Abstract base class for ArdourFader

This allows derivative projects to use other fader
render implementations.

libs/widgets/ardour_fader.cc

@@ -44,40 +44,23 @@ using namespace ArdourWidgets;
 std::list<ArdourFader::FaderImage*> ArdourFader::_patterns;
 
 ArdourFader::ArdourFader (Gtk::Adjustment& adj, int orientation, int fader_length, int fader_girth)
-	: _layout (0)
+	: FaderWidget (adj, orientation)
-	, _tweaks (Tweaks(0))
+	, _layout (0)
-	, _adjustment (adj)
 	, _text_width (0)
 	, _text_height (0)
 	, _span (fader_length)
 	, _girth (fader_girth)
 	, _min_span (fader_length)
 	, _min_girth (fader_girth)
-	, _orien (orientation)
 	, _pattern (0)
-	, _hovering (false)
-	, _dragging (false)
 	, _centered_text (true)
 	, _current_parent (0)
 	, have_explicit_bg (false)
 	, have_explicit_fg (false)
 	, outline_color (0)
 {
-	_default_value = _adjustment.get_value();
 	update_unity_position ();
 
-	add_events (
-			  Gdk::BUTTON_PRESS_MASK
-			| Gdk::BUTTON_RELEASE_MASK
-			| Gdk::POINTER_MOTION_MASK
-			| Gdk::SCROLL_MASK
-			| Gdk::ENTER_NOTIFY_MASK
-			| Gdk::LEAVE_NOTIFY_MASK
-			);
-
-	_adjustment.signal_value_changed().connect (mem_fun (*this, &ArdourFader::adjustment_changed));
-	_adjustment.signal_changed().connect (mem_fun (*this, &ArdourFader::adjustment_changed));
-	signal_grab_broken_event ().connect (mem_fun (*this, &ArdourFader::on_grab_broken_event));
 	if (_orien == VERT) {
 		CairoWidget::set_size_request(_girth, _span);
 	} else {
@@ -85,7 +68,6 @@ ArdourFader::ArdourFader (Gtk::Adjustment& adj, int orientation, int fader_lengt
 	}
 
 	outline_color = UIConfigurationBase::instance().color ("fader outline");
-
 }
 
 ArdourFader::~ArdourFader ()
@@ -102,7 +84,6 @@ ArdourFader::flush_pattern_cache () {
 	_patterns.clear();
 }
 
-
 cairo_pattern_t*
 ArdourFader::find_pattern (double afr, double afg, double afb,
 			double abr, double abg, double abb,
@@ -440,156 +421,6 @@ ArdourFader::on_size_allocate (Gtk::Allocation& alloc)
 	update_unity_position ();
 }
 
