Separate Ardour UI widgets into dedicated library

9 files changed, 712 insertions, 0 deletions

diff --git a/libs/widgets/widgets/ardour_button.h b/libs/widgets/widgets/ardour_button.h
new file mode 100644
index 0000000000..a51575e616
--- /dev/null
+++ b/libs/widgets/widgets/ardour_button.h
@@ -0,0 +1,221 @@
+/*
+    Copyright (C) 2010 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 _WIDGETS_ARDOUR_BUTTON_H_
+#define _WIDGETS_ARDOUR_BUTTON_H_
+
+#include <list>
+#include <stdint.h>
+
+#include <gtkmm/action.h>
+
+#include "pbd/signals.h"
+#include "gtkmm2ext/ardour_icon.h"
+#include "gtkmm2ext/binding_proxy.h"
+#include "gtkmm2ext/activatable.h"
+#include "gtkmm2ext/cairo_widget.h"
+
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API ArdourButton : public CairoWidget , public Gtkmm2ext::Activatable
+{
+	public:
+	enum Element {
+		Edge = 0x1,
+		Body = 0x2,
+		Text = 0x4,
+		Indicator = 0x8,
+		unused = 0x10,
+		Menu = 0x20,
+		Inactive = 0x40, // no _action is defined AND state is not used
+		VectorIcon = 0x80,
+		IconRenderCallback = 0x100,
+	};
+
+	typedef void (* rendercallback_t) (cairo_t*, int, int, uint32_t, void*);
+
+	static Element default_elements;
+	static Element led_default_elements;
+	static Element just_led_default_elements;
+
+	ArdourButton (Element e = default_elements);
+	ArdourButton (const std::string&, Element e = default_elements);
+	virtual ~ArdourButton ();
+
+	enum Tweaks {
+		Square = 0x1,
+		TrackHeader = 0x2,
+		OccasionalText = 0x4,
+		unused4 = 0x8,
+	};
+
+	Tweaks tweaks() const { return _tweaks; }
+	void set_tweaks (Tweaks);
+
+	void set_active_state (Gtkmm2ext::ActiveState);
+	void set_visual_state (Gtkmm2ext::VisualState);
+
+	void set_custom_led_color (const uint32_t c, const bool useit = true);
+
+	void set_act_on_release (bool onRelease) { _act_on_release = onRelease; }
+
+	Element elements() const { return _elements; }
+	void set_elements (Element);
+	void add_elements (Element);
+
+	Gtkmm2ext::ArdourIcon::Icon icon() const { return _icon; }
+	void set_icon (Gtkmm2ext::ArdourIcon::Icon);
+	void set_icon (rendercallback_t, void*);
+
+	void set_corner_radius (float);
+
+	void set_text (const std::string&, bool markup = false);
+	const std::string& get_text () { return _text; }
+	bool get_markup () const { return _markup; }
+	void set_angle (const double);
+	void set_alignment (const float, const float);
+	void get_alignment (float& xa, float& ya) {xa = _xalign; ya = _yalign;};
+
+	void set_led_left (bool yn);
+	void set_distinct_led_click (bool yn);
+
+	void set_layout_ellipsize_width (int w);
+	void set_layout_font (const Pango::FontDescription&);
+	void set_text_ellipsize (Pango::EllipsizeMode);
+
+    /* Sets the text used for size request computation. Pass an
+     * empty string to return to the default behavior which uses
+     * the currently displayed text for measurement. */
+	void set_sizing_text (const std::string&);
+	const std::string& get_sizing_text () {return _sizing_text;}
+
+	sigc::signal<void, GdkEventButton*> signal_led_clicked;
+	sigc::signal<void> signal_clicked;
+
+	boost::shared_ptr<PBD::Controllable> get_controllable() { return binding_proxy.get_controllable(); }
+	void set_controllable (boost::shared_ptr<PBD::Controllable> c);
+	void watch ();
+
+	void set_related_action (Glib::RefPtr<Gtk::Action>);
+
+	bool on_button_press_event (GdkEventButton*);
+	bool on_button_release_event (GdkEventButton*);
+
+	void set_image (const Glib::RefPtr<Gdk::Pixbuf>&);
