Add a function for figuring out information about an event struct

Signed-off-by: Uli Schlachter <psychon@znc.in>

2 files changed, 47 insertions, 0 deletions

diff --git a/src/xcb_errors.c b/src/xcb_errors.c
index 266159d..b796ae4 100644
--- a/src/xcb_errors.c
+++ b/src/xcb_errors.c
@@ -223,3 +223,36 @@ const char *xcb_errors_get_name_for_error(xcb_errors_context_t *ctx,
 		*extension = best->static_info->name;
 	return get_strings_entry(best->static_info->strings_errors, error_code - best->first_error);
 }
+
+const char *xcb_errors_get_name_for_xcb_event(xcb_errors_context_t *ctx,
+		xcb_generic_event_t *event, const char **extension)
+{
+	struct extension_info_t *xkb = ctx->extensions;
+
+	/* Find the xkb extension, if present */
+	while (xkb != NULL && strcmp(xkb->static_info->name, "xkb") != 0)
+		xkb = xkb->next;
+
+	if (event->response_type == XCB_GE_GENERIC) {
+		/* XGE offers extension's major code and event sub-type. */
+		xcb_ge_generic_event_t *ge = (void *) event;
+		if (extension)
+			*extension = xcb_errors_get_name_for_major_code(ctx,
+					ge->extension);
+		return xcb_errors_get_name_for_xge_event(ctx,
+				ge->extension, ge->event_type);
+	}
+	if (xkb != NULL && xkb->first_event != 0
+			&& event->response_type == xkb->first_event) {
+		/* There is no nice struct that defines the common fields for
+		 * XKB events, but the event type is always in the second byte.
+		 * In xcb_generic_event_t, this is the pad0 field.
+		 */
+		if (extension)
+			*extension = xkb->static_info->name;
+		return xcb_errors_get_name_for_xge_event(ctx,
+				xkb->major_opcode, event->pad0);
+	}
+	/* Generic case, decide only based on the response_type. */
+	return xcb_errors_get_name_for_event(ctx, event->response_type, extension);
+}
diff --git a/src/xcb_errors.h b/src/xcb_errors.h
index 1c8b66a..378913b 100644
--- a/src/xcb_errors.h
+++ b/src/xcb_errors.h
@@ -116,6 +116,20 @@ const char *xcb_errors_get_name_for_xge_event(xcb_errors_context_t *ctx,
 		uint8_t major_code, uint16_t event_type);
 
 /**
+ * Get a human printable name describing the type of some event.
+ *
+ * @param ctx An errors context, created with @ref xcb_errors_context_new ()
+ * @param event The event to investigate.
+ * @param extension Will be set to the name of the extension that generated this
+ * event or NULL for unknown events or core X11 events. This argument may be
+ * NULL.
+ * @return A string allocated in static storage that contains a name for this
+ * event or NULL for unknown event types.
+ */
+const char *xcb_errors_get_name_for_xcb_event(xcb_errors_context_t *ctx,
+		xcb_generic_event_t *event, const char **extension);
+
+/**
  * Get the name corresponding to some error.
  *
  * @param ctx An errors context, created with @ref xcb_errors_context_new ()