Summary

This pull request refactors and improves the handling of paragraph and list styles within the Android EnrichedText editor. The changes focus on making the application and removal of styles more robust, consistent, and maintainable, especially when dealing with zero-width spaces and multi-paragraph selections. The code now uses replacement-based updates for styling, improves span boundary safety, and enhances style state detection logic.

Refactoring and Consistency Improvements

• Refactored the application of list and paragraph styles to use dedicated replacement builders (buildStyledListReplacement and buildStyledParagraphReplacement), ensuring more consistent handling of zero-width spaces and multi-paragraph selections.
• Improved span removal logic to safely handle boundaries and avoid errors, and to ensure zero-width spaces are properly removed or inserted as needed.

Style State Detection and Emission

• Reworked the logic for detecting and emitting the current style state, especially for paragraph and list styles, by introducing new helper methods like getCoveredParagraphStyleStart and enhancing alignment handling.

Span Application and Alignment

• Updated span application to use applyParagraphSpan instead of direct setSpan calls for list styles, improving the reliability of span application over paragraphs.
• Modified alignment application to apply alignment spans per paragraph within a list, ensuring more granular and accurate alignment styling.

Code Quality and Safety

• Added safety checks for span boundaries (e.g., using coerceAtMost, coerceAtLeast, coerceIn) to prevent out-of-bounds errors.

Minor Improvements

• Updated imports and replaced usage of EnrichedParagraphSpan with EnrichedSpan for better type safety and future extensibility.
• Minor fixes to ensure that zero-width spaces are inserted or removed in a transaction-safe manner, reducing the risk of inconsistent text state.

Test Plan

First scenario

1. Open the editor app
2. Apply lisst styles
3. Type some text
4. Apply alignment

Second scenario

1. Type two paragraphs of text
2. Apply any header styles
3. Select these two paragraphs
4. Observe that heading style is enabled in the toolbar

• Steps to reproduce the bug (if this is a bug fix)
• Steps to verify the new feature
• Expected vs actual results
• Any special conditions or edge cases to test

Screenshots / Videos

First scenario

Second scenario

Compatibility