Description

On Android, calling canvas.ResetState() inside a custom GraphicsView (IDrawable) appears to clear the platform scaling, so subsequent draws render at half width and half height on a device with density > 1. The problem doesn’t show on the first Draw, but starts on the second Draw call (e.g., after an Invalidate()), which suggests the scaling info is lost/reset.

Steps to Reproduce

// SomeView.cs
public class SomeView : GraphicsView, IDrawable
{
    public SomeView()
    {
        Drawable = this;

        // Force a second Draw shortly after the first to expose the bug
        Loaded += (_, __) =>
        {
            Microsoft.Maui.Controls.Device.StartTimer(
                TimeSpan.FromMilliseconds(50),
                () => { Invalidate(); return false; } // one-shot
            );
        };
    }

    public void Draw(ICanvas canvas, RectF dirtyRect)
    {
        canvas.ResetState();                 // <-- culprit
        canvas.FillColor = Colors.Yellow;
        canvas.FillRectangle(dirtyRect);     // On 2nd Draw: only half width/height is painted
    }
}

<!-- Usage in a page -->
<Grid WidthRequest="200" HeightRequest="200" BackgroundColor="Red">
    <local:SomeView WidthRequest="200" HeightRequest="200" />
</Grid>

Steps to reproduce

• Add the SomeView above to a page (Android).
• Run the app. The first draw looks correct (yellow over red).
• The timer triggers Invalidate() → second Draw happens.
• Now only the top-left quarter of the 200×200 area is filled (i.e., half width & half height on density=2).

Actual behavior

• After the second Draw, content is rendered at half size (as if density scaling were removed).
• Empirically, multiplying coordinates/sizes by DeviceDisplay.Current.MainDisplayInfo.Density restores expected size.
• Interaction events (StartInteraction, DragInteraction, etc.) appear consistent with MAUI points, so the mismatch seems to stem from ResetState() clearing the canvas scale.

Expected behavior

• ResetState() should not drop the device-density scaling that GraphicsView relies on.
• Drawing calls should continue to use the same coordinate system across successive Draw invocations.

Environment:
.NET MAUI: 9 and 10-preview7
Platform: Android
Device: Android Tablet - simulator - pixel C API28

Notes

• A related discussion exists (not necessarily the same root cause): [Android] GraphicsView， The drawn image can also be visible outside the canvas #20834
• Another developer confirmed that avoiding ResetState() prevents the issue.

Link to public reproduction project repository

No response

Version with bug

10.0.0-preview.7

Is this a regression from previous behavior?

No, this is something new

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

All versions

Did you find any workaround?

Workarounds

• Avoid calling canvas.ResetState().
• Or manually reapply scaling after ResetState():

var density = DeviceDisplay.Current.MainDisplayInfo.Density;
canvas.Scale(density);

• Alternatively, multiply all draw coordinates by density

Relevant log output