Show relationships on top of other elements

[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?

Issue Number: #1073

What is the new behavior?

Diagram items are sorted in a way that lines will always be rendered on top, irregardless the nesting structure.

Does this PR introduce a breaking change?

• Yes
• No

Other information

I wanted to solve it by adding sorting ownedPresentation, but that did not work (#1083).

I also did some cleanup.

[sourcery-ai]

Sourcery Code Quality Report

✅  Merging this PR will increase code quality in the affected files by 0.22%.

Quality metrics	Before	After	Change
Complexity	1.47 ⭐	1.40 ⭐	-0.07 👍
Method Length	30.52 ⭐	30.19 ⭐	-0.33 👍
Working memory	5.38 ⭐	5.35 ⭐	-0.03 👍
Quality	85.82% ⭐	86.04% ⭐	0.22% 👍

Other metrics	Before	After	Change
Lines	1371	1387	16

Changed files	Quality Before	Quality After	Quality Change
gaphor/core/modeling/diagram.py	88.76% ⭐	88.51% ⭐	-0.25% 👎
gaphor/core/modeling/element.py	94.13% ⭐	94.00% ⭐	-0.13% 👎
gaphor/core/modeling/presentation.py	86.56% ⭐	86.56% ⭐	0.00%
gaphor/core/modeling/tests/test_diagram.py	94.57% ⭐	94.94% ⭐	0.37% 👍
gaphor/services/undomanager.py	82.41% ⭐	82.74% ⭐	0.33% 👍
gaphor/services/tests/test_undo_presentation.py	80.69% ⭐	80.66% ⭐	-0.03% 👎

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

File	Function	Complexity	Length	Working Memory	Quality	Recommendation
gaphor/services/undomanager.py	UndoManager.undo_delete_element_event	9 🙂	121 😞	9 🙂	59.53% 🙂	Try splitting into smaller methods
gaphor/services/undomanager.py	UndoManager.undo_association_set_event	3 ⭐	81 🙂	11 😞	66.82% 🙂	Extract out complex expressions
gaphor/services/undomanager.py	UndoManager.undo_association_add_event	1 ⭐	75 🙂	10 😞	71.60% 🙂	Extract out complex expressions
gaphor/services/undomanager.py	UndoManager.undo_association_delete_event	1 ⭐	75 🙂	10 😞	71.60% 🙂	Extract out complex expressions
gaphor/services/undomanager.py	UndoManager.undo_attribute_change_event	0 ⭐	59 ⭐	11 😞	73.16% 🙂	Extract out complex expressions

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.

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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]

Nice fix and I like the additional cleanups!