-bool
-ArdourFader::on_grab_broken_event (GdkEventGrabBroken* ev)
-{
-	if (_dragging) {
-		remove_modal_grab();
-		_dragging = false;
-		gdk_pointer_ungrab (GDK_CURRENT_TIME);
-		StopGesture (0);
-	}
-	return (_tweaks & NoButtonForward) ? true : false;
-}
-
-bool
-ArdourFader::on_button_press_event (GdkEventButton* ev)
-{
-	if (ev->type != GDK_BUTTON_PRESS) {
-		if (_dragging) {
-			remove_modal_grab();
-			_dragging = false;
-			gdk_pointer_ungrab (GDK_CURRENT_TIME);
-			StopGesture (ev->state);
-		}
-		return (_tweaks & NoButtonForward) ? true : false;
-	}
-
-	if (ev->button != 1 && ev->button != 2) {
-		return false;
-	}
-
-	add_modal_grab ();
-	StartGesture (ev->state);
-	_grab_loc = (_orien == VERT) ? ev->y : ev->x;
-	_grab_start = (_orien == VERT) ? ev->y : ev->x;
-	_grab_window = ev->window;
-	_dragging = true;
-	gdk_pointer_grab(ev->window,false,
-			GdkEventMask( Gdk::POINTER_MOTION_MASK | Gdk::BUTTON_PRESS_MASK |Gdk::BUTTON_RELEASE_MASK),
-			NULL,NULL,ev->time);
-
-	if (ev->button == 2) {
-		set_adjustment_from_event (ev);
-	}
-
-	return (_tweaks & NoButtonForward) ? true : false;
-}
-
-bool
-ArdourFader::on_button_release_event (GdkEventButton* ev)
-{
-	double ev_pos = (_orien == VERT) ? ev->y : ev->x;
-
-	switch (ev->button) {
-	case 1:
-		if (_dragging) {
-			remove_modal_grab();
-			_dragging = false;
-			gdk_pointer_ungrab (GDK_CURRENT_TIME);
-			StopGesture (ev->state);
-
-			if (!_hovering) {
-				if (!(_tweaks & NoVerticalScroll)) {
-					Keyboard::magic_widget_drop_focus();
-				}
-				queue_draw ();
-			}
-
-			if (ev_pos == _grab_start) {
-				/* no motion - just a click */
-				ev_pos = rint(ev_pos);
-
-				if (ev->state & Keyboard::TertiaryModifier) {
-					_adjustment.set_value (_default_value);
-				} else if (ev->state & Keyboard::GainFineScaleModifier) {
-					_adjustment.set_value (_adjustment.get_lower());
-#if 0 // ignore clicks
-				} else if (ev_pos == slider_pos) {
-					; // click on current position, no move.
-				} else if ((_orien == VERT && ev_pos < slider_pos) || (_orien == HORIZ && ev_pos > slider_pos)) {
-					/* above the current display height, remember X Window coords */
-					_adjustment.set_value (_adjustment.get_value() + _adjustment.get_step_increment());
-				} else {
-					_adjustment.set_value (_adjustment.get_value() - _adjustment.get_step_increment());
-#endif
-				}
-			}
-			return true;
-		}
-		break;
-
-	case 2:
-		if (_dragging) {
-			remove_modal_grab();
-			_dragging = false;
-			StopGesture (ev->state);
-			set_adjustment_from_event (ev);
-			gdk_pointer_ungrab (GDK_CURRENT_TIME);
-			return true;
-		}
-		break;
-
-	default:
-		break;
-	}
-	return false;
-}
-
-bool
-ArdourFader::on_scroll_event (GdkEventScroll* ev)
-{
-	double increment = 0;
-	if (ev->state & Keyboard::GainFineScaleModifier) {
-		if (ev->state & Keyboard::GainExtraFineScaleModifier) {
-			increment = 0.05 * _adjustment.get_step_increment();
-		} else {
-			increment = _adjustment.get_step_increment();
-		}
-	} else {
-		increment = _adjustment.get_page_increment();
-	}
-
-	bool vertical = false;
-	switch (ev->direction) {
-		case GDK_SCROLL_UP:
-		case GDK_SCROLL_DOWN:
-			vertical = !(ev->state & Keyboard::ScrollHorizontalModifier);
-			break;
-		default:
-			break;
-	}
-	if ((_orien == VERT && !vertical) ||
-	    ((_tweaks & NoVerticalScroll) && vertical)) {
-		return false;
-	}
-
-	switch (ev->direction) {
-		case GDK_SCROLL_UP:
-		case GDK_SCROLL_RIGHT:
-			_adjustment.set_value (_adjustment.get_value() + increment);
-			break;
-		case GDK_SCROLL_DOWN:
-		case GDK_SCROLL_LEFT:
-			_adjustment.set_value (_adjustment.get_value() - increment);
-			break;
-		default:
-			return false;
-	}
-
-	return true;
-}
-
 bool
 ArdourFader::on_motion_notify_event (GdkEventMotion* ev)
 {
@@ -633,12 +464,6 @@ ArdourFader::on_motion_notify_event (GdkEventMotion* ev)
 	return true;
 }
 
-void
-ArdourFader::adjustment_changed ()
-{
-	queue_draw ();
-}
-
 /** @return pixel offset of the current value from the right or bottom of the fader */
 int
 ArdourFader::display_span ()
@@ -672,30 +497,6 @@ ArdourFader::update_unity_position ()
 	queue_draw ();
 }
 
-bool
-ArdourFader::on_enter_notify_event (GdkEventCrossing*)
-{
-	_hovering = true;
-	if (!(_tweaks & NoVerticalScroll)) {
-		Keyboard::magic_widget_grab_focus ();
-	}
-	queue_draw ();
-	return false;
-}
-
-bool
-ArdourFader::on_leave_notify_event (GdkEventCrossing*)
-{
-	if (!_dragging) {
-		_hovering = false;
-		if (!(_tweaks & NoVerticalScroll)) {
-			Keyboard::magic_widget_drop_focus();
-		}
-		queue_draw ();
-	}
-	return false;
-}
-
 void
 ArdourFader::set_adjustment_from_event (GdkEventButton* ev)
 {
@@ -716,19 +517,6 @@ ArdourFader::set_default_value (float d)
 	update_unity_position ();
 }
 
