[Bug] Nodes cannot be moved with the mouse in version 7.0.0

[shiguHa]

Describe the bug
When using version 7.0.0 nodes cannot be moved with the mouse. This issue does not occur in version 6.6.0, where nodes can be moved as expected.

To Reproduce

1. Add version 7.0.0 of the Nodeify library to your WPF .Net8 project. (not installed other libraries)
2. Use the following XAML code to place a NodifyEditor and so.

https://github.com/miroiu/nodify/wiki/Nodes-Overview

<Window x:Class="LeanNodify.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:LeanNodify"
        xmlns:nodify="clr-namespace:Nodify;assembly=Nodify"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <nodify:NodifyEditor>
            <nodify:NodifyEditor.ItemsSource>
                <CompositeCollection>
                    <nodify:StateNode Content="My node" />
                </CompositeCollection>
            </nodify:NodifyEditor.ItemsSource>
        </nodify:NodifyEditor>
    </Grid>
</Window>

4. Run the application and try to drag the node with the mouse.

Expected behavior
The node should be draggable and movable with the mouse.

Additional context

This issue does not occur in version 6.6.0, where nodes can be moved as expected.

Environment

• Nodify Version: 7.0.0
• Windows11 Home
• VisualStudio2022
• .NET Version: 8

[jpk6789]

Hi,

I tested this what you said and I can not reproduce your problems. I created a new .Net8.0 project, added Nodify 7.0.0, copied your code and let it run on the same type of system you mentioned (Win 11, Visual Studio 2022) and it worked as expected. See the attached video:

2025-01-10.17-28-07.mp4

Are there maybe other circumstances, which lead to this behavior?

[miroiu]

I tested the same thing and could not reproduce it. Did you customize any gesture or did you change the NodifyEditor.MouseActionSuppressionThreshold?

[shiguHa]

Thank you for your swift response and tested!!

See the attached video.
I created a new .Net8.0 project, added Nodify 7.0.0.
I change it to version 6.6.0 it works as expected.

IssueNodifyMove2025-01-11.mp4

I tested the same thing and could not reproduce it. Did you customize any gesture or did you change the NodifyEditor.MouseActionSuppressionThreshold?

Not custmize any gesture and not change the NodifyEditor.MouseActionSuppressionThreshold

Has the operation method changed in ver7.0.0 from ver6.6.0?
Just left-click and drag the mouse on the node, right?

If there is anything I can do please say so!

[miroiu]

Can you try the following code and let me know what's written in the output window? And is it only the StateNode that doesn't work? Did you also try dragging a Node?

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    static MainWindow()
    {
        InputProcessor.Shared<ItemContainer>.RegisterHandlerFactory(editor => new CustomInputHandler());
    }

    private class CustomInputHandler : IInputHandler
    {
        public bool RequiresInputCapture => false;

        public void HandleEvent(InputEventArgs e)
        {
            if (e.RoutedEvent != MouseMoveEvent)
            {
                Debug.WriteLine(e.RoutedEvent.Name);
            }
        }
    }
}

[axionl]

I encountered a similar problem, which did not occur on the old version either.

When the Nodify Editor loses focus, such as opening a file dialog box, it cannot capture the LostMouseCapture event, resulting in the left mouse button not being able to select and drag and drop normally.

Before:

After:

Can you try the following code and let me know what's written in the output window? And is it only the StateNode that doesn't work? Did you also try dragging a Node?

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    static MainWindow()
    {
        InputProcessor.Shared<ItemContainer>.RegisterHandlerFactory(editor => new CustomInputHandler());
    }

    private class CustomInputHandler : IInputHandler
    {
        public bool RequiresInputCapture => false;

        public void HandleEvent(InputEventArgs e)
        {
            if (e.RoutedEvent != MouseMoveEvent)
            {
                Debug.WriteLine(e.RoutedEvent.Name);
            }
        }
    }
}

[shiguHa]

@miroiu
I tried the code, and the following was written in the output window.
Normally, "MouseDown".

MouseDown
MouseDown
MouseDown
MouseUp
MouseDown

I also tested with Node, GroupingNode, and KnotNode, but similarly, Node does not move.

[miroiu]

@axionl I'll try to reproduce your issue whenever I have time. It would be very helpful if you could provide a minimal code example that demonstrates the problem.

@shiguHa I believe the issue is related to the mouse not being captured for some reason. I’ve created a PR with a potential fix for this. Would you be able to test the fix in the fix/199-drag-item-containers branch and let me know if it resolves the issue?

[shiguHa]

@miroiu
Thank you for fix the source code.
I tried debugging, but it didn't resolve the issue.

I modified the code as shown below, and now the node moves with drag.

Before:

nodify/Nodify/Containers/States/Default.cs

Lines 45 to 49 in bc01626

	EditorGestures.ItemContainerGestures gestures = EditorGestures.Mappings.ItemContainer;
	if (gestures.Drag.Matches(e.Source, e))
	{
	_isDragging = Element.IsDraggable;
	}

After:

 EditorGestures.ItemContainerGestures gestures = EditorGestures.Mappings.ItemContainer; 
 if (true) 
 { 
     _isDragging = Element.IsDraggable; 
 } 

It seems that gestures.Drag.Matches(e.Source,e) is returning False.

I also checked the Matches method of Nodify.Interactivity.InputGestureRef, but since I don't have a full understanding of the entire code, I couldn't identify the cause.

I apologize if I’m saying something off the mark.

[miroiu]

It's the Matches method of the Nodify.Interactivity.MouseGesture that you can debug.

nodify/Nodify/Interactivity/Gestures/MouseGesture.cs

Lines 72 to 90 in 13f75c2

	public override bool Matches(object targetElement, InputEventArgs inputEventArgs)
	{
	if (inputEventArgs is MouseButtonEventArgs || inputEventArgs is MouseWheelEventArgs)
	{
	bool matches = base.Matches(targetElement, inputEventArgs);
	if (IgnoreModifierKeysOnRelease && IsButtonReleased(inputEventArgs))
	{
	ModifierKeys prevModifiers = Modifiers;
	Modifiers = ModifierKeys.None;
	matches |= base.Matches(targetElement, inputEventArgs);
	Modifiers = prevModifiers;
	}
	return matches && MatchesKeyboard();
	}
	return false;
	}