Added #

• Flutter Shortcuts / Actions pattern for keyboard handling — enables consumers to override, extend, or remap any keyboard shortcut
• Worksheet.shortcuts parameter — custom shortcut bindings merged on top of defaults
• Worksheet.actions parameter — custom action overrides merged on top of defaults
• DefaultWorksheetShortcuts — static map of ~44 default shortcut bindings (both control: and meta: variants for cross-platform)
• 13 Intent classes (MoveSelectionIntent, GoToCellIntent, ClearCellsIntent, etc.)
• 13 Action classes with WorksheetActionContext interface for dependency injection
• WorksheetActionContext — abstract interface implemented by the widget state, avoiding 6+ constructor params per Action
• New shortcuts: Ctrl+C/X/V (copy/cut/paste), Ctrl+D (fill down), Ctrl+R (fill right), Delete/Backspace (clear cells)
• Worksheet.editController parameter for integrated cell editing — renders CellEditorOverlay internally, handles type-to-edit, commit-and-navigate, and F2/double-tap editing
• Type-to-edit: printable characters start editing the focused cell with that character as initial content
• Commit-and-navigate: Enter (down), Shift+Enter (up), Tab (right), Shift+Tab (left) commit the edit and move selection
• CellEditorOverlay.onCommitAndNavigate callback for directional commit with row/column delta
• Arrow keys commit the edit and navigate when editing (via CellEditorOverlay)
• Tap outside the editing cell commits the current edit
• EditCommitResult value class on EditController
• Backspace/Delete tests for editing vs navigation mode

Deprecated #

• KeyboardHandler class — use the Shortcuts / Actions pattern instead (see worksheet_intents.dart)

Changed #

• Worksheet widget now uses Shortcuts -> Actions -> Focus widget tree instead of Focus(onKeyEvent:) with KeyboardHandler
• Destructive actions (ClearCells, Cut, Paste, FillDown, FillRight) check readOnly in isEnabled() as defense-in-depth
• Cell-level actions (copy, cut, paste, clear, select-all) are disabled while the editController is editing, so Ctrl+C/X/V/A and Backspace/Delete reach the text field for in-cell editing
• CellEditorOverlay uses TextField with InputDecoration.collapsed for proper cursor rendering, text selection, and double-click word selection
• Parent double-tap handler suppressed while editing so the TextField's word-select gesture wins the gesture arena
• Pointer-down within the editing cell is passed through to the TextField for cursor repositioning instead of committing the edit
• TilePainter.editingCell field hides tile-rendered text for the cell being edited (avoids double rendering)

Added #

• WorksheetController.getCellScreenBounds() — returns screen-space Rect for a cell, accounting for zoom, scroll offset, and headers
• WorksheetController.ensureCellVisible() — simplified scroll-to-cell that uses the attached layout
• WorksheetController.hasLayout / layoutSolver / headerWidth / headerHeight — public read access to the widget's internal layout state
• WorksheetController.attachLayout() / detachLayout() — called by the Worksheet widget to share its internal LayoutSolver

Fixed #

• Cell text disappearing on alternating rows after column resize — cell backgrounds straddling a tile boundary overflowed into adjacent tiles because PictureRecorder cullRect is only a hint; added hard clipRect to tile canvas
• Deferred TextPainter disposal until after PictureRecorder.endRecording() to prevent premature native Paragraph resource release

Changed #

• Worksheet widget now attaches its LayoutSolver and header dimensions to the controller after initialization
• Simplified _ensureSelectionVisible in Worksheet to use ensureCellVisible
• Example app no longer creates a duplicate LayoutSolver; uses controller.getCellScreenBounds() instead
• Updated GETTING_STARTED.md, COOKBOOK.md, API.md, and ARCHITECTURE.md to reflect the new API

Added #

• CellFormat class with Excel-style format codes for cell display formatting
• 16 built-in format presets (currency, percentage, date, scientific, fraction, etc.)
• CellFormatType enum with 12 format categories
• Cell.format field for per-cell formatting
• Cell.displayValue getter — uses format when present
• Cell.copyWithFormat() method
• WorksheetData.getFormat()/setFormat() with backward-compatible defaults
• SparseWorksheetData format storage with change events and batch support
• DataChangeType.cellFormat event type

Changed #

• TilePainter and FrozenLayer use CellFormat when rendering cell content
• Cell.isEmpty considers format field

Deprecated #

• CellStyle.numberFormat — use CellFormat on Cell instead

Added #

• Built-in keyboard navigation in Worksheet widget (arrow keys, Tab, Enter, Home/End, PageUp/Down, F2, Escape, Ctrl+A)
• 18 widget-level keyboard navigation tests
• Release process checklist in CLAUDE.md

