Copilot instructions

1---
2description: Critical guidance for CollectionView/CarouselView handler detection
3applyTo: "src/Controls/src/Core/Handlers/Items/**,src/Controls/src/Core/Handlers/Items2/**"
4---
5 
6# CollectionView Handler Detection
7 
8## Handler Implementation Status
9 
10There are **TWO separate handler implementations**, but they apply to **different platforms**:
11 
121. **Items/** (`Handlers/Items/`) - Contains code for **ALL platforms** (Android, iOS, Windows, MacCatalyst, Tizen)
132. **Items2/** (`Handlers/Items2/`) - Contains code for **iOS/MacCatalyst ONLY**
14 
15### Platform-Specific Deprecation
16 
17The deprecation of Items/ **only applies to iOS/MacCatalyst**:
18 
19| Platform | Active Handler | Notes |
20|----------|----------------|-------|
21| **Android** | `Items/Android/` | **ONLY implementation** - Items2/ has no Android code |
22| **Windows** | `Items/` | **ONLY implementation** - Items2/ has no Windows code |
23| **iOS** | `Items2/iOS/` | Items/ iOS code is deprecated |
24| **MacCatalyst** | `Items2/iOS/` | Items/ MacCatalyst code is deprecated |
25 
26**CRITICAL**: Items2/ is **iOS/MacCatalyst only**. There is NO Items2/ code for Android or Windows.
27 
28---
29 
30## Which Handler to Work On
31 
32### Decision Tree by Platform
33 
34```
35Is the issue/PR for Android or Windows?
36  YES → Work on Items/ (it's the ONLY implementation)
37  NO  → Continue...
38 
39Is the issue/PR for iOS or MacCatalyst?
40  YES → Work on Items2/ (Items/ is deprecated for iOS)
41  NO  → Check platform and find appropriate handler
42```
43 
44### Detection Algorithm
45 
46Check which handler directory the files are in:
47 
48```bash
49# Check changed files in a PR
50git diff <base-branch>..<pr-branch> --name-only | grep -i "handlers/items"
51 
52# Look for path pattern:
53# - Contains "/Items/Android/" → Android (ONLY implementation, work here)
54# - Contains "/Items/Windows/" or ".Windows.cs" → Windows (ONLY implementation, work here)
55# - Contains "/Items2/iOS/" or "Items2/*.iOS.cs" → iOS/MacCatalyst (CURRENT)
56# - Contains "/Items/*.iOS.cs" (not Items2) → iOS (DEPRECATED, prefer Items2/)
57```
58 
59### Default Behavior by Platform
60 
61| Platform | Default Action |
62|----------|----------------|
63| **Android** | ✅ Work on `Items/Android/` - it's the only option |
64| **Windows** | ✅ Work on `Items/` Windows files - it's the only option |
65| **iOS/MacCatalyst** | ✅ Work on `Items2/` - Items/ is deprecated for iOS |
66 
67### When to Work on Items/ for iOS (Deprecated)
68 
69Only work on Items/ iOS code when:
70- PR explicitly modifies Items/ iOS files
71- User explicitly requests changes to deprecated handlers
72- Maintaining backward compatibility for a specific fix
73 
74---
75 
76## Quick Reference
77 
78| Path Pattern | Platform | Status |
79|--------------|----------|--------|
80| `Handlers/Items/Android/` | Android | **ACTIVE** (only implementation) |
81| `Handlers/Items/*.Windows.cs` | Windows | **ACTIVE** (only implementation) |
82| `Handlers/Items2/iOS/` | iOS/MacCatalyst | **ACTIVE** (current) |
83| `Handlers/Items/*.iOS.cs` | iOS/MacCatalyst | **DEPRECATED** (use Items2/) |
84 
85---
86 
87## Common Mistakes to Avoid
88 
89❌ **Wrong**: "Items/ is deprecated, so I should check if Items2/ needs the same Android fix"
90- Items2/ has NO Android code - there's nothing to check
91 
92❌ **Wrong**: "This Android fix should also go in Items2/"
93- Items2/ is iOS-only, Android code only exists in Items/
94 
95✅ **Correct**: "This is an Android-only issue, so I work in Items/Android/ which is the only Android implementation"
96