feat: Add comprehensive keyboard shortcuts and VS Code-style Command Palette System

KEYBOARD_SHORTCUTS.md

@@ -0,0 +1,392 @@
+# Keyboard Shortcuts & Command Palette
+
+## Overview
+
+ResCanvas now features a comprehensive keyboard shortcuts system and VS Code-style command palette for power users to work efficiently without mouse/toolbar interactions.
+
+## Features
+
+### ⌨️ Keyboard Shortcuts
+
+- **Tools**: Single-key shortcuts (P, E, R, C, L, A) for quick tool switching
+- **Edit**: Ctrl+Z/Ctrl+Shift+Z for undo/redo
+- **Canvas**: Ctrl+R refresh, Ctrl+Shift+K clear
+- **Commands**: Ctrl+K command palette, Ctrl+/ shortcuts help
+
+### 🎯 Command Palette (Ctrl+K)
+
+VS Code-style quick access to all commands:
+- Fuzzy search with keyword matching
+- Keyboard navigation (↑↓ arrows, Enter to select)
+- Recent commands tracking
+- Category grouping
+- Shortcut display for each command
+
+### 📖 Keyboard Shortcuts Help (Ctrl+/)
+
+Comprehensive shortcut reference:
+- Organized by category (Tools, Edit, Canvas, Commands)
+- Tab navigation between categories
+- Search/filter functionality
+- Platform-specific display (⌘ for Mac, Ctrl for Windows/Linux)
+
+## Usage
+
+### Opening Dialogs
+
+```javascript
+// Command Palette
+Press: Ctrl+K (Cmd+K on Mac)
+
+// Shortcuts Help
+Press: Ctrl+/ (Cmd+/ on Mac)
+
+// Cancel/Close
+Press: Escape
+```
+
+### Available Shortcuts
+
+#### Tools (No modifiers)
+- `P` - Pen tool
+- `E` - Eraser
+- `R` - Rectangle
+- `C` - Circle
+- `L` - Line
+- `A` - Arrow
+
+#### Edit Operations
+- `Ctrl+Z` - Undo
+- `Ctrl+Shift+Z` - Redo
+
+#### Canvas Operations
+- `Ctrl+R` - Refresh canvas
+- `Ctrl+Shift+K` - Clear canvas
+- `Ctrl+,` - Canvas settings (if available)
+
+#### Commands
+- `Ctrl+K` - Command palette
+- `Ctrl+/` - Keyboard shortcuts help
+- `Escape` - Cancel current action
+
+## Architecture
+
+### Core Services
+
+#### KeyboardShortcutManager (`frontend/src/services/KeyboardShortcuts.js`)
+
+Manages registration and execution of keyboard shortcuts:
+
+```javascript
+import { KeyboardShortcutManager } from '../services/KeyboardShortcuts';
+
+const manager = new KeyboardShortcutManager();
+
+// Register a shortcut
+manager.register(
+  'k',                           // key
+  { ctrl: true },                // modifiers
+  () => openCommandPalette(),    // action
+  'Open Command Palette',        // description
+  'Commands'                     // category
+);
+
+// Handle key events
+document.addEventListener('keydown', (e) => manager.handleKeyDown(e));
+```
+
+Features:
+- Conflict detection and warnings
+- Input field detection (shortcuts disabled in text inputs)
+- Platform-aware display (⌘/Ctrl)
+- Enable/disable shortcuts dynamically
+- Category grouping
+
+#### CommandRegistry (`frontend/src/services/CommandRegistry.js`)
+
+Central registry for all executable commands:
+
+```javascript
+import { commandRegistry } from '../services/CommandRegistry';
+
+// Register a command
+commandRegistry.register({
+  id: 'canvas.clear',
+  label: 'Clear Canvas',
+  description: 'Remove all strokes from canvas',
+  keywords: ['delete', 'erase', 'reset'],
+  action: () => clearCanvas(),
+  category: 'Canvas',
+  shortcut: { key: 'k', modifiers: { ctrl: true, shift: true } },
+  enabled: () => editingEnabled  // Optional condition
+});
