Add general popup menu for model browser

[amolenaar]

PR Type

What kind of change does this PR introduce?

• Bug fix
• Feature
• Chore (refactoring, formatting, local variables, other cleanup)
• Documentation content changes

What is the current behavior?

When you cleaned the whole model, there's no way to easily create new top-level packages without putting them in a diagram as well.

Issue Number: #1954

What is the new behavior?

When no element is selected, you can add top level diagrams and packages.

This allows to add top-level packages and diagrams from anywhere within the model browser (tree view).

You can now deselect the selected element in the model browser with Ctrl+mouse click.

Does this PR introduce a breaking change?

• Yes
• No

Other information

I considered adding it to the "create diagram" button in the header bar as well.

• Renamed "tree component" on layout level as model_browser, as it's called in the docs.
• Fixed issue where only new popover menu's were created and none were cleaned up
• Remove GTK4 related code from Namespace component.
• Break dependency from tree component/namespace on function in main window module.

[sourcery-ai]

Sourcery Code Quality Report

✅  Merging this PR will increase code quality in the affected files by 1.01%.

Quality metrics	Before	After	Change
Complexity	3.08 ⭐	2.80 ⭐	-0.28 👍
Method Length	67.94 🙂	67.20 🙂	-0.74 👍
Working memory	4.55 ⭐	4.28 ⭐	-0.27 👍
Quality	72.53% 🙂	73.54% 🙂	1.01% 👍

Other metrics	Before	After	Change
Lines	1668	1666	-2

Changed files	Quality Before	Quality After	Quality Change
gaphor/ui/mainwindow.py	71.94% 🙂	71.88% 🙂	-0.06% 👎
gaphor/ui/namespace.py	73.23% 🙂	76.77% ⭐	3.54% 👍
gaphor/ui/namespaceview.py	49.69% 😞	55.49% 🙂	5.80% 👍
gaphor/ui/treecomponent.py	67.87% 🙂	67.20% 🙂	-0.67% 👎
gaphor/ui/tests/test_mainwindow.py	90.31% ⭐	90.31% ⭐	0.00%
gaphor/ui/tests/test_namespace.py	90.38% ⭐	89.94% ⭐	-0.44% 👎
gaphor/ui/tests/test_treecomponent.py	85.70% ⭐	85.73% ⭐	0.03% 👍
tests/test_diagram_tools.py	71.30% 🙂	71.30% 🙂	0.00%

Here are some functions in these files that still need a tune-up:

File	Function	Complexity	Length	Working Memory	Quality	Recommendation
gaphor/ui/treecomponent.py	list_item_factory_setup	12 🙂	510 ⛔		33.41% 😞	Try splitting into smaller methods
gaphor/ui/namespaceview.py	namespace_view	14 🙂	293 ⛔		35.73% 😞	Try splitting into smaller methods
gaphor/ui/mainwindow.py	MainWindow.open	3 ⭐	388 ⛔		47.74% 😞	Try splitting into smaller methods
gaphor/ui/treecomponent.py	select_element	17 🙂	130 😞		49.65% 😞	Try splitting into smaller methods
gaphor/ui/namespace.py	popup_model	9 🙂	213 ⛔	8 🙂	52.95% 🙂	Try splitting into smaller methods

Legend and Explanation

The emojis denote the absolute quality of the code:

• ⭐ excellent
• 🙂 good
• 😞 poor
• ⛔ very poor

The 👍 and 👎 indicate whether the quality has improved or gotten worse with this pull request.

---

Please see our documentation here for details on how these metrics are calculated.

We are actively working on this report - lots more documentation and extra metrics to come!

Help us improve this quality report!

[danyeaw]

I like being able to right-click and add a new Package. The refactoring you did also is really nice, I like how the GTK4 and GTK3 code is split apart more for this component.

I noticed when I right-click and go to New Diagram, only the Class Diagram is displayed. Was this on purpose? Do we need diagrams that don't exist within any namespace / package?

[amolenaar]

I noticed when I right-click and go to New Diagram, only the Class Diagram is displayed. Was this on purpose? Do we need diagrams that don't exist within any namespace / package?

Somehow the menu is not resizing to contain all diagram types.

[amolenaar]

Not sure why the popup menu is not resizing.

Anyway, it may make sense to add all entries in the main menu anyhow:

[danyeaw]

Thanks @amolenaar, nice improvement!