Adding before widget from different parent should not work

[pbk0]

Version of Dear PyGui

Version: 1.0.2
Operating System: Windows 11

My Issue/Question

Adding before widget from different parent should not work

To Reproduce

First snippet: Works as expected

import dearpygui.dearpygui as dpg

dpg.create_context()
dpg.create_viewport()
dpg.setup_dearpygui()

with dpg.window(label="Dear PyGui Demo", width=800, height=800,
                pos=(100, 100), tag="__demo_id") as w1:

    p1 = dpg.add_collapsing_header(label="some label 111", default_open=True,)
    a1 = dpg.add_text(default_value="Some text 111", parent=p1)
    p2 = dpg.add_collapsing_header(label="some label 222", default_open=True,)
    a2 = dpg.add_text(default_value="Some text 222", parent=p2)

dpg.show_viewport()
dpg.start_dearpygui()
dpg.destroy_context()

Second snippet: Should fail but works

• I am trying to add a2 before a1 which has different parent
• Was expecting this to raise error (or else what is the use for dpg.move_item()

import dearpygui.dearpygui as dpg

dpg.create_context()
dpg.create_viewport()
dpg.setup_dearpygui()

with dpg.window(label="Dear PyGui Demo", width=800, height=800,
                pos=(100, 100), tag="__demo_id") as w1:

    p1 = dpg.add_collapsing_header(label="some label 111", default_open=True,)
    a1 = dpg.add_text(default_value="Some text 111", parent=p1)
    p2 = dpg.add_collapsing_header(label="some label 222", default_open=True,)
    a2 = dpg.add_text(default_value="Some text 222", parent=p2, before=a1)  # only difference is added `before=a1`

dpg.show_viewport()
dpg.start_dearpygui()
dpg.destroy_context()

[Pcothren]

explicate naming of parents during item creation is accepted, it allows for the order of the code and the layout to be decoupled, which can help with maintaining code.

move item is useful after the item has been created (typically at run time) when that item needs to change containers or move up or down in their container order.

[Pcothren]

ah, I see the parent named is not the same parent of the item named in the before keyword.

Maybe we shouldn't allow both of those to be accepted (its ambiguous) in reality the parent keyword is not needed when assigning the before keyword.

The reason this is working currently is due to the order the keywords are being parsed.
DPG is assigning the parent as p2, then DPG is parsing the before keyword and locating the widget and reassigning the parent again to the parent of the named before item and placing it to before it in the items order.

DPG is essentially moving the item 2 times underneath

[pbk0]

@Pcothren I personally do not use with context. as I am building a custom OOP layer on internal_dpg. But you can see the code using with context below.

What bothers me is before arg is taking precedence and does not respect the with context of immediate parent i.e. p2

import dearpygui.dearpygui as dpg

dpg.create_context()
dpg.create_viewport()
dpg.setup_dearpygui()

with dpg.window(label="Dear PyGui Demo", width=800, height=800,
                pos=(100, 100), tag="__demo_id") as w1:

    with dpg.collapsing_header(label="some label 111", default_open=True,) as p1:
        a1 = dpg.add_text(default_value="Some text 111")

    with dpg.collapsing_header(label="some label 222", default_open=True,) as p2:
        a2 = dpg.add_text(default_value="Some text 222", before=a1)

dpg.show_viewport()
dpg.start_dearpygui()
dpg.destroy_context()

Another solution if it makes sense is remove before argument completely. The rationale is:

• There are some widgets that do not use before arg anyways. (example menu_bar, tooltip etc.)
• And those who want before can anyways use .move() method.
• This will also avoid any overhead of
  • checking if either parent or before is supplied
  • widgets created in with context should not use parent kwarg (as someone can use wrong dpg id)

[hoffstadt]

Yeah, "before" and "parent" are an either/or situation. If you want to append to a container, use "parent". If you want to insert an item before another item, use "before". When used together, "before" takes priority.

[hoffstadt]

This is specified here.