Dock floated tool window cant be docked

[KrzysztofDusko]

Hi.
On current master (11.1.999-cibuild0045533-beta) floated tool window cannot be docked.

11.0.9

11.1.999-cibuild0045533-beta
no drop indicator is visible.

11.1.999-cibuild0045533-beta is prerelase but maybe this will be hapefull for you.

PS Thanks for so great project !

[wieslawsoltes]

I do not use yet 11.1 betas and those contain breaking changes. Do either you can fix yourself them or wait for official release. The other question is why it got broken and maybe it's just Avalonia bugs.

[KrzysztofDusko]

Thanks for answer. I will try investigate this myself ( its bug or behavior change planed with 11.1). With newest Official everything works fine.

[KrzysztofDusko]

last version with proper behavior is 11.1.999-cibuild0043540-beta
11.1.999-cibuild0043576-beta is first version of Avalonia with "bug"
this commit
AvaloniaUI/Avalonia@36e7ab5

or this? AvaloniaUI/Avalonia@9708426

[wieslawsoltes]

Yeah that looks like it might broke the drag ☹️

[KrzysztofDusko]

i checked and AvaloniaUI/Avalonia@36e7ab5 is causing this issue..
-> this code works fine

                if (e.Pointer.IsPrimary)
                {
                    // SendMessage's return value is dependent on the message send.  WM_SYSCOMMAND
                    // and WM_LBUTTONUP return value just signify whether the WndProc handled the
                    // message or not, so they are not interesting
                    SendMessage(_hwnd, (int)WindowsMessage.WM_SYSCOMMAND, (IntPtr)SC_MOUSEMOVE, IntPtr.Zero);
                    SendMessage(_hwnd, (int)WindowsMessage.WM_LBUTTONUP, IntPtr.Zero, IntPtr.Zero);
                }
                else
                {
                    throw new InvalidOperationException("BeginMoveDrag Failed");
                }

but Dispatcher.UIThread.Post introduced by this commit causing problem....

[KrzysztofDusko]

...And from Dock perpective:

Dock/src/Dock.Avalonia/Controls/HostWindow.axaml.cs

Lines 102 to 107 in 9cded63

	BeginMoveDrag(e);
	if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
	{
	EndDrag(e);
	}

BeginMoveDrag with new (dispatcher) implemetation immediatly returns and this fires on windows platforms EndDrag(e). Old BeginMoveDrag...

[KrzysztofDusko]

FYI ->
AvaloniaUI/Avalonia#14891

[BAndysc]

I don't think EndDrag was needed there at all: #327