Why PullGestureRecognizer doesn't work at all?

[kyuranger]

Here is my code:

<Border Width="500"
    Height="500"
    Margin="5"
		Background="Red"
    Name="border">		
</Border>

And:

 public MainView2()
 {
     InitializeComponent();        
     border.GestureRecognizers.Add(new PullGestureRecognizer()
     {
         PullDirection = PullDirection.TopToBottom,
     });
     border.AddHandler(Gestures.PullGestureEvent, (s, e) =>
     {
     });
     border.AddHandler(Gestures.PullGestureEndedEvent, (s, e) =>
     {
     });
 }

And I add breakpoint to PullGestureEvent and PullGestureEndedEvent above. However, no matter I drag from top to bottom, the breakpoint never works. What's wrong with my code?

[thevortexcloud]

I could be wrong, but I seem to vaguely recall that some gesture recognisers are touch only. Which means you need a real touch screen to use them. But I also don't have much experience using them.

[IanRawley]

PullGestureRecognizer is Touch or Pen only. I'm not really sure why? Maybe to avoid conflicts with drag-and-drop?
ScrollGestureRecognizer as well.

Edit: PullGestureRecognizer was added with RefreshContainer, so possibly just a direct port from somewhere else.

[kyuranger]

I could be wrong, but I seem to vaguely recall that some gesture recognisers are touch only. Which means you need a real touch screen to use them. But I also don't have much experience using them.

I am working on a cross-platform program and I hope that the display is the same on different platforms. In the past, I used Thumb to achieve the drag effect, but using Thumb requires you to add additional controls, while PullGestureRecognizer does not. But as you said, PullGestureRecognizer may not support mouse control.

[kyuranger]

PullGestureRecognizer is Touch or Pen only. I'm not really sure why? Maybe to avoid conflicts with drag-and-drop? ScrollGestureRecognizer as well.

Edit: PullGestureRecognizer was added with RefreshContainer, so possibly just a direct port from somewhere else.

If this is the case, I can only use Thumb to implement it as I did before.

[thevortexcloud]

I'm not really sure why?

I wish I knew. It's a fairly weird restriction to me and it probably makes testing a lot harder.

[LaurentInSeattle]

Maybe... Removing this check in PullGestureRecognizer.cs would make it work with the mouse ?

protected override void PointerPressed(PointerPressedEventArgs e)
{
if (Target != null && Target is Visual visual && (e.Pointer.Type == PointerType.Touch || e.Pointer.Type == PointerType.Pen))
{

[kyuranger]

I tried to Override this method as you said but found that some methods in it are private (such as PullGestureEventArgs.GetNextFreeId()), so it is not feasible at all.

[LaurentInSeattle]

The gesture is indeed recognized and the events are fired if:

• Duplicate original, edit
• you do remove the pointer type test
• you add something like :
  private static int _nextId = 1;
  internal static int GetNextFreeId() => _nextId++;
  to replace the internal GetNextFreeId from the event args

Works on my machine :)

Ugly work around for sure but proves that the Avalonia code could easily be fixed...