Factor out 'persistent' tooltip code from the panner

interface and use it for processor box sliders (#4461).


git-svn-id: svn://localhost/ardour2/branches/3.0@12661 d708f5d6-7413-0410-9779-e7cbd77b26cf

13 files changed, 318 insertions, 96 deletions

diff --git a/gtk2_ardour/mono_panner.cc b/gtk2_ardour/mono_panner.cc
index 8b28d7f1a4..7dd16d4853 100644
--- a/gtk2_ardour/mono_panner.cc
+++ b/gtk2_ardour/mono_panner.cc
@@ -31,6 +31,7 @@
 #include "gtkmm2ext/gtk_ui.h"
 #include "gtkmm2ext/keyboard.h"
 #include "gtkmm2ext/utils.h"
+#include "gtkmm2ext/persistent_tooltip.h"
 
 #include "ardour/pannable.h"
 #include "ardour/panner.h"
@@ -64,6 +65,7 @@ MonoPanner::MonoPanner (boost::shared_ptr<ARDOUR::Panner> panner)
         , accumulated_delta (0)
         , detented (false)
         , position_binder (position_control)
+	, _dragging (false)
 {
         if (!have_colors) {
                 set_colors ();
@@ -73,6 +75,8 @@ MonoPanner::MonoPanner (boost::shared_ptr<ARDOUR::Panner> panner)
         position_control->Changed.connect (connections, invalidator(*this), boost::bind (&MonoPanner::value_change, this), gui_context());
 
 	ColorsChanged.connect (sigc::mem_fun (*this, &MonoPanner::color_handler));
+
+	set_tooltip ();
 }
 
 MonoPanner::~MonoPanner ()
@@ -81,12 +85,8 @@ MonoPanner::~MonoPanner ()
 }
 
 void
-MonoPanner::set_drag_data ()
+MonoPanner::set_tooltip ()
 {
-        if (!_drag_data_label) {
-                return;
-        }
-
         double pos = position_control->get_value(); // 0..1
 
         /* We show the position of the center of the image relative to the left & right.
@@ -101,7 +101,7 @@ MonoPanner::set_drag_data ()
         snprintf (buf, sizeof (buf), "L:%3d R:%3d",
                   (int) rint (100.0 * (1.0 - pos)),
                   (int) rint (100.0 * pos));
-        _drag_data_label->set_markup (buf);
+        _tooltip.set_tip (buf);
 }
 
 bool
@@ -255,6 +255,7 @@ MonoPanner::on_button_press_event (GdkEventButton* ev)
         last_drag_x = ev->x;
 
         _dragging = false;
+	_tooltip.target_stop_drag ();
         accumulated_delta = 0;
         detented = false;
 
@@ -290,6 +291,7 @@ MonoPanner::on_button_press_event (GdkEventButton* ev)
                 }
 
                 _dragging = false;
+		_tooltip.target_stop_drag ();
 
         } else if (ev->type == GDK_BUTTON_PRESS) {
 
@@ -299,8 +301,8 @@ MonoPanner::on_button_press_event (GdkEventButton* ev)
                 }
 
                 _dragging = true;
+		_tooltip.target_start_drag ();
                 StartGesture ();
-		show_drag_data_window ();
         }
 
         return true;
@@ -318,11 +320,10 @@ MonoPanner::on_button_release_event (GdkEventButton* ev)
         }
 
         _dragging = false;
+	_tooltip.target_stop_drag ();
         accumulated_delta = 0;
         detented = false;
 
-	hide_drag_data_window ();
-
         if (Keyboard::modifier_state_contains (ev->state, Keyboard::TertiaryModifier)) {
 		_panner->reset ();
         } else {
diff --git a/gtk2_ardour/mono_panner.h b/gtk2_ardour/mono_panner.h
index 3b7a37c993..1c387ad32c 100644
--- a/gtk2_ardour/mono_panner.h
+++ b/gtk2_ardour/mono_panner.h
@@ -63,7 +63,7 @@ class MonoPanner : public PannerInterface
 
         BindingProxy position_binder;
 
-        void set_drag_data ();
+        void set_tooltip ();
 
         struct ColorScheme {
             uint32_t outline;
@@ -74,6 +74,8 @@ class MonoPanner : public PannerInterface
             uint32_t pos_fill;
         };
 
