keyboard: add utilities for pointer keys

References: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3803

include/wlr/types/wlr_keyboard.h

@@ -115,6 +115,23 @@ bool wlr_keyboard_set_keymap(struct wlr_keyboard *kb,
 
 bool wlr_keyboard_keymaps_match(struct xkb_keymap *km1, struct xkb_keymap *km2);
 
+/**
+ * Interpret pointer button key symbols.
+ *
+ * Returns a button code (BTN_*) if the key symbol is a pointer button
+ * (XKB_KEY_Pointer_Button*), 0 otherwise.
+ */
+uint32_t wlr_keyboard_keysym_to_pointer_button(xkb_keysym_t keysym);
+
+/**
+ * Interpret pointer motion key symbols.
+ *
+ * Sets dx and dy to horizontal and vertical motion deltas (0, 1 or -1) if the
+ * key symbol is a pointer motion (XKB_KEY_Pointer_*). Otherwise, sets both dx
+ * and dy to 0.
+ */
+void wlr_keyboard_keysym_to_pointer_motion(xkb_keysym_t keysym, int *dx, int *dy);
+
 /**
  * Set the keyboard repeat info.
  *

types/wlr_keyboard.c

@@ -1,4 +1,5 @@
 #include <assert.h>
+#include <linux/input-event-codes.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
@@ -304,3 +305,46 @@ bool wlr_keyboard_keymaps_match(struct xkb_keymap *km1,
 	free(km2_str);
 	return result;
 }
+
+uint32_t wlr_keyboard_keysym_to_pointer_button(xkb_keysym_t keysym) {
+	switch (keysym) {
+	case XKB_KEY_Pointer_Button1:
+		return BTN_LEFT;
+	case XKB_KEY_Pointer_Button2:
+		return BTN_MIDDLE;
+	case XKB_KEY_Pointer_Button3:
+		return BTN_RIGHT;
+	default:
+		return 0;
+	}
+}
+
+void wlr_keyboard_keysym_to_pointer_motion(xkb_keysym_t keysym, int *dx, int *dy) {
+	*dx = 0;
+	switch (keysym) {
+	case XKB_KEY_Pointer_Right:
+	case XKB_KEY_Pointer_DownRight:
+	case XKB_KEY_Pointer_UpRight:
+		*dx = 1;
+		break;
+	case XKB_KEY_Pointer_Left:
+	case XKB_KEY_Pointer_DownLeft:
+	case XKB_KEY_Pointer_UpLeft:
+		*dx = -1;
+		break;
+	}
+
+	*dy = 0;
+	switch (keysym) {
+	case XKB_KEY_Pointer_Down:
+	case XKB_KEY_Pointer_DownLeft:
+	case XKB_KEY_Pointer_DownRight:
+		*dy = 1;
+		break;
+	case XKB_KEY_Pointer_Up:
+	case XKB_KEY_Pointer_UpLeft:
+	case XKB_KEY_Pointer_UpRight:
+		*dy = -1;
+		break;
+	}
+}