From 9f2796ebac59794514bb3dc7fd6f2f76f4af3856 Mon Sep 17 00:00:00 2001
From: Pietro Gagliardi <pietro10@mac.com>
Date: Sun, 2 Jun 2019 10:06:50 -0400
Subject: [PATCH] Added uiEventFree(). Now to add it to the tests and see what
 AddressSanitizer says afterward.

---
 common/events.c           | 21 +++++++++++++++++++++
 common/programmererrors.h |  6 ++++++
 doc/events.md             | 10 ++++++++++
 ui.h                      |  2 +-
 4 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/common/events.c b/common/events.c
index 932aa3b6..f0481b20 100644
--- a/common/events.c
+++ b/common/events.c
@@ -24,6 +24,7 @@ static int handlerCmp(const void *a, const void *b)
 
 struct uiEvent {
 	uiEventOptions opts;
+	bool internal;
 	uiprivArray handlers;
 	uiprivArray unusedIDs;
 	bool firing;
@@ -59,6 +60,26 @@ uiEvent *uiNewEvent(const uiEventOptions *options)
 	return ret; \
 }
 
+void uiFreeEvent(uiEvent *e)
+{
+	if (!uiprivCheckInitializedAndThread())
+		return;
+	checkEventNonnull(e, /* nothing */);
+	if (e->internal) {
+		uiprivProgrammerErrorFreeingInternalEvent();
+		return;
+	}
+	checkEventNotFiring(e, /* nothing */);
+	if (e->handlers.len != 0) {
+		uiprivProgrammerErrorFreeingEventInUse();
+		return;
+	}
+
+	uiprivArrayFree(e->unusedIDs);
+	uiprivArrayFree(e->handlers);
+	uiprivFree(e);
+}
+
 static bool checkEventSender(const uiEvent *e, void *sender, const char *func)
 {
 	if (e->opts.Global && sender != NULL) {
diff --git a/common/programmererrors.h b/common/programmererrors.h
index a8292b9d..cfa61ed3 100644
--- a/common/programmererrors.h
+++ b/common/programmererrors.h
@@ -36,3 +36,9 @@
 
 #define uiprivProgrammerErrorRecursiveEventFire() \
 	uiprivProgrammerError("attempt to fire a uiEvent while it is already being fired")
+
+#define uiprivProgrammerErrorFreeingInternalEvent() \
+	uiprivProgrammerError("attempt to free a libui-provided uiEvent")
+
+#define uiprivProgrammerErrorFreeingEventInUse() \
+	uiprivProgrammerError("attempt to free a uiEvent that still has handlers registered")
diff --git a/doc/events.md b/doc/events.md
index d0647ec6..27279d17 100644
--- a/doc/events.md
+++ b/doc/events.md
@@ -50,6 +50,16 @@ uiEvent *uiNewEvent(const uiEventOptions *options);
 
 It is a programmer error to specify `NULL` for `options`.
 
+### `uiFreeEvent()`
+
+```c
+uiprivExtern void uiFreeEvent(uiEvent *e);
+```
+
+Frees the given event. The event must not be a libui-provided event, and must not have any handlers registered to it.
+
+It is a programmer error to pass `NULL` for the given event, or to pass in an event that is currently firing.
+
 ### `uiEventAddHandler()`
 
 ```c
diff --git a/ui.h b/ui.h
index 161a783b..23c02427 100644
--- a/ui.h
+++ b/ui.h
@@ -54,7 +54,7 @@ struct uiEventOptions {
 };
 
 uiprivExtern uiEvent *uiNewEvent(const uiEventOptions *options);
-// TODO uiFreeEvent()
+uiprivExtern void uiFreeEvent(uiEvent *e);
 uiprivExtern int uiEventAddHandler(uiEvent *e, uiEventHandler handler, void *sender, void *data);
 uiprivExtern void uiEventDeleteHandler(uiEvent *e, int id);
 uiprivExtern void uiEventFire(uiEvent *e, void *sender, void *args);