Currently, it is not possible to add any RadElement to a TabStripItem in DocumentTabStrip.

Resolution: 
Use the static class RadDockEvents to subscribe to events before InitializeComponent

Would be useful to have the option to create the tab close button theme which depends on the states of the button's containing tab.

Hidden HostWindows are not loaded correctly when the load operation is performed twice.

FIX. RadDock - with two nested docks, setting the DocumentTabsAlignment of the other dock automatically sets the same on the inner one and this cannot be changed. Once you change it and reload the design time, its setting is being reset.

To reproduce 
- add RadDock with couple DocumenWindows in it
- add second RadDock with coupld DocumentWindows in it, in one of the windows of the first dock
- set Raddock2 DoumentTabsAlignment to top
- set DocumentTabStrip2 TabStripAlignment also to top or default
- drag a radbutton into documentwindow3 and double click it, to get a click event
- go into code view and remove the created event manually
- change back to form view. the alignment in DocumentTabStrip2 has been automatically changed to bottom

To reproduce:
- Add 2 DockWindows and dock it Add about 10 controls in one of the windows. AutoHide them and show them one after another, you will notice that the old one is visible somewhere in the middle of the animation.
- Also you will notice that AutoHideWindowDisplayed and AutoHideWindowDisplaying events are fired twice.

1. Create a new project with RadDock and add 5 tool windows.
2. Dock all tool windows to bottom.
3. Reset the order of the tool windows to not be 1-5
4. Set the group to auto-hide
5. Save dashboard layout
6. Load dashboard layout

1. Create a project with RadDock.
2. Add several tool windows.
3. Run the project.
4. Auto hide all tool windows at the bottom.
5. Close the last tool window.
6. Save the layout.
7. Load the layout.

as magnetic behaviour I mean that when you move a window close to another window, the first window just snap to the other. The same behaviour is fine when you resize a window.
The magnetic behaviour helps you to arrange floating windows into the screen, so people dont get crazy trying to align and resize all the floating windows around in the screen.

support of Pin tab operation in DocumentContainer of RadDock

The issue is reproduced when the Theme service of Windows is stopped and classic windows desktop is used

I have issues with Databindings for RadToggleButton and RadDock ToolWindow.

Here are 3 scenarios to try with my repro application.

ToggleButton
Click the radToggleButtonElement1, notice that the binding never occurs.

ToolWindow Docking issue 1
Dock the toolWindow1 to the left over ToolWindow2
Click toolWindow2
Click toolWindow1
Click toolWindow2
Notice each time you click another tool window, the binding is triggered even if the property value hasn't changed.

ToolWindow Dockin issue 2
Dock the toolWindow1 to the left over toolWindow2
Notice that the binding is triggered, but with the previous value (Floating instead of Docked)
close the toolWindow1
Notice that the binding is triggered, but with the previous value (Docked instead of Hidden)

These are the steps to reproduce the bug:

1. Start dragging a docked window tab (but don't leave the tab bounds for now).
2. While still holding the left mouse button, click the right mouse button to let the context menu appear.
3. Now drag the tab outside the tab bar until the window gets undocked (for example to the blue region above the docked windows).
4. Finish dragging by releasing the left mouse button.
5. Move the mouse cursor over the title bar of another docked window -> the window is undocked without interacting with it and will stick to the cursor until you click the mouse button to release it.

Workaround:
   bool flag = false;
        public Form1()
        {
            InitializeComponent();
            
            ContextMenuService menuService = this.radDock1.GetService<ContextMenuService>();
            menuService.ContextMenuDisplaying += menuService_ContextMenuDisplaying;

            DragDropService service = this.radDock1.GetService<DragDropService>();
            service.Starting += service_Starting;
        }

        void service_Starting(object sender, StateServiceStartingEventArgs e)
        {
            e.Cancel = flag;
            flag = false;
        }

        void menuService_ContextMenuDisplaying(object sender, ContextMenuDisplayingEventArgs e)
        {
            flag = true;
        }

To reproduce:
- Add 2 RadFoms to a raddock in mdi mode.
- Dock the windows by using the left or right docking guide in the center.
- You will notice that the behavior is the same as like using the left or right side guides.

How to reproduce: check the attached project and video

Workaround:
public partial class RadForm1 : Telerik.WinControls.UI.RadForm
{
    public RadForm1()
    {
        InitializeComponent();
        radDock1.FloatingWindowCreated += RadDock1_FloatingWindowCreated;
    }

    private void RadDock1_FloatingWindowCreated(object sender, Telerik.WinControls.UI.Docking.FloatingWindowEventArgs e)
    {
        e.Window = new MyWindow(this.radDock1);
    }
}

public class MyWindow : FloatingWindow
{
    SizeF oldDpi = new SizeF(1, 1);

    public MyWindow(RadDock dockManager) : base (dockManager)
    { }
    protected override void HandleDpiChanged()
    {
        
        base.HandleDpiChanged();
        SizeF descale = new SizeF(1f / this.FormElement.DpiScaleFactor.Width, 1f / this.FormElement.DpiScaleFactor.Height);
        this.Scale(descale);
        var dpi = NativeMethods.GetMonitorDpi(Screen.FromRectangle(this.Bounds), NativeMethods.DpiType.Effective);
        if (oldDpi != dpi)
        {
            SizeF sz = new SizeF(dpi.Width / oldDpi.Width, dpi.Height / oldDpi.Height);

            this.Scale(dpi);
        }

        oldDpi = dpi;
    }
}

A nice addition to the existing RadDock implementation for re-docking floating windows will be the ability to re-dock floating windows to documents if the previous state of the floating window was a document window.

A user should be able to scroll to a desired item (window) by selecting it from the overflow menu. Currently, the selected item is inserted at the first position and the order of items is changed.

If we set the AutoHideSize of a ToolWindow to the RadDock size, upon opening the AutoHide window we will notice that there is a gap of about 20px between the edge of RadDock and the AutoHide window.

Let's have a ToolWindow in a RadDock. Float the ToolWindow and then close the FloatingWindow.
Save the layout, close the application and start it again. Load the layout and display the hidden ToolWindow by calling the DisplayWindow method. The ToolWindow will become docked instead of floating.

After a very specific sequence of steps, you may end up with an xml file of the RadDock layout that contains two windows, although there is only one window at the time the xml file is saved. In addition, when a floating window is loaded, it needs a click in order to get a caption string at the titlebar.

When you have a big UserControl in a DocumentWindow and you scroll down this UC, the UC is prescrolled when you try to set the focus on a control of the UC.