Quicksilver plugins in Objective-C

Quicksilver is a ubiquitous application. Everyone knows about it, and most people use it to bolster their productivity. The application is able to catalog portions of your hard drive to give you instant access to your documents and software. Various plugins extend Quicksilver’s functionality and add more actions (such as calculations, dictionary lookups or scaling images) as well as allow it to index a wider range of files. This system is so powerful, that in two keystrokes it is possible to locate almost any file buried in your hard drive, and two more to perform an action on it such as deleting, renaming, etc. However, due to limited documentation and the application only being a Beta release, writing a plugin remains a mystery to most developers. This article aims to illustrate the steps needed in order to write a working Quicksilver plugin in Xcode and Objective-C. (Python programmers may use PyObjC).

Setting up Xcode

Required Resources

Quicksilver Developer Release

Creating a Quicksilver plugin firstly requires having the developer release of the application installed. This is exactly the same as the normal release, but includes the headers in the Quicksilver frameworks which we’ll need to make extensive use of. The latest version of the developer release is always available at http://getqs.com/dev/, so download it and replace your existing copy of Quicksilver with this application.

Xcode Quicksilver Plugin Project Template

The second resource we’ll make use of is a project template for creating Quicksilver plugins. Although the official download is available from the Quicksilver website, it happens to be very old and neglected and doesn’t work with Xcode 2.1. For this reason, I’ve made available a revised edition that should prove sufficient for creating plugins. Download the plugin template and extract the contents to /Library/Application Support/Apple/Developer Tools/Project Templates/Bundle/.

QS Project Template

Make sure you get the whole folder. The complete path to the Quicksilver Plug-in.xcodeproj file should be /Library/Application Support/Apple/Developer Tools/Project Templates/Bundle/Quicksilver Plug-in/Quicksilver Plug-in.xcodeproj.

In Xcode 3.1+, the project template can go into ~/Library/Application Support/Developer/Shared/Xcode/Project Templates/Bundle/Quicksilver Plug-in.
For interface development, download the Interface Project Template for Xcode.

Xcode Preferences

Adding Source Trees

We’ve got all the resources we need, but for Xcode to correctly parse the project template we just installed, we need to create a Source Tree that points to the Quicksilver Frameworks directory. In the Xcode Preferences, go to the Source Trees section. Add a new entry with the setting name as QSFrameworks. Set the path for this item to /Applications/Quicksilver.app/Contents/Frameworks/ or the equivalent. Now that Xcode is correctly configured, we can start exploring the plugin template and begin to engender amazing Quicksilver plugins.

Before you start writing Your Incredible Plugin™, take a few minutes to familiarize yourself with a some key aspects of Quicksilver plugin development. There are several steps you must take to ensure your plugin is fully compatible and usable by Quicksilver, but once you get these out of the way, it couldn’t be easier to write your plugin’s code.

Also in this series

Info.plist - QSPlugIn

The various sections of Quicksilver plugins, including the basics on how to properly configure your plugin, setup the correct options and settings, and how and where to write your plugin.

Quicksilver Actions

A quick look at QSActions in the Info.plist, followed by our first look at the code needed to get a plugin up and running.

Quicksilver Interface Creation

A thorough guide on the techniques to create a working Quicksilver interface. Includes an Xcode project template to minimize the effort required.

Stay tuned for the next installments in the series.