feat: more complete main window implementation by larsoner · Pull Request #741 · pyapp-kit/magicgui

larsoner · 2026-08-24T13:28:19Z

Closes #601
Closes #604

So... the "next week" I promised in 2023 has finally arrived 😅 This PR has the 43 commits from that PR, plus what Claude Fable found while reviewing (below is its summary). I reviewed the commits and they make sense to me. Notably I removed the backend autodetection since we should probably scope / implement that separately. (Automatic IPython importing can be problematic, and maybe it should be opt-in, etc.)

Before the Fable fixes:

After:

Qt (I'm on macOS so the menu isn't captured in-window):

Merged with current main (~3 yrs of drift)
Made the ipynb MainWindow work as a real Container: children now flow into the grid's central cell (previously main.append(...) raised KeyError).
Implemented ipynb MenuBar/Menu as a row of Dropdowns per the MainWindow for ipywidgets #601 discussion (first entry is the title placeholder; selecting an entry fires its callback and resets); nested submenus raise NotImplementedError for now.
Fixed grid placement: each bar/dock box gets its own Layout instance (they shared one, so GridspecLayout.__setitem__ stacked all eight into a single cell), and the grid templates are set via the attributes _update_layout() re-applies, so empty areas collapse and the central widget gets 1fr.
ipynb StatusBar: added widgets are tracked separately from the message label and spacer, negative insert positions append (matching Qt), and message timeouts use get_running_loop() instead of the deprecated get_event_loop().
set_menu_bar(None) / set_status_bar(None) no longer crash in the ipynb backend.
Drive-by fix for a pre-existing bug on main: Qt Container/Dialog reported layout == "vertical" regardless of orientation (isinstance(self, QHBoxLayout) can never be true for a backend widget).
Exported Menu/MenuBar from magicgui.widgets, and fixed a raise self._ipywidget → return typo in _mgui_get_native_layout.
Added backend-parametrized tests for the dock/toolbar/status-bar/menu APIs (should address the codecov failure).
Moved the root example.py into docs/examples/applications/main_window.py.
Dropped the _choose_backend() jupyter auto-detection for now — it's separable and changes default-backend behavior for all users, so it can be its own PR.

…into main-window

Resolves conflicts from ~3 years of drift. Notable resolution: keep the Container-based Qt MainWindow composition from pyapp-kit#686 (central widget swapped under a QMainWindow) and graft on the new _mgui_add_dock_widget/_mgui_add_tool_bar/_mgui_set_status_bar/ _mgui_set_menu_bar methods, instead of this branch's QBaseWidget rewrite that reimplemented the container protocol by hand. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

…f layout isinstance(self, QtW.QHBoxLayout) can never be true for a backend widget; check the layout object instead. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

- MainWindow now builds on Container: the H/VBox created by Container becomes the central widget of the IpyMainWindow grid, and container children flow into it (previously append() raised KeyError because __init__ skipped Container entirely and nothing was wired to the central cell). Container child management is routed through a _box attribute so subclasses can redirect it. - Grid uses auto/1fr templates so empty bars collapse and the central widget takes the remaining space (per the mapping discussed in pyapp-kit#601). - MenuBar/Menu implemented as a row of Dropdowns: the first entry acts as the menu title, selecting an entry fires its callback and resets the selection. Nested menus raise NotImplementedError for now. - StatusBar: added widgets tracked separately from the message label and spacer; negative insert positions append (matching Qt, where insertWidget(-1) is out-of-range); use get_running_loop() for message timeouts instead of the deprecated get_event_loop(). - set_menu_bar(None)/set_status_bar(None) no longer raise. - Fix _mgui_get_native_layout (raise -> return) and export Menu/MenuBar from magicgui.widgets. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

…ends Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Auto-selecting the ipynb backend inside a Jupyter kernel is separable from the main-window work and changes behavior for all existing notebook users of the qt backend, so it should be its own PR. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

GridspecLayout.__setitem__ writes the cell position into child.layout.grid_area, so the bar/dock boxes must not share a Layout instance (previously all eight ended up stacked in one cell). Also set the grid templates via the private attributes that GridspecLayout._update_layout re-applies on every assignment, so empty bars collapse and the central widget row/column gets 1fr. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Matches Qt, where a toolbar spans its area and add_spacer() pushes subsequent items to the far side. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

codecov · 2026-08-24T13:32:02Z

Codecov Report

❌ Patch coverage is 90.11236% with 44 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.15%. Comparing base (355bbe4) to head (22d75e8).

