def constraint(self, item: Item, handle: Handle,
glue_item: Item) -> MultiConstraint:
"""Return connection position constraint between item's handle and the
port."""
origin = MatrixProjection(self.point, glue_item.matrix_i2c)
point = MatrixProjection(handle.pos, item.matrix_i2c)
c = PositionConstraint(origin.pos, point.pos)
return MultiConstraint(origin, point, c)
def constraint(self, item: Item, handle: Handle,
glue_item: Item) -> Constraint:
"""Create connection line constraint between item's handle and the
port."""
start = MatrixProjection(self.start, glue_item.matrix_i2c)
end = MatrixProjection(self.end, glue_item.matrix_i2c)
point = MatrixProjection(handle.pos, item.matrix_i2c)
line = LineConstraint((start.pos, end.pos), point.pos)
return MultiConstraint(start, end, point, line)
def test_original_updates_when_projection_is_changed(solver, position, matrix,
result):
pos = Position(0, 0)
proj = MatrixProjection(pos, matrix)
solver.add_constraint(proj)
solver.solve()
proj.x, proj.y = position
solver.solve()
assert pos.x == result[0]
assert pos.y == result[1]
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 constraint(self, item, handle, glue_item):
"""Create connection line constraint between item's handle and the
port."""
start = MatrixProjection(self.start, glue_item.matrix_i2c)
end = MatrixProjection(self.end, glue_item.matrix_i2c)
point = MatrixProjection(handle.pos, item.matrix_i2c)
x, y = item.matrix_i2c.transform_point(*handle.pos)
x, y = glue_item.matrix_i2c.inverse().transform_point(x, y)
# keep message at the same distance from head or bottom of lifetime
# line depending on situation
height = self.end.y - self.start.y
if y / height < 0.5:
delta = y - self.start.y
align = 0
else:
delta = y - self.end.y
align = 1
line = LineAlignConstraint((start, end), point, align, delta)
return MultiConstraint(start, end, point, line)
def test_matrix_projection_sets_handlers_just_in_time():
pos = Position(0, 0)
matrix = Matrix()
proj = MatrixProjection(pos, matrix)
def handler(c):
pass
assert not matrix._handlers
assert not pos.x._handlers
assert not pos.y._handlers
proj.add_handler(handler)
assert matrix._handlers
assert pos.x._handlers
assert pos.y._handlers
proj.remove_handler(handler)
assert not matrix._handlers
assert not pos.x._handlers
assert not pos.y._handlers
def test_matrix_projection_exposes_variables():
proj = MatrixProjection(Position(0, 0), Matrix())
assert isinstance(proj.x, Variable)
assert isinstance(proj.y, Variable)