vis-lua: introduce pre-save hook

The first argument is the file object while the second argument denotes
the full path to which it will be written. Path might be `nil` if the
file is going to be written to stdout.

The Lua function is expected to return a boolean value indicating whether
the write operation should proceed or be aborted.

1 files changed, 1 insertions, 0 deletions

diff --git a/vis-core.h b/vis-core.h
index 6d79f18..56c51bf 100644
--- a/vis-core.h
+++ b/vis-core.h
@@ -191,6 +191,7 @@ enum VisEvents {
 	VIS_EVENT_START,
 	VIS_EVENT_QUIT,
 	VIS_EVENT_FILE_OPEN,
+	VIS_EVENT_FILE_SAVE_PRE,
 	VIS_EVENT_FILE_SAVE_POST,
 	VIS_EVENT_FILE_CLOSE,
 	VIS_EVENT_WIN_OPEN,