Add settings search highlighting

[VicenteCartas]

Summary

• add rendered-text search indexing for shared settings pages while preserving explicit route aliases and excluding internal route IDs
• highlight matching tokens with a non-mutating JLayer overlay that supports plain text, Swing HTML, read-only editor panes, table cells, and standard table headers
• preserve section expansion state during filtering, avoid changing unrelated pages, and use simple viewport scrolling to prevent overlay artifacts
• add focused coverage for normalization, HTML geometry, renderer text, filtered and offscreen table rows, viewport clipping, lazy indexing, and reversible expansion behavior

Acknowledgements

This work builds on @hokvel's experimental MekHQ PR MegaMek/mekhq#9566, which introduced the user-visible-text-only search direction and highlighted matches in Campaign Options. This PR generalizes those ideas into the shared settings framework and replaces HTML text mutation with a non-mutating JLayer overlay after testing showed that HTML insertion could alter layout.

Validation

• ./gradlew :megamek:test --tests "megamek.client.ui.settings.*" :megamek:checkstyleMain :megamek:checkstyleTest
• manual long-page scrolling with active highlights using the mouse wheel and scrollbar
• manual highlight-legibility checks in light and dark themes in MegaMek and MekHQ

Video

Recording.2026-08-05.135348.mp4

[Copilot]

Pull request overview

Adds normalized settings-search indexing and a non-mutating highlight overlay for settings pages, so matches can be visually emphasized across common Swing components (including HTML text and table renderers) while preserving navigation behavior and section expansion state.

Changes:

• Introduces SettingsSearchText utilities for extracting rendered display text (plain/HTML/table/header) and mapping normalized tokens back to source offsets.
• Adds SettingsSearchHighlightLayerUI and wires it into SettingsContentHost to paint highlight overlays without modifying underlying component text/layout.
• Updates settings routing/pane logic to index rendered route/page text, exclude internal route IDs, preserve expansion state during filtering, and adds extensive unit/UI tests.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
megamek/src/megamek/client/ui/settings/SettingsSearchText.java	New rendered-text extraction + normalization/range mapping utilities for search/highlighting.
megamek/src/megamek/client/ui/settings/SettingsSearchHighlightLayerUI.java	New LayerUI overlay that computes and paints match highlight bounds across supported Swing components.
megamek/src/megamek/client/ui/settings/SettingsRoute.java	Switches route search indexing to rendered path text and rendered section text (excluding internal IDs).
megamek/src/megamek/client/ui/settings/SettingsPane.java	Tracks current route + expansion state across filtering; applies highlights and restores expansion state on clear.
megamek/src/megamek/client/ui/settings/SettingsPagePanel.java	Expands search indexing to include rendered titles/summaries/static content and full-page text; exposes expansion state APIs.
megamek/src/megamek/client/ui/settings/SettingsNavigationPanel.java	Publishes normalized filter changes via listener callback.
megamek/src/megamek/client/ui/settings/SettingsContentHost.java	Wraps content scrollpane in JLayer and enables simple scroll mode to support overlay repainting.
megamek/unittests/megamek/client/ui/settings/SettingsSearchTextTest.java	New tests for rendered text extraction, normalization, tokenization, and range mapping.
megamek/unittests/megamek/client/ui/settings/SettingsSearchHighlightLayerUITest.java	New headless UI tests verifying overlay painting behavior and geometry across component types.
megamek/unittests/megamek/client/ui/settings/SettingsRouteTest.java	Adds coverage ensuring internal IDs aren’t searchable and HTML labels don’t leak tokens.
megamek/unittests/megamek/client/ui/settings/SettingsPaneTest.java	Adds coverage for filter-driven expansion behavior, restoration, highlighting, and stale index clearing.
megamek/unittests/megamek/client/ui/settings/SettingsPagePanelTest.java	Adds coverage for page/body search text, rendered HTML, static components, and table/header search text behavior.
megamek/unittests/megamek/client/ui/settings/SettingsNavigationPanelTest.java	Adds coverage that filter callbacks publish normalized text.
megamek/unittests/megamek/client/ui/settings/SettingsContentHostTest.java	Adds coverage for highlight non-mutation and viewport SIMPLE_SCROLL_MODE.

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[codecov]

Codecov Report

❌ Patch coverage is 78.30375% with 110 lines in your changes missing coverage. Please review.
✅ Project coverage is 32.77%. Comparing base (60cccd2) to head (cb3a9db).
⚠️ Report is 92 commits behind head on main.

Files with missing lines	Patch %	Lines
...nt/ui/settings/SettingsSearchHighlightLayerUI.java	70.85%	32 Missing and 40 partials ⚠️
...megamek/client/ui/settings/SettingsSearchText.java	83.43%	8 Missing and 18 partials ⚠️
...k/src/megamek/client/ui/settings/SettingsPane.java	85.00%	1 Missing and 5 partials ⚠️
.../megamek/client/ui/settings/SettingsPagePanel.java	91.11%	0 Missing and 4 partials ⚠️
...ek/client/ui/settings/SettingsNavigationPanel.java	75.00%	0 Missing and 1 partial ⚠️
.../src/megamek/client/ui/settings/SettingsRoute.java	83.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8646      +/-   ##
============================================
+ Coverage     32.58%   32.77%   +0.19%     
- Complexity    23857    24221     +364     
============================================
  Files          3428     3441      +13     
  Lines        333573   334799    +1226     
  Branches      58537    58797     +260     
============================================
+ Hits         108694   109747    +1053     
- Misses       212381   212435      +54     
- Partials      12498    12617     +119     

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[IllianiBird]

Nothing serious stands out