From 95949e62675bbc2c6b0395415e4247019b70576c Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 15 Apr 2025 21:59:40 +0200
Subject: [PATCH] Implement multi-touch support for ArdourKnobs

---
 libs/widgets/ardour_ctrl_base.cc        | 36 +++++++++++++++++++++++++
 libs/widgets/widgets/ardour_ctrl_base.h |  3 +++
 2 files changed, 39 insertions(+)

diff --git a/libs/widgets/ardour_ctrl_base.cc b/libs/widgets/ardour_ctrl_base.cc
index 857efa3280..303501ac37 100644
--- a/libs/widgets/ardour_ctrl_base.cc
+++ b/libs/widgets/ardour_ctrl_base.cc
@@ -60,6 +60,7 @@ ArdourCtrlBase::ArdourCtrlBase (Flags flags)
 	, _dead_zone_delta (0)
 {
 	UIConfigurationBase::instance().ColorsChanged.connect (sigc::mem_fun (*this, &ArdourCtrlBase::color_handler));
+	add_events (Gdk::TOUCH_UPDATE_MASK | Gdk::TOUCH_BEGIN_MASK | Gdk::TOUCH_END_MASK);
 
 #ifdef VBM
 	_flags = (Flags)(static_cast <int>(_flags) | (int)NoHorizontal);
@@ -257,6 +258,41 @@ ArdourCtrlBase::on_button_release_event (GdkEventButton *ev)
 	return true;
 }
 
+bool
+ArdourCtrlBase::on_touch_begin_event (GdkEventTouch *ev)
+{
+	_grabbed_x = ev->x;
+	_grabbed_y = ev->y;
+	_dead_zone_delta = 0;
+	_grabbed = true;
+	_tooltip.start_drag();
+	set_active_state (Gtkmm2ext::ExplicitActive);
+	StartGesture (ev->state);
+	return true;
+}
+
+bool
+ArdourCtrlBase::on_touch_end_event (GdkEventTouch *ev)
+{
+	_tooltip.stop_drag();
+	_grabbed = false;
+	StopGesture (ev->state);
+	unset_active_state ();
+	return true;
+}
+
+bool
+ArdourCtrlBase::on_touch_update_event (GdkEventTouch* ev)
+{
+	GdkEventMotion mev;
+	mev.window = ev->window;
+	mev.time   = ev->time;
+	mev.x      = ev->x;
+	mev.y      = ev->y;
+	mev.state  = Gdk::BUTTON1_MASK;
+	return ArdourCtrlBase::on_motion_notify_event (&mev);
+}
+
 void
 ArdourCtrlBase::color_handler ()
 {
diff --git a/libs/widgets/widgets/ardour_ctrl_base.h b/libs/widgets/widgets/ardour_ctrl_base.h
index 7d0e541257..df252c0f5c 100644
--- a/libs/widgets/widgets/ardour_ctrl_base.h
+++ b/libs/widgets/widgets/ardour_ctrl_base.h
@@ -77,6 +77,9 @@ public:
 	bool on_button_release_event (GdkEventButton*);
 	bool on_scroll_event (GdkEventScroll* ev);
 	bool on_motion_notify_event (GdkEventMotion *ev) ;
+	bool on_touch_begin_event (GdkEventTouch*);
+	bool on_touch_end_event (GdkEventTouch*);
+	bool on_touch_update_event (GdkEventTouch*);
 
 	void color_handler ();