Pre- and post-savefile callbacks.

The constructor of class SavefileCallback can be used to add a callback
which is called before a game is saved and after it's restored.  This is
useful to move data in and out of you.props, or after a restore if
there's data not stored in the savefile which can be easily regenerated.

NOTE: I experienced some weirdness with C++ global constructors, and
since global constructors probably differ with compiler and system,
until this has been tested on all compiler/system combinations, any code
which uses the callbacks should fail gracefully if the callbacks aren't
called.

1 files changed, 11 insertions, 0 deletions

diff --git a/crawl-ref/source/files.h b/crawl-ref/source/files.h
index 3c05196f4a..80dcf2c3ec 100644
--- a/crawl-ref/source/files.h
+++ b/crawl-ref/source/files.h
@@ -145,4 +145,15 @@ private:
     std::string filename;
 };
 
+class SavefileCallback
+{
+public:
+    typedef void (*callback)(bool saving);
+
+    SavefileCallback(callback func);
+
+    static void pre_save();
+    static void post_restore();
+};
+
 #endif