Files with missing lines	Patch %	Lines
src/magicgui/backends/_ipynb/widgets.py	85.14%	26 Missing ⚠️
src/magicgui/backends/_qtpy/widgets.py	86.66%	14 Missing ⚠️
src/magicgui/widgets/bases/_menubar.py	93.44%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #741      +/-   ##
==========================================
+ Coverage   89.52%   90.15%   +0.62%     
==========================================
  Files          40       43       +3     
  Lines        4899     5314     +415     
==========================================
+ Hits         4386     4791     +405     
- Misses        513      523      +10

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

test_widgets.py::test_bound_callable_catches_recursion carries a FIXME saying it must run before any test swaps backends between qt and ipynb, or it stack-overflows on Windows. test_main_window.py sorted before test_widgets.py and its backend-parametrized tests swap backends, which crashed the three Windows jobs on CI. Rename the file so it collects after test_widgets.py. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

The namespace from runpy.run_path is discarded, so widgets created by an example are garbage-collected at an arbitrary later point during event processing. A still-visible widget whose C++ side is deleted mid-event-loop can receive a paintEvent during deletion, which PyQt5 escalates to a process abort: RuntimeError: wrapped C/C++ object of type QRangeSlider has been deleted as seen intermittently on the windows-latest (3.12) pyqt5 job in test_example[demo_widgets/range_slider.py] (e.g. the scheduled main run on 2026-08-22, and both pyapp-kit#741 and pyapp-kit#742). Close (hide) all top-level widgets first so nothing can paint, then deleteLater() + sendPostedEvents(None, DeferredDelete) to destroy the native widgets (and stop their timers) while hidden -- note that processEvents() alone does NOT dispatch DeferredDelete events -- then gc.collect() for anything left over. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* test: deterministically tear down example widgets The namespace from runpy.run_path is discarded, so widgets created by an example are garbage-collected at an arbitrary later point during event processing. A still-visible widget whose C++ side is deleted mid-event-loop can receive a paintEvent during deletion, which PyQt5 escalates to a process abort: RuntimeError: wrapped C/C++ object of type QRangeSlider has been deleted as seen intermittently on the windows-latest (3.12) pyqt5 job in test_example[demo_widgets/range_slider.py] (e.g. the scheduled main run on 2026-08-22, and both #741 and #742). Close (hide) all top-level widgets first so nothing can paint, then deleteLater() + sendPostedEvents(None, DeferredDelete) to destroy the native widgets (and stop their timers) while hidden -- note that processEvents() alone does NOT dispatch DeferredDelete events -- then gc.collect() for anything left over. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> * test: allow pytest-qt >=4.5 everywhere except PySide2 pytest-qt 4.4.0 is incompatible with recent PySide6: qtbot.waitSignal fails with 'SystemError: <method disconnect of SignalInstance> returned a result with an exception set' and a TimeoutError in test_parent_changed (reproduced locally with PySide6 6.11.2 + pytest-qt 4.4.0; fixed by pytest-qt 4.5.0, see pytest-dev/pytest-qt#552). This is what has been failing every pyside6 CI job (and the scheduled runs on main) since at least mid-July. pytest-qt 4.5 dropped PySide2, so the pyside2 dependency group keeps the 4.4.0 pin via a separate test-qt-legacy group, declared as a uv conflict so universal resolution still succeeds. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> * build: emit core metadata 2.4 until twine accepts 2.5 hatchling 1.32.0 (2026-08-11) bumped the default core metadata version to 2.5, which the twine run by build-and-inspect-python-package rejects ('InvalidDistribution: 2.5 is not a valid metadata version'). Nobody noticed because build-and-inspect needs the test job, which has been red since mid-July (see previous commit). Verified locally: with this setting both the wheel and sdist emit Metadata-Version 2.4 and pass 'twine check --strict'. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> * style(pre-commit.ci): auto fixes [...] --------- Co-authored-by: Claude Fable 5 <noreply@anthropic.com> Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

# Conflicts: # src/magicgui/backends/_ipynb/widgets.py # src/magicgui/widgets/bases/_toolbar.py

larsoner · 2026-08-26T13:44:50Z

Okay merged main in to resolve conflicts and pushed one last test fix (locally things were failing... had to do with not completely un-setting states

tlambert03 · 2026-08-29T06:59:52Z

Thanks a lot for coming back to this @larsoner, I'm more or less happy to merge this. Strictly new feature, shouldn't affect any existing behavior (unless someone is creating a concrete MainWindowProtocol outside of magicgui, which I don't expect).

local claude review did surface these two small bugs... do you agree that they should be fixed? Or is it wrong?