+
+	void set_fixed_colors   (const uint32_t active_color, const uint32_t inactive_color);
+	void set_active_color   (const uint32_t active_color);
+	void set_inactive_color (const uint32_t inactive_color);
+
+	void set_fallthrough_to_parent(bool fall) { _fallthrough_to_parent = fall; }
+
+	unsigned int char_pixel_width() { if (_char_pixel_width < 1) recalc_char_pixel_geometry() ; return _char_pixel_width; }
+	unsigned int char_pixel_height() { if (_char_pixel_height < 1) recalc_char_pixel_geometry() ; return _char_pixel_height; }
+	float char_avg_pixel_width() { if (_char_pixel_width < 1) recalc_char_pixel_geometry() ; return _char_avg_pixel_width; }
+
+	protected:
+	void render (Cairo::RefPtr<Cairo::Context> const&, cairo_rectangle_t*);
+	void on_size_request (Gtk::Requisition* req);
+	void on_size_allocate (Gtk::Allocation&);
+	void on_style_changed (const Glib::RefPtr<Gtk::Style>&);
+	void on_name_changed ();
+	void on_realize ();
+	bool on_enter_notify_event (GdkEventCrossing*);
+	bool on_leave_notify_event (GdkEventCrossing*);
+	bool on_grab_broken_event(GdkEventGrabBroken*);
+	bool on_focus_in_event (GdkEventFocus*);
+	bool on_focus_out_event (GdkEventFocus*);
+	bool on_key_release_event (GdkEventKey *);
+	bool on_key_press_event (GdkEventKey *);
+
+	void controllable_changed ();
+	PBD::ScopedConnection watch_connection;
+
+	protected:
+	Glib::RefPtr<Pango::Layout> _layout;
+	Glib::RefPtr<Gdk::Pixbuf>   _pixbuf;
+	std::string                 _text;
+	std::string                 _sizing_text;
+	bool                        _markup;
+	Element                     _elements;
+	Gtkmm2ext::ArdourIcon::Icon _icon;
+	rendercallback_t            _icon_render_cb;
+	void*                       _icon_render_cb_data;
+	Tweaks                      _tweaks;
+	BindingProxy                binding_proxy;
+
+	void set_text_internal ();
+	void recalc_char_pixel_geometry ();
+	unsigned int _char_pixel_width;
+	unsigned int _char_pixel_height;
+	float _char_avg_pixel_width;
+
+	int   _text_width;
+	int   _text_height;
+	float _diameter;
+	float _corner_radius;
+	int   _corner_mask;
+
+	double _angle;
+	float _xalign, _yalign;
+
+	uint32_t fill_inactive_color;
+	uint32_t fill_active_color;
+
+	uint32_t text_active_color;
+	uint32_t text_inactive_color;
+
+	uint32_t led_active_color;
+	uint32_t led_inactive_color;
+	uint32_t led_custom_color;
+	bool     use_custom_led_color;
+
+	cairo_pattern_t* convex_pattern;
+	cairo_pattern_t* concave_pattern;
+	cairo_pattern_t* led_inset_pattern;
+	cairo_rectangle_t* _led_rect;
+
+	bool _act_on_release;
+	bool _led_left;
+	bool _distinct_led_click;
+	bool _hovering;
+	bool _focused;
+	int  _fixed_colors_set;
+	bool _fallthrough_to_parent;
+	int _layout_ellipsize_width;
+	Pango::EllipsizeMode _ellipsis;
+	bool _update_colors;
+	int _pattern_height;
+
+	void setup_led_rect ();
+	void set_colors ();
+	void color_handler ();
+	void build_patterns ();
+	void ensure_layout ();
+
+	void action_toggled ();
+	void action_sensitivity_changed ();
+	void action_visibility_changed ();
+	void action_tooltip_changed ();
+};
+
+} /* end namespace */
+
+#endif
diff --git a/libs/widgets/widgets/ardour_display.h b/libs/widgets/widgets/ardour_display.h
new file mode 100644
index 0000000000..c8d566cd85
--- /dev/null
+++ b/libs/widgets/widgets/ardour_display.h
@@ -0,0 +1,55 @@
+/*
+    Copyright (C) 2014 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 _WIDGETS_ARDOUR_DISPLAY_H_
