def test_projection_updates_when_matrix_is_changed(solver):
pos = Position(0, 0)
matrix = Matrix()
proj = MatrixProjection(pos, matrix)
solver.add_constraint(proj)
solver.solve()
matrix.translate(2, 3)
solver.solve()
assert proj.x == 2
assert proj.y == 3
def on_adjustment_changed(self, adj):
"""Change the transformation matrix of the view to reflect the value of
the x/y adjustment (scrollbar)."""
value = adj.get_value()
if value == 0.0:
return
m = Matrix()
if adj is self.hadjustment:
m.translate(self._last_hvalue - value, 0)
self._last_hvalue = value
elif adj is self.vadjustment:
m.translate(0, self._last_vvalue - value)
self._last_vvalue = value
self._scrolling_updated(m)
