Application: gvSIG desktop » gvSIG scripting

from gvsig import currentLayer

from geom import POINT, LINE, POLYGON

from commonsdialog import msgbox

def main():

  """

  Modify layer data definition and adds new fields to store features geometry 

  information.

  If is points layer type adds 'X' 'Y' and 'Z' coordinates

  If is lines layer type adds perimeter value

  IF is polygons layer adds Area and perimeter values

  """

  #

  #Invoke gvsig.currentLayer function to get active layer

  #If not view or active layer in view raise RuntimeException

  layer = gvsig.currentLayer()

  # Gets layer type. If layer type is not supported shows a message, else 

  # adds geometry information to features

  layertype = layer.getTypeVectorLayer()

  if layertype.isSubTypeOf(POINT):

      addInfoToPoint(layer)

  elif layertype.isSubTypeOf(LINE):

      addInfoToLine(layer)

  elif layertype.isSubTypeOf(POLYGON):

      addInfoToPolygon(layer)

  else:

      text = """This layer is not supported. 

      Layer type must be:

        - Points

        - Line

        - Polygon

      Finish script."""

      title = "Warning",

      messageType = commonsdialog.FORBIDEN

      commonsdialog.msgbox(text ,

        title,

        messageType

      )

def addToPoint(layer):

  layer.edit()

  schema = layer.getSchema()

  xName=generateUniqColumnName(schema,"X")

  schema.append(xName, "Double", size=15, precision = 3)

  yName=generateUniqColumnName(schema,"Y")

  schema.append(yName, "Double", size=15, precision = 3)

  zName=generateUniqColumnName(schema,"Z")

  schema.append(zName, "Double", size=15, precision = 3)

  layer.updateSchema(schema)

  for feature in layer.features():

    feature.edit()

    point = feature.geometry()

    feature.set(xName,point.getX())

    feature.set(yName,point.getY())

    if point.getDimension()>2:

      feature.set(zName,point.getCoordinateAt(2))

    layer.update(feature)

  layer.commit() 

def addInfoToPolygon(layer):

  layer.edit()

  schema = layer.getSchema()

  areaName=generateUniqColumnName(schema,"Area")

  schema.append(areaName, "Double", size=15, precision = 3)

  perimeterName=generateUniqColumnName(schema,"Perimeter")

  schema.append(perimeterName, "Double", size=15, precision = 3)

  layer.updateSchema(schema)

  for feature in layer.features():

    feature.edit()

    polygon = feature.geometry()

    feature.set(areaName,polygon.area())

    feature.set(perimeterName,polygon.perimeter())

    layer.update(feature)

def addInfoToLine(layer):

  layer.edit()

  schema = layer.getSchema()

  perimeterName=generateUniqColumnName(schema,"Perimeter")

  schema.append(perimeterName, "Double", size=15, precision = 3)

  layer.updateSchema(schema)

  for feature in layer.features():

    feature.edit()

    line = feature.geometry()

    feature.set(perimeterName,line.perimeter())

    layer.update(feature)

  layer.commit() 

def generateUniqColumnName(schema, name):

   cont = 1

   name2 = name

   while True:

     attr = schema.get(name2)

     if attr == None:

       return name2

     cont += 1

     name2 = "%s%s" % (name , cont)