gaphas/tests/test_canvas.py

import pytest

from gaphas.canvas import Canvas
from gaphas.connections import ConnectionError
from gaphas.connector import ConnectionSink, Connector
from gaphas.item import Element as Box
from gaphas.item import Line
from gaphas.matrix import Matrix
from gaphas.model import Model


def test_canvas_is_a_view_model(canvas):
    assert isinstance(canvas, Model)


def test_update_matrices():
    """Test updating of matrices."""
    c = Canvas()
    i = Box(c.connections)
    ii = Box(c.connections)
    c.add(i)
    c.add(ii, i)

    i.matrix.translate(5.0, 0.0)
    ii.matrix.translate(0.0, 8.0)

    assert c.get_matrix_i2c(i) == Matrix(1, 0, 0, 1, 5, 0)
    assert c.get_matrix_i2c(ii) == Matrix(1, 0, 0, 1, 5, 8)


def test_reparent():
    c = Canvas()
    b1 = Box(c.connections)
    b2 = Box(c.connections)
    c.add(b1)
    c.add(b2, b1)
    c.reparent(b2, None)


def count(i):
    return len(list(i))


def test_connect_item():
    c = Canvas()
    b1 = Box(c.connections)
    b2 = Box(c.connections)
    line = Line(c.connections)
    c.add(b1)
    c.add(b2)
    c.add(line)

    c.connections.connect_item(line, line.handles()[0], b1, b1.ports()[0])
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 1

    # Add the same
    with pytest.raises(ConnectionError):
        c.connections.connect_item(line, line.handles()[0], b1, b1.ports()[0])
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 1


def test_disconnect_item_with_callback():
    c = Canvas()
    b1 = Box(c.connections)
    b2 = Box(c.connections)
    line = Line(c.connections)
    c.add(b1)
    c.add(b2)
    c.add(line)

    events = []

    def callback(*args):
        events.append("called")

    c.connections.connect_item(
        line, line.handles()[0], b1, b1.ports()[0], callback=callback
    )
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 1

    c.connections.disconnect_item(line, line.handles()[0])
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 0
    assert events == ["called"]


def test_disconnect_item_with_constraint():
    c = Canvas()
    b1 = Box(c.connections)
    b2 = Box(c.connections)
    line = Line(c.connections)
    c.add(b1)
    c.add(b2)
    c.add(line)

    cons = b1.ports()[0].constraint(line, line.handles()[0], b1)

    c.connections.connect_item(
        line, line.handles()[0], b1, b1.ports()[0], constraint=cons
    )
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 1

    assert len(c.solver.constraints) == 13

    c.connections.disconnect_item(line, line.handles()[0])
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 0

    assert len(c.solver.constraints) == 12


def test_disconnect_item_by_deleting_element():
    c = Canvas()
    b1 = Box(c.connections)
    b2 = Box(c.connections)
    line = Line(c.connections)
    c.add(b1)
    c.add(b2)
    c.add(line)

    events = []

    def callback(*args):
        events.append("called")

    c.connections.connect_item(
        line, line.handles()[0], b1, b1.ports()[0], callback=callback
    )
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 1

    c.remove(b1)

    assert count(c.connections.get_connections(handle=line.handles()[0])) == 0
    assert events == ["called"]


def test_disconnect_item_with_constraint_by_deleting_element():
    c = Canvas()
    b1 = Box(c.connections)
    b2 = Box(c.connections)
    line = Line(c.connections)
    c.add(b1)
    c.add(b2)
    c.add(line)

    cons = b1.ports()[0].constraint(line, line.handles()[0], b1)

    c.connections.connect_item(
        line, line.handles()[0], b1, b1.ports()[0], constraint=cons
    )
    assert count(c.connections.get_connections(handle=line.handles()[0])) == 1

    ncons = len(c.solver.constraints)
    assert ncons == 13

    c.remove(b1)

    assert count(c.connections.get_connections(handle=line.handles()[0])) == 0

    assert 6 == len(c.solver.constraints)


def test_remove_connected_item():
    """Test adding canvas constraint."""
    canvas = Canvas()

    l1 = Line(canvas.connections)
    canvas.add(l1)

    b1 = Box(canvas.connections)
    canvas.add(b1)

    number_cons1 = len(canvas.solver.constraints)

    b2 = Box(canvas.connections)
    canvas.add(b2)

    number_cons2 = len(canvas.solver.constraints)

    conn = Connector(l1, l1.handles()[0], canvas.connections)
    sink = ConnectionSink(b1)

    conn.connect(sink)

    assert canvas.connections.get_connection(l1.handles()[0])

    conn = Connector(l1, l1.handles()[1], canvas.connections)
    sink = ConnectionSink(b2)

    conn.connect(sink)

    assert canvas.connections.get_connection(l1.handles()[1])

    assert number_cons2 + 2 == len(canvas.solver.constraints)

    canvas.remove(b1)

    # Expecting a class + line connected at one end only
    assert number_cons1 + 1 == len(canvas.solver.constraints)