-void
-ArdourFader::set_tweaks (Tweaks t)
-{
-	bool need_redraw = false;
-	if ((_tweaks & NoShowUnityLine) ^ (t & NoShowUnityLine)) {
-		need_redraw = true;
-	}
-	_tweaks = t;
-	if (need_redraw) {
-		queue_draw();
-	}
-}
-
 void
 ArdourFader::set_text (const std::string& str, bool centered, bool expose)
 {

libs/widgets/fader_widget.cc

@@ -0,0 +1,247 @@
+/*
+ * Copyright (C) 2024 Robin Gareus <robin@gareus.org>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "gtkmm2ext/keyboard.h"
+#include "widgets/fader_widget.h"
+
+using namespace Gtk;
+using namespace ArdourWidgets;
+using namespace Gtkmm2ext;
+
+FaderWidget::FaderWidget (Gtk::Adjustment& adj, int orien)
+	: _adjustment (adj)
+	, _tweaks (Tweaks(0))
+	, _orien (orien)
+	, _dragging (false)
+	, _hovering (false)
+	, _grab_window (0)
+	, _grab_loc (0)
+	, _grab_start (0)
+{
+	_default_value = _adjustment.get_value();
+
+	add_events (Gdk::BUTTON_PRESS_MASK
+	            | Gdk::BUTTON_RELEASE_MASK
+	            | Gdk::POINTER_MOTION_MASK
+	            | Gdk::SCROLL_MASK
+	            | Gdk::ENTER_NOTIFY_MASK
+	            | Gdk::LEAVE_NOTIFY_MASK
+	           );
+
+	_adjustment.signal_value_changed().connect (mem_fun (*this, &FaderWidget::adjustment_changed));
+	_adjustment.signal_changed().connect (mem_fun (*this, &FaderWidget::adjustment_changed));
+	signal_grab_broken_event ().connect (mem_fun (*this, &FaderWidget::on_grab_broken_event));
+}
+
+void
+FaderWidget::set_tweaks (Tweaks t)
+{
+	bool need_redraw = false;
+	if ((_tweaks & NoShowUnityLine) ^ (t & NoShowUnityLine)) {
+		need_redraw = true;
+	}
+	_tweaks = t;
+	if (need_redraw) {
+		queue_draw();
+	}
+}
+
+bool
+FaderWidget::on_button_press_event (GdkEventButton* ev)
+{
+	if (ev->button == 1 && ev->type == GDK_2BUTTON_PRESS && (_tweaks & DoubleClickReset)) {
+		_adjustment.set_value (_default_value);
+		return true;
+	}
+
+	if (ev->type != GDK_BUTTON_PRESS) {
+		if (_dragging) {
+			remove_modal_grab();
+			_dragging = false;
+			gdk_pointer_ungrab (GDK_CURRENT_TIME);
+			StopGesture (ev->state);
+		}
+		return (_tweaks & NoButtonForward) ? true : false;
+	}
+
+	if (ev->button != 1 && ev->button != 2) {
+		return false;
+	}
+
+	add_modal_grab ();
+	StartGesture (ev->state);
+	_grab_loc = (_orien == VERT) ? ev->y : ev->x;
+	_grab_start = (_orien == VERT) ? ev->y : ev->x;
+	_grab_window = ev->window;
+	_dragging = true;
+	gdk_pointer_grab (ev->window,false,
+			GdkEventMask( Gdk::POINTER_MOTION_MASK | Gdk::BUTTON_PRESS_MASK |Gdk::BUTTON_RELEASE_MASK),
+			NULL,NULL,ev->time);
+
+	if (ev->button == 2) {
+		set_adjustment_from_event (ev);
+	}
+
+	return (_tweaks & NoButtonForward) ? true : false;
+}
+
+bool
+FaderWidget::on_enter_notify_event (GdkEventCrossing*)
+{
+	_hovering = true;
+	if (!(_tweaks & NoVerticalScroll)) {
+		Keyboard::magic_widget_grab_focus ();
+	}
+	queue_draw ();
+	return false;
+}
+
+bool
+FaderWidget::on_leave_notify_event (GdkEventCrossing*)
+{
+	if (!_dragging) {
+		_hovering = false;
+		if (!(_tweaks & NoVerticalScroll)) {
