Window position is invalidated when setting a label to it

[ludg1e]

Version of Dear PyGui

Version: 1.9.1
Operating System: Windows 10

My Issue/Question

When a label is set on a window, DPG invalidates the window position
While this may be or not of importance for the main window, modals created as windows (with dpg.window and modal=True) to be shown after aren't centered since the window position is broken due to setting a label to them

A workaround is to tell DPG that the position is valid with: dpg.reset_pos(tag)

To Reproduce

Steps to reproduce the behavior:

1. Create a modal with dpg.window and modal=True and set to it a label
2. Add additional code to show the modal when clicking a button (for e.g)
3. The modal isn't centered

Expected behavior

The modal should be centered

Screenshots/Video

Without the workaround:

With the workaround:

Standalone, minimal, complete and verifiable example

import dearpygui.dearpygui as dpg

dpg.create_context()

dpg.create_viewport(
    title="hello bro",
    width=700,
    height=500,
)

with dpg.window(tag="main_window"):
    dpg.add_text("Hello world")
    dpg.add_input_text(label="string")
    dpg.add_slider_float(label="float")
    dpg.add_separator()

    with dpg.group(
        tag="categories",
        width=700,
        parent="main_window",
        horizontal=False,
    ):
        with dpg.collapsing_header(
            label="Input",
            tag="categories_input",
            parent="categories",
            default_open=False,
        ):
            dpg.add_button(
                label="Mouse",
                tag="categories_input_mouse",
                width=700,
                parent="categories_input",
                callback=lambda: dpg.configure_item("mouse_modal", show=True),
            )

dpg.set_primary_window("main_window", True)

with dpg.window(
    label="Mouse settings",
    tag="mouse_modal",
    width=500,
    height=300,
    show=False,
    no_resize=True,
    no_title_bar=False,
    no_collapse=True,
    no_close=True,
    modal=True,
    no_open_over_existing_popup=True,
):
    dpg.add_text(
        "All those beautiful files will be deleted.\nThis operation cannot be undone!"
    )
    dpg.add_separator()
    dpg.add_checkbox(label="Don't ask me next time")
    with dpg.group(horizontal=True):
        dpg.add_button(
            label="OK",
            width=75,
            callback=lambda: dpg.configure_item("mouse_modal", show=False),
        )
        dpg.add_button(
            label="Cancel",
            width=75,
            callback=lambda: dpg.configure_item("mouse_modal", show=False),
        )

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

Also Tetane's workaround is applied from issue #1978

cc: @v-ein (thanks for the help on Discord!)

[v-ein]

For future reference:

• It's a side effect of the commit b081e6f, which is a fix for Window width changes if window label is set #346.
• At some point, this "dirtyPos = true" line had got a comment saying "this is necessary because imgui considers it a new window" - see it after commit ee26195. For some reason, the comment got lost in future commits.