Have Combobox Listen to AddLayer Event?

MikeMacRae

I am building an addin combobox. The combobox will populate a list of all the layers that are in the TOC in ArcMap upon initialization of ArcMap. The user will choose a layer and some actions will take place.

What I want to do is have the comobox listen to the Table of Contents and update any time the user adds or removes a layer automatically. Is this possible?

Thanks

FreddieGibson

You would need to implement both the ComboBox and an Application Extension. The Application Extension would need to listen for changes in the TOC and you'd need to build a hook to feed the values to the ComboBox. I haven't tested it, but I'm thinking it'd look something like this.

import arcpy
import pythonaddins

class ComboBoxClass(object):
    """Implementation for ComboBox"""
    def __init__(self):
        self.items = list()
        self.editable = self.enabled = True
        self.dropdownWidth = self.width = 'WWWWWW'
        ComboBoxClass._hook = self        

class ExtensionClass(object):
    """Implementation for Application Extension """
    def __init__(self):
        self.enabled = True
        ExtensionClass._hook = self
        
    def itemAdded(self, new_item):
        ComboBoxClass._hook.items.extend([new_item])
        
    def itemDeleted(self, deleted_item):
        ComboBoxClass._hook.items.remove(deleted_item)