keyboard: absolve release event if press was bound

When key press events are handled by compositor keybindings, do not
forward the corresponding release events to clients.

include/key-state.h

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __LABWC_KEY_STATE_H
+#define __LABWC_KEY_STATE_H
+
+void key_state_set_pressed(uint32_t keycode, bool ispressed);
+void key_state_store_pressed_keys_as_bound(void);
+bool key_state_corresponding_press_event_was_bound(uint32_t keycode);
+void key_state_bound_key_remove(uint32_t keycode);
+
+#endif /* __LABWC_KEY_STATE_H */

src/key-state.c

@@ -0,0 +1,69 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+#define MAX_PRESSED_KEYS (16)
+
+struct key_array {
+	uint32_t keys[MAX_PRESSED_KEYS];
+	int nr_keys;
+};
+
+static struct key_array pressed, bound;
+
+static void
+remove_key(struct key_array *array, uint32_t keycode)
+{
+	bool shifting = false;
+
+	for (int i = 0; i < MAX_PRESSED_KEYS; ++i) {
+		if (array->keys[i] == keycode) {
+			--array->nr_keys;
+			shifting = true;
+		}
+		if (shifting) {
+			array->keys[i] = i < MAX_PRESSED_KEYS - 1
+				? array->keys[i + 1] : 0;
+		}
+	}
+}
+
+static void
+add_key(struct key_array *array, uint32_t keycode)
+{
+	array->keys[array->nr_keys++] = keycode;
+}
+
+void
+key_state_set_pressed(uint32_t keycode, bool ispressed)
+{
+	if (ispressed) {
+		add_key(&pressed, keycode);
+	} else {
+		remove_key(&pressed, keycode);
+	}
+}
+
+void
+key_state_store_pressed_keys_as_bound(void)
+{
+	memcpy(bound.keys, pressed.keys, MAX_PRESSED_KEYS * sizeof(uint32_t));
+	bound.nr_keys = pressed.nr_keys;
+}
+
+bool
+key_state_corresponding_press_event_was_bound(uint32_t keycode)
+{
+	for (int i = 0; i < bound.nr_keys; ++i) {
+		if (bound.keys[i] == keycode) {
+			return true;
+		}
+	}
+	return false;
+}
+
+void
+key_state_bound_key_remove(uint32_t keycode)
+{
+	remove_key(&bound, keycode);
+}

src/keyboard.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #include <wlr/backend/multi.h>
 #include <wlr/backend/session.h>
+#include "key-state.h"
 #include "labwc.h"
 
 static void
@@ -101,6 +102,19 @@ handle_compositor_keybindings(struct wl_listener *listener,
 
 	bool handled = false;
 
+	key_state_set_pressed(keycode,
+		event->state == WL_KEYBOARD_KEY_STATE_PRESSED);
+
+	/*
+	 * If a press event was handled by a compositor binding, then do not
+	 * forward the corresponding release event to clients
+	 */
+	if (key_state_corresponding_press_event_was_bound(keycode)
+			&& event->state == WL_KEYBOARD_KEY_STATE_RELEASED) {
+		key_state_bound_key_remove(keycode);
+		return true;
+	}
+
 	uint32_t modifiers =
 		wlr_keyboard_get_modifiers(device->keyboard);
 
@@ -152,6 +166,11 @@ handle_compositor_keybindings(struct wl_listener *listener,
 			handled |= handle_keybinding(server, modifiers, syms[i]);
 		}
 	}
+
+	if (handled) {
+		key_state_store_pressed_keys_as_bound();
+	}
+
 	return handled;
 }
 

src/meson.build

@@ -6,6 +6,7 @@ labwc_sources = files(
   'foreign.c',
   'interactive.c',
   'keyboard.c',
+  'key-state.c',
   'layers.c',
   'main.c',
   'osd.c',