+#define _WIDGETS_ARDOUR_DISPLAY_H_
+
+#include <list>
+#include <stdint.h>
+
+#include <gtkmm/action.h>
+#include <gtkmm/menu.h>
+#include <gtkmm/menuitem.h>
+
+#include "widgets/ardour_dropdown.h"
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API ArdourDisplay : public ArdourWidgets::ArdourDropdown
+{
+public:
+
+	ArdourDisplay (Element e = default_elements);
+	virtual ~ArdourDisplay ();
+
+	boost::shared_ptr<PBD::Controllable> get_controllable() { return binding_proxy.get_controllable(); }
+	void set_controllable (boost::shared_ptr<PBD::Controllable> c);
+
+	bool on_scroll_event (GdkEventScroll* ev);
+
+	void add_controllable_preset (const char*, float);
+	void handle_controllable_preset (float p);
+
+	void controllable_changed ();
+	PBD::ScopedConnection watch_connection;
+};
+
+} /* end namespace */
+
+#endif /* __gtk2_ardour_ardour_menu_h__ */
diff --git a/libs/widgets/widgets/ardour_dropdown.h b/libs/widgets/widgets/ardour_dropdown.h
new file mode 100644
index 0000000000..93e866d011
--- /dev/null
+++ b/libs/widgets/widgets/ardour_dropdown.h
@@ -0,0 +1,60 @@
+/*
+    Copyright (C) 2014 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 _WIDGETS_ARDOUR_DROPDOWN_H_
+#define _WIDGETS_ARDOUR_DROPDOWN_H_
+
+#include <list>
+#include <stdint.h>
+
+#include <gtkmm/action.h>
+#include <gtkmm/menu.h>
+#include <gtkmm/menuitem.h>
+
+#include "widgets/ardour_button.h"
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API ArdourDropdown : public ArdourButton
+{
+public:
+
+	ArdourDropdown (Element e = default_elements);
+	virtual ~ArdourDropdown ();
+
+	bool on_button_press_event (GdkEventButton*);
+	bool on_scroll_event (GdkEventScroll*);
+	void menu_size_request(Gtk::Requisition*);
+
+	void clear_items ();
+	void AddMenuElem (Gtk::Menu_Helpers::Element e);
+
+	void disable_scrolling();
+
+	Gtk::Menu_Helpers::MenuList& items () { return _menu.items (); }
+
+private:
+	Gtk::Menu      _menu;
+
+	bool _scrolling_disabled;
+};
+
+} /* end namespace */
+
+#endif
diff --git a/libs/widgets/widgets/ardour_knob.h b/libs/widgets/widgets/ardour_knob.h
new file mode 100644
index 0000000000..84bb974adf
--- /dev/null
+++ b/libs/widgets/widgets/ardour_knob.h
@@ -0,0 +1,133 @@
+/*
+    Copyright (C) 2014 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 __gtk2_ardour_ardour_knob_h__
+#define __gtk2_ardour_ardour_knob_h__
+
+#include <list>
+#include <stdint.h>
+
+#include <gtkmm/action.h>
+
+#include "pbd/signals.h"
+
+#include "gtkmm2ext/binding_proxy.h"
+#include "gtkmm2ext/activatable.h"
+#include "gtkmm2ext/cairo_widget.h"
+#include "gtkmm2ext/persistent_tooltip.h"
+
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API KnobPersistentTooltip : public Gtkmm2ext::PersistentTooltip
+{
+public:
+	KnobPersistentTooltip (Gtk::Widget* w);
+
+	void start_drag ();
+	void stop_drag ();
+	bool dragging () const;
+
+private:
+	bool _dragging;
+};
+
+
+class LIBWIDGETS_API ArdourKnob : public CairoWidget , public Gtkmm2ext::Activatable
+{
+public:
+
+	enum Element {
+		Arc = 0x1,
+		Bevel = 0x2,
+		unused2 = 0x4,
+		unused3 = 0x8,
+		unused4 = 0x10,
+		unused5 = 0x20,
+	};
+
+	enum Flags {
+		NoFlags = 0,
+		Detent = 0x1,
+		ArcToZero = 0x2,
+	};
+
+	ArdourKnob (Element e = default_elements, Flags flags = NoFlags);
+	virtual ~ArdourKnob ();
+
+	void set_active_state (Gtkmm2ext::ActiveState);
+	void set_visual_state (Gtkmm2ext::VisualState);
+
+	Element elements() const { return _elements; }
+	void set_elements (Element);
