Unable to select checkboxes within a DataTable displayed in an AlertDialog with scrolling

[bfrench4255]

Question

I'm unable to select DataTable checkboxes when the table is displayed within an AlertDialog with scrolling enabled, and I'm at a loss as to why?

The code example launches an AlertDialog with a scrolling Column containing a DataTable. I'm unable to select the DataTable checkboxes with this code example. The on_select_change function is never called. However, if I remove the scroll=ScrollMode.ALWAYS from the following Column definition within the code:

    table = Column (
        controls = [table_def],
        expand=True,
        scroll=ScrollMode.ALWAYS
    )

The on_select_change function is called, but is always "row unselected". Not sure what I'm overlooking here...

Thanks!!

Code sample

import flet
from flet import (
    Page,
    Column,
    MainAxisAlignment,
    ElevatedButton,
    Text,
    AlertDialog,
    DataTable,
    colors,
    DataColumn,
    DataCell,
    DataRow,
    TextAlign,
    ScrollMode
)

active_page = None
from app.frontend.state.State import AddPatientPhenotypeState
class AlertDialogtControl(flet.UserControl):

    def __init__(self, page: Page, results: list):
        super().__init__()
        self.__results = results
        self.__page = page
        self.__popup = None

    def row_select_change(self, e):
        if e.control.selected:
            print(f'row selected')
        else:
            print('row unselected')
        self.__page.update()

    def cancel_add(self, e):
        self.__popup.open = False
        self.__page.update()

    def build(self):
        table_columns = ['Column 1', "Column 2", "Column 3"]
        table_headers = []
        for table_column in table_columns:
            table_headers.append(DataColumn(Text(table_column)))

        rows=[]
        for result in self.__results:
            cells = [
                DataCell(Text(result.get('column1'))),
                DataCell(Text(result.get('column2'))),
                DataCell(Text(result.get('column3')))
            ]
            data_row = DataRow(
                cells,
                on_select_changed=self.row_select_change,
                selected=False
            )
            rows.append(data_row)

        table_def = DataTable (
            heading_row_color=colors.TEAL_800,
            show_checkbox_column=True,
            columns=table_headers,
            rows=rows,
            expand=True,
            column_spacing=50,
            data_row_height=100
        )
        cancel_button = ElevatedButton (
            text="Cancel",
            on_click=self.cancel_add,
            bgcolor=colors.BLACK,
            color=colors.WHITE
        )
        table = Column (
            controls = [table_def],
            expand=True,
            scroll=ScrollMode.ALWAYS
        )

        alert_dialog_contents = Column (
            controls=[table],
            alignment=MainAxisAlignment.CENTER,
            expand=True
        )

        popup = AlertDialog(
            title=Text("Select Data", text_align=TextAlign.CENTER),
            content=alert_dialog_contents,
            modal=False,
            actions_alignment=MainAxisAlignment.CENTER,
            actions = [
                cancel_button
            ]
        )
        self.__popup = popup
        return popup

def create_data():
    table_data = []
    for row_count in range(100):
        row = {
            "column1": "column1 text",
            "column2": "column2 text",
            "column3": "column3 text",
        }
        table_data.append(row)

    return table_data

def main(page: Page):
    table_data = create_data()
    controller = AlertDialogtControl(page, table_data)
    popup = controller.build()
    global active_page
    active_page = page

    page.overlay.append(popup)
    popup.open=True
    page.update()

flet.app(target=main, view=flet.WEB_BROWSER)

Error message

No error messages...

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• I have searched for answers to my question both in the issues and in previous discussions.