Initial commit: add all skills files

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

android-native-dev/references/accessibility.md

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+# Accessibility Guidelines
+
+Comprehensive accessibility requirements for Android applications.
+
+## Core Requirements
+
+### Minimum Standards
+
+| Requirement | Specification |
+|-------------|---------------|
+| Color contrast (text) | 4.5:1 minimum |
+| Color contrast (large text) | 3:1 minimum |
+| Color contrast (UI components) | 3:1 minimum |
+| Touch targets | 48 × 48dp minimum |
+| Content descriptions | All interactive elements |
+| Focus indicators | Clearly visible |
+| Screen reader support | Proper semantics |
+
+## Content Labels
+
+### contentDescription
+
+Use for non-text interactive elements.
+
+**When to use:**
+- ImageView, ImageButton
+- CheckBox, Switch (state description)
+- Custom drawable views
+- Icons that convey meaning
+
+**When NOT to use:**
+- TextView (uses text content automatically)
+- Decorative images (set to null)
+- Elements with labelFor relationship
+
+### android:hint
+
+Use for editable text fields to show placeholder text.
+
+**Important**: Don't use contentDescription on EditText—it interferes with accessibility services.
+
+### android:labelFor
+
+Link labels to input fields by setting labelFor on the TextView to reference the EditText ID.
+
+## Label Best Practices
+
+### Do's
+
+| Practice | Example |
+|----------|---------|
+| Be concise | "Save" not "Click here to save" |
+| Describe action/purpose | "Delete message" |
+| Be unique in context | "Delete item 3" not just "Delete" |
+| Update dynamically | "Pause" ↔ "Play" based on state |
+
+### Don'ts
+
+| Avoid | Reason |
+|-------|--------|
+| Include element type | TalkBack announces "button" automatically |
+| Say "button", "image", etc. | Redundant with accessibility info |
+| Use "click" or "tap" | Input method varies |
+| Leave empty/generic | "Button" or "Image" is unhelpful |
+
+### Examples
+
+| Bad | Good |
+|-----|------|
+| "Save button" | "Save" |
+| "Click here to submit" | "Submit" |
+| "Image" | "Profile photo of John" |
+| "Button 1" | "Add to cart" |
+
+## Focus and Navigation
+
+### Focus Groups
+
+Group related elements using `screenReaderFocusable="true"` on the container and `focusable="false"` on child elements. TalkBack will announce all children's content in a single utterance.
+
+### Headings
+
+Mark section headers with `accessibilityHeading="true"`. Users can navigate between headings for quick scanning.
+
+### Pane Titles
+
+Identify screen regions with `accessibilityPaneTitle`. Accessibility services announce pane changes.
+
+### Focus Order
+
+- Natural reading order (top-to-bottom, start-to-end)
+- Use `accessibilityTraversalBefore/After` for custom order
+- Ensure all interactive elements are focusable
+- Skip decorative elements
+
+## Decorative Elements
+
+Skip elements that don't convey information:
+- Set `contentDescription="@null"`
+- Or set `importantForAccessibility="no"`
+
+## Custom Accessibility Actions
+
+### Adding Actions
+
+Provide alternatives for gesture-based interactions using `ViewCompat.addAccessibilityAction()`. This exposes swipe actions to accessibility services.
+
+### Replacing Action Labels
+
+Make default actions more descriptive using `ViewCompat.replaceAccessibilityAction()`. Example: "Double tap and hold to add to favorites" instead of generic "long press".
+
+## Color and Visual Cues
+
+### Don't Rely on Color Alone
+
+Combine color with other indicators:
+
+| Information | Color + Alternative |
+|-------------|---------------------|
+| Error state | Red + error icon + text |
+| Success | Green + checkmark + text |
+| Required field | Red asterisk + "Required" label |
+| Selected item | Highlight + checkmark + bold |
+| Link text | Blue + underline |
+
+### Contrast Testing
+
+Use tools to verify contrast:
+- Android Accessibility Scanner
+- Contrast Checker plugins
+- Manual calculation: (L1 + 0.05) / (L2 + 0.05)
+
+## Touch Targets
+
+### Minimum Sizes
+
+| Element | Minimum | Recommended |
+|---------|---------|-------------|
+| Standard | 48 × 48dp | 48 × 48dp |
+| Primary actions | 48 × 48dp | 56 × 56dp |
+| Kids apps | 56 × 56dp | 64 × 64dp |
+
+### Spacing
+
+- Minimum 8dp between adjacent touch targets
+- Visual element can be smaller if touch area is adequate (use padding)
+
+## Screen Reader Announcements
+
+### Live Regions
+
+Announce dynamic content changes using `accessibilityLiveRegion`:
+
+| Mode | Usage |
+|------|-------|
+| polite | Announces when user is idle |
+| assertive | Interrupts current speech |
+| none | No automatic announcements |
+
+### Custom Announcements
+
+Use `announceForAccessibility()` sparingly—prefer live regions.
+
+## Keyboard and Hardware Navigation
+
+### Focus Indicators
+
+- Visible focus state for all interactive elements
+- Don't remove default focus indicators
+- Custom focus: 2dp+ border or background change
+
+### Keyboard Shortcuts
+
+- Support Tab navigation
+- Enter/Space for activation
+- Arrow keys for lists/grids
+- Escape for dismissal
+
+## Testing Accessibility
+
+### Manual Testing
+
+1. **TalkBack**: Navigate entire app with screen reader
+2. **Switch Access**: Test with switch navigation
+3. **Keyboard**: Navigate with external keyboard only
+4. **Magnification**: Test with zoom enabled
+5. **Large text**: Test with 200% font scale
+6. **High contrast**: Test with high contrast mode
+
+### Automated Testing
+
+| Tool | Purpose |
+|------|---------|
+| Accessibility Scanner | On-device scanning |
+| Espresso Accessibility Checks | Automated UI tests |
+| Lint checks | Static analysis |
+
+### Checklist
+
+- [ ] All interactive elements have descriptions
+- [ ] Touch targets are 48dp minimum
+- [ ] Color contrast meets requirements
+- [ ] Focus order is logical
+- [ ] Headings are properly marked
+- [ ] Custom actions have descriptive labels
+- [ ] Live regions announce important changes
+- [ ] Keyboard navigation works
+- [ ] Works with TalkBack enabled
+- [ ] Works with large text (200%)