C#•2y ago

✅ Avalonia — stop children from triggering parent events

<StackPanel Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" 
            Orientation="Horizontal" 
            Background="Black" 
            Opacity="0.7" PointerPressed="InputElement_OnPointerPressed">
    <Button Command="{Binding NewWindowCommand}">S</Button>
    <Button Command="{Binding MainViewCommand}">Home</Button>
</StackPanel>

<StackPanel Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="3" 
            Orientation="Horizontal" 
            Background="Black" 
            Opacity="0.7" PointerPressed="InputElement_OnPointerPressed">
    <Button Command="{Binding NewWindowCommand}">S</Button>
    <Button Command="{Binding MainViewCommand}">Home</Button>
</StackPanel>

with the following codebehind

private void InputElement_OnPointerPressed(object? sender, PointerPressedEventArgs e)
{
    BeginMoveDrag(e);
}

private void InputElement_OnPointerPressed(object? sender, PointerPressedEventArgs e)
{
    BeginMoveDrag(e);
}

makes it so that clicking on the buttons doesn't trigger their commands, but rather the click gets captured by the parent and the window gets dragged

10 Replies

JakenVeina•2y ago

PointerPressed being the Avalonia-equivalent of MouseClick? seems like it must be a tunneling event, instead of bubbling? your goal here would be that clicking anywhere ELSE in the stack panel allows you to drag the whole thing, but only if it's empty space? maybe verify this with some debug logging, cause I fail to see how else this would be the case, other than a bug arguably, if the event is tunneling instead of bubbling, that in itself could be considered a bug

AngiusOP•2y ago

Basically, yeah

JakenVeina•2y ago

definitely doesn't make conventional sense see if you can debug and figure out how the even is being routed maybe button commands are tied to some OTHER event? like, WPF has MouseButtonDown and MouseButtonUp?

AngiusOP•2y ago

Adding

if (e.Source is not StackPanel) return;

if (e.Source is not StackPanel) return;

fixed it

JakenVeina•2y ago

eewwwwww if you're gonna go that route, it ought to be if (e.Source is not this) or whatever that still bugs me, though, bubbling events shouldn't work that way

AngiusOP•2y ago

this is MainWindow not StackPanel

JakenVeina•2y ago

then reference it by name

AngiusOP•2y ago

I guess I could do (e.Source as Control) is { Name: "TopBar" }

JakenVeina•2y ago

or jusy e.Source == _topBar

AngiusOP•2y ago

_topBar doesn't exist e.Source is not StackPanel { Name: "TopBar" } works fine so I'm just gonna leave it

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✅ Avalonia — stop children from triggering parent events