Commit Graph

3 Commits

Author SHA1 Message Date
Emmanuele Bassi
4dd1de4129 Use explicit values for constraint strength
Instead of playing games with mapping negative symbolic values to
positive ones, let's use the appropriate constants everywhere. This
allows us to use:

        GTK_CONSTRAINT_STRENGTH_WEAK * 2

Or

        GTK_CONSTRAINT_STRENGTH_STRONG + 1

In code using the public API.

We also store the strength values as integers, so we can compare them
properly, and only turn them into doubles when they are inserted into
the solver, just like every other variable.
2019-07-01 12:39:24 +01:00
Matthias Clasen
2f97134a08 Amend a constraint solver test
Make the 'repeat edit' test make more than to
suggestions in a single edit phase. It turns out
that this does not work, whereas just doing
two in a row does.
2019-07-01 00:10:11 +01:00
Emmanuele Bassi
6b308cd71e Add constraint solver
GtkConstraintSolver is an implementation of the Cassowary constraint
solving algorithm:

  http://constraints.cs.washington.edu/cassowary/

The Cassowary method allows to incrementally solve a tableau of linear
equations, in the form of:

  x = y × coefficient + constant

with different weights, or strengths, applied to each one.

These equations can be used to describe constraints applied to a layout
of UI elements, which allows layout managers using the Cassowary method
to quickly, and efficiently, lay out widgets in complex relations
between themselves and their parent container.
2019-06-30 23:42:44 +01:00