Files
AmiReel/.github/instructions/performance.instructions.md
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klevze 603af17e56 Remove legacy WPF app, flatten WinUI project to repo root, rename namespace
The repo carried two parallel UIs (WPF + WinUI) sharing Models/Services via
cross-directory Link includes. Now that WinUI is the only frontend, collapse
the structure so the WinUI project IS the repo root instead of a nested
sibling folder:

- Delete the WPF project entirely (App.xaml, MainWindow.xaml, csproj) and its
  bin/obj output
- Move AmiReel.WinUI/* up to the repo root (App, MainWindow, MainPage,
  DialogHelper, Assets, Package.appxmanifest, app.manifest, Properties,
  .github/instructions, AGENTS.md) via git mv, preserving history
- Rename AmiReel.WinUI.csproj -> AmiReel.csproj; regenerate the solution as
  AmiReel.slnx (the newer XML solution format) with a single project
- Rename namespace AmigaDB.VideoRenderer.{Models,Services} -> AmiReel.{...}
  and AmiReel_WinUI -> AmiReel across all files, including the embedded
  ffmpeg/ffprobe resource logical names in the csproj and ToolExtractor
- Models/ and Services/ no longer need the Link-based cross-directory
  <Compile Include>; they're picked up by the SDK's default globbing now
  that they live under the project directory
- Rename assets/ -> branding/ (source icon art) to avoid a case-insensitive
  collision with Assets/ (packaged tile art) once both sit at repo root
- Merge the two .gitignore files into one; track the PublishProfiles pubxml
  files instead of ignoring them (no secrets, and they keep publish
  reproducible across machines) as branding, gitignore, etc.
- Simplify publish-win-x64.ps1 (drop the -Target Wpf/WinUI switch, there's
  only one target now) and rewrite README.md to describe the single-project
  layout, build/run/publish commands, and file structure

Verified: dotnet build succeeds for both AmiReel.csproj and AmiReel.slnx, and
the built exe launches and renders identically to before the move.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 14:07:10 +02:00

54 lines
2.7 KiB
Markdown

---
description: 'Performance requirements for data binding, layout, threading, and collection virtualization'
applyTo: '**/*.cs, **/*.xaml'
---
# Performance
These rules apply to **every feature and change**. They are not optional add-ons.
---
## Rules
- **Use `x:Bind`** (compiled bindings) instead of `{Binding}` — it's faster and type-safe.
- Use **`x:Load`** (or `x:DeferLoadStrategy`) to defer loading of UI elements not immediately visible.
- Avoid heavy work on the UI thread — use `Task.Run` for CPU-bound work and `async/await` for I/O.
- Use **virtualizing panels** (`ItemsRepeater` with `StackLayout`, or `ListView`) for long lists — never use `StackPanel` with hundreds of items.
- **Cache** expensive computations and HTTP responses when appropriate.
- Minimize XAML visual tree depth — deep nesting hurts layout performance.
- Use **incremental loading** (`ISupportIncrementalLoading`) for large data sets.
- Profile with **Visual Studio Diagnostics Tools** and **PerfView** before and after optimizations.
- Be cautious with `DispatcherQueue.TryEnqueue` — don't flood the dispatcher queue.
## Anti-patterns
- Blocking the UI thread with `.Result` or `.GetAwaiter().GetResult()`.
- Loading all data upfront when only a subset is needed.
- Creating new `HttpClient` instances per request (use `IHttpClientFactory`).
- Using `FindName()` or `VisualTreeHelper` in tight loops.
## Validation
- Build & register the MSIX package — see **Build, Run & Deploy** in `.github/agents/Agents.md`.
### Verification Checklist
- [ ] No blocking calls on the UI thread
- [ ] `x:Bind` is used instead of `{Binding}`
- [ ] Large lists use virtualization
## Must Read & Research
> **Agent Rule:** Before any performance-sensitive change (data binding, layout, collections, async), you **must** fetch and review these references using `fetch_webpage`. Apply what you learn.
| # | Reference | When to consult |
|---|---|---|
| 1 | [Performance best practices for WinUI 3](https://learn.microsoft.com/en-us/windows/apps/performance/) | Any change touching UI rendering, data loading, or threading |
| 2 | [x:Bind markup extension](https://learn.microsoft.com/en-us/windows/uwp/xaml-platform/x-bind-markup-extension) | Adding or modifying XAML data bindings |
| 3 | [x:Load attribute](https://learn.microsoft.com/en-us/windows/uwp/xaml-platform/x-load-attribute) | Deferring UI element loading |
| 4 | [Optimize XAML layout](https://learn.microsoft.com/en-us/windows/apps/performance/optimize-xaml-layout) | Restructuring XAML panels, reducing visual tree depth |
| 5 | [ListView optimization](https://learn.microsoft.com/en-us/windows/apps/performance/optimize-listview) | Working with lists, collections, or `ItemsRepeater` |