notifier_sample.py

#!/usr/bin/env python

'''

    This sample Python plugin demonstrates how to use notifiers in Python.
    
    To use, embed the command in a form and change item selection, the command
    should update.
    
'''

import lx
import lxifc
import lxu.select
import lxu.command

SERVER_NAME = "item.setSize"

class Command (lxu.command.BasicCommand):
    
    def __init__ (self):
        
        '''
            Initialize command class. Adds a single queryable argument for
            setting and getting the current selected item size.
        '''
        
        lxu.command.BasicCommand.__init__(self)
        
        self.dyna_Add ('size', lx.symbol.sTYPE_FLOAT)
        self.basic_SetFlags(0, lx.symbol.fCMDARG_QUERY)
        
        self.scn_svc = lx.service.Scene ()
        self.sel_svc = lx.service.Selection ()
        self.not_svc = lx.service.NotifySys ()
        
        self.notifier = lx.object.Notifier ()
        
        self.locator_type = self.scn_svc.ItemTypeLookup (lx.symbol.sITYPE_LOCATOR)
        
    def cmd_Flags (self):
        
        '''
            This command performs scene altering operations.
        '''
        
        return lx.symbol.fCMD_MODEL | lx.symbol.fCMD_UNDO
    
    def basic_Enable (self, msg):
        
        '''
            Only enable the command if at least one locator type item is selected.
        '''
        
        item_sel = lxu.select.ItemSelection().current()
        
        for item in item_sel:
            if item.TestType (self.locator_type) == True:
                return True
            
        return False
    
    def cmd_Query (self, index, vaQuery):
        
        '''
            Query the command value by reading size channel on all selected
            locator items. The values are added to an array and if the values
            all differ, modo will show "(mixed)" on the control.
        '''
        
        if index != 0:
            return
    
        item_sel = lxu.select.ItemSelection().current()
        scene = lxu.select.SceneSelection().current()
        
        val_array = lx.object.ValueArray (vaQuery)
        chan_read = lx.object.ChannelRead (scene.Channels (lx.symbol.s_ACTIONLAYER_EDIT, self.sel_svc.GetTime ()))
        
        for item in item_sel:
            if item.TestType (self.locator_type) == True:
                size = chan_read.Double (item, item.ChannelLookup (lx.symbol.sICHAN_LOCATOR_SIZE))
                val_array.AddFloat (size)
    
    def basic_Execute(self, msg, flags):
        
        '''
            In the execute method, the channel value is set on each of the size
            channels.
        '''
        
        item_sel = lxu.select.ItemSelection().current()
        scene = lxu.select.SceneSelection().current()
        
        if self.dyna_IsSet (0) == False:
            return
        
        chan_write = lx.object.ChannelWrite (scene.Channels (lx.symbol.s_ACTIONLAYER_EDIT, self.sel_svc.GetTime ()))
        size = self.attr_GetFlt (0)
        
        for item in item_sel:
            if item.TestType (self.locator_type) == True:
                chan_write.Double (item, item.ChannelLookup (lx.symbol.sICHAN_LOCATOR_SIZE), size)
                
    def cmd_NotifyAddClient (self, argument, object):
        
        '''
            Add a single notifier to the command. This will send disable events
            when the item selection changes.
        '''
        
        self.notifier = self.not_svc.Spawn ("select.event", "item +d")
        self.notifier.AddClient (object)
        
    def cmd_NotifyRemoveClient (self, object):
        
        '''
            Remove the notifier.
        '''
        
        self.notifier.RemoveClient (object)

'''
    Initialize the plugin.
'''

lx.bless(Command, SERVER_NAME)