From 3266b1acb0c101ff7224f9123539e758bb7e7512 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 21 Jun 2022 21:34:08 +0200
Subject: [PATCH] Add API to query currently held modifiers keys

---
 libs/gtkmm2ext/gtkmm2ext/keyboard.h |  3 ++-
 libs/gtkmm2ext/keyboard.cc          | 32 +++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/libs/gtkmm2ext/gtkmm2ext/keyboard.h b/libs/gtkmm2ext/gtkmm2ext/keyboard.h
index af390d27bf..d16d32d7e6 100644
--- a/libs/gtkmm2ext/gtkmm2ext/keyboard.h
+++ b/libs/gtkmm2ext/gtkmm2ext/keyboard.h
@@ -113,7 +113,8 @@ public:
 		set_modifier (newval, RangeSelectModifier);
 	}
 
-	bool key_is_down (uint32_t keyval);
+	bool  key_is_down (uint32_t keyval);
+	guint modifier_state ();
 
 	static GdkModifierType RelevantModifierKeyMask;
 
diff --git a/libs/gtkmm2ext/keyboard.cc b/libs/gtkmm2ext/keyboard.cc
index 06c7034c36..b17814c81e 100644
--- a/libs/gtkmm2ext/keyboard.cc
+++ b/libs/gtkmm2ext/keyboard.cc
@@ -476,6 +476,38 @@ Keyboard::key_is_down (uint32_t keyval)
 	return find (state.begin (), state.end (), keyval) != state.end ();
 }
 
+guint
+Keyboard::modifier_state ()
+{
+	int mask = 0;
+	for (auto const& keyval : state) {
+		switch (keyval) {
+			case GDK_Meta_R:
+			case GDK_Meta_L:
+				mask |= GDK_MOD2_MASK;
+				break;
+			case GDK_Shift_R:
+			case GDK_Shift_L:
+				mask |= GDK_SHIFT_MASK;
+				break;
+			case GDK_Caps_Lock:
+				mask |= GDK_LOCK_MASK;
+				break;
+			case GDK_Alt_R:
+			case GDK_Alt_L:
+				mask |= GDK_MOD1_MASK;
+				break;
+			case GDK_Control_R:
+			case GDK_Control_L:
+				mask |= GDK_CONTROL_MASK;
+				break;
+			default:
+				break;
+		}
+	}
+	return mask & RelevantModifierKeyMask;
+}
+
 bool
 Keyboard::enter_window (GdkEventCrossing*, Gtk::Window* win)
 {