Metrics Module

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type: module title: Metrics Module created: '2026-05-25' updated: '2026-05-25' tags:

• domain/metrics status: mature related:
• 'Feature Location Module'
• 'Plugin Extensions Module'
• 'Feature Metrics View'
• 'HAnS Feature Model' sources:
• .raw/ProjectMetrics.java
• .raw/FeatureScattering.java
• .raw/FeatureTangling.java
• .raw/NestingDepths.java
• .raw/MetricsViewFactory.java

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Metrics Module

Package: se.isselab.HAnS.metrics

ProjectMetrics — data model

Immutable snapshot constructed from 3 maps. All aggregate fields computed at construction time.

Field	Type	Description
tanglingMap	Map<FeatureModelFeature, HashSet<FeatureModelFeature>>	Per-feature set of features it tangles with
featureFileMappings	Map<String, FeatureFileMapping>	LPQ → file mapping for every feature
nestingDepthMap	Map<String, List<Pair<String, Integer>>>	LPQ → list of (filePath, nestingDepth)
NumberOfFeatures	int	featureFileMappings.size()
NumberOfAnnotatedFiles	int	Distinct file paths across all mappings
AvgScatteringDegree	double	Mean of per-feature scattering degrees
AvgLinesOfFeatureCode	double	Mean of per-feature total line counts
AvgNestingDepth	double	Mean over all (feature, file) nesting depth pairs

Calculator classes

All three: utility classes (private constructor, static methods only).

FeatureScattering

static int getScatteringDegree(FeatureFileMapping)

Algorithm: For each file, collect annotated lines into TreeSet<Integer> (sorted, deduped). Walk sorted set — new segment when line != prevLine + 1. Sum segments across files.

[!key-insight] O(N log N) per file. Two adjacent lines = 1 segment.

FeatureTangling

static int getFeatureTanglingDegree(Project, FeatureModelFeature) static Map<FeatureModelFeature, HashSet<FeatureModelFeature>> getTanglingMap(Project)

Algorithm: Build filePath → {feature → [FeatureLocationBlock]}. For each pair (A, B) in same file, if any block of A hasSharedLines() with any block of B, record A→B and B→A (symmetric).

Intersection test: !(other.start > this.end || other.end < this.start)

[!key-insight] Symmetric and per-line-overlap. Two features in the same file but non-overlapping blocks are NOT tangled.

NestingDepths

static List<Pair<String,Integer>> getFeatureNestingDepths(Project, FeatureModelFeature) static Map<String, List<Pair<String,Integer>>> getNestingDepthMap(Map<String,FeatureFileMapping>)

Algorithm: For each (feature, file), count blocks of other features that fully contain each block of this feature (isInsideOfBlock: other.start ≤ this.start AND other.end ≥ this.end). depth = 1 + maxContainmentCount.

Exposed dimensions: avgNestingDepth, maxNestingDepth, minNestingDepth (set on FeatureModelFeature by GetProjectMetrics).

[!key-insight] Base depth is 1 (not 0).

MetricsViewFactory — UI wiring

createToolWindowContent() calls triggerService() immediately.

triggerService(): gets MetricsService project service → getProjectMetricsBackground(metrics → refreshTableContent()).

Dumb mode: deferred via DumbService.runWhenSmart().

refreshTableContent(): clears panel, builds new JBTable (10 columns, all sortable), wraps in JBScrollPane, adds to BorderLayout.CENTER. Root features skipped. Title bar has manual "Refresh" button.

Related

• Plugin Extensions Module — ProjectMetricsService orchestrates calculators
• Feature Location Module — FeatureFileMapping / FeatureLocationBlock are calculator inputs
• Feature Metrics View — UI consumer