+	bool _dragging;
+
         static ColorScheme colors;
         static void set_colors ();
         static bool have_colors;
diff --git a/gtk2_ardour/panner_interface.cc b/gtk2_ardour/panner_interface.cc
index 09155c6b79..09cf29dfd6 100644
--- a/gtk2_ardour/panner_interface.cc
+++ b/gtk2_ardour/panner_interface.cc
@@ -19,6 +19,7 @@
 
 #include <gtkmm.h>
 #include "gtkmm2ext/keyboard.h"
+#include "gtkmm2ext/persistent_tooltip.h"
 #include "panner_interface.h"
 #include "panner_editor.h"
 #include "global_signals.h"
@@ -32,9 +33,7 @@ using namespace Gtkmm2ext;
 
 PannerInterface::PannerInterface (boost::shared_ptr<Panner> p)
 	: _panner (p)
-	, _drag_data_window (0)
-	, _drag_data_label (0)
-        , _dragging (false)
+	, _tooltip (this)
 	, _editor (0)
 {
         set_flags (Gtk::CAN_FOCUS);
@@ -49,66 +48,14 @@ PannerInterface::PannerInterface (boost::shared_ptr<Panner> p)
 
 PannerInterface::~PannerInterface ()
 {
-	delete _drag_data_window;
 	delete _editor;
 }
 
-void
-PannerInterface::show_drag_data_window ()
-{
-        if (!_drag_data_window) {
-		_drag_data_window = new Window (WINDOW_POPUP);
-		_drag_data_window->set_name (X_("ContrastingPopup"));
-		_drag_data_window->set_position (WIN_POS_MOUSE);
-		_drag_data_window->set_decorated (false);
-		
-		_drag_data_label = manage (new Label);
-		_drag_data_label->set_use_markup (true);
-		
-		_drag_data_window->set_border_width (6);
-		_drag_data_window->add (*_drag_data_label);
-		_drag_data_label->show ();
-		
-		Window* toplevel = dynamic_cast<Window*> (get_toplevel());
-		if (toplevel) {
-			_drag_data_window->set_transient_for (*toplevel);
-		}
-	}
-
-	set_drag_data ();
-	
-        if (!_drag_data_window->is_visible ()) {
-                /* move the window a little away from the mouse */
-                int rx, ry;
-                get_window()->get_origin (rx, ry);
-                _drag_data_window->move (rx, ry + get_height());
-                _drag_data_window->present ();
-        }
-}
-
-void
-PannerInterface::hide_drag_data_window ()
-{
-        if (_drag_data_window) {
-                _drag_data_window->hide ();
-        }
-}
-
 bool
 PannerInterface::on_enter_notify_event (GdkEventCrossing *)
 {
 	grab_focus ();
 	Keyboard::magic_widget_grab_focus ();
-
-	_drag_data_timeout = Glib::signal_timeout().connect (sigc::mem_fun (*this, &PannerInterface::drag_data_timeout), 500);
-	
-	return false;
-}
-
-bool
-PannerInterface::drag_data_timeout ()
-{
-	show_drag_data_window ();
 	return false;
 }
 
@@ -116,12 +63,6 @@ bool
 PannerInterface::on_leave_notify_event (GdkEventCrossing *)
 {
 	Keyboard::magic_widget_drop_focus ();
-
-	_drag_data_timeout.disconnect ();
-	if (!_dragging) {
-		hide_drag_data_window ();
-	}
-	
 	return false;
 }
 
@@ -134,7 +75,7 @@ PannerInterface::on_key_release_event (GdkEventKey*)
 void
 PannerInterface::value_change ()
 {
-	set_drag_data ();
+	set_tooltip ();
 	queue_draw ();
 }
 
@@ -167,3 +108,28 @@ PannerInterface::edit ()
 	_editor = editor ();
 	_editor->show ();
 }
+
+PannerPersistentTooltip::PannerPersistentTooltip (Gtk::Widget* w)
+	: PersistentTooltip (w)
+	, _dragging (false)
+{
+
+}
+
+void
+PannerPersistentTooltip::target_start_drag ()
+{
+	_dragging = true;
+}
+
+void
+PannerPersistentTooltip::target_stop_drag ()
+{
+	_dragging = false;
+}
+
+bool
+PannerPersistentTooltip::dragging () const
+{
+	return _dragging;
+}
diff --git a/gtk2_ardour/panner_interface.h b/gtk2_ardour/panner_interface.h
index 8dd19d1a14..02f4e210bd 100644
--- a/gtk2_ardour/panner_interface.h
+++ b/gtk2_ardour/panner_interface.h
@@ -23,6 +23,7 @@
 #include <boost/shared_ptr.hpp>
 #include <gtkmm/drawingarea.h>
 #include <gtkmm/label.h>
+#include "gtkmm2ext/persistent_tooltip.h"
 #include "pbd/destructible.h"
 
 namespace ARDOUR {
@@ -31,6 +32,21 @@ namespace ARDOUR {
 
 class PannerEditor;
 