+
+// Execute command
+await commandRegistry.execute('canvas.clear');
+
+// Search commands
+const results = commandRegistry.search('clear');
+```
+
+Features:
+- Command search with keyword matching
+- Enabled/visible state functions
+- Event listeners for execution tracking
+- Category organization
+- Batch registration
+
+### Components
+
+#### CommandPalette (`frontend/src/components/CommandPalette.jsx`)
+
+VS Code-style command search and execution:
+
+```jsx
+<CommandPalette
+  open={commandPaletteOpen}
+  onClose={() => setCommandPaletteOpen(false)}
+  commands={commandRegistry.getAll()}
+  onExecute={(command) => command.action()}
+/>
+```
+
+Features:
+- Fuzzy search with keyword matching
+- Keyboard navigation (↑↓, Enter, Escape)
+- Recent commands tracking (localStorage)
+- Category headers
+- Shortcut display
+- Empty state messaging
+
+#### KeyboardShortcutsHelp (`frontend/src/components/KeyboardShortcutsHelp.jsx`)
+
+Comprehensive shortcuts reference:
+
+```jsx
+<KeyboardShortcutsHelp
+  open={shortcutsHelpOpen}
+  onClose={() => setShortcutsHelpOpen(false)}
+  shortcuts={manager.getAllShortcuts()}
+/>
+```
+
+Features:
+- Tab navigation by category
+- Search/filter shortcuts
+- Platform-specific key display
+- Quick tips section
+- Responsive design
+
+### Configuration
+
+#### Default Shortcuts (`frontend/src/config/shortcuts.js`)
+
+Centralized shortcut definitions:
+
+```javascript
+export const DEFAULT_SHORTCUTS = [
+  {
+    id: 'tool.pen',
+    key: 'p',
+    modifiers: {},
+    label: 'Select Pen Tool',
+    description: 'Switch to pen/brush tool for drawing',
+    category: 'Tools',
+    keywords: ['draw', 'brush', 'pencil']
+  },
+  // ... more shortcuts
+];
+```
+
+## Integration
+
+### Canvas Component
+
+The Canvas component registers all shortcuts on mount:
+
+```javascript
+// In Canvas.js
+useEffect(() => {
+  const manager = new KeyboardShortcutManager();
+
+  // Register commands
+  commandRegistry.register({
+    id: 'edit.undo',
+    label: 'Undo',
+    action: undo,
+    shortcut: { key: 'z', modifiers: { ctrl: true } }
+  });
+
+  // Register keyboard shortcuts
+  manager.register('z', { ctrl: true }, undo, 'Undo', 'Edit');
+
+  // Add global listener
+  const handleKeyDown = (e) => manager.handleKeyDown(e);
+  document.addEventListener('keydown', handleKeyDown);
+
+  return () => {
+    document.removeEventListener('keydown', handleKeyDown);
+    manager.clear();
+  };
+}, [dependencies]);
+```
+
+### Adding New Shortcuts
+
+1. **Define the action function** in your component
+2. **Add command to registry** in the useEffect hook:
+
+```javascript
+commandRegistry.register({
+  id: 'feature.myAction',
+  label: 'My Action',
+  description: 'Description of what it does',
+  keywords: ['search', 'terms'],
+  action: myActionFunction,
+  category: 'Feature',
+  shortcut: { key: 'm', modifiers: { ctrl: true } },
+  enabled: () => someCondition  // Optional
+});
+```
+
+3. **Register keyboard shortcut**:
+
+```javascript
+manager.register(
+  'm',
+  { ctrl: true },
+  myActionFunction,
+  'My Action',
+  'Feature'
+);
+```
+
+## Best Practices
+
+### 1. Use Descriptive Labels
+```javascript
+// Good
+label: 'Clear Canvas'
+description: 'Remove all strokes from canvas'
+
+// Bad
+label: 'Clear'
+description: 'Clears stuff'
