Development:Third-Party Preference Panes
See Bug 384800 for more information on the status of this page. The current how-to should not be attempted by people unfamiliar with Xcode and its related tools or the Camino codebase.
Contents
Who should read this document?
Camino, per our mission statement, "is an open source web browser developed with a focus on providing the best possible experience for Mac OS X users." This, along with the limited time available for our all-volunteer programming team to implement features, means that certain choices have to be made about what should and shouldn't be part of the Camino application itself. As with Firefox extensions, there are many opportunities for third-party developers to step in and provide niche features or UI for things that Camino doesn't provide by default. This document is intended to provide a jumping-off point for third-party developers interested in developing additional preference panes for Camino.
Getting started
These instructions assume a basic working knowledge of Apple's Developer Tools, including Xcode and Interface Builder, as well as the Objective-C language itself. If you are unfamiliar with these, Apple Developer Connection is an excellent place to start learning.
Applicability and support
These instructions can be used by anyone developing preference panes on Mac OS X 10.4 or higher, with Xcode 2.4.x or higher and Interface Builder 2.x or higher, to be deployed on any version of Camino from 1.5 onward (thus requiring Mac OS X 10.3.9 or higher). Developers may choose to support only Mac OS X 10.4+ or Camino 2.0pre+, but this is highly discouraged unless certain limitations of the Mac OS or Camino/Gecko code make supporting Mac OS X 10.3.9 or the Camino 1.5 branch impossible.
Disclaimer
These instructions are presented in good faith, but we make no guarantees as to the stability of Camino's APIs (even across minor versions), and we cannot guarantee preference panes developed using this guide will not set your cat -- or your users' cats, or both -- on fire.
Creating the Xcode project
Camino's preference panes are standard Apple PreferencePanes with a small twist: their creator code is MOZC (Camino's creator code) instead of the default ????. You can change this in the Properties tab of Xcode's Target Info window (see screenshot).
We've put together a [CBSamplePane.zip sample Xcode project] (download size) for developers to use when writing preference panes for Camino. Feel free to use this project as a starting point, or make your own. If you use the provided project, make sure you change your preference pane's bundle identifier from org.mozilla.caminoprefpane, as bundle ID conflicts can prevent your pane from loading. Bundle identifiers generally take the form of tld.developer.productname, so your preference pane might be com.johndoe.awesomeprefs, for example.
Laying out the UI
In order to keep the UI of your preference panes as consistent as possible with the preference panes shipped with Camino itself, please use our NIB Editing Guide as a reference for laying out the UI when developing preference panes for Camino.
Using Camino methods
If you plan to use any of Camino's methods, your preference pane should subclass Camino's PreferencePaneBase class. This means that PreferencePaneBase.h is a required header. If you plan to deploy your preference pane on Camino 1.5.x, you'll also need to compile PreferencePaneBase.mm (in the Compile Sources phase of the target). This step is unnecessary if you plan to deploy your preference pane only for Camino 1.6 or higher. [Will bad things happen if the prefpane and the app both have a copy of PreferencePaneBase.mm compiled into them? -cl]
In order for the -bundle_loader switch to do its job, you'll need to tell the linker where it can find a Camino application. Using the Target Info window, point the linker's "Bundle Loader" to a copy of Camino on your hard disk. For example, if Camino is in your Applications folder, it would look like this [needs to be re-screenshot -cl]:
If you have multiple copies of Camino, point it to the oldest one you plan to support with your preference pane.
You'll also need to copy over any Camino header files for methods you're using in your preference pane. You can add them to the Copy Headers phase of the project, like this:
That's it! You should be able to build the project and test your preference pane with Camino. Remember to re-launch Camino after placing the preference pane in [~]/Library/Application Suppport/Camino/PreferencePanes/.
Using Gecko functions and methods
Using Gecko code in a third-party preference pane is somewhat more involved. You'll need to copy the proper headers (see above) and link against the appropriate libraries. [An example here would be great. -cl]
If there's something in Gecko you really need to use that simply doesn't have a Cocoa wrapper on it in Camino, please bring it to our attention. We may be willing to add wrapper code for it, since one architectural goal we have for Camino is to hide Gecko from our developers as much as possible.
Other potential gotchas and caveats
Crossing that bridge when we come to it...