+class PannerPersistentTooltip : public Gtkmm2ext::PersistentTooltip
+{
+public:
+	PannerPersistentTooltip (Gtk::Widget* w);
+
+	void target_start_drag ();
+	void target_stop_drag ();
+
+	bool dragging () const;
+
+private:
+	bool _dragging;
+};
+	
+
 /** Parent class for some panner UI classes that contains some common code */
 class PannerInterface : public Gtk::DrawingArea, public PBD::Destructible
 {
@@ -45,10 +61,8 @@ public:
 	void edit ();
 
 protected:
-	virtual void set_drag_data () = 0;
+	virtual void set_tooltip () = 0;
 
-	void show_drag_data_window ();
-	void hide_drag_data_window ();
 	void value_change ();
 	
         bool on_enter_notify_event (GdkEventCrossing *);
@@ -58,14 +72,9 @@ protected:
 	bool on_button_release_event (GdkEventButton*);
 
 	boost::shared_ptr<ARDOUR::Panner> _panner;
-        Gtk::Window* _drag_data_window;
-        Gtk::Label*  _drag_data_label;
-        bool _dragging;
+	PannerPersistentTooltip _tooltip;
 
 private:
-	bool drag_data_timeout ();
-	sigc::connection _drag_data_timeout;
-
 	virtual PannerEditor* editor () = 0;
 	PannerEditor* _editor;
 };
diff --git a/gtk2_ardour/processor_box.cc b/gtk2_ardour/processor_box.cc
index 525aca33e9..ac35204fb7 100644
--- a/gtk2_ardour/processor_box.cc
+++ b/gtk2_ardour/processor_box.cc
@@ -411,6 +411,7 @@ ProcessorEntry::Control::Control (Glib::RefPtr<Gdk::Pixbuf> s, Glib::RefPtr<Gdk:
 	: _control (c)
 	, _adjustment (gain_to_slider_position_with_max (1.0, Config->get_max_gain()), 0, 1, 0.01, 0.1)
 	, _slider (s, sd, &_adjustment, 0, false)
+	, _slider_persistant_tooltip (&_slider)
 	, _button (ArdourButton::Element (ArdourButton::Text | ArdourButton::Indicator))
 	, _ignore_ui_adjustment (false)
 	, _visible (false)
@@ -454,6 +455,9 @@ ProcessorEntry::Control::Control (Glib::RefPtr<Gdk::Pixbuf> s, Glib::RefPtr<Gdk:
 	
 	control_changed ();
 	set_tooltip ();
+
+	/* We're providing our own PersistentTooltip */
+	set_no_tooltip_whatsoever (_slider);
 }
 
 void
@@ -470,11 +474,13 @@ ProcessorEntry::Control::set_tooltip ()
 	if (c->toggled ()) {
 		s << (c->get_value() > 0.5 ? _("on") : _("off"));
 	} else {
-		s << c->internal_to_interface (c->get_value ());
+		s << setprecision(2) << fixed;
+		s << c->internal_to_user (c->get_value ());
 	}
 	
 	ARDOUR_UI::instance()->set_tip (_label, s.str ());
-	ARDOUR_UI::instance()->set_tip (_slider, s.str ());
+	_slider_persistant_tooltip.set_tip (s.str ());
+//	ARDOUR_UI::instance()->set_tip (_slider, " ");
 	ARDOUR_UI::instance()->set_tip (_button, s.str ());
 }
 
@@ -498,6 +504,7 @@ ProcessorEntry::Control::slider_adjusted ()
 	}
 
 	c->set_value (c->interface_to_internal (_adjustment.get_value ()));
+	set_tooltip ();
 }
 
 void
@@ -537,8 +544,6 @@ ProcessorEntry::Control::control_changed ()
 		s.precision (1);
 		s.setf (ios::fixed, ios::floatfield);
 		s << c->internal_to_user (c->get_value ());
-		
-		_slider.set_tooltip_text (s.str ());
 	}
 	
