topic Re: How can I write a python add-in which zooms to each selected polygon after each button click? in Python Questions

How can I write a python add-in which zooms to each selected polygon after each button click?

RobertBuckley1 — Thu, 02 Jul 2015 18:25:42 GMT

I want to have a button in a toolbar which when clicked, zooms to the extent of the next selected polygon. I am not sure whether this tool has been developed yet (although i´m sure it has) and do not know whether it should be a python button, or tool class.

Following code creates a list of selected elements. I want to go to the next row after each mouse click.

mxd = arcpy.mapping.MapDocument('CURRENT')

df = arcpy.mapping.ListDataFrames(mxd, "Layers") [0]

Envelopes = [] # store extents here

# find the selection set

SelLayer = arcpy.mapping.ListLayers(mxd,data_frame=df)[0] # first layer

fidSet = arcpy.Describe(SelLayer).FIDSet

if len(fidSet) == 0:

arcpy.AddMessage("Nothing selected")

else:

# now cursor through it an get the geometries

# storing their extents into a list

with arcpy.da.SearchCursor(SelLayer,"SHAPE@") as SCur:

for feat in SCur:

# I'm going to assume polygon/polyline

Envelopes.append(feat[0].extent) # grab the envelope

df.extent = Envelopes[0] # first extent

arcpy.RefreshActiveView()

The code creates the list, but how can I use a button zoom to the next row extent?

Re: How can I write a python add-in which zooms to each selected polygon after each button click?

WesMiller — Thu, 02 Jul 2015 19:49:01 GMT

You could create a layer file from your selected features then use the data driven pages toolbar to move forward and backward through your feature layer.

Re: How can I write a python add-in which zooms to each selected polygon after each button click?

DavidLamb — Thu, 02 Jul 2015 20:35:44 GMT

If you are using a python add-in wizard, you can do something like this. On the first click, you store the envelopes in a class level property. If the list isn't empty then keep going through and setting extents. This worked on my machine running 10.2

import arcpy

import pythonaddins

class ButtonClass1(object):

"""Implementation for zoomto_addin.button (Button)"""

def __init__(self):

self.enabled = True

self.checked = False

self.mxd = None

self.df = None

self.envelopes = []

self.lastIndex = 0

def onClick(self):

print "clicked"

if len(self.envelopes)<1:

self.mxd = arcpy.mapping.MapDocument('CURRENT')

self.df = arcpy.mapping.ListDataFrames(self.mxd, "Layers") [0]

print "getting stuff"

# find the selection set

SelLayer = arcpy.mapping.ListLayers(self.mxd,data_frame=self.df)[0] # first layer

fidSet = arcpy.Describe(SelLayer).FIDSet

if len(fidSet) == 0:

arcpy.AddMessage("Nothing selected")

else:

# now cursor through it an get the geometries

# storing their extents into a list

with arcpy.da.SearchCursor(SelLayer,"SHAPE@") as SCur:

for feat in SCur:

# I'm going to assume polygon/polyline

self.envelopes.append(feat[0].extent) # grab the envelope

print len(self.envelopes)

self.lastIndex = 0

self.setExtent

else:

self.setExtent()

def setExtent(self):

print len(self.envelopes)

print self.lastIndex

if self.lastIndex < (len(self.envelopes)-1):

self.df.extent = self.envelopes[self.lastIndex]

arcpy.RefreshActiveView()

self.lastIndex += 1

else:

self.lastIndex = 0

self.df.extent = self.envelopes[self.lastIndex]

arcpy.RefreshActiveView()

self.lastIndex += 1