--- a/python/apps/diagrameditor.py	Sat Nov 10 11:53:55 2012 +0100
+++ b/python/apps/diagrameditor.py	Sun Nov 11 10:49:46 2012 +0100
@@ -19,12 +19,19 @@
       path.lineTo(pt)
    return path
 
+def equalSpace(n, l):
+   offset = 15
+   if n == 1:
+      return [l / 2]
+   elif n > 1:
+      return [offset + (l - offset*2)/(n - 1)*i for i in range(n)]
+   return []
+
 class Connection(QGraphicsPathItem):
    """ Implementation of a connection between blocks """
    def __init__(self, fromPort, toPort):
       super(Connection, self).__init__()
-      self.pos1, self.pos2 = None, None
-      self.fromPort, self.toPort = None, None
+      self.pos2 = self.fromPort = self.toPort = None
       self.setFlag(self.ItemIsSelectable, True)
       self.setFlag(self.ItemClipsToShape, True)
       pen = QPen(Qt.blue, 2)
@@ -39,7 +46,7 @@
       self.setToPort(toPort)
    def mouseDoubleClickEvent(self, event):
       pos = event.scenePos()
-      pts = [self.pos1] + [v.pos() for v in self.vias] + [self.pos2]
+      pts = [self.getPos1()] + [v.pos() for v in self.vias] + [self.pos2]
       idx = 0
       tidx = 0
       for p1, p2 in zip(pts[0:-1], pts[1:]):
@@ -70,7 +77,6 @@
          self.setFromPort(None)
          self.setToPort(None)
          scene.removeItem(self)
-      
    def setFromPort(self, fromPort):
       if self.fromPort:
          self.fromPort.posCallbacks.remove(self.setBeginPos)
@@ -78,7 +84,7 @@
       self.fromPort = fromPort
       if self.fromPort:
          self.fromPort.connection = self
-         self.setBeginPos(fromPort.scenePos())
+         self.updateLineStukken()
          self.fromPort.posCallbacks.append(self.setBeginPos)
    def setToPort(self, toPort):
       if self.toPort:
@@ -89,8 +95,10 @@
          self.setEndPos(toPort.scenePos())
          self.toPort.connection = self
          self.toPort.posCallbacks.append(self.setEndPos)
+   def getPos1(self):
+      if self.fromPort:
+         return self.fromPort.scenePos()
    def setBeginPos(self, pos1):
-      self.pos1 = pos1
       self.updateLineStukken()
    def setEndPos(self, endpos):
       self.pos2 = endpos
@@ -107,9 +115,10 @@
          This algorithm determines the optimal routing of all signals.
          TODO: implement nice automatic line router
       """
-      if self.pos1 is None or self.pos2 is None:
+      pos1 = self.getPos1()
+      if pos1 is None or self.pos2 is None:
          return
-      pts = [self.pos1] + [v.pos() for v in self.vias] + [self.pos2]
+      pts = [pos1] + [v.pos() for v in self.vias] + [self.pos2]
       self.arrowhead.setPos(self.pos2)
       if pts[-1].x() < pts[-2].x():
          self.arrowhead.setRotation(-90)
@@ -164,7 +173,6 @@
       pen = QPen(Qt.blue, 2)
       pen.setCapStyle(Qt.RoundCap)
       self.setPen(pen)
-      self.name = name
       self.textItem = QGraphicsTextItem(name, self)
       self.setName(name)
       self.posCallbacks = []
@@ -209,9 +217,6 @@
       """ Move function without moving the other selected elements """
       p = self.mapToParent(event.pos())
       self.setPos(p)
-   def mySetPos(self, p):
-      # TODO: use this instead of itemChange?
-      self.setPos(p)
    def itemChange(self, change, value):
       if change == self.ItemPositionChange:
          for cb in self.posChangeCallbacks:
@@ -264,12 +269,11 @@
       self.buttonItemAddOutput = QGraphicsProxyWidget(self)
       self.buttonItemAddOutput.setWidget(button)
       self.buttonItemAddOutput.setVisible(False)
-
       # Inputs and outputs of the block:
       self.inputs = []
       self.outputs = []
       # Update size:
-      self.sizer.mySetPos(QPointF(60, 40)) # This is a better resize function
+      self.sizer.setPos(QPointF(60, 40)) # This is a better resize function
    def editParameters(self):
       pd = ParameterDialog(self, self.window())
       pd.exec_()
@@ -290,7 +294,6 @@
    def addOutput(self, o):
       self.outputs.append(o)
       self.updateSize()
-
    def contextMenuEvent(self, event):
       menu = QMenu()
       pa = menu.addAction('Parameters')
@@ -302,54 +305,27 @@
             child.setVisible(value)
       return super(BlockItem, self).itemChange(change, value)
    def myDelete(self):
-         # TODO: move the below to blockitem:
          scene = self.scene()
          if scene:
             for p in self.inputs + self.outputs:
                if p.connection:
                   p.connection.myDelete()
             scene.removeItem(self)
-
    def updateSize(self):
       rect = self.rect()
       h, w = rect.height(), rect.width()
       self.buttonItemAddInput.setPos(0, h + 4)
       self.buttonItemAddOutput.setPos(w+10, h+4)
-      for inp in self.inputs:
-         inp.setX(0.0)
-      for inp in self.outputs:
-         inp.setX(w)
-      if len(self.inputs) == 1:
-         self.inputs[0].setPos(0.0, h / 2)
-      elif len(self.inputs) > 1:
-         y = 15
-         dy = (h - 30) / (len(self.inputs) - 1)
-         for inp in self.inputs:
-            inp.setPos(0.0, y)
-            y += dy
-      if len(self.outputs) == 1:
-         self.outputs[0].setPos(w, h / 2)
-      elif len(self.outputs) > 1:
-         y = 15
-         dy = (h - 30) / (len(self.outputs) - 1)
-         for outp in self.outputs:
-            outp.setPos(w, y)
-            y += dy
-      
+      for inp, y in zip(self.inputs, equalSpace(len(self.inputs), h)):
+         inp.setPos(0.0, y)
+      for outp, y in zip(self.outputs, equalSpace(len(self.outputs), h)):
+         outp.setPos(w, y)
    def changeSize(self, p):
-      """ Resize block function """
-      w, h = p.x(), p.y()
-      # Limit the block size:
-      h = 20 if h < 20 else h
-      w = 40 if w < 40 else w
+      h = 20 if p.y() < 20 else p.y()
+      w = 40 if p.x() < 40 else p.x()
       self.setRect(0.0, 0.0, w, h)
-      # center label:
       rect = self.label.boundingRect()
-      lw, lh = rect.width(), rect.height()
-      lx = (w - lw) / 2
-      ly = (h - lh) / 2
-      self.label.setPos(lx, ly)
-      # Update port positions:
+      self.label.setPos((w - rect.width()) / 2, (h - rect.height()) / 2)
       self.updateSize()
       return QPointF(w, h)
 
