: # Local parameters 12: type = "png" 13: localdir = os.environ['HOME'] + "/Pictures/Screenshots" 14: tf, tfname = tempfile.mkstemp(suffix='.'+type, dir=localdir) 15: bgcolor = (61, 101, 156) 16: border = 16 17: desktop = os.environ['HOME'] + "/Desktop/" 18: fname = desktop + datetime.now().strftime("%Y%m%d-%H%M%S." + type) 19: impbcopy = os.environ['HOME'] + '/Dropbox/bin/impbcopy' 20: optipng = '/usr/local/bin/optipng' 21: 22: # Dialog box configuration 23: conf = ''' 24: # Window properties 25: *.title = Snapshot 26: 27: # Border checkbox properties 28: bd.type = checkbox 29: bd.label = Background border 30: bd.x = 10 31: bd.y = 60 32: 33: # Save file checkbox properties 34: sf.type = checkbox 35: sf.label = Save file to Desktop 36: sf.x = 10 37: sf.y = 35 38: 39: # Default button 40: db.type = defaultbutton 41: db.label = Clipboard 42: 43: # Cancel button 44: cb.type = cancelbutton 45: ''' 46: 47: # Capture a portion of the screen and save it to a temporary file. 48: status = subprocess.call(["screencapture", "-io", "-t", type, tfname]) 49: 50: # Exit if the user canceled the screencapture. 51: if not status == 0: 52: os.remove(tfname) 53: sys.exit() 54: 55: # Open the dialog box and get the input. 56: dialog = Pashua.run(conf) 57: if dialog['cb'] == '1': 58: os.remove(tfname) 59: sys.exit() 60: 61: # Add a desktop background border if asked for. 62: snap = Image.open(tfname) 63: if dialog['bd'] == '1': 64: # Make a solid-colored background bigger than the screenshot. 65: snapsize = tuple([ x + 2*border for x in snap.size ]) 66: bg = Image.new('RGB', snapsize, bgcolor) 67: bg.paste(snap, (border, border)) 68: bg.save(tfname) 69: 70: # Optimize the file. 71: subprocess.call([optipng, '-quiet', tfname]) 72: 73: # Put the image on the clipboard. 74: subprocess.call([impbcopy, tfname]) 75: 76: # Save to Desktop if asked for. 77: if dialog['sf'] == '1': 78: shutil.copyfile(tfname, fname) 79: 80: # Delete the temporary file 81: os.remove(tfname)The first thing of note is that the script relies on two nonstandard libraries, i.e., two libraries that don’t come with macOS. The first is Pashua , which handles the SnapClip window and its controls. Pashua is an application written by Carsten Blüm and has libraries for several scripting languages , including Python.
The second nonstandard library is Pillow , which handles the addition of the border to the screenshot. Pillow is a fork of and drop-in replacement for PIL, the