Fixed #

• Selection and header layers now repaint on selection change (CustomPainter repaint listenable)

Changed #

• Simplified example/main.dart by removing manual keyboard handling code
• Updated COOKBOOK.md keyboard navigation section to reflect built-in support

Added #

• Screenshot in README.md via golden test
• GitHub Actions CI workflow for automated testing
• Codecov integration for coverage reporting
• Roboto font bundled for consistent text rendering

Fixed #

• Resolved all dart analyzer warnings in lib/ and test/
• Fixed installation instructions to use pub.dev version
• Golden tests excluded from CI (platform-dependent font rendering)

Changed #

• README badges: pub.dev version, license, CI status, coverage

Added #

• Example application with 50,000 rows of sample sales data
• Performance benchmarks for tile rendering (< 8ms target)
• Performance benchmarks for hit testing (< 100μs target)
• Scroll performance benchmarks
• Large dataset integration tests
• Memory leak tests
• Comprehensive documentation suite:
  • ARCHITECTURE.md with rendering pipeline deep dive
  • GETTING_STARTED.md with installation and basic usage
  • COOKBOOK.md with practical recipes
  • PERFORMANCE.md optimization guide
  • THEMING.md customization guide
  • TESTING.md testing patterns
  • API.md quick reference
• Updated PLAN.md to reflect completed implementation

Changed #

• Version bumped to 1.0.0 for production release

Added #

• WorksheetWidget - Main public StatefulWidget
• WorksheetController - Programmatic control aggregating sub-controllers
• WorksheetThemeData - Complete theming and styling support
• WorksheetTheme - InheritedWidget for theme propagation
• Complete public API exports in worksheet.dart
• Gesture handling integration
• Layer composition using Stack

Added #

• RenderLayer - Abstract interface for render layers
• SelectionLayer - Selection highlight painting
• SelectionRenderer - Selection visual rendering
• HeaderLayer - Row and column header layer
• HeaderRenderer - A,B,C column and 1,2,3 row labels
• FrozenLayer - Infrastructure for frozen panes (not fully wired)

Added #

• EditController - Cell editing orchestration with start/commit/cancel flow
• EditTrigger enum - Double-tap, keyboard, and typing triggers
• CellEditorOverlay - Floating text editor widget for cell editing

Added #

• SelectionController - Selection state machine with single/range/row/column modes
• HitTester - Coordinate resolution from screen to worksheet space
• HitTestResult - Types for cell, header, and resize handle hits
• GestureHandler - Unified gesture processing
• KeyboardHandler - Arrow keys and keyboard shortcuts
• ScaleHandler - Pinch-to-zoom gesture handling

Added #

• ZoomController - Zoom level management extending ValueNotifier
• Support for 10%-400% zoom range (0.1 to 4.0)
• zoomIn(), zoomOut(), and reset() methods
• Zoom clamping and validation

Added #

• ScrollAnchor - Position preservation during zoom
• WorksheetScrollPhysics - Custom scroll momentum physics
• ViewportDelegate - Interface for viewport management
• WorksheetViewport - TwoDimensionalScrollable integration
• WorksheetScrollDelegate - Child management for 2D scrolling

Added #

• TileCoordinate - Tile grid position representation
• TileConfig - Configuration with 256px tiles, LRU cache settings
• Tile - Single cached tile with GPU-backed ui.Picture
• TilePainter - Cell painting with level-of-detail (LOD) rendering
• TileCache - LRU eviction cache for tiles
• TileManager - Tile lifecycle orchestration

Performance #

• GPU-backed tile caching for smooth scrolling
• Level-of-detail rendering based on zoom level
• LRU cache eviction to manage memory

Added #

• WorksheetData - Abstract interface for worksheet data access
• SparseWorksheetData - Map-based sparse storage implementation
• DataChangeEvent - Granular change events for reactive updates
• SpanList - Cumulative row/column sizes with O(log n) lookups
• LayoutSolver - Position to index conversion
• VisibleRangeCalculator - Viewport to CellRange queries
• ZoomTransformer - Zoom-aware coordinate math with ZoomBucket enum

Performance #

• O(log n) binary search for position lookups
• Memory-efficient sparse data storage

Added #

• Initial project scaffolding
• CellCoordinate - Immutable (row, col) address with Excel notation (A1, AA100)
• CellRange - Rectangular cell selection with normalization and contains()
• CellValue - Union type supporting text, number, boolean, formula, error, date
• CellStyle - Font, color, alignment, and border styling
• FreezeConfig - Configuration for frozen panes
• Full test coverage for all core models
• CLAUDE.md development guide
• PLAN.md implementation plan

Technical #

• TDD workflow with tests written before implementation
• SOLID principles applied throughout
• Immutable models with proper equality/hashCode