@cvp thank you very much.
i prefer to use uitableviewcontroller,it connect data source and delegate automatically.
your code works but when I transfer to UITableViewController,it crashs.

@cvp i don’t understand how to .. i want to subclass a UITableViewcontroller and add a action when i left swipe a cell.
could you show me the right way in the code i provided?
sorry for my poor understanding.

@cvp i try the code below,but still crash,what’s the problem?

from objc_util import *
import ui

@on_main_thread
def main_tableview():
    def tableView_numberOfRowsInSection_(_self, _cmd,_tv,_section):
        return 3
    
    def numberOfSectionsInTableView_(_self, _cmd,_tv):
        return 1
    
    def tableView_cellForRowAtIndexPath_(_self, _cmd,_tv,_indexpath):
        cell=ObjCInstance(_tv).dequeueReusableCellWithIdentifier("cell1") 
        if cell==None:
            cell=ObjCClass('UITableViewCell').alloc().initWithStyle_reuseIdentifier_(3,"cell2")
        
        cell.textLabel().text = 'test'
        return cell.ptr
    
    def tableView_trailingSwipeActionsConfigurationForRowAtIndexPath_(_self,_cmd,_tv,_indexPath): 
        return None
        
    tvc1 = create_objc_class('UITableViewController',ObjCClass('UITableViewController'),methods=[tableView_numberOfRowsInSection_,numberOfSectionsInTableView_,tableView_cellForRowAtIndexPath_,tableView_trailingSwipeActionsConfigurationForRowAtIndexPath_])
    
    return  tvc1.alloc().init().autorelease()   
    
@on_main_thread
def main():

    root_vc = UIApplication.sharedApplication().keyWindow().rootViewController()
    tbc=main_tableview()
    root_vc.presentViewController_animated_completion_(tbc, True, None)
    
if __name__=='__main__':
    main()

@cvp when i comment # return none,i got it.
thanks very much.

@cvp thanks

i have checked _objc_exception.txt and saw nothing in this crash.
try the example you provided,when i do a left swipe,it just show “delete” button.
i have no idea how the code below work

    # set actions if swipe
    UIContextualAction = ObjCClass('UIContextualAction').alloc()
    UIContextualAction.setTitle_("Drizzel's action 😅")
    # block does not have parameter nor return, thus we can use a Python def
    UIContextualAction.setHandler_(handler)
    UIContextualAction.setBackgroundColor_(ObjCClass('UIColor').blueColor().colorWithAlphaComponent(0.5))
    
    UISwipeActionsConfiguration = ObjCClass('UISwipeActionsConfiguration').configurationWithActions_([UIContextualAction])

hey~i need to return none in a objc new class function,but it crash’s when i use return none.how can i solve it? thanks very much.

def tableView_trailingSwipeActionsConfigurationForRowAtIndexPath_(_self,_cmd,_tv,_indexPath):       
        return None

@JonB

thanks.
it seems not convenient for debug, and i still use objc_util as OC bridge.

@JonB

run more than once will raise such errs,then how to solve?

ctypes_patch.make_callback_returnable(CGSize)
File "/private/var/mobile/Containers/Shared/AppGroup/02422888-CC52-45FC-BB53-72013D3F4AFA/Pythonista3/Documents/site-packages/ctypes_patch.py", line 128, in make_callback_returnable
raise ValueError("The ctype {} already has a getfunc")
ValueError: The ctype {} already has a getfunc

latest when i try rubicon_objc.
the code below, run once is normal. run anther time will raise a err.
how can i solve it? thanks in advance

RuntimeError: An Objective-C class named b'Handler' already exists

code:

from rubicon.objc import NSObject, objc_method

class Handler(NSObject):
@objc_method
def initWithValue_(self, v: int):
self.value = v
return self

@objc_method
def pokeWithValue_andName_(self, v: int, name) -> float:
    print("My name is", name)
    return v / 2.0

my_handler = Handler.alloc().initWithValue(42)

@JonB @mikael @cvp and other dear friends

Sincerely,many thanks to you all!
i love to stay here.

anyone can help? please

@JonB

thank you all

when i overwrite a method requested a return type in a new class.
number and string can be returned directly.
cell object in tableview is returned in cell.ptr
but how to return a CGSize structure?
objc's CGSize does't work

@mcriley821

it still can’t work.

superclass=NSObject is default when new class is created.

i created a new class and add a function to methods.
but it showed such error.
how can i return cgsize correctly?
thanks in advcance.