+			Keyboard::magic_widget_drop_focus();
+		}
+		queue_draw ();
+	}
+	return false;
+}
+
+bool
+FaderWidget::on_button_release_event (GdkEventButton* ev)
+{
+	double ev_pos = (_orien == VERT) ? ev->y : ev->x;
+
+	switch (ev->button) {
+	case 1:
+		if (_dragging) {
+			remove_modal_grab();
+			_dragging = false;
+			gdk_pointer_ungrab (GDK_CURRENT_TIME);
+			StopGesture (ev->state);
+
+			if (!_hovering) {
+				if (!(_tweaks & NoVerticalScroll)) {
+					Keyboard::magic_widget_drop_focus();
+				}
+				queue_draw ();
+			}
+
+			if (ev_pos == _grab_start) {
+				/* no motion - just a click */
+				ev_pos = rint(ev_pos);
+
+				if (ev->state & Keyboard::TertiaryModifier) {
+					_adjustment.set_value (_default_value);
+				} else if (ev->state & Keyboard::GainFineScaleModifier) {
+					_adjustment.set_value (_adjustment.get_lower());
+#if 0 // ignore clicks
+				} else if (ev_pos == slider_pos) {
+					; // click on current position, no move.
+				} else if ((_orien == VERT && ev_pos < slider_pos) || (_orien == HORIZ && ev_pos > slider_pos)) {
+					/* above the current display height, remember X Window coords */
+					_adjustment.set_value (_adjustment.get_value() + _adjustment.get_step_increment());
+				} else {
+					_adjustment.set_value (_adjustment.get_value() - _adjustment.get_step_increment());
+#endif
+				}
+			}
+			return true;
+		}
+		break;
+
+	case 2:
+		if (_dragging) {
+			remove_modal_grab();
+			_dragging = false;
+			StopGesture (ev->state);
+			set_adjustment_from_event (ev);
+			gdk_pointer_ungrab (GDK_CURRENT_TIME);
+			return true;
+		}
+		break;
+
+	default:
+		break;
+	}
+	return false;
+}
+
+bool
+FaderWidget::on_scroll_event (GdkEventScroll* ev)
+{
+	double increment = 0;
+	if (ev->state & Keyboard::GainFineScaleModifier) {
+		if (ev->state & Keyboard::GainExtraFineScaleModifier) {
+			increment = 0.05 * _adjustment.get_step_increment();
+		} else {
+			increment = _adjustment.get_step_increment();
+		}
+	} else {
+		increment = _adjustment.get_page_increment();
+	}
+
+	bool vertical = false;
+	switch (ev->direction) {
+		case GDK_SCROLL_UP:
+		case GDK_SCROLL_DOWN:
+			vertical = !(ev->state & Keyboard::ScrollHorizontalModifier);
+			break;
+		default:
+			break;
+	}
+	if ((_orien == VERT && !vertical) ||
+	    ((_tweaks & NoVerticalScroll) && vertical)) {
+		return false;
+	}
+
+	switch (ev->direction) {
+		case GDK_SCROLL_UP:
+		case GDK_SCROLL_RIGHT:
+			_adjustment.set_value (_adjustment.get_value() + increment);
+			break;
+		case GDK_SCROLL_DOWN:
+		case GDK_SCROLL_LEFT:
+			_adjustment.set_value (_adjustment.get_value() - increment);
+			break;
+		default:
+			return false;
+	}
+
+	return true;
+}
+
+void
+FaderWidget::adjustment_changed ()
+{
+	queue_draw ();
+}
+
+bool
+FaderWidget::on_grab_broken_event (GdkEventGrabBroken* ev)
+{
+	if (_dragging) {
+		remove_modal_grab();
+		_dragging = false;
+		gdk_pointer_ungrab (GDK_CURRENT_TIME);
+		StopGesture (0);
+	}
+	return (_tweaks & NoButtonForward) ? true : false;
+}

