gaphas/tests/test_canvas.py

import cairo
import pytest

from gaphas.canvas import Canvas, ConnectionError
from gaphas.examples import Box
from gaphas.item import Line


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

    i.matrix = (1.0, 0.0, 0.0, 1.0, 5.0, 0.0)
    ii.matrix = (1.0, 0.0, 0.0, 1.0, 0.0, 8.0)

    updated = c.update_matrices([i])

    assert i._matrix_i2c == cairo.Matrix(1, 0, 0, 1, 5, 0)
    assert ii._matrix_i2c == cairo.Matrix(1, 0, 0, 1, 5, 8)


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


# fixme: what about multiple constraints for a handle?
#        what about 1d projection?


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


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

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

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


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

    events = []

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

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

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


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

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

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

    ncons = len(c.solver.constraints)
    assert ncons == 5

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

    assert len(c.solver.constraints) == 4


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

    events = []

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

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

    c.remove(b1)

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


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

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

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

    ncons = len(c.solver.constraints)
    assert ncons == 5

    c.remove(b1)

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

    assert 2 == len(c.solver.constraints)


def test_line_projection():
    """Test projection with line's handle on element's side.

    """
    line = Line()
    line.matrix.translate(15, 50)
    h1, h2 = line.handles()
    h1.pos = (0, 0)
    h2.pos = (20, 20)

    box = Box()
    box.matrix.translate(10, 10)
    box.width = 40
    box.height = 20

    canvas = Canvas()
    canvas.add(line)
    canvas.add(box)

    # move line's second handle on box side
    h2.pos = (5, -20)


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

    """
    canvas = Canvas()

    from gaphas.aspect import Connector, ConnectionSink

    l1 = Line()
    canvas.add(l1)

    b1 = Box()
    canvas.add(b1)

    number_cons1 = len(canvas.solver.constraints)

    b2 = Box()
    canvas.add(b2)

    number_cons2 = len(canvas.solver.constraints)

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

    conn.connect(sink)

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

    conn = Connector(l1, l1.handles()[1])
    sink = ConnectionSink(b2, b2.ports()[0])

    conn.connect(sink)

    assert canvas.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)