Prevent Windows from floating if no decoration

* Windows users cannot move a window which has no native decorations. Toggling a dock widget's titlebar off also removes native decorations on a floating window. Until we implement a replacement titlebar by overriding paintEvents, simply force the floating window to go back to docked state after we toggled the titlebar off.

qt/details_dialog.py

@@ -10,11 +10,13 @@ from PyQt5.QtCore import Qt
 from PyQt5.QtWidgets import QDockWidget, QWidget
 
 from .details_table import DetailsModel
+from hscommon.plat import ISLINUX
 
 
 class DetailsDialog(QDockWidget):
     def __init__(self, parent, app, **kwargs):
         super().__init__(parent, Qt.Tool, **kwargs)
+        self.parent = parent
         self.app = app
         self.model = app.model.details_panel
         self.setAllowedAreas(Qt.AllDockWidgetAreas)
@@ -44,6 +46,10 @@ class DetailsDialog(QDockWidget):
         if not self.app.prefs.details_dialog_titlebar_enabled \
                 and not self.titleBarWidget():
             self.setTitleBarWidget(QWidget())
+            # Windows (and MacOS?) users cannot move a floating window which
+            # has not native decoration so we force it to dock for now
+            if not ISLINUX:
+                self.setFloating(False)
         elif self.titleBarWidget() is not None:
             # resets to the default title bar
             self.setTitleBarWidget(None)