This PR is written to solve #236.

Below is an exerpt from my response the issue:

If self._toplevel is created with iconify=True, then execution is stuck until opening back the window. This is caused by src/ttkbootstrap/window.py Window.init and Toplevel.init:

# Function continue above...

if iconify:
    self.iconify()

# Function continues...

if alpha is not None:
    if self.winsys == 'x11':
        self.wait_visibility(self)
    self.attributes("-alpha", alpha)

# Function continue below...

Linux uses x11 display system. The Window/Toplevel was iconified before setting alpha, which causes wait_visibility() to get stuck until user open back the window. Hence, deiconify() in src/ttkbootstrap/dialogs/dialogs Dialog.build could not be called until user open back the window.

It seems like the visbility check is introduced by 2abfeb4 in response to #108 so removing that check is not an option.

This PR would swap iconify() and set alpha such that alpha is set when 'visbible' before iconifying. Note that iconify() has to be called before self.transient(transient) to avoid error.