libs/widgets/slider_controller.cc

@@ -30,8 +30,8 @@
 using namespace PBD;
 using namespace ArdourWidgets;
 
-SliderController::SliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int orientation, int fader_length, int fader_girth)
+SliderController::SliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int orien)
-	: ArdourFader (*adj, orientation, fader_length, fader_girth)
+	: FaderWidget (*adj, orien)
 	, _ctrl (mc)
 	, _ctrl_adj (adj)
 	, _spin_adj (0, 0, 1.0, .1, .01)
@@ -75,7 +75,7 @@ SliderController::on_button_press_event (GdkEventButton *ev)
 		return true;
 	}
 
-	return ArdourFader::on_button_press_event (ev);
+	return FaderWidget::on_button_press_event (ev);
 }
 
 bool
@@ -85,7 +85,7 @@ SliderController::on_enter_notify_event (GdkEventCrossing* ev)
 	if (c) {
 		PBD::Controllable::GUIFocusChanged (std::weak_ptr<PBD::Controllable> (c));
 	}
-	return ArdourFader::on_enter_notify_event (ev);
+	return FaderWidget::on_enter_notify_event (ev);
 }
 
 bool
@@ -94,7 +94,7 @@ SliderController::on_leave_notify_event (GdkEventCrossing* ev)
 	if (_binding_proxy.get_controllable()) {
 		PBD::Controllable::GUIFocusChanged (std::weak_ptr<PBD::Controllable> ());
 	}
-	return ArdourFader::on_leave_notify_event (ev);
+	return FaderWidget::on_leave_notify_event (ev);
 }
 
 void
@@ -133,11 +133,24 @@ SliderController::spin_adjusted ()
 
 
 VSliderController::VSliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int fader_length, int fader_girth)
-	: SliderController (adj, mc, VERT, fader_length, fader_girth)
+	: FaderWidget (*adj, VERT)
+	, SliderController (adj, mc, VERT)
+	, ArdourFader (*adj, VERT, fader_length, fader_girth)
 {
 }
 
 HSliderController::HSliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int fader_length, int fader_girth)
-	: SliderController (adj, mc, HORIZ, fader_length, fader_girth)
+	: FaderWidget (*adj, HORIZ)
+	, SliderController (adj, mc, HORIZ)
+	, ArdourFader (*adj, HORIZ, fader_length, fader_girth)
 {
 }
+
+#ifdef LIVETRAX
+TraxSliderController::TraxSliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int fader_length, int fader_girth)
+	: FaderWidget (*adj, VERT)
+	, SliderController (adj, mc, VERT)
+	, TraxFader (*adj, fader_length, fader_girth)
+{
+}
+#endif

libs/widgets/widgets/ardour_fader.h

@@ -28,33 +28,22 @@
 
 #include "gtkmm2ext/cairo_widget.h"
 #include "gtkmm2ext/colors.h"
+
+#include "widgets/fader_widget.h"
 #include "widgets/visibility.h"
 
 namespace ArdourWidgets {
 
-class LIBWIDGETS_API ArdourFader : public CairoWidget
+class LIBWIDGETS_API ArdourFader : virtual public FaderWidget
 {
 public:
 	ArdourFader (Gtk::Adjustment& adjustment, int orientation, int span, int girth);
 	virtual ~ArdourFader ();
 	static void flush_pattern_cache();
 
-	sigc::signal<void,int> StartGesture;
-	sigc::signal<void,int> StopGesture;
-	sigc::signal<void> OnExpose;
-
 	void set_default_value (float);
 	void set_text (const std::string&, bool centered = true, bool expose = true);
 
-	enum Tweaks {
-		NoShowUnityLine = 0x1,
-		NoButtonForward = 0x2,
-		NoVerticalScroll = 0x4,
-	};
-
-	Tweaks tweaks() const { return _tweaks; }
-	void set_tweaks (Tweaks);
-
 	void set_bg (Gtkmm2ext::Color);
 	void set_fg (Gtkmm2ext::Color);
 	void unset_bg ();
@@ -65,40 +54,21 @@ protected:
 	void on_size_allocate (Gtk::Allocation& alloc);
 
 	void render (Cairo::RefPtr<Cairo::Context> const&, cairo_rectangle_t*);
-	bool on_grab_broken_event (GdkEventGrabBroken*);
-	bool on_button_press_event (GdkEventButton*);
-	bool on_button_release_event (GdkEventButton*);
 	bool on_motion_notify_event (GdkEventMotion*);
-	bool on_scroll_event (GdkEventScroll* ev);
-	bool on_enter_notify_event (GdkEventCrossing* ev);
-	bool on_leave_notify_event (GdkEventCrossing* ev);
 
 	void on_state_changed (Gtk::StateType);
 	void on_style_changed (const Glib::RefPtr<Gtk::Style>&);
 
-	enum Orientation {
-		VERT,
-		HORIZ,
-	};
-
 private:
 	Glib::RefPtr<Pango::Layout> _layout;
 	std::string                 _text;
-	Tweaks                      _tweaks;
-	Gtk::Adjustment&            _adjustment;
 	int _text_width;
 	int _text_height;
 
 	int _span, _girth;
 	int _min_span, _min_girth;
-	int _orien;
 	cairo_pattern_t* _pattern;
-	bool _hovering;
+
-	GdkWindow* _grab_window;
-	double _grab_loc;
-	double _grab_start;
-	bool _dragging;
-	float _default_value;
 	int _unity_loc;
 	bool _centered_text;
 
