Add MetaButton Widget

A Button that changes functionality.

* right click: show a drop-down to pick what left click will do
* left click: activate selected action

libs/widgets/metabutton.cc

@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2025 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/utils.h"
+
+#include "widgets/metabutton.h"
+
+using namespace Gtk;
+using namespace std;
+using namespace ArdourWidgets;
+
+MetaButton::MetaButton ()
+	: _active (0)
+{
+	_menu.signal_size_request ().connect (sigc::mem_fun (*this, &MetaButton::menu_size_request));
+	_menu.set_reserve_toggle_size (false);
+
+	add_elements (default_elements);
+	add_elements (ArdourButton::Menu);
+}
+
+MetaButton::~MetaButton ()
+{
+}
+
+void
+MetaButton::menu_size_request (Requisition* req)
+{
+	req->width = max (req->width, get_allocation ().get_width ());
+}
+
+void
+MetaButton::clear_items ()
+{
+	_menu.items ().clear ();
+}
+
+void
+MetaButton::add_item (std::string const& label, std::string const& menutext, sigc::slot<void> const& cb)
+{
+	using namespace Menu_Helpers;
+
+	add_sizing_text (label);
+	MenuList& items = _menu.items ();
+	items.push_back (MetaElement (label, menutext, cb, sigc::mem_fun (*this, &MetaButton::activate_item)));
+	if (items.size () == 1) {
+		_menu.set_active (0);
+		set_text (label);
+	}
+}
+
+bool
+MetaButton::on_button_press_event (GdkEventButton* ev)
+{
+	MetaMenuItem const* current_active = dynamic_cast<MetaMenuItem*> (_menu.get_active ());
+
+	if (ev->type == GDK_BUTTON_PRESS && ev->button == 3) {
+		Gtkmm2ext::anchored_menu_popup (&_menu, this, current_active ? current_active->menutext () : "", 3, ev->time);
+	}
+
+	if (ev->type == GDK_BUTTON_PRESS && ev->button == 1) {
+		if (current_active) {
+			current_active->activate ();
+		}
+	}
+
+	return true;
+}
+
+void
+MetaButton::activate_item (MetaMenuItem const* e)
+{
+	set_text (e->label ());
+	e->activate ();
+}
+
+void
+MetaButton::set_active (std::string const& menulabel)
+{
+	guint c     = 0;
+	bool  found = false;
+
+	for (auto& i : _menu.items ()) {
+		if (i.get_label () == menulabel) {
+			if (_menu.get_active () != &i) {
+				_menu.set_active (c);
+			}
+			set_text (dynamic_cast<MetaMenuItem*> (&i)->label ());
+			set_active_state (Gtkmm2ext::ExplicitActive);
+			_active = c;
+			found   = true;
+			break;
+		}
+		++c;
+	}
+	if (!found) {
+		set_active_state (Gtkmm2ext::Off);
+	}
+	StateChanged (); /* EMIT SIGNAL */
+}
+
+void
+MetaButton::set_index (guint index)
+{
+	guint c = 0;
+	for (auto& i : _menu.items ()) {
+		if (c == index) {
+			_menu.set_active (c);
+			set_text (dynamic_cast<MetaMenuItem*> (&i)->label ());
+			break;
+		}
+		++c;
+	}
+}

libs/widgets/widgets/metabutton.h

@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2025 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/menu.h>
+#include <gtkmm/menuitem.h>
+
+#include "widgets/ardour_button.h"
+#include "widgets/visibility.h"
+
+namespace ArdourWidgets {
+
+class LIBWIDGETS_API MetaButton : public ArdourButton
+{
+public:
+	MetaButton ();
+	virtual ~MetaButton ();
+
+	void add_item (std::string const& label, std::string const& menutext, sigc::slot<void> const&);
+	void clear_items ();
+
+	void set_active (std::string const&);
+	void set_index (guint);
+
+	guint index () const
+	{
+		return _active;
+	}
+
+protected:
+	bool on_button_press_event (GdkEventButton*);
+	void menu_size_request (Gtk::Requisition*);
+
+private:
+	class MetaMenuItem : public Gtk::MenuItem
+	{
+	public:
+		MetaMenuItem (std::string const& label, std::string const& menutext, sigc::slot<void> const& cb)
+			: Gtk::MenuItem (menutext, false)
+			, _label (label)
+			, _cb (cb)
+		{
+		}
+
+		void activate () const
+		{
+			_cb ();
+		}
+
+		std::string label () const
+		{
+			return _label;
+		}
+
+		std::string menutext () const
+		{
+			return get_label ();
+		}
+
+	private:
+		std::string      _label;
+		sigc::slot<void> _cb;
+	};
+
+	class MetaElement : public Gtk::Menu_Helpers::MenuElem
+	{
+	public:
+		typedef sigc::slot<void, MetaMenuItem const*> SlotActivate;
+
+		MetaElement (std::string const& label, std::string const& menutext, sigc::slot<void> const& cb, SlotActivate const& wrap)
+		    : Gtk::Menu_Helpers::MenuElem ("")
+		{
+			MetaMenuItem* mmi = manage (new MetaMenuItem (label, menutext, cb));
+			child_->unreference ();
+			set_child (mmi);
+			child_->signal_activate ().connect (sigc::bind (wrap, mmi));
+			child_->show ();
+		}
+	};
+
+	void activate_item (MetaMenuItem const*);
+
+	Gtk::Menu _menu;
+	guint     _active;
+};
+
+} // namespace ArdourWidgets

libs/widgets/wscript

@@ -33,6 +33,7 @@ widgets_sources = [
         'fastmeter.cc',
         'frame.cc',
         'focus_entry.cc',
+        'metabutton.cc',
         'pane.cc',
         'paths_dialog.cc',
         'popup.cc',