"/home/yossef/notes/git/projects/maplibra/risks/Theme Controller Risks.md"

path: maplibra/risks/Theme Controller Risks.md

- **fileName**: Theme Controller Risks
- **Created on**: 2026-06-16 00:48:42

Theme Controller Risks

Migrated from: obs_vault

Parent: ../flows/Theme Change.md

This note covers the UI controller that applies theme changes through the map and the shell.

Main Source File

• src/ui/ThemeController.js

What It Does

• Watches the theme toggle button, storage events, and system color-scheme changes.
• Applies the chosen theme to the map, the layer manager, and the pathfinding controller.

Why It Matters

• This is the bridge between user intent and the actual visual theme state.

Risks

• destroy() removes a handler reference that is not the same function object used during addEventListener, so teardown is likely incomplete.
• The controller also adds anonymous storage and media-query listeners without a matching cleanup path.
• toggleTheme() and applyTheme() both call the persistence path, which can duplicate theme-changed events.
• With onThemeChange provided, controller propagation to layer manager and pathfinding controller is delegated outside the class.

See Also

• ../flows/Theme Change.md

• ./Error Toast and Location Validation.md

• ./Shell Bootstrap Risks.md

• ./Theme Controller Listener Cleanup.md

• ./Theme Tests and Fix Plan.md

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