Missing title bar when using wm manage and wm forget

Question

I am using wm manage and wm forget to dock and undock a frame from a Tk application.

When I undock the frame f1, sometimes the title bar of the view is not displayed. The frame does not undock correctly and so I can not handle it on the screen.

set f1 [winfo parent $w]
# get state of Dock button
set state [$T header state get DockBtn detach]

if {!$state} {
    puts "  -- detach, undock, deconnect"

    # detach the widget f1
    grid forget       $f1   
    wm manage       $f1
    wm protocol     $f1 WM_DELETE_WINDOW {}
    event generate  $f1 <<DetachedTab>>

    set DockState 0
} else {
    if {$DockState == 0} {
        puts "  -- attach, dock"
        wm forget $f1

        # add to my panedwindow f1
        $panedW add $f1 -width 300

        set DockState 1  
    }
}

Answer 1

I suspect the problem is that you use grid forget to detach the frame from the parent when converting to a managed window. However you use $panedW add to re-attach it to the main application window. That suggests your parent is actually a panedwindow widget. This means the manager is not grid but panedwindow - you can test this using winfo manager $f1. If this is the case you have conflicting window management. You need to be consistent in both parts of the function.