Use default title bar to preserve GUI float decorations (bug #53276) * QUnixTerminalImpl.cpp (QUnixTerminalImpl::setBackgroundColor): Use cascading style sheets to set the background color of the TerminalView. * documentation-dock-widget.cc (constructor): Use setWindowTitle() for default title bar instead of set_title(). * files-dock-widget.cc (constructor): Ditto. * history-dock-widget.cc (history_dock_widget::construct): Ditto. * file-editor.cc (file_editor::construct): Ditto. * terminal-dock-widget.cc (constructor): Ditto. * workspace-view.cc (constructor): Ditto. * octave-dock-widget.cc (label_dock_widget::label_dock_widget): Initialize m_default_float_button and m_default_close_button to nullptr then check for the existence of these buttons in the default title bar. Change spacing between title bar icons from 0 to 10. Do not call setTitleBarWidget(). (label_dock_widget::set_title): Use m_title_widget for pointer instead of titleBarWidget(). Call setTitleBarWidget(m_title_widget) to activate use of custom title bar. (qdockwidget_css): Added. New local routine that constructs the cascading style sheet for the QDockWidget used in several places. (octave_dock_widget::octave_dock_widget): Initialize m_recent_float_geom, m_recent_dock_area, m_recent_dock_geom, m_waiting_for_mouse_button_release. Remove m_floating. Connect the topLevelChanged() signal to the toplevel_change() slot. Do not restrict features floatable and closeable. If the m_default_float_button was found, disconnect its default slots and connect it instead to slot make_window(). Enable queuing of make_window() via the queue_make_window() signal. Enable queuing of make_widget() via the queue_make_widget() signal. Connect the m_dock_action triggered() signal to make_window() slot rather than change_floating(). Set the style sheet (icons and tooltips) for the dockable widget and disable the main widget's tooltip. Set all dock widget features. (octave_dock_widget::make_window): Change the input to be bool (unused) so that the function can be used as a slot. Prevent follow-up calls by setting m_waiting_for_mouse_button_release to 'false'. Set focus to the predecessor in tab list. Set floating off prior to making it a toplevel window. Do not perform a second reparent with a custom title bar. Get geometry from m_recent_float_geom rather than settings. Drop use of m_floating. Make the (un)dock icon adjustment more elaborate by using style sheets via the set_style() function. Disconnect the existing behavior and connect the "make widget" behavior into the appropriate button/action. Call raise(), show(), activateWindow() and setFocus() to bring the new window to the front of the GUI desktop. (octave_dock_widget::make_widget): Drop the dock/not-dock logic. When adding widget back to parent window set the area to m_recent_dock_area. Make the (un)dock icon adjustment more elaborate by using style sheets via set_style() function. Disconnect the existing behavior and connect the "make window" behavior into the appropriate button/action. (octave_dock_widget::default_dock): Added. Simply call base setFloating() with argument "false". (octave_dock_widget::event): Reimplement the virtual low-level function to check if a conversion from widget to window took place as a result of a double-click or if a button release took place after a window drag, and if so set m_waiting_for_mouse_button_release to 'false' and emit a queued make_window(). (octave_dock_widget::handle_settings): Get the geometry and docked layout information, stored in m_recent_float_geom, m_recent_dock_area and m_recent_dock_geom. (octave_dock_widget::save_settings): Get saved geometry info from m_recent_float_geom, m_recent_dock_area and m_recent_dock_geom. Use isFloating() rather than m_floating for "Floating" state. (octave_dock_widget::change_floating): Removed. (octave_dock_widget::store_geometry): Added. Reuasable routine to save geometry and dock info in the appropriate variables based on isFloating() state. (octave_dock_widget::moveEvent): Added. Reimplemented virtual routine to store the geometry whenever the widget is moved. (octave_dock_widget::resizeEvent): Added. Reimplemented virtual routine to store the geometry whenever the widget is resized. (octave_dock_widget::toplevel_change): Added. Puts a fallback behavior in place in case the transition to a toplevel window fails on some OS. Also, handles drag-to-float by setting m_waiting_for_mouse_button_release to 'true' if toplevel input is true. If toplevel input is false, set m_waiting_for_mouse_button_release to 'false'. If need to reparent, emit queue_make_widget() to avoid button-click/double-click corruption. (octave_dock_widget::set_style): Use isFloating() instead of m_floating. Condition the style changes to custom title bar widgets on titleBarWidget() and use CSS style sheets to match the default title bar color scheme to that of the custom title bar. Break the css into string variables css_foreground and css_background providing better control in the qdockwidget_css() routine. * octave-dock-widget.h (label_dock_widget:QDockWidget): Add pointers