[ENH] Display Widgets on Top option

Orange/canvas/application/canvasmain.py

@@ -616,6 +616,13 @@ def setup_actions(self):
             QAction(self.tr("Reset Widget Settings..."), self,
                     triggered=self.reset_widget_settings)
 
+        self.float_widgets_on_top_action = \
+            QAction(self.tr("Float Widgets on Top"), self,
+                    checkable=True,
+                    toolTip=self.tr("Widgets are always displayed above other windows."))
+        self.float_widgets_on_top_action.toggled.connect(
+            self.set_float_widgets_on_top_enabled)
+
     def setup_menu(self):
         if sys.platform == "darwin" and QT_VERSION >= 0x50000:
             self.__menu_glob = QMenuBar(None)
@@ -694,6 +701,7 @@ def setup_menu(self):
         self.view_menu.addSeparator()
 
         self.view_menu.addAction(self.toogle_margins_action)
+        self.view_menu.addAction(self.float_widgets_on_top_action)
         menu_bar.addMenu(self.view_menu)
 
         # Options menu
@@ -760,6 +768,10 @@ def restore(self):
             settings.value("quick-help/visible", True, type=bool)
         )
 
+        self.float_widgets_on_top_action.setChecked(
+            settings.value("widgets-float-on-top", False, type=bool)
+        )
+
         self.__update_from_settings()
 
     def set_document_title(self, title):
@@ -1655,6 +1667,14 @@ def reset_widget_settings(self):
                     "Settings will still be reset at next application start",
                     parent=self)
 
+    def set_float_widgets_on_top_enabled(self, enabled):
+        wm = self.current_document().scheme().widget_manager
+
+        settings = QSettings()
+        settings.setValue("mainwindow/widgets-float-on-top", bool(enabled))
+        wm.show_widgets_on_top_changed()
+
+
     def show_report_view(self):
         from Orange.canvas.report.owreport import OWReport
         doc = self.current_document()

Orange/canvas/config.py

@@ -85,6 +85,9 @@ def init():
       "Use a popover menu to select a widget when clicking on a category "
       "button"),
 
+     ("mainwindow/widgets-float-on-top", bool, False,
+      "Float widgets on top of other windows"),
+
      ("mainwindow/number-of-recent-schemes", int, 15,
       "Number of recent workflows to keep in history"),
 

Orange/canvas/scheme/widgetsscheme.py

@@ -25,10 +25,10 @@
 
 import sip
 
-from AnyQt.QtWidgets import QWidget, QShortcut, QLabel, QSizePolicy, QAction
+from AnyQt.QtWidgets import QWidget, QShortcut, QLabel, QSizePolicy, QAction, qApp
 from AnyQt.QtGui import QKeySequence, QWhatsThisClickedEvent
 
-from AnyQt.QtCore import Qt, QObject, QCoreApplication, QTimer, QEvent
+from AnyQt.QtCore import Qt, QObject, QCoreApplication, QTimer, QEvent, QSettings
 from AnyQt.QtCore import pyqtSignal as Signal
 
 from .signalmanager import SignalManager, compress_signals, can_enable_dynamic
@@ -258,6 +258,11 @@ def __init__(self, parent=None):
         # Tracks the widget in the update loop by the SignalManager
         self.__updating_widget = None
 
+        if hasattr(qApp, "applicationStateChanged"):
+            # disables/enables widget floating when app (de)activates
+            # available in Qt >= 5.2
+            qApp.applicationStateChanged.connect(self.show_widgets_on_top_changed)
+
     def set_scheme(self, scheme):
         """
         Set the :class:`WidgetsScheme` instance to manage.
@@ -597,6 +602,9 @@ def create_widget_instance(self, node):
         widget.setCaption(node.title)
         # befriend class Report
         widget._Report__report_view = self.scheme().report_view
+
+        self.__set_float_on_top(widget)
+
         # Schedule an update with the signal manager, due to the cleared
         # implicit Initializing flag
         self.signal_manager()._update()
@@ -627,6 +635,15 @@ def widget_processing_state(self, widget):
         """
         return self.__widget_processing_state[widget]
 
+    def show_widgets_on_top_changed(self):
+        """
+        `Float Widgets on Top` menu option has changed.
+
+        Update the flag on existing widgets.
+        """
+        for widget in self.__widget_for_node.values():
+            self.__set_float_on_top(widget)
+
     def __create_delayed(self):
         if self.__init_queue:
             state = self.__init_queue.popleft()
@@ -790,6 +807,29 @@ def __on_env_changed(self, key, newvalue, oldvalue):
         for widget in self.__widget_for_node.values():
             widget.workflowEnvChanged(key, newvalue, oldvalue)
 
+    def __set_float_on_top(self, widget):
+        """Set or unset widget's float on top flag"""
+        settings = QSettings()
+        should_float_on_top = settings.value("mainwindow/widgets-float-on-top", False, type=bool)
+        if hasattr(qApp, "applicationState"):
+            # only float on top when the application is active
+            # available in Qt >= 5.2
+            should_float_on_top &= qApp.applicationState() == Qt.ApplicationActive
+        float_on_top = widget.windowFlags() & Qt.WindowStaysOnTopHint
+
+        if float_on_top == should_float_on_top:
+            return
+
+        widget_was_visible = widget.isVisible()
+        if should_float_on_top:
+            widget.setWindowFlags(Qt.WindowStaysOnTopHint)
+        else:
+            widget.setWindowFlags(widget.windowFlags() & ~Qt.WindowStaysOnTopHint)
+
+        # Changing window flags hid the widget
+        if widget_was_visible:
+            widget.show()
+
 
 def user_message_from_state(message_group):
     return UserMessage(