TypeError: invalid result type for callback function

def collectionView_layout_sizeForItemAtIndexPath_(_self, _cmd, _cv, _la, _ip):
return CGSize(340,300)

methods = [collectionView_layout_sizeForItemAtIndexPath_]

DataSource = create_objc_class('DataSource', methods=methods, protocols=['UICollectionViewDelegateFlowLayout', 'UICollectionViewDataSource', 'UICollectionViewDelegate'])

@JonB

thank you very much for detailed reply.
i will have more tests and try to understand it indepth.
maybe ask later when i meet new question,thank you again.

thanks to you all. sloved!
and sorry for my wrong code format,i'll correct it in my next post.

how to understand thread clearly? see my comments
I run these code and return such results.

<NSThread: 0x2828f0780>{number = 7, name = (null)}
<NSThread: 0x28285b100>{number = 1, name = main}
<NSThread: 0x2828f0780>{number = 7, name = (null)}

import threading
from objc_util import  *
import ui

td=ObjCClass('NSThread')
print(td.currentThread())
#why isn't this in a mainthread? it shows in background thread.

#it shows in background thread,it's okay
@ui.in_background
def test1():
    print(td.currentThread())

#it shows in main thread,it's okay
@on_main_thread
def main():
    global td   
    print(td.currentThread())
    test1()

if __name__=='__main__':
    main()

when I run these code, it shows a error name lib is not defineded?

how to slove? thanks

import ui
from objc_util import *

def change(sender):
lb.text='new'

@on_main_thread
def main():
v=ui.View()
v.background_color='white'

lb=ui.Label(text='old')
btn=ui.Button(title='press',action=change)

v.add_subview(lb)
v.add_subview(btn)

v.present()

if name=='main':
main()

@dgelessus

great！it has worked under your kind guidance！
thank you very very much!

@dgelessus

sir,I read your latest replies in the forum and interested in rubicon.objc you mentioned.I have installed it by pip install rubicon.objc with stash but it doesn’t work.

when I run
from rubicon.objc import NSInteger, NSObject, ObjCProtocol, objc_method

it showed a error, could you give me a help? thanks so much.

Traceback (most recent call last):
File "/private/var/mobile/Containers/Shared/AppGroup/02422888-CC52-45FC-BB53-72013D3F4AFA/Pythonista3/Documents/t_rubicon.py", line 1, in <module>
from rubicon.objc import NSInteger, NSObject, ObjCProtocol, objc_method
File "/private/var/mobile/Containers/Shared/AppGroup/02422888-CC52-45FC-BB53-72013D3F4AFA/Pythonista3/Documents/site-packages-3/rubicon/objc/init.py", line 15, in <module>
from . import runtime # noqa: F401
File "/private/var/mobile/Containers/Shared/AppGroup/02422888-CC52-45FC-BB53-72013D3F4AFA/Pythonista3/Documents/site-packages-3/rubicon/objc/runtime.py", line 2, in <module>
from ctypes import (
File "/var/containers/Bundle/Application/789BA705-9D92-409A-8DF3-9D0806F2BD5B/Pythonista3.app/Frameworks/Py3Kit.framework/pylib/ctypes/util.py", line 72, in <module>
from ctypes.macholib.dyld import dyld_find as _dyld_find
ModuleNotFoundError: No module named 'ctypes.macholib'