@@ -113,7 +83,6 @@ private:
 	uint32_t outline_color;
 
 	void create_patterns();
-	void adjustment_changed ();
 	void set_adjustment_from_event (GdkEventButton *);
 	void update_unity_position ();
 	int  display_span ();

libs/widgets/widgets/fader_widget.h

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2024 Robin Gareus <robin@gareus.org>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#pragma once
+
+#include <gtkmm/adjustment.h>
+#include "gtkmm2ext/cairo_widget.h"
+
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API FaderWidget : public virtual CairoWidget
+{
+public:
+	FaderWidget (Gtk::Adjustment&, int orient);
+	virtual ~FaderWidget () {};
+
+	sigc::signal<void,int> StartGesture;
+	sigc::signal<void,int> StopGesture;
+	sigc::signal<void> OnExpose;
+
+	virtual void set_default_value (float) = 0;
+
+	enum Tweaks {
+		NoShowUnityLine = 0x1,
+		NoButtonForward = 0x2,
+		NoVerticalScroll = 0x4,
+		DoubleClickReset = 0x8,
+	};
+
+	enum Orientation {
+		VERT,
+		HORIZ,
+	};
+
+	void set_tweaks (Tweaks);
+	Tweaks tweaks() const { return _tweaks; }
+
+	virtual void set_bg (Gtkmm2ext::Color) = 0;
+	virtual void set_fg (Gtkmm2ext::Color) = 0;
+	virtual void unset_bg () = 0;
+	virtual void unset_fg () = 0;
+
+protected:
+	bool on_button_press_event (GdkEventButton*);
+	bool on_button_release_event (GdkEventButton*);
+	bool on_enter_notify_event (GdkEventCrossing* ev);
+	bool on_leave_notify_event (GdkEventCrossing* ev);
+	bool on_scroll_event (GdkEventScroll* ev);
+	bool on_grab_broken_event (GdkEventGrabBroken*);
+
+	void adjustment_changed ();
+
+	virtual void set_adjustment_from_event (GdkEventButton*) = 0;
+
+	Gtk::Adjustment& _adjustment;
+
+	Tweaks _tweaks;
+	int    _orien;
+	bool   _dragging;
+	bool   _hovering;
+	float  _default_value;
+
+
+	GdkWindow* _grab_window;
+	double     _grab_loc;
+	double     _grab_start;
+};
+
+}

libs/widgets/widgets/slider_controller.h

@@ -29,6 +29,7 @@
 #include <gtkmm/adjustment.h>
 #include <gtkmm/spinbutton.h>
 
+#include "widgets/fader_widget.h"
 #include "widgets/ardour_fader.h"
 #include "widgets/binding_proxy.h"
 #include "widgets/visibility.h"
@@ -39,10 +40,10 @@ namespace PBD {
 
 namespace ArdourWidgets {
 
-class LIBWIDGETS_API SliderController : public ArdourWidgets::ArdourFader
+class LIBWIDGETS_API SliderController : virtual public ArdourWidgets::FaderWidget
 {
 public:
-	SliderController (Gtk::Adjustment* adj, std::shared_ptr<PBD::Controllable> mc, int orientation, int, int);
+	SliderController (Gtk::Adjustment* adj, std::shared_ptr<PBD::Controllable> mc, int orien);
 
 	virtual ~SliderController () {}
 
@@ -65,13 +66,13 @@ protected:
 	bool _spin_ignore;
 };
 
-class LIBWIDGETS_API VSliderController : public SliderController
+class LIBWIDGETS_API VSliderController : public SliderController, public ArdourFader
 {
 public:
 	VSliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int, int);
 };
 
-class LIBWIDGETS_API HSliderController : public SliderController
+class LIBWIDGETS_API HSliderController : public SliderController, public ArdourFader
 {
 public:
 	HSliderController (Gtk::Adjustment *adj, std::shared_ptr<PBD::Controllable> mc, int, int);

libs/widgets/wscript

@@ -29,6 +29,7 @@ widgets_sources = [
         'binding_proxy.cc',
         'eventboxext.cc',
         'choice.cc',
+        'fader_widget.cc',
         'fastmeter.cc',
         'frame.cc',
         'focus_entry.cc',