From 8406e60522bb8d09649193be43c1c819edc1d059 Mon Sep 17 00:00:00 2001
From: Mel Collins <sigh@ambimist.com>
Date: Thu, 3 Aug 2023 15:18:26 +0200
Subject: Add InputEventKey.location to tell left from right

This adds a new enum `KeyLocation` and associated property
`InputEventKey.location`, which indicates the left/right location of key
events which may come from one of two physical keys, eg. Shift, Ctrl.

It also adds simulation of missing Shift KEYUP events for Windows.
When multiple Shifts are held down at the same time, Windows natively
only sends a KEYUP for the last one to be released.
---
 platform/linuxbsd/x11/display_server_x11.cpp |  8 ++++++++
 platform/linuxbsd/x11/key_mapping_x11.cpp    | 22 ++++++++++++++++++++++
 platform/linuxbsd/x11/key_mapping_x11.h      |  2 ++
 3 files changed, 32 insertions(+)

(limited to 'platform/linuxbsd')

diff --git a/platform/linuxbsd/x11/display_server_x11.cpp b/platform/linuxbsd/x11/display_server_x11.cpp
index 13a0a9f877..1794efc3cd 100644
--- a/platform/linuxbsd/x11/display_server_x11.cpp
+++ b/platform/linuxbsd/x11/display_server_x11.cpp
@@ -3501,6 +3501,7 @@ void DisplayServerX11::_handle_key_event(WindowID p_window, XKeyEvent *p_event,
 				bool keypress = xkeyevent->type == KeyPress;
 				Key keycode = KeyMappingX11::get_keycode(keysym_keycode);
 				Key physical_keycode = KeyMappingX11::get_scancode(xkeyevent->keycode);
+				KeyLocation key_location = KeyMappingX11::get_location(xkeyevent->keycode);
 
 				if (keycode >= Key::A + 32 && keycode <= Key::Z + 32) {
 					keycode -= 'a' - 'A';
@@ -3538,6 +3539,8 @@ void DisplayServerX11::_handle_key_event(WindowID p_window, XKeyEvent *p_event,
 						k->set_unicode(fix_unicode(tmp[i]));
 					}
 
+					k->set_location(key_location);
+
 					k->set_echo(false);
 
 					if (k->get_keycode() == Key::BACKTAB) {
@@ -3563,6 +3566,8 @@ void DisplayServerX11::_handle_key_event(WindowID p_window, XKeyEvent *p_event,
 	Key keycode = KeyMappingX11::get_keycode(keysym_keycode);
 	Key physical_keycode = KeyMappingX11::get_scancode(xkeyevent->keycode);
 
+	KeyLocation key_location = KeyMappingX11::get_location(xkeyevent->keycode);
+
 	/* Phase 3, obtain a unicode character from the keysym */
 
 	// KeyMappingX11 also translates keysym to unicode.
@@ -3662,6 +3667,9 @@ void DisplayServerX11::_handle_key_event(WindowID p_window, XKeyEvent *p_event,
 	if (keypress) {
 		k->set_unicode(fix_unicode(unicode));
 	}
+
+	k->set_location(key_location);
+
 	k->set_echo(p_echo);
 
 	if (k->get_keycode() == Key::BACKTAB) {
diff --git a/platform/linuxbsd/x11/key_mapping_x11.cpp b/platform/linuxbsd/x11/key_mapping_x11.cpp
index c0e6b91d57..b589a2a573 100644
--- a/platform/linuxbsd/x11/key_mapping_x11.cpp
+++ b/platform/linuxbsd/x11/key_mapping_x11.cpp
@@ -1113,6 +1113,20 @@ void KeyMappingX11::initialize() {
 	xkeysym_unicode_map[0x13BD] = 0x0153;
 	xkeysym_unicode_map[0x13BE] = 0x0178;
 	xkeysym_unicode_map[0x20AC] = 0x20AC;
+
+	// Scancode to physical location map.
+	// Ctrl.
+	location_map[0x25] = KeyLocation::LEFT;
+	location_map[0x69] = KeyLocation::RIGHT;
+	// Shift.
+	location_map[0x32] = KeyLocation::LEFT;
+	location_map[0x3E] = KeyLocation::RIGHT;
+	// Alt.
+	location_map[0x40] = KeyLocation::LEFT;
+	location_map[0x6C] = KeyLocation::RIGHT;
+	// Meta.
+	location_map[0x85] = KeyLocation::LEFT;
+	location_map[0x86] = KeyLocation::RIGHT;
 }
 
 Key KeyMappingX11::get_keycode(KeySym p_keysym) {
@@ -1173,3 +1187,11 @@ char32_t KeyMappingX11::get_unicode_from_keysym(KeySym p_keysym) {
 	}
 	return 0;
 }
+
+KeyLocation KeyMappingX11::get_location(unsigned int p_code) {
+	const KeyLocation *location = location_map.getptr(p_code);
+	if (location) {
+		return *location;
+	}
+	return KeyLocation::UNSPECIFIED;
+}
diff --git a/platform/linuxbsd/x11/key_mapping_x11.h b/platform/linuxbsd/x11/key_mapping_x11.h
index ae8fd67f27..a51ee5f48e 100644
--- a/platform/linuxbsd/x11/key_mapping_x11.h
+++ b/platform/linuxbsd/x11/key_mapping_x11.h
@@ -54,6 +54,7 @@ class KeyMappingX11 {
 	static inline HashMap<unsigned int, Key, HashMapHasherKeys> scancode_map;
 	static inline HashMap<Key, unsigned int, HashMapHasherKeys> scancode_map_inv;
 	static inline HashMap<KeySym, char32_t, HashMapHasherKeys> xkeysym_unicode_map;
+	static inline HashMap<unsigned int, KeyLocation, HashMapHasherKeys> location_map;
 
 	KeyMappingX11() {}
 
@@ -64,6 +65,7 @@ public:
 	static unsigned int get_xlibcode(Key p_keysym);
 	static Key get_scancode(unsigned int p_code);
 	static char32_t get_unicode_from_keysym(KeySym p_keysym);
+	static KeyLocation get_location(unsigned int p_code);
 };
 
 #endif // KEY_MAPPING_X11_H
-- 
cgit v1.2.3