def __init__(self, parent=None):
super(ControlPointGraphicsItem, self).__init__(parent)
self.underlying_ellipse_item = QGraphicsEllipseItem()
self.underlying_ellipse_item.setRect(-POINT_SIZE_2, -POINT_SIZE_2, POINT_SIZE, POINT_SIZE)
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self._x = 0
self.curve_item = None
self.connectors = list()
class ControlPointGraphicsItem(QGraphicsWidget):
"""
This item represents a point on a scene
"""
position_changed = Signal(name="position_changed")
def __init__(self, parent=None):
super(ControlPointGraphicsItem, self).__init__(parent)
self.underlying_ellipse_item = QGraphicsEllipseItem()
self.underlying_ellipse_item.setRect(-POINT_SIZE_2, -POINT_SIZE_2, POINT_SIZE, POINT_SIZE)
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self._x = 0
self.curve_item = None
self.connectors = list()
def set_x(self, value):
"""
The x position could only be changed in the case
interval [x_0, x_1] changed or degree of polynomial
was changed
"""
self._x = value
self.setPos(self._x, self.pos().y())
def get_x(self):
return self._x
def mouseMoveEvent(self, event):
assert isinstance(event, QGraphicsSceneMouseEvent)
if event.scenePos().y() < MAX_LINE_Y:
self.setPos(self._x, MAX_LINE_Y)
elif event.scenePos().y() > MIN_LINE_Y:
self.setPos(self._x, MIN_LINE_Y)
else:
self.setPos(self._x, event.scenePos().y())
x = property(get_x, set_x)
def itemChange(self, change, value):
if change == QGraphicsItem.ItemPositionHasChanged:
for connector in self.connectors:
connector.update_position()
if self.curve_item:
self.curve_item.update_position()
self.position_changed.emit()
return super(ControlPointGraphicsItem, self).itemChange(change, value)
def remove_connector(self, connector):
from connector import Connector
assert isinstance(connector, Connector)
self.connectors.remove(connector)
def remove_connectors(self):
for connector in self.connectors:
connector.start_item.remove_connector(connector)
connector.end_item.remove_connector(connector)
self.scene().removeItem(connector)
def add_connector(self, connector):
self.connectors.append(connector)
def add_curve(self, curve_item):
self.curve_item = curve_item
def paint(self, painter, option, widget=None):
assert isinstance(painter, QPainter)
self.underlying_ellipse_item.paint(painter, option, widget)
def boundingRect(self):
return self.underlying_ellipse_item.boundingRect()
def shape(self):
return self.underlying_ellipse_item.shape()