---
name: maui-graphics-drawing
description: >
  Guidance for custom drawing with Microsoft.Maui.Graphics, GraphicsView, canvas drawing operations,
  shapes, paths, text rendering, image drawing, shadows, clipping, and canvas state management.
  USE FOR: "custom drawing", "GraphicsView", "canvas drawing", "draw shapes", "draw path",
  "draw text", "ICanvas", "IDrawable", "shadows", "clipping", "Microsoft.Maui.Graphics".
  DO NOT USE FOR: view animations (use maui-animations), gesture handling on drawn elements
  (use maui-gestures), or app icons (use maui-app-icons-splash).
---

# .NET MAUI Graphics Drawing

## Common gotchas

| Issue | Fix |
|---|---|
| Nothing draws on screen | Ensure `Drawable` is set on `GraphicsView` and the control has non-zero `HeightRequest`/`WidthRequest` |
| State bleeds between shapes | Wrap isolated sections in `SaveState()` / `RestoreState()` pairs |
| Shadows stick to later draws | Call `canvas.SetShadow(SizeF.Zero, 0, null)` after drawing the shadowed element |
| Clipping never resets | Clipping is cumulative per frame — use `SaveState`/`RestoreState` around clip regions |
| UI freezes during drawing | Never do I/O, network, or heavy computation inside `Draw()` — it runs on the UI thread |

## Canvas state — always pair Save/Restore

⚠️ Unpaired `SaveState`/`RestoreState` causes state leaks across draw calls.

```csharp
// ✅ Correct — isolated state
canvas.SaveState();
canvas.StrokeColor = Colors.Red;
canvas.StrokeSize = 6;
canvas.DrawRectangle(10, 10, 80, 80);
canvas.RestoreState();
// Stroke reverts to previous values

// ❌ Wrong — state leaks to everything drawn after
canvas.StrokeColor = Colors.Red;
canvas.StrokeSize = 6;
canvas.DrawRectangle(10, 10, 80, 80);
// Every subsequent shape is now red with size 6
```

Saves/restores: stroke, fill, font, shadow, clip, and transforms. Nest calls for layered isolation.

## Triggering redraws

```csharp
// ✅ Correct — queue a redraw
graphicsView.Invalidate();

// ❌ Wrong — never call Draw() directly
myDrawable.Draw(canvas, rect);
```

- `Invalidate()` queues a redraw; the framework calls `IDrawable.Draw` on the next frame.
- ⚠️ Avoid calling `Invalidate()` in a tight loop — batch state changes, then invalidate once.

## Performance tips

- **Keep `Draw()` fast** — pre-compute paths and data outside the draw method; `Draw()` is called on every frame.
- **Reuse `PathF` objects** — create them once, store as fields, draw repeatedly.
- **Use `MeasureFirstItem`-style thinking** — if drawing many identical items, calculate dimensions once.
- **Minimize allocations** — avoid `new PathF()` inside `Draw()` when the path doesn't change.

```csharp
// ✅ Pre-computed path (field)
private readonly PathF _starPath = BuildStarPath();

public void Draw(ICanvas canvas, RectF dirtyRect)
{
    canvas.FillPath(_starPath);
}

// ❌ Allocating every frame
public void Draw(ICanvas canvas, RectF dirtyRect)
{
    var path = new PathF();
    // ...build path every frame...
    canvas.FillPath(path);
}
```

## Shadows and clipping — sticky state pitfalls

Shadows apply to **all subsequent draws** until explicitly removed. Clips accumulate and can only be undone with `RestoreState()`:

```csharp
// ✅ Shadow: remove after use
canvas.SetShadow(new SizeF(5, 5), 4, Colors.Gray);
canvas.FillRectangle(20, 20, 100, 60);
canvas.SetShadow(SizeF.Zero, 0, null); // ← must remove

// ✅ Clip: isolate with SaveState/RestoreState
canvas.SaveState();
canvas.ClipRectangle(20, 20, 100, 100);
canvas.FillRectangle(0, 0, 200, 200); // clipped
canvas.RestoreState();                  // clip removed

// ❌ Clip persists — everything after is also clipped
canvas.ClipRectangle(20, 20, 100, 100);
canvas.FillEllipse(150, 150, 50, 50); // unintentionally clipped!
```

## Set properties BEFORE draw calls

```csharp
// ✅ Properties then draw
canvas.StrokeColor = Colors.Blue;
canvas.DrawRectangle(10, 10, 100, 50);

// ❌ Setting after draw has no effect on previous shape
canvas.DrawRectangle(10, 10, 100, 50);
canvas.StrokeColor = Colors.Blue;
```

## Decision framework

| Need | Approach |
|---|---|
| Simple shapes / static graphics | Single `IDrawable`, draw in `Draw()` |
| Animated graphics | Update state externally, call `Invalidate()` from timer/animation |
| Complex layered scene | Multiple `SaveState`/`RestoreState` blocks, or separate drawables |
| Hit testing on drawn elements | Track shape bounds manually — `GraphicsView` has no built-in hit test on drawn content |
| Platform-specific rendering | Use handlers/platform code; `Microsoft.Maui.Graphics` is cross-platform only |

## Quick checklist

- [ ] `GraphicsView` has `Drawable` set and non-zero size
- [ ] `Draw()` is fast — no I/O, no heavy allocations
- [ ] Every `SaveState()` has a matching `RestoreState()`
- [ ] Shadows removed with `SetShadow(SizeF.Zero, 0, null)` after use
- [ ] Clips wrapped in `SaveState`/`RestoreState` blocks
- [ ] Properties set **before** the draw call they apply to
- [ ] `Invalidate()` used instead of calling `Draw()` directly


---
Source attribution: davidortinau
Original project: https://github.com/davidortinau/maui-skills/blob/79bb4bfd8f671ed0dd97bdf92a36430928e8d984/plugins/maui-skills/skills/maui-graphics-drawing/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 David Ortinau

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: davidortinau
Original project: https://github.com/davidortinau/maui-skills/blob/79bb4bfd8f671ed0dd97bdf92a36430928e8d984/plugins/maui-skills/skills/maui-graphics-drawing/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering, Product Management
Roles: Frontend Developer, Mobile Developer, Product Manager
Specialties: API, Frontend, Testing
Tools: Microsoft.Maui.Graphics
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 09929db4d5316faa3ba311e6d73fce5581c5342a4056fd0e7c9d911a45c7af99