- Cassowary constraint solver
Cassowary is an incremental
constraint solving toolkit that efficiently solves systems of linear equalities and inequalities. Constraints may be either requirements or preferences. Client code specifies the constraints to be maintained, and the solver updates the constrained variables to have values that satisfy the constraints.Cassowary was developed by Greg Badros and Alan Borning, and was optimized for user interface applications. Badros used Cassowary amongst others for implementing Constraint Cascading Style Sheets (CCSS), an extension to
Cascading Style Sheets (CSS). CCSS adds support for layout constraints. These allow designers to describe the layout of aweb page in a more flexible manner. Cassowary is used to solve these constraints and calculate the final layout.Smalltalk ,C++ and Java versions are available in the main distribution. Furthermore, there are bindings forGNU Guile ,STk and Python.Other people have ported the solver to
Squeak and the.NET framework (Cassowary.net).Cassowary is used by
Scwm , the Scheme Constraints Window Manager.External links
* [http://www.cs.washington.edu/research/constraints/cassowary/ project page at the University of Washington]
* [http://jozilla.net/software/cassowary_net Cassowary.net]
Wikimedia Foundation. 2010.