+```
+
+### 2. Add Keywords for Searchability
+```javascript
+keywords: ['delete', 'erase', 'reset', 'remove']  // Good
+keywords: []  // Bad
+```
+
+### 3. Check Conditions Before Execution
+```javascript
+action: () => {
+  if (!editingEnabled) {
+    showSnackbar('Action disabled in view-only mode');
+    return;
+  }
+  performAction();
+}
+```
+
+### 4. Provide Feedback
+```javascript
+action: () => {
+  setDrawMode('pen');
+  showSnackbar('Pen tool selected');  // User feedback
+}
+```
+
+### 5. Avoid Input Field Conflicts
+The KeyboardShortcutManager automatically disables shortcuts when typing in input fields. For special cases:
+
+```javascript
+manager.register(
+  'enter',
+  {},
+  submitForm,
+  'Submit Form',
+  'Actions',
+  false  // allowInInput = false (default)
+);
+```
+
+## Testing
+
+### Manual Testing Checklist
+
+- [ ] Ctrl+K opens command palette
+- [ ] Ctrl+/ opens shortcuts help
+- [ ] Escape closes dialogs
+- [ ] Tool shortcuts (P, E, R, C, L, A) switch tools
+- [ ] Ctrl+Z / Ctrl+Shift+Z perform undo/redo
+- [ ] Ctrl+R refreshes canvas
+- [ ] Shortcuts disabled when typing in text fields
+- [ ] Command palette search works
+- [ ] Recent commands are tracked
+- [ ] Arrow keys navigate command palette
+- [ ] Enter executes selected command
+
+### Unit Tests
+
+```javascript
+// Example test for KeyboardShortcutManager
+import { KeyboardShortcutManager } from '../services/KeyboardShortcuts';
+
+test('registers and executes shortcut', () => {
+  const manager = new KeyboardShortcutManager();
+  const mockAction = jest.fn();
+
+  manager.register('k', { ctrl: true }, mockAction);
+
+  const event = new KeyboardEvent('keydown', {
+    key: 'k',
+    ctrlKey: true
+  });
+
+  manager.handleKeyDown(event);
+
+  expect(mockAction).toHaveBeenCalled();
+});
+```
+
+## Troubleshooting
+
+### Shortcuts Not Working
+
+1. **Check console for conflicts**: The manager logs conflicts when registering duplicate shortcuts
+2. **Verify enabledcondition**: Commands with `enabled: () => false` won't execute
+3. **Check input focus**: Shortcuts are disabled in text inputs by default
+4. **Inspect event listeners**: Ensure the global keydown listener is attached
+
+### Command Palette Empty
+
+1. **Verify command registration**: Check `commandRegistry.getAll()` in console
+2. **Check visible conditions**: Commands with `visible: () => false` won't appear
+3. **Clear browser cache**: Recent commands stored in localStorage may cause issues
+
+### Platform-Specific Issues
+
+- **Mac**: Uses `⌘` (Command) key instead of Ctrl
+- **Detection**: Based on `navigator.platform.toUpperCase().indexOf('MAC')`
+- **Both supported**: `event.ctrlKey || event.metaKey` handles both
+
+## Future Enhancements
+
+- [ ] User-customizable shortcut mappings
+- [ ] Macro recording (repeat action sequences)
+- [ ] Vim-mode keybindings
+- [ ] Quick command history (Ctrl+P style)
+- [ ] Contextual command suggestions
+- [ ] Shortcut conflict resolution UI
+- [ ] Export/import shortcut configurations
+- [ ] Workspace-specific shortcuts
+
+## Resources
+
+- **VS Code Shortcuts**: Inspiration for command palette UX
+- **Figma Shortcuts**: Reference for design tool workflows
+- **Material-UI**: Component library used for dialogs
+- **Web Keyboard API**: MDN documentation for key events