Arcs for OmniGraffle

Using

1. Download arc_bits.zip (14 KB).
2. Install the script.
3. In OmniGraffle open a new document and select > Arc.
4. In the first window that appears, enter the desired angle for your arc, between 0 and 360 like it says...
5. The following window asks for the radius. Something between 10 and 100 is probably sensible, but bigger numbers can be used if you're a real risk-taker with nerves of steel. (I myself once went as high as 137.)
6. Hit OK... tada!

Stencil version

Drag arcs from the stencil to your document. They can then be resized and edited with just as much difficulty as ones created by the script method.

Tips and other uses

If you draw lots of arcs with the same angle, but different radii, you can make little radar/wave/what-everyone-thinks-a-wireless-network-should-be-drawn-like–type things. [Indeed, Ben Ransford has adapted my script to allow you to do exactly that, with only one run of a script. See his blog post on the matter for more details.]

Resizing and rotating these things is a bit if a pain. Select more than one object (possibly even an arc and a dummy object you make temporarily) to get the usual resizing handles. Alternatively, the geometry palette lets you resize and rotate numerically. Also on the geometry palette you can flip the selection up/down or left/right. This may be easier than rotating if you're after something which is a multiple of 90°

If there are common arcs you use often it's probably easiest to make your own stencil (Stencils > New Stencil then save it in ~/Library/Application Support/OmniGraffle/Stencils/) with them ready to use.

Testimonials

• "I like them very much."
• "...practically worthless."
• "...still really neat."
• "...too cumbersome and problematic to be worth it."
• "You have provided a work-around, where previously I was at a loss!"

(All taken from the OmniGraffle mailing list.)

Known 'features'

• Some people have noticed that the script may not run when selected from the menu when using OmniGraffle 3.1.2, and only works when opened from the Finder. This was due to a change in the way Script Editor and OmniGraffle work together. Using OmniGraffle 3.2 or later fixes the problem.
• There is no error checking. As such, if you do anything out of the ordinary the script will almost certainly give strange—or no—results. Obvious things which come to mind which will confuse it are putting in negative numbers, or words. If you do do something funny, OmniGraffle will give you the option to edit the script. Feel free! Let me know if you come up with anything great.
• Multiple arcs are always drawn in the same place. Best to move your arc once it's been drawn if you are doing more than one of the same radius.

Things to maybe get around to some nice day

• Maybe some error checking here and there might be a good idea.
• Let the start angle be specified by the user? (It did this originally, but then you had to go through three dumb dialog boxes to get one little arc.)
• Other suggestions and comments are more than welcome.

Acknowledgements

• Applescript sine function from the Applescript Guidebook [no longer online]
• Ben Ransford has created an enhanced version of this script specifically for drawing radio-wave like shapes.

Version history

1.0 (2005-05-17)

Modified the arc stencil to make it slightly more compact. (The script remains unchanged, so still v1.0.)

1.0 (2005-05-15)

Initial release. Apparently works with OmniGraffle versions 3.2 beta 1, 3.2 and 3.2.1. Should also work fine with corresponding Pro versions of OmniGraffle.