how to manage scrollbar with not visible items in PySimpleGUI

i have developed a PySimpleGUI application and i must show a list of items depending from the number of rows readed from a file.
I know that is not possible to create components dinamically in PySimpleGUI, so i've defined a max number of components and set they as not visible until the file is readed.

After the reading, i set the desired number of rows as visible, but the scrollbar of the Column container remains unusable.

Initial situation:

After the reading:

I also try to leave an item of the row always visibile, and in this case scrollbar works well:

Initial situation with index always visible:

After the reading with index always visible:

Code:

def getLayoutFramePars():
sub_layout = []
for node_index in range(30):
line = addParLine(node_index)
sub_layout.append(line)
layout = [
[
sg.Col(
layout=sub_layout,
background_color=Blue4,
expand_x=True,
expand_y=True,
)
]
]
return layout
def addParLine(index):
text_index = str(index)
if index < 10:
text_index = "0" + text_index
KEY_LABEL_INDEX = PREFIX_PAR_LABEL_INDEX + text_index
KEY_LABEL_NAME = PREFIX_PAR_LABEL_NAME + text_index
KEY_LABEL_VALUE = PREFIX_PAR_LABEL_VALUE + text_index
KEY_BUTTON_READ = PREFIX_PAR_BUTTON_READ_VALUE + text_index
KEY_BUTTON_SEND = PREFIX_PAR_BUTTON_SEND_VALUE + text_index
layout = [
sg.Text(
key=KEY_LABEL_INDEX,
text=text_index,
size=LABEL_SIZE_05,
justification=ALIGN_CENTER,
visible=False,
pad=5,
),
sg.Text(
'',
key=KEY_LABEL_NAME,
size=LABEL_SIZE_20,
relief=sg.RELIEF_SUNKEN,
justification=ALIGN_CENTER,
visible=False,
pad=5,
),
sg.InputText(
'',
key=KEY_LABEL_VALUE,
size=LABEL_SIZE_30,
justification=ALIGN_LEFT,
text_color=Blue2,
background_color=LightGrey,
enable_events=True,
visible=False,
pad=5,
),
sg.Button(
key=KEY_BUTTON_READ,
button_text='Leggi',
size=BUTTON_SIZE_14,
button_color=BUTTON_COLOR_BLUE,
visible=False,
pad=5,
),
sg.Button(
key=KEY_BUTTON_SEND,
button_text='Invia',
size=BUTTON_SIZE_14,
button_color=BUTTON_COLOR_BLUE,
visible=False,
pad=5,
),
]
return layout
def initLayoutBody():
layout = [
[
sg.Text(
text="##",
size=LABEL_SIZE_05,
text_color=DarkOrange,
justification=ALIGN_CENTER,
pad=5,
),
sg.Text(
text="Nome",
size=LABEL_SIZE_20,
text_color=DarkOrange,
justification=ALIGN_CENTER,
pad=5,
),
sg.Text(
text="Valore",
size=LABEL_SIZE_30,
text_color=DarkOrange,
justification=ALIGN_CENTER,
pad=5,
),
],
[
sg.Column(
key=KEY_FRAME_PARS,
size=(750, 300),
layout=getLayoutFramePars(),
element_justification=ALIGN_LEFT,
scrollable=True,
vertical_scroll_only=True,
background_color=DarkGreen,
),
]
]
return layout

Could someone help me to understand what i do wrong and how to solve this problem?

Thanks

Call following methods after you update the content of the column.

• window.refresh() to update the GUI.
• window[column_key].contents_changed() to update the new scroll area
  to match the new contents.