Usually double clicking with primary mouse button (usually left mouse button) on the title bar of the floating window results in docking it again. But sometimes this does not work as I have reported already by email to IDM support with an example workspace file where 2 views could not be changed from floating state to docking state by double click on title bar. But there is a second method to dock a floating window which always works.
Click with left mouse button on the title bar of the floating Workspace Manager window and hold left mouse button. You see now on every side of the main window a small window symbol and there are 5 small window symbols in the middle of the main window, see power tip Tabbed Child Windows
. While still holding left mouse button, you have to move the mouse pointer
now over the window symbol on the side you want the window docked. You will see a shadow window if you have moved the mouse pointer over the window symbol. Now release the left mouse button and the window is docked.
BTW: If you want to avoid undocking a view by left clicking on the title bar of the view, hold left mouse button and move the mouse pointer before releasing the left mouse button, right click on the title bar of the view and uncheck from context menu with left mouse button the option Undockable
. Now the view can't become a floating window by drag and drop. Just a double click on the title bar converts the window to a floating window.
Workspace Manager view in UEStudio is the enhanced File Tree view of UltraEdit.