 	_ignore_ui_adjustment = false;
diff --git a/gtk2_ardour/processor_box.h b/gtk2_ardour/processor_box.h
index 67a9e315d5..d300f70d5a 100644
--- a/gtk2_ardour/processor_box.h
+++ b/gtk2_ardour/processor_box.h
@@ -34,6 +34,7 @@
 #include "gtkmm2ext/click_box.h"
 #include "gtkmm2ext/dndvbox.h"
 #include "gtkmm2ext/pixfader.h"
+#include "gtkmm2ext/persistent_tooltip.h"
 
 #include "pbd/stateful.h"
 #include "pbd/signals.h"
@@ -189,6 +190,7 @@ private:
 		Gtk::Adjustment _adjustment;
 		Gtkmm2ext::HSliderController _slider;
 		Gtk::Label _label;
+		Gtkmm2ext::PersistentTooltip _slider_persistant_tooltip;
 		/* things for a button */
 		ArdourButton _button;
 		bool _ignore_ui_adjustment;
diff --git a/gtk2_ardour/stereo_panner.cc b/gtk2_ardour/stereo_panner.cc
index 5ee75ecc19..ebb55e7c86 100644
--- a/gtk2_ardour/stereo_panner.cc
+++ b/gtk2_ardour/stereo_panner.cc
@@ -30,6 +30,7 @@
 #include "gtkmm2ext/gtk_ui.h"
 #include "gtkmm2ext/keyboard.h"
 #include "gtkmm2ext/utils.h"
+#include "gtkmm2ext/persistent_tooltip.h"
 
 #include "ardour/pannable.h"
 #include "ardour/panner.h"
@@ -70,6 +71,7 @@ StereoPanner::StereoPanner (boost::shared_ptr<Panner> panner)
 	, detented (false)
 	, position_binder (position_control)
 	, width_binder (width_control)
+	, _dragging (false)
 {
 	if (!have_colors) {
 		set_colors ();
@@ -80,6 +82,8 @@ StereoPanner::StereoPanner (boost::shared_ptr<Panner> panner)
 	width_control->Changed.connect (connections, invalidator(*this), boost::bind (&StereoPanner::value_change, this), gui_context());
 
 	ColorsChanged.connect (sigc::mem_fun (*this, &StereoPanner::color_handler));
+
+	set_tooltip ();
 }
 
 StereoPanner::~StereoPanner ()
@@ -88,12 +92,8 @@ StereoPanner::~StereoPanner ()
 }
 
 void
-StereoPanner::set_drag_data ()
+StereoPanner::set_tooltip ()
 {
-	if (!_drag_data_label) {
-		return;
-	}
-
 	double pos = position_control->get_value(); // 0..1
 
 	/* We show the position of the center of the image relative to the left & right.
@@ -108,7 +108,7 @@ StereoPanner::set_drag_data ()
 	snprintf (buf, sizeof (buf), "L:%3d R:%3d Width:%d%%", (int) rint (100.0 * (1.0 - pos)),
 	          (int) rint (100.0 * pos),
 	          (int) floor (100.0 * width_control->get_value()));
-	_drag_data_label->set_markup (buf);
+	_tooltip.set_tip (buf);
 }
 
 bool
@@ -360,8 +360,6 @@ StereoPanner::on_button_press_event (GdkEventButton* ev)
 			return true;
 		}
 
-		show_drag_data_window ();
-
 		if (ev->y < 20) {
 			/* top section of widget is for position drags */
 			dragging_position = true;
@@ -395,6 +393,7 @@ StereoPanner::on_button_press_event (GdkEventButton* ev)
 		}
 
 		_dragging = true;
+		_tooltip.target_start_drag ();
 	}
 
 	return true;
@@ -414,14 +413,13 @@ StereoPanner::on_button_release_event (GdkEventButton* ev)
 	bool const dp = dragging_position;
 
 	_dragging = false;
+	_tooltip.target_stop_drag ();
 	dragging_position = false;
 	dragging_left = false;
 	dragging_right = false;
 	accumulated_delta = 0;
 	detented = false;
 
-	hide_drag_data_window ();
-
 	if (Keyboard::modifier_state_contains (ev->state, Keyboard::TertiaryModifier)) {
 		_panner->reset ();
 	} else {
diff --git a/gtk2_ardour/stereo_panner.h b/gtk2_ardour/stereo_panner.h
index 19fa0c056e..8b62b7d82a 100644
--- a/gtk2_ardour/stereo_panner.h
+++ b/gtk2_ardour/stereo_panner.h
@@ -72,7 +72,7 @@ class StereoPanner : public PannerInterface
         BindingProxy position_binder;
         BindingProxy width_binder;
 