+	void add_elements (Element);
+	static Element default_elements;
+
+	void set_tooltip_prefix (std::string pfx) { _tooltip_prefix = pfx; controllable_changed (true); }
+
+	boost::shared_ptr<PBD::Controllable> get_controllable() { return binding_proxy.get_controllable(); }
+ 	void set_controllable (boost::shared_ptr<PBD::Controllable> c);
+
+	bool on_button_press_event (GdkEventButton*);
+	bool on_button_release_event (GdkEventButton*);
+	bool on_scroll_event (GdkEventScroll* ev);
+	bool on_motion_notify_event (GdkEventMotion *ev) ;
+
+	void color_handler ();
+
+  protected:
+	void render (Cairo::RefPtr<Cairo::Context> const&, cairo_rectangle_t*);
+	void on_size_request (Gtk::Requisition* req);
+	void on_size_allocate (Gtk::Allocation&);
+	void on_style_changed (const Glib::RefPtr<Gtk::Style>&);
+	void on_name_changed ();
+	bool on_enter_notify_event (GdkEventCrossing*);
+	bool on_leave_notify_event (GdkEventCrossing*);
+	bool on_focus_in_event (GdkEventFocus*);
+	bool on_focus_out_event (GdkEventFocus*);
+
+	void controllable_changed (bool force_update = false);
+	PBD::ScopedConnection watch_connection;
+
+
+  private:
+	Element _elements;
+	BindingProxy binding_proxy;
+
+	bool _hovering;
+	float _grabbed_x;
+	float _grabbed_y;
+
+	float _val; // current value [0..1]
+	float _normal; // default value, arc
+	float _dead_zone_delta;
+
+	Flags _flags;
+
+	void action_sensitivity_changed ();
+	void action_visibility_changed ();
+	void action_tooltip_changed ();
+
+	std::string _tooltip_prefix;
+	KnobPersistentTooltip _tooltip;
+};
+
+} /* namespace */
+
+#endif /* __gtk2_ardour_ardour_knob_h__ */
diff --git a/libs/widgets/widgets/ardour_spacer.h b/libs/widgets/widgets/ardour_spacer.h
new file mode 100644
index 0000000000..520ad670af
--- /dev/null
+++ b/libs/widgets/widgets/ardour_spacer.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef _WIDGETS_ARDOUR_SPACER_H_
+#define _WIDGETS_ARDOUR_SPACER_H_
+
+#include "gtkmm2ext/cairo_widget.h"
+
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API ArdourVSpacer : public CairoWidget
+{
+public:
+	ArdourVSpacer (float r = 0.75f);
+
+protected:
+	void render (Cairo::RefPtr<Cairo::Context> const& ctx, cairo_rectangle_t* r) {
+		float h = r->height * ratio;
+		float t = .5f * (r->height - h);
+		ctx->rectangle (0, t, 1, h);
+		ctx->set_source_rgb (0, 0, 0);
+		ctx->fill ();
+	}
+
+	void on_size_request (Gtk::Requisition* req) {
+		req->width = 1;
+		req->height = 0;
+		CairoWidget::on_size_request (req);
+	}
+
+	float ratio;
+};
+
+} /* end namespace */
+
+#endif
diff --git a/libs/widgets/widgets/ardour_spinner.h b/libs/widgets/widgets/ardour_spinner.h
new file mode 100644
index 0000000000..b0928fa432
--- /dev/null
+++ b/libs/widgets/widgets/ardour_spinner.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2016 Robin Gareus <robin@gareus.org>
+ * Copyright (C) 2011 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef _WIDGETS_ARDOUR_SPINNER_H_
+#define _WIDGETS_ARDOUR_SPINNER_H_
+
+#include <boost/algorithm/string.hpp>
+#include <gtkmm.h>
+
+#include "pbd/controllable.h"
+
+#include "widgets/ardour_button.h"
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API ArdourSpinner : public Gtk::Alignment
+{
+	public:
+		ArdourSpinner (boost::shared_ptr<PBD::Controllable>, Gtk::Adjustment* adj);
+
+		virtual ~ArdourSpinner ();
+
+	protected:
+		bool on_button_press_event (GdkEventButton*);
+		bool on_button_release_event (GdkEventButton*);
+		bool on_scroll_event (GdkEventScroll* ev);
