class myToolbar:

  def __init__(self, iface, toolBar):
    # References to QGIS interface
    self.iface = iface
    self.canvas = iface.mapCanvas()

    # Actions
    self.addFeatureAction = QAction(QIcon(
      ":/myPlugin/images/icon.png"),
      u"Add nodes or edges",
      self.iface.mainWindow())
    self.addFeatureAction.setWhatsThis(u"MyPlugin: Add nodes or edges")
    self.addFeatureAction.setStatusTip(u"MyPlugin: Add nodes or edges")

    # Set checkable
    self.addFeatureAction.setCheckable(True)

    # Disable tools
    self.addFeatureAction.setEnabled(False)

    # Connect signals
    self.addFeatureAction.triggered.connect(self.newFeatureRun)

    # Add action to toolBar
    toolBar.addAction(self.anadirFeatureAction)

    # Create tools
    self.newFeatureTool = addFeaturesTool(self.iface)
    self.newFeatureTool.setAction(self.addFeatureAction)

    # Store previous tool
    self.previousTool = self.canvas.mapTool()

    # Activate tools on layer change
    QObject.connect(self.iface,  SIGNAL("currentLayerChanged(QgsMapLayer*)"), self.onCurrentLayerChanged)
    QObject.connect(self.iface.mapCanvas(), SIGNAL("layersChanged()"), self.onCurrentLayerChanged)

  def onCurrentLayerChanged(self):
    try:
      layer = self.canvas.currentLayer()

      if layer == None or layer.type() != QgsMapLayer.VectorLayer
        or not self.iface.legendInterface().isLayerVisible(layer):
          self.addFeatureAction.setEnabled(False)
          return

      # Activate according geometry
      if layer.geometryType() == QGis.Point:
        if layer.customProperty("customEditable"):
          self.addFeatureAction.setEnabled(True)
        else:
          self.addFeatureAction.setEnabled(False)
      elif layer.geometryType() == QGis.Line:
        if layer.customProperty("customEditable"):
          self.addFeatureAction.setEnabled(True)
        else:
          self.addFeatureAction.setEnabled(False)
      else:
        self.addFeatureAction.setEnabled(False)
    except Exception as e:
      QgsMessageLog.logMessage( "ERROR onCurrentLayerChanged: {0}".format(e), "issueLayers", 2)

  def newFeatureRun(self):
    if self.addFeatureAction.isChecked():
      # Save last tool and select new one
      self.previousTool = self.canvas.mapTool()
      self.canvas.setMapTool(self.newFeatureTool)
    else:
      tmpTool = self.canvas.mapTool()
      self.canvas.setMapTool(self.previousTool)

class addFeaturesTool(QgsMapTool):

  def __init__(self, iface):

    QgsMapTool.__init__(self, iface.mapCanvas())

    self.iface = iface
    self.canvas = iface.mapCanvas()

    self.layer = None

    self.previousNode = QgsPoint(0,0)
    self.nextNode = QgsPoint(0,0)

    # Rubberband
    self.rubber = QgsRubberBand(self.canvas,  False)

    # Lists to store initial and end nodes
    self.capturedNodes = []
    self.markers = []

    self.cursor = QCursor(QPixmap(["16 16 3 1",
                                  "      c None",
                                  ".     c #FF0000",
                                  "+     c #FFFFFF",
                                  "                ",
                                  "       +.+      ",
                                  "      ++.++     ",
                                  "     +.....+    ",
                                  "    +.     .+   ",
                                  "   +.   .   .+  ",
                                  "  +.    .    .+ ",
                                  " ++.    .    .++",
                                  " ... ...+... ...",
                                  " ++.    .    .++",
                                  "  +.    .    .+ ",
                                  "   +.   .   .+  ",
                                  "   ++.     .+   ",
                                  "    ++.....+    ",
                                  "      ++.++     ",
                                  "       +.+      "]))


  def canvasPressEvent(self,event):
    pass

  def canvasMoveEvent(self,event):
    ptCursor = self.toMapCoordinates(event.pos())

    self.rubber.movePoint(ptCursor)
    pass

  def canvasReleaseEvent(self,event):
    if event.button() == Qt.LeftButton:
      coordinates = self.toMapCoordinates(event.pos())
      if self.layer.geometryType() == QGis.Point:
        self.addNode( coordinates )
      elif self.layer.geometryType() == QGis.Line:
        self.addEdgeExtrem( coordenadas )
    else:
      self.resetCaptura()
    pass

  def activate(self):
    self.layer = self.canvas.currentLayer()

    caps = self.layer.dataProvider().capabilities()
    if not caps & QgsVectorDataProvider.AddFeatures:
      QMessageBox.critical(None, "MyPlugin",
        u"Layer provider does not allow to add new elements")
      return

    QgsMapTool.activate(self)
    self.canvas.setCursor(self.cursor)

  def deactivate(self):
    self.resetCapture()
    QgsMapTool.deactivate(self)

  def resetCapture(self):
    self.capturedNodes = []

    self.rubber.reset(False)

    for mItem in self.markers:
      self.canvas.scene().removeItem(mItem)
      del mItem

  def isZoomTool(self):
    return False

  def isTransient(self):
    return False

  def isEditTool(self):
    return True

  def addNode(self, coord):
    # Adds node

  def saveNode(self, point):
    # Saves node to layer

  def addEdgeExtrem(self, coord):
    # Add extrems to edge

  def addEdge(self, previousNode, currentNode):
    # adds new edge