BlazorWebView - Mouse Events not being triggered in Android

Description

Setting @onmouse* callbacks works as expected when running the app in a Windows machine, but in Android it doesn’t work (both emulator and physical device tested, in Debug and Release modes). Some times the event pass through, but it’s so slow that it becomes unusable, but most of the times it doesn’t work at all. This was tested using .Net calls like @onmouse* in Blazor components, but accessing the javascript counter parts with IJSRuntime produces the same effect.

Steps to Reproduce

https://github.com/Secrop/MauiBlazor_MouseEvent_Bug.App

1. new .Net Maui Blazor App
2. new Component with:

<div 
style="width:200px;height:200px;border:1px solid black;user-select:none;"
@onmousedown="MouseDown"
@onmousemove="MouseMove" 
@onmouseup="MouseUp" 
@onmouseleave="MouseUp">
    <div>X: @X</div>
    <div>Y: @Y</div>
</div>

@code {
    private double X;
    private double Y;
    private bool dragg = false;
    private void MouseDown(MouseEventArgs args)
    {
        dragg = true;
    }

    public void MouseUp(MouseEventArgs args)
    {
        dragg = false;
        X = -1;
        Y = -1;
        StateHasChanged();
    }

    public void MouseMove(MouseEventArgs args)
    {
        if (dragg) {
            X = args.ClientX;
            Y = args.ClientY;
            StateHasChanged();
        } 
    }
}

1. Add the component to Index.razor
2. Run the app in Android and click-drag inside the component.

Link to public reproduction project repository

No response

Version with bug

8.0.0-preview.7.8842 - thought 7.0.92 shows the same problem

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

Android 11, 12, 13

Did you find any workaround?

No response

Relevant log output

No response

[drasticactions]

@Secrop Having an entire reproduction project (as in, a complete project we can build) makes it easier for anyone to debug and identify the issue, and helps create an agreed codebase where we should both, hopefully, be able to see the same issue. Copy and pasting code can lead to cases where it can “happen” to work for one side, leading to a lot of back and forth. Also, if you create the reproduction project, that can be used as the base for test cases that can be added to this repo to prevent the error in the future, should it exist. For example, https://github.com/dotnet/maui/issues/16877, this person provided a full reproduction sample, which I could then check out, debug, and create my own example with a more root case reproduction.

That’s why I put the label on there.

[Secrop]

@drasticactions Here’s a small project that procuces the error: https://github.com/Secrop/MauiBlazor_MouseEvent_Bug.App

It will run as expected in a Windows machine, but it will fail in an Android device/emulator. I haven’t tested IOS, or Tizen, so I cannot tell if this is exclusive for Android.