CATweaker – an Xcode plugin for creating beautiful CAMediaTimingFunction curve




A helper tool for creating beautiful CAMediaTimingFunction curve.

alt Window

CATweaker come with an Xcode plugin:

CATweakerSense for Xcode


CATweakerSense is an Xcode plugin that makes working with CAMediaTimingFunction more visual.

You might use ColorSense before. It let you pick up a color right from Xcode caret.

CATweakerSense is like ColorSense, but it lets you pick a CAMediaTimingFunction curve. When you put the caret on one of your CAMediaTimingFunction, it automatically shows the actual time curve as an overlay, and you can even adjust it on-the-fly with the curve adjuster.

The plugin also adds some items to the Edit menu to enable and to disable CATweakerSense temporarily. These menu items have no keyboard shortcuts by default, but you can set them via the system’s keyboard preferences (Xcode’s own preferences won’t show them).

alt Xcode Plugin

alt Xcode Plugin


Install via Alcatraz.


Simply build the Xcode project and restart Xcode. The plugin will automatically be installed in ~/Library/Application Support/Developer/Shared/Xcode/Plug-ins. To uninstall, just remove the plugin from there (and restart Xcode).

If you get a “Permission Denied” error while building, please see this issue.

This is tested on OS X 10.9.2 with Xcode 6.2.


  • It only works for constant point value, something like [CAMediaTimingFunction functionWithControlPoints: abc/def : 0.1 : 0.15 : 0.9]; won’t work.

Next move

I am planing to bring keyFrame animation into this plugin. So one can create more complex animation like “spring”, “decay”, “path” through the popover adjuster. If you have some great ideas, I am more than happy to hear from you.


This work is derived from the awesome ColorSense plugin of Ole Zorn(@olemoritz). Thanks Ole!


Xu Lian

I’m a Mac and iOS developer, the founder of Beyondcow, follow me on Twitter or Github.