-        void set_drag_data ();
+        void set_tooltip ();
 
         struct ColorScheme {
             uint32_t outline;
@@ -88,6 +88,8 @@ class StereoPanner : public PannerInterface
                 Inverted
         };
 
+	bool _dragging;
+
         static ColorScheme colors[3];
         static void set_colors ();
         static bool have_colors;
diff --git a/libs/gtkmm2ext/gtkmm2ext/persistent_tooltip.h b/libs/gtkmm2ext/gtkmm2ext/persistent_tooltip.h
new file mode 100644
index 0000000000..edd1e199e4
--- /dev/null
+++ b/libs/gtkmm2ext/gtkmm2ext/persistent_tooltip.h
@@ -0,0 +1,67 @@
+/*
+    Copyright (C) 2012 Paul Davis
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef gtkmm2ext_persistent_tooltip_h
+#define gtkmm2ext_persistent_tooltip_h
+
+#include <sigc++/trackable.h>
+
+namespace Gtkmm2ext {
+
+/** A class which offers a tooltip-like window which can be made to
+ *  stay open during a drag.
+ */
+class PersistentTooltip : public sigc::trackable
+{
+public:
+	PersistentTooltip (Gtk::Widget *);
+	virtual ~PersistentTooltip ();
+	
+	void set_tip (std::string);
+
+	virtual bool dragging () const;
+
+private:
+	bool timeout ();
+	void show ();
+	void hide ();
+	bool enter (GdkEventCrossing *);
+	bool leave (GdkEventCrossing *);
+	bool press (GdkEventButton *);
+	bool release (GdkEventButton *);
+
+	/** The widget that we are providing a tooltip for */
+	Gtk::Widget* _target;
+	/** Our window */
+	Gtk::Window* _window;
+	/** Our label */
+	Gtk::Label* _label;
+	/** true if we are `dragging', in the sense that button 1
+	    is being held over _target.
+	*/
+	bool _maybe_dragging;
+	/** Connection to a timeout used to open the tooltip */
+	sigc::connection _timeout;
+	/** The tip text */
+	std::string _tip;
+};
+
+}
+
+#endif
diff --git a/libs/gtkmm2ext/gtkmm2ext/utils.h b/libs/gtkmm2ext/gtkmm2ext/utils.h
index b7e27ea351..c4c9a4125c 100644
--- a/libs/gtkmm2ext/gtkmm2ext/utils.h
+++ b/libs/gtkmm2ext/gtkmm2ext/utils.h
@@ -108,6 +108,8 @@ namespace Gtkmm2ext {
 	void rounded_bottom_half_rectangle (cairo_t*, double x, double y, double w, double h, double r=10);
 
 	Gtk::Label* left_aligned_label (std::string const &);
+
+	void set_no_tooltip_whatsoever (Gtk::Widget &);
 };
 