+
+		void controllable_changed ();
+		PBD::ScopedConnection watch_connection;
+
+	private:
+
+		bool entry_focus_out (GdkEventFocus*);
+		void entry_activated ();
+		gint switch_to_button ();
+		gint switch_to_spinner ();
+
+		void ctrl_adjusted();
+		void spin_adjusted();
+
+		ArdourWidgets::ArdourButton _btn;
+		Gtk::Adjustment* _ctrl_adj;
+		Gtk::Adjustment  _spin_adj;
+		Gtk::SpinButton  _spinner;
+		bool             _switching;
+		bool             _switch_on_release;
+		bool             _ctrl_ignore;
+		bool             _spin_ignore;
+
+		boost::shared_ptr<PBD::Controllable> _controllable;
+
+};
+
+} /* end namespace */
+
+#endif
diff --git a/libs/widgets/widgets/tooltips.h b/libs/widgets/widgets/tooltips.h
new file mode 100644
index 0000000000..1a75e1c5eb
--- /dev/null
+++ b/libs/widgets/widgets/tooltips.h
@@ -0,0 +1,41 @@
+/*
+    Copyright (C) 2014 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 _WIDGETS_TOOLTIPS_H_
+#define _WIDGETS_TOOLTIPS_H_
+
+#include <string>
+
+namespace Gtk {
+	class Widget;
+}
+
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+extern LIBWIDGETS_API void set_tooltip (Gtk::Widget& w, const std::string& text);
+
+extern LIBWIDGETS_API void set_tooltip (Gtk::Widget* w, const std::string& text);
+
+extern LIBWIDGETS_API void set_tooltip (Gtk::Widget* w, const std::string& text, const std::string& help_text);
+
+}
+
+#endif
diff --git a/libs/widgets/widgets/ui_config.h b/libs/widgets/widgets/ui_config.h
new file mode 100644
index 0000000000..4087dae192
--- /dev/null
+++ b/libs/widgets/widgets/ui_config.h
@@ -0,0 +1,31 @@
+#ifndef _WIDGETS_UI_BASE_H_
+#define _WIDGETS_UI_BASE_H_
+
+#include <cassert>
+
+#include "pbd/stateful.h"
+#include "canvas/colors.h"
+
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API UIConfigurationBase : public PBD::Stateful
+{
+protected:
+	virtual ~UIConfigurationBase() { _instance = 0; }
+	static UIConfigurationBase* _instance;
+
+public:
+	static UIConfigurationBase& instance() { return *_instance; }
+
+	sigc::signal<void>  DPIReset;
+	sigc::signal<void>  ColorsChanged;
+
+	virtual float get_ui_scale () = 0;
+	virtual bool get_widget_prelight () const = 0;
+	virtual ArdourCanvas::Color color (const std::string&, bool* failed = 0) const = 0;
+};
+
+}
+#endif
diff --git a/libs/widgets/widgets/visibility.h b/libs/widgets/widgets/visibility.h
new file mode 100644
index 0000000000..e12f2522ab
--- /dev/null
+++ b/libs/widgets/widgets/visibility.h
@@ -0,0 +1,45 @@
+/*
+    Copyright (C) 2013 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 __libwidgets_visibility_h__
+#define __libwidgets_visibility_h__
+
+#if defined(COMPILER_MSVC)
+  #define LIBWIDGETS_DLL_IMPORT __declspec(dllimport)
+  #define LIBWIDGETS_DLL_EXPORT __declspec(dllexport)
+  #define LIBWIDGETS_DLL_LOCAL
+#else
+  #define LIBWIDGETS_DLL_IMPORT __attribute__ ((visibility ("default")))
+  #define LIBWIDGETS_DLL_EXPORT __attribute__ ((visibility ("default")))
+  #define LIBWIDGETS_DLL_LOCAL  __attribute__ ((visibility ("hidden")))
+#endif
+
+#ifdef LIBWIDGETS_STATIC // libwidgets is not a DLL
+#define LIBWIDGETS_API
+#define LIBWIDGETS_LOCAL
+#else
+  #ifdef LIBWIDGETS_DLL_EXPORTS // defined if we are building the libwidgets DLL (instead of using it)
+    #define LIBWIDGETS_API LIBWIDGETS_DLL_EXPORT
+  #else
+    #define LIBWIDGETS_API LIBWIDGETS_DLL_IMPORT
+  #endif
+  #define LIBWIDGETS_LOCAL LIBWIDGETS_DLL_LOCAL
+#endif
+
+#endif /* __libwidgets_visibility_h__ */