Support display and connection of attributes that are part of GroupAttributes

[cbentejac]

Description

This PR replaces #2544 and #2754.

The main feature of this PR is that it adds the support of connections between attributes that are part of a GroupAttribute. Prior to this PR, these attributes could neither be connected individually, nor be displayed in the Graph Editor; they were however visible and editable in the Node Editor.

GroupAttributes are now displayed in the Graph Editor with a right chevron, which means they can be expanded when clicked upon. When this happens, all the children attributes of the clicked GroupAttribute are displayed below it, in a tree view with the indentation reflecting their depth level.

Connections between two GroupAttributes of a similar structure are now supported. If the GroupAttributes have different structures, the connection will be refused straight away and the user will not even be able to select the group's pin.

Connecting two GroupAttributes together explicitly connects all their children attributes together. If any of the children attributes is disconnected or reconnected to another attribute, then the connection between the groups is broken.

Features list

• Add the notion of depth for attributes that are children of a GroupAttribute. An attribute that has no parent will have a depth of 0, and it will increase of 1 for every parent;
• Add a flatStaticChildren property for every attribute that may have children that contains the flattened list of said children;
• Correctly evaluate links when they reference children attributes, hence adding the support of the connection of individual attributes within groups;
• Add an icon to expand or collapse GroupAttributes and display their children attributes in their node in the Graph Editor with a tree view. These children attributes are graphically connectable;
• Display the full name of the attribute in its tooltip in the Graph Editor. If an attribute childAttribute is a child of a group groupAttribute, its name will be displayed as groupAttribute.childAttribute, making the relationship between the two obvious.

Implementation remarks

Connections between attributes used to be handle directly with the addEdge and removeEdge methods. Two new methods, connectTo and disconnectEdge, are added and now directly call addEdge and removeEdge while handling all the specific connection/disconnection operations that are required when connecting GroupAttributes together.

[codecov]

Codecov Report

❌ Patch coverage is 95.72447% with 18 lines in your changes missing coverage. Please review.
✅ Project coverage is 79.68%. Comparing base (f7a48c9) to head (aafd268).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
meshroom/core/attribute.py	90.51%	13 Missing ⚠️
meshroom/core/graph.py	85.18%	4 Missing ⚠️
meshroom/core/node.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2965      +/-   ##
===========================================
+ Coverage    78.91%   79.68%   +0.76%     
===========================================
  Files           59       64       +5     
  Lines         8305     8600     +295     
===========================================
+ Hits          6554     6853     +299     
+ Misses        1751     1747       -4     

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[Copilot]

Pull request overview

This PR adds comprehensive support for connecting and displaying GroupAttribute children in the Graph Editor. Previously, attributes nested within GroupAttributes were only accessible in the Node Editor. Now users can expand GroupAttributes to view and connect their child attributes directly in the Graph Editor.

Key changes:

• Introduces connectTo() and disconnectEdge() methods to replace direct addEdge()/removeEdge() calls, enabling proper handling of GroupAttribute connections
• Adds expand/collapse UI with chevron icons for GroupAttributes in the Graph Editor, displaying children in a tree view with depth-based indentation
• Implements structural validation for GroupAttribute connections, ensuring only compatible structures can be connected

Reviewed changes

Copilot reviewed 29 out of 29 changed files in this pull request and generated 13 comments.

Show a summary per file

File	Description
meshroom/core/attribute.py	Core logic for attribute connections, depth tracking, flatStaticChildren property, and GroupAttribute validation/connection handling
meshroom/core/graph.py	Updated addEdge/removeEdge to return edge tuples, added cyclic dependency detection
meshroom/core/exception.py	Added InvalidEdgeError and CyclicDependencyError exceptions
meshroom/core/node.py	Enhanced CompatibilityNode to handle GroupAttribute deserialization
meshroom/ui/commands.py	Updated AddEdgeCommand and RemoveEdgeCommand to use new connectTo/disconnectEdge methods with proper undo/redo
meshroom/ui/graph.py	Fixed edge removal logic for non-ListAttribute edges
meshroom/ui/qml/GraphEditor/AttributePin.qml	Major UI enhancements: expand/collapse functionality, tree view with depth-based padding, improved connection validation
meshroom/ui/qml/GraphEditor/Node.qml	Updated to use generateAttributesModel for dynamic attribute display including children
meshroom/ui/qml/GraphEditor/GraphEditor.qml	Enhanced edge rendering with getAttributePin() to show edges for collapsed GroupAttributes
meshroom/ui/qml/MaterialIcons/MaterialToolLabel.qml	Refactored component to expose icon and label separately for better flexibility
tests/test_groupAttributes.py	Comprehensive test suite for GroupAttribute connections, structure validation, and serialization
tests/nodes/test/*.py	New test nodes (GroupAttributes, Position, Color, NestedPosition, NestedColor, NestedTest)
All other test files	Converted from graph.addEdge() to attribute.connectTo() calls

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