Attached is a patch to draw connections more pretty. Screenshot here:
<http://unununium.org/~indigo/fancy_nova_connections.png>
I realize some people may prefer straight or right-angled lines; I think
those can be implemented after there is some sort of preferences system
in place (something I'll probably tackle in the future)
=== modified file 'source/pyqt_gui/pyqt_patcher_xlets.py'
--- source/pyqt_gui/pyqt_patcher_xlets.py 2007-09-12 10:19:01 +0000
+++ source/pyqt_gui/pyqt_patcher_xlets.py 2007-09-24 01:04:36 +0000
@@ -24,27 +24,85 @@
# $LastChangedDate$
# $LastChangedBy$
+from __future__ import division
+
+from math import log
import py_nova
import PyQt4.QtCore as QtCore
import PyQt4.QtGui as QtGui
-class connection_line(QtGui.QGraphicsLineItem):
+class connection_line(QtGui.QGraphicsPathItem):
+ width = 4
+ inner_color = QtGui.QColor(0x9a89c2)
+ outer_color = QtGui.QColor(0x38128d)
+
def __init__(self, connection):
self.connection = connection
- if connection:
- QtGui.QGraphicsLineItem.__init__(self, None,
connection.canvas.scene)
+ assert connection, 'can not create a connection_line without a
connection'
+ QtGui.QGraphicsPathItem.__init__(self, None, connection.canvas.scene)
- pen = QtGui.QPen((QtCore.Qt.white))
- pen.setWidth(2)
+ pen = QtGui.QPen(self.outer_color)
+ pen.setWidth(self.width)
+ pen.setCapStyle(QtCore.Qt.RoundCap)
self.setPen(pen)
self.setAcceptedMouseButtons(QtCore.Qt.RightButton)
+ self.child_line = QtGui.QGraphicsPathItem(self)
+ pen.setWidth(self.width-2)
+ pen.setColor(self.inner_color)
+ self.child_line.setPen(pen)
+
def mousePressEvent (self, event):
if self.connection.canvas.edit:
if event.button() == QtCore.Qt.RightButton and event.modifiers()
== QtCore.Qt.ShiftModifier:
self.connection.schedule_removal()
+ def update_endpoints (self, start, end):
+ path = QtGui.QPainterPath(start)
+
+ # how much connections want to point away from their xlets. When the
+ # vertical distance between outlet and inlet are less than this, the
+ # connection will begin to "double back" on itself; ie, bend such that
+ # it can be intersected twice with a horizonal line.
+
+ # there are two factors that affect stiffness; when the boxes are not
+ # very far apart horizontally, it makes sense to reduce the stiffness.
+ # This prevents the connection from making a sharp Z when two xlets are
+ # aligned vertically, and very near each other.
+
+ # the other factor involves connections that go from a low outlet to a
+ # higher inlet. As the vertical difference becomes greater, we need a
+ # higher stiffness to compensate for the greater "pull" on the
+ # connection.
+ stiffness = max(
+ min(abs(start.x() - end.x()) / 2, 100),
+ log(max(start.y() - end.y(), 0.001)) * 30
+ )
+
+ if end.y() - start.y() < stiffness:
+ c1_y = start.y() + stiffness / 2
+ c2_y = end.y() - stiffness / 2
+ else:
+ c1_y = c2_y = start.y() + (end.y() - start.y()) / 2
+
+ # x_offset moves the two control points to the left. This is done when
+ # going from a low outlet to high inlet and the horizontal difference
+ # between them is not very large, to avoid a straight vertical line.
+ if abs(start.x() - end.x()) < 20 and end.y() < start.y():
+ x_offset = 20 - abs(start.x() - end.x())
+ else:
+ x_offset = 0
+
+ path.cubicTo(
+ start.x()-x_offset, c1_y,
+ end.x()-x_offset, c2_y,
+ end.x(), end.y())
+
+ for l in [self, self.child_line]:
+ l.setPath(path)
+ self.update()
+
class Connection(py_nova.connection_wrapper):
def __init__(self, canvas):
@@ -87,8 +145,7 @@
mapped_outlet_coord = outlet.mapToScene(outlet_coord)
mapped_inlet_coord = inlet.mapToScene(inlet_coord)
- self.line.setLine(QtCore.QLineF(mapped_outlet_coord,
mapped_inlet_coord))
- self.line.update()
+ self.line.update_endpoints(mapped_outlet_coord, mapped_inlet_coord)
def hide(self):
self.line = None
_______________________________________________
nova-dev mailing list
[email protected]
http://klingt.org/cgi-bin/mailman/listinfo/nova-dev
http://tim.klingt.org/nova
