Reference

Variables

class cassowary.Variable

Variable.value

The current value of the variable. If the variable is part of a constraint, the value will be updated as constraints are applied and changed.

Variable.__init__(name, value=0.0)

Define a new variable. Value is optional, but will affect the constraint solving process if multiple solutions are possible.

Solvers

class cassowary.SimplexSolver

A class for collecting constraints into a system and solving them.

SimplexSolver.add_constraint(constraint, strength=REQUIRED, weight=1.0)

Add a new constraint to the solver system. A constraint is a mathematical expression involving 1 or more variables, and an equality or inequality.

strength is optional; by default, all constraints are added as REQUIRED constraints.

weight is optional; by default, all constraints have an equal weight of 1.0.

Returns the constraint that was added.

SimplexSolver.remove_constraint(var)

Remove a new constraint to the solver system.

Returns the constraint that was added.

SimplexSolver.add_stay(var, strength=REQUIRED, weight=1.0)

Add a stay constraint to the solver system for the current value of the variable var.

strength is optional; by default, all constraints are added as REQUIRED constraints.

weight is optional; by default, all constraints have an equal weight of 1.0.

Returns the constraint that was added.

SimplexSolver.add_edit_var(var)

Mark a variable as being an edit variable. This allows you to suggest values for the variable once you start an edit context.

SimplexSolver.remove_edit_var(var)

Remove the variable from the list of edit variables.

SimplexSolver.edit()

Returns a context manager that can be used to manage the edit process.

SimplexSolver.suggest_value(var, value)

Suggest a new value for a edit variable.

This method can only be invoked while inside an edit context. var must be a variable that has been identified as an edit variable in the current edit context.

SimplexSolver.resolve()

Force a solver system to resolve any ambiguities. Useful when introducing edit constraints.