Qt MenuBar._mgui_clear is an empty stub (docstring only, no body) — src/magicgui/backends/_qtpy/widgets.py. So main.menu_bar.clear() silently does nothing on Qt while it works on ipynb. One-line fix : self._qwidget.clear().
_SupportsMenus._menus is never cleared, so menu_bar["File"] still returns the stale menu after clear().

- Qt MenuBar._mgui_clear was a docstring-only stub; now calls QMenuBar.clear() - MenuBarWidget.clear()/MenuWidget.clear() now also clear the frontend _menus dict so menu_bar['File'] no longer returns a stale menu after clear() - test_window.py asserts both (empty native actions/children, KeyError lookup) Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_012eVFkZ4Tnh6ZABSqb17H1K

larsoner · 2026-08-29T08:45:45Z

Claude was right! Fixes pushed

tlambert03 · 2026-08-29T11:37:41Z

thanks!

tlambert03 and others added 30 commits October 8, 2023 20:28

wip

b19e898

update ipywidgets implementation

a2244de

fix hints

bad9c5e

add test

5f75b46

feat: support button icons

804da76

adding iconbtn

c991ce0

match color to palette in qt

b3a29ec

update ipywidgets

d48b10d

bump superqt

a665276

add pytest-pretty

2c1a201

test: add tests

5d1b227

fix icon

1b907d1

extract logic, fix 3.8

6933b32

Merge branch 'icons' into toolbars

721a0b9

update color

d27c283

change with palette

62daa67

Merge branch 'main' into toolbars

1e89504

unions

7f39313

wip

ff3b001

Merge remote-tracking branch 'origin/toolbars' into main-window

9385303

wpi

8242141

adding menus

db0e68f

Merge branch 'main' into main-window

c48e9d0

style(pre-commit.ci): auto fixes [...]

db81067

extend menu

b100bda

Merge branch 'main-window' of https://github.com/tlambert03/magicgui …

3b9f785

…into main-window

menu stuff

025323d

style(pre-commit.ci): auto fixes [...]

b2584d9

update menus

5704bee

Merge branch 'main-window' of https://github.com/tlambert03/magicgui …

fd0a329

…into main-window

tlambert03 and others added 15 commits October 22, 2023 15:58

starting on ipywidgets

706004f

update example

dc008d6

add central

e1a68e4

Merge branch 'main' into main-window

300c79a

Merge branch 'main-window' of https://github.com/tlambert03/magicgui …

511a174

…into main-window

style(pre-commit.ci): auto fixes [...]

778c0ea

fix: Container/Dialog orientation reported as 'vertical' regardless o…

5cfe28f

…f layout isinstance(self, QtW.QHBoxLayout) can never be true for a backend widget; check the layout object instead. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test: cover MainWindow dock/toolbar/status-bar/menu APIs on both back…

f68feb3

…ends Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs: move main-window demo from repo root into the examples gallery

d06db48

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

style: ruff fixes

44c2db8

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

fix: stretch ipynb toolbars across their bar area so spacers expand

ccda75e

Matches Qt, where a toolbar spans its area and add_spacer() pushes subsequent items to the far side. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tlambert03 and others added 4 commits August 26, 2026 14:29

Merge branch 'main' into main-window-604

f5f8234

Merge remote-tracking branch 'upstream/main' into main-window-604

6f874e3

# Conflicts: # src/magicgui/backends/_ipynb/widgets.py # src/magicgui/widgets/bases/_toolbar.py

style(pre-commit.ci): auto fixes [...]

2c70182

FIX: Test order shouldnt matter

b7184c6

tlambert03 merged commit 505321b into pyapp-kit:main Aug 29, 2026
31 checks passed

Navigation Menu

Uh oh!

feat: more complete main window implementation - #741

feat: more complete main window implementation#741
tlambert03 merged 58 commits into
pyapp-kit:mainfrom
larsoner:main-window-604

larsoner commented Aug 24, 2026

Uh oh!

codecov Bot commented Aug 24, 2026 •

edited

Loading

Uh oh!

larsoner commented Aug 26, 2026

Uh oh!

tlambert03 commented Aug 29, 2026

Uh oh!

larsoner commented Aug 29, 2026

Uh oh!

tlambert03 commented Aug 29, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Uh oh!

Conversation

larsoner commented Aug 24, 2026

Uh oh!

codecov Bot commented Aug 24, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

larsoner commented Aug 26, 2026

Uh oh!

tlambert03 commented Aug 29, 2026

Uh oh!

larsoner commented Aug 29, 2026

Uh oh!

tlambert03 commented Aug 29, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

codecov Bot commented Aug 24, 2026 •

edited

Loading