@@ -377,7 +353,6 @@
    def test(self):
       self.rotate(30)
       self.zoomAll()
-
    def wheelEvent(self, event):
       pos = event.pos()
       posbefore = self.mapToScene(pos)
@@ -415,12 +390,10 @@
    def __init__(self, parent=None):
       super(DiagramScene, self).__init__(parent)
       self.startedConnection = None
-
    def saveDiagram(self, filename):
       items = self.items()
       blocks = [item for item in items if type(item) is BlockItem]
       connections = [item for item in items if type(item) is Connection]
-
       doc = md.Document()
       modelElement = doc.createElement('system')
       doc.appendChild(modelElement)
@@ -540,12 +513,12 @@
       super(DiagramScene, self).mouseMoveEvent(event)
    def mouseReleaseEvent(self, event):
       if self.startedConnection:
-         items = self.items(event.scenePos())
-         for item in items:
+         for item in self.items(event.scenePos()):
             if type(item) is PortItem:
-               self.startedConnection.setToPort(item)
-               self.startedConnection = None
-               return
+               if item.direction == 'input' and item.connection == None:
+                  self.startedConnection.setToPort(item)
+                  self.startedConnection = None
+                  return
          self.startedConnection.myDelete()
          self.startedConnection = None
       super(DiagramScene, self).mouseReleaseEvent(event)
@@ -555,7 +528,6 @@
       self.startedConnection.setEndPos(pos)
       self.addItem(self.startedConnection)
    def deleteItems(self):
-      # Try to delete all currently selected items:
       for item in list(self.selectedItems()):
          item.myDelete()
 
@@ -600,14 +572,11 @@
       act('Load', QKeySequence.Open, self.editor.load)
       act('Full screen', QKeySequence("F11"), self.toggleFullScreen)
       act('Fit in view', QKeySequence("F8"), self.editor.zoomAll)
-
       self.library = LibraryWidget() 
       libraryDock = QDockWidget('Library', self)
       libraryDock.setWidget(self.library)
       self.addDockWidget(Qt.LeftDockWidgetArea, libraryDock)
-
       self.editor.loadDiagram('diagram2.usd')
-
    def toggleFullScreen(self):
       self.setWindowState(self.windowState() ^ Qt.WindowFullScreen)
       self.editor.zoomAll()
@@ -616,7 +585,6 @@
    if sys.version_info.major != 3:
       print('Please use python 3.x')
       sys.exit(1)
-
    app = QApplication(sys.argv)
    main = Main()
    main.show()