 #endif /*  __gtkmm2ext_utils_h__ */
diff --git a/libs/gtkmm2ext/persistent_tooltip.cc b/libs/gtkmm2ext/persistent_tooltip.cc
new file mode 100644
index 0000000000..d50bbe7588
--- /dev/null
+++ b/libs/gtkmm2ext/persistent_tooltip.cc
@@ -0,0 +1,148 @@
+/*
+    Copyright (C) 2012 Paul Davis
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <gtkmm/window.h>
+#include <gtkmm/label.h>
+#include "gtkmm2ext/persistent_tooltip.h"
+
+#include "i18n.h"
+
+using namespace std;
+using namespace Gtk;
+using namespace Gtkmm2ext;
+
+/** @param target The widget to provide the tooltip for */
+PersistentTooltip::PersistentTooltip (Gtk::Widget* target)
+	: _target (target)
+	, _window (0)
+	, _label (0)
+	, _maybe_dragging (false)
+{
+	target->signal_enter_notify_event().connect (sigc::mem_fun (*this, &PersistentTooltip::enter), false);
+	target->signal_leave_notify_event().connect (sigc::mem_fun (*this, &PersistentTooltip::leave), false);
+	target->signal_button_press_event().connect (sigc::mem_fun (*this, &PersistentTooltip::press), false);
+	target->signal_button_release_event().connect (sigc::mem_fun (*this, &PersistentTooltip::release), false);
+}
+
+PersistentTooltip::~PersistentTooltip ()
+{
+	delete _window;
+}
+
+bool
+PersistentTooltip::enter (GdkEventCrossing *)
+{
+	_timeout = Glib::signal_timeout().connect (sigc::mem_fun (*this, &PersistentTooltip::timeout), 500);
+	return false;
+}
+
+bool
+PersistentTooltip::timeout ()
+{
+	show ();
+	return false;
+}
+
+bool
+PersistentTooltip::leave (GdkEventCrossing *)
+{
+	_timeout.disconnect ();
+	if (!dragging ()) {
+		hide ();
+	}
+
+	return false;
+}
+
+bool
+PersistentTooltip::press (GdkEventButton* ev)
+{
+	if (ev->type == GDK_BUTTON_PRESS && ev->button == 1) {
+		_maybe_dragging = true;
+	}
+
+	return false;
+}
+
+bool
+PersistentTooltip::release (GdkEventButton* ev)
+{
+	if (ev->type == GDK_BUTTON_RELEASE && ev->button == 1) {
+		_maybe_dragging = false;
+	}
+
+	return false;
+}
+
+bool
+PersistentTooltip::dragging () const
+{
+	return _maybe_dragging;
+}
+
+void
+PersistentTooltip::hide ()
+{
+	if (_window) {
+		_window->hide ();
+	}
+}
+
+void
+PersistentTooltip::show ()
+{
+	if (!_window) {
+		_window = new Window (WINDOW_POPUP);
+		_window->set_name (X_("ContrastingPopup"));
+		_window->set_position (WIN_POS_MOUSE);
+		_window->set_decorated (false);
+
+		_label = manage (new Label);
+		_label->set_use_markup (true);
+
+		_window->set_border_width (6);
+		_window->add (*_label);
+		_label->show ();
+
+		Gtk::Window* tlw = dynamic_cast<Gtk::Window*> (_target->get_toplevel ());
+		if (tlw) {
+			_window->set_transient_for (*tlw);
+		}
+	}
+	
+	set_tip (_tip);
+
+        if (!_window->is_visible ()) {
+                /* move the window a little away from the mouse */
+                int rx, ry;
+                _target->get_window()->get_origin (rx, ry);
+                _window->move (rx, ry + _target->get_height());
+                _window->present ();
+        }
+}
+
+void
+PersistentTooltip::set_tip (string t)
+{
+	_tip = t;
+
+	if (_label) {
+		_label->set_markup (t);
+	}
+}
diff --git a/libs/gtkmm2ext/utils.cc b/libs/gtkmm2ext/utils.cc
index 63d7655331..11c5b90722 100644
--- a/libs/gtkmm2ext/utils.cc
+++ b/libs/gtkmm2ext/utils.cc
@@ -30,6 +30,7 @@
 #include <gtkmm/paned.h>
 #include <gtkmm/label.h>
 #include <gtkmm/comboboxtext.h>
+#include <gtkmm/tooltip.h>
 
 #include "i18n.h"
 
@@ -631,3 +632,21 @@ Gtkmm2ext::left_aligned_label (string const & t)
 	l->set_alignment (0, 0.5);
 	return l;
 }
+
+static bool
+make_null_tooltip (int, int, bool, const Glib::RefPtr<Gtk::Tooltip>& t)
+{
+	t->set_tip_area (Gdk::Rectangle (0, 0, 0, 0));
+	return true;
+}
+
+/** Hackily arrange for the provided widget to have no tooltip,
+ *  and also to stop any other widget from providing one while
+ * the mouse is over w.
+ */
+void
+Gtkmm2ext::set_no_tooltip_whatsoever (Gtk::Widget& w)
+{
+	w.property_has_tooltip() = true;
+	w.signal_query_tooltip().connect (sigc::ptr_fun (make_null_tooltip));
+}
diff --git a/libs/gtkmm2ext/wscript b/libs/gtkmm2ext/wscript
index 1d386ce6ee..2f7d8b77b4 100644
--- a/libs/gtkmm2ext/wscript
+++ b/libs/gtkmm2ext/wscript
@@ -45,6 +45,7 @@ gtkmm2ext_sources = [
         'idle_adjustment.cc',
         'keyboard.cc',
         'motionfeedback.cc',
+        'persistent_tooltip.cc',
         'prolooks_helpers.c',
         'pixfader.cc',
         'pixscroller.cc',