[JereKuusela]

I need help with understanding the code in "How to" list.
I just couldn't find explanations anywhere.

Link to it

or here:

import e32, appuifw

class CustomList( object ):
def __init__( self, aList=[], aObserver=lambda:None,
aEmptyMessage=u'No data'):
self._iList = aList
self._mObserver = aObserver
self._iEmptyMessage = unicode(aEmptyMessage)
self._iCnv = appuifw.Canvas( self._redraw,
resize_callback=self._redraw )
self._iBindings = {}
appuifw.app.body = self._iCnv
if self._iList:
self._iListbox = appuifw.Listbox(self._iList, self._observer)
else:
self._iListbox = None

def _showEmpty( self ):
if not self._iCnv:
self._iCnv = appuifw.Canvas()
appuifw.app.body = self._iCnv

def _redraw(self, aRect=None):
try:
self._iCnv.clear()
dimentions = self._iCnv.measure_text(self._iEmptyMessage,
font='dense')
width = abs(dimentions[0][0])+abs(dimentions[0][2])
height = abs(dimentions[0][1])+abs(dimentions[0][3])
self._iCnv.text(((self._iCnv.size[0]-width)/2,
(self._iCnv.size[1]-height)/2),
self._iEmptyMessage)
exceptass

def _observer(self):
self._mObserver()

def bind(self, aEventCode, aCallback):
self._iBindings[aEventCode] = aCallback
self._iCnv.bind(aEventCode, aCallback)
if self._iListbox:
self._iListbox.bind(aEventCode, aCallback)

def current(self):
return self._iListbox.current()

def set_list(self, aList, current=None):
self._iList = aList
if self._iList and current:
if not self._iListbox:
self._iListbox = appuifw.Listbox(self._iList, self._observer)
appuifw.app.body = self._iListbox
for key in self._iBindings:
self._iListbox.bind(key, self._iBindings[key])

self._iListbox.set_list( aList, current )

if appuifw.app.body is not self._iListbox:
appuifw.app.body = self._iListbox

elif self._iList and not current:
if not self._iListbox:
self._iListbox = appuifw.Listbox(self._iList, self._observer)
appuifw.app.body = self._iListbox
for key in self._iBindings:
self._iListbox.bind(key, self._iBindings[key])

self._iListbox.set_list( aList )

if appuifw.app.body is not self._iListbox:
appuifw.app.body = self._iListbox

else:
self._showEmpty()




if __name__ == "__main__":
from key_codes import EScancode5
def feed():
lb.set_list([u'Item0',u'Item1',u'Item2',u'Item3',
u'Item4',u'Item5',u'Item6',u'...'],3)
appuifw.app.menu = ([(u'Empty list', lambda:empty(),
(u'Exit', lambda:APP_LOCK.signal()))])

def empty():
lb.set_list([])
appuifw.app.menu = ([(u'Feed list', lambda:feed(),
(u'Exit', lambda:APP_LOCK.signal()))])


def observer():
appuifw.note(u'Index: %d'%(lb.current()), 'info', 1)


APP_LOCK = e32.Ao_lock()
appuifw.app.title = u'Custom listbox'
appuifw.app.exit_key_handler = APP_LOCK.signal
appuifw.app.menu = ([(u'Feed list', lambda:feed(),
(u'Exit', lambda:APP_LOCK.signal()))])

lb = CustomList(aObserver=observer)
lb.bind(EScancode5, lambda:appuifw.note(u'Key 5', 'info', 1))
APP_LOCK.wait()

Thanks in advance.

[kiran10182]

Welcome to the Forum Nokia Discussion Boards.

The article you are referring is in Python. And you are in Symbian C++ category.
I think moderator will move this to an appropriate category.

Now onwards ask Python questions here: http://discussion.forum.nokia.com/fo...play.php?f=102

Kiran.

[JereKuusela]

Ups :P
Not sure what I was thinking...