m_default_float_button and m_default_close_button. (label_dock_widget::set_title): Add note about selecting use of default or custom title bar via this routine. (octave_dock_widget:label_dock_widget): Add variables m_recent_float_geom, m_recent_dock_area, m_recent_dock_geom for avoiding using the file settings as an intermediate storage space. Add boolean variable m_waiting_for_mouse_button_release for implementing a single delayed make_window() if needed. (octave_dock_widget::make_window): Change to a public slot with an unused bool input variable. (octave_dock_widget::make_widget): Change to a public slot. (octave_dock_widget::queue_make_window): Added. New signal to queue make_window() and avoid crash when calling make_widget() directly. (octave_dock_widget::queue_make_widget): Added. New signal to queue make_widget() and avoid mouse click corruption when calling make_widget() directly. (octave_dock_widget::event): Added. Reimplement low-level event() routine, check for double-click float and for drag-and-drop float. (octave_dock_widget::moveEvent): Added. Declartion of reimplemented virtual routine. (octave_dock_widget::resizeEvent): Ditto. (octave_dock_widget::default_dock): Added. A simple routine that calls the default setFloating(false). (octave_dock_widget::change_floating): Removed. (octave_dock_widget::toplevel_change): Added. React to topLevelChanged() signal and install the default button action in case toplevel transition fails. Check if (re)parent action needed. (octave_dock_widget::store_geometry): Added. An in-memory copy of the geometry. * variable-editor.cc (variable_dock_widget::variable_dock_widget): Initialize two new state variables m_waiting_for_mouse_move and m_waiting_for_mouse_button_release intending to identify exactly when a float-by-mouse-drag occurs in order to circumvent Qt bug QTBUG-44813. Use pointer m_title_widget instead of titleBarWidget() and construct the layout unconditionally. (variable_dock_widget::toplevel_change): Remove the default input from setFocus(). If toplevel is true, set m_waiting_for_mouse_move in case a mouse-drag occurs. If toplevel is not true, clear the state variables m_waiting_for_mouse_move and m_waiting_for_mouse_button_release. (variable_dock_widget::change_fullscreen): Fix a bug in which geometry was not properly restored during the fullscreen-to-dock transition by moving the copy m_prev_geom after the variable_dock_widget is floated rather than before. (variable_dock_widget::handle_focus_change): Condition the label adjustment on the presence of custom titleBarWidget(). (variable_dock_widget::event): Added. The state-machine logic for detecting a drag-and-drop floating change. When that happens queue a redock-undock. (variable_editor::variable_editor): Use setWindowTitle() for default title bar instead of set_title(). Added to address QTBUG-44813 by using a very simple state machine to identify float-by-mouse-drag from mouse move and button press events. Then emit queue_unfloat_float() to redock and undock the QDockWidget directly which doesn't have the bug. (variable_dock_widget::unfloat_float): Short slot that does setFloating(true) followed by setFloating(false). This code is conditioned on the yet-to-be- fully determined Qt bug range, and need a NULL-function slot routine. (variable_editor::variable_editor): Initialize new variables m_focus_widget and m_focus_widget_vdw to nullptr. Use setWindowTitle() rather than set_title(). (variable_editor::focusInEvent): Make the focusing rules more complex and use the variables m_focus_widget and m_focus_widget_vdw for logic. (variable_editor::focusOutEvent): Removed. (variable_editor::edit_variable): Make the connection between signal queue_unfloat_float() and slot unfloat_float() pre-processor conditioned on the range for Qt bug QTBUG-44813. Condition the connection between the model's update_lable_signal() and label's setText() slot on the presence of custom titleBarWidget(). (variable_editor::variable_destroyed): If the variable_dock_widget that is destroyed matches m_focus_widget_vdw then clear both that variable and m_focus_widget. Make use of the focusInEvent() routine to set the focus to the next logical variable_dock_widget. (variable_editor::variable_focused): Make the association between the currently-focused object and the variable_dock_widget on which it resides. * variable-editor.h (variable_dock_widget:label_dock_widget): Define QTBUG_44813_FIX_VERSION as an indefinite version in the future when Qt developers fix QTBUG-44813. (variable_dock_widget::queue_unfloat_float): Added. New signal. (variable_dock_widget::unfloat_float): Added. New protected slot. (variable_dock_widget::event): Added. Conditioned on QTBUG-44813 range, the overrided virtual function that will identify float-by-mouse-drag scenario. Requires new private Boolean variables m_waiting_for_mouse_move, m_waiting_for_mouse_button_release and m_waiting_for_activation_change. (variable_editor:octave_dock_widget): Change m_variable_focus_widget to m_focus_widget and add variable_dock_widget pointer m_focus_widget_vdw. (variable_editor::focusOutEvent): Removed.