events: Make debug logging of the event queue a hint instead of an #ifdef.

This makes it easy to toggle it on when debugging a new platform (or just
getting more visibility into an app) without having to rebuild SDL.

--HG--
extra : rebase_source : b8676f90fbb0b57a6d210ba17af0f69b3e543fe4
diff --git a/include/SDL_hints.h b/include/SDL_hints.h
index 3c91277..cd5adb2 100644
--- a/include/SDL_hints.h
+++ b/include/SDL_hints.h
@@ -1079,6 +1079,29 @@
 
 
 /**
+ *  \brief  A variable controlling whether SDL logs all events pushed onto its internal queue.
+ *
+ *  This variable can be set to the following values:
+ *
+ *    "0"     - Don't log any events (default)
+ *    "1"     - Log all events except mouse and finger motion, which are pretty spammy.
+ *    "2"     - Log all events.
+ *
+ *  This is generally meant to be used to debug SDL itself, but can be useful
+ *  for application developers that need better visibility into what is going
+ *  on in the event queue. Logged events are sent through SDL_Log(), which
+ *  means by default they appear on stdout on most platforms or maybe
+ *  OutputDebugString() on Windows, and can be funneled by the app with
+ *  SDL_LogSetOutputFunction(), etc.
+ *
+ *  This hint can be toggled on and off at runtime, if you only need to log
+ *  events for a small subset of program execution.
+ */
+#define SDL_HINT_EVENT_LOGGING   "SDL_EVENT_LOGGING"
+
+
+
+/**
  *  \brief  An enumeration of hint priorities
  */
 typedef enum
diff --git a/src/SDL.c b/src/SDL.c
index be9eee8..6e80178 100644
--- a/src/SDL.c
+++ b/src/SDL.c
@@ -139,10 +139,9 @@
     if ((flags & SDL_INIT_EVENTS)) {
 #if !SDL_EVENTS_DISABLED
         if (SDL_PrivateShouldInitSubsystem(SDL_INIT_EVENTS)) {
-            if (SDL_StartEventLoop() < 0) {
+            if (SDL_EventsInit() < 0) {
                 return (-1);
             }
-            SDL_QuitInit();
         }
         SDL_PrivateSubsystemRefCountIncr(SDL_INIT_EVENTS);
 #else
@@ -333,8 +332,7 @@
 #if !SDL_EVENTS_DISABLED
     if ((flags & SDL_INIT_EVENTS)) {
         if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_EVENTS)) {
-            SDL_QuitQuit();
-            SDL_StopEventLoop();
+            SDL_EventsQuit();
         }
         SDL_PrivateSubsystemRefCountDecr(SDL_INIT_EVENTS);
     }
diff --git a/src/events/SDL_events.c b/src/events/SDL_events.c
index 2f5bfd7..1177d6c 100644
--- a/src/events/SDL_events.c
+++ b/src/events/SDL_events.c
@@ -33,8 +33,6 @@
 #include "../video/SDL_sysvideo.h"
 #include "SDL_syswm.h"
 
-/*#define SDL_DEBUG_EVENTS 1*/
-
 /* An arbitrary limit so we don't have unbounded growth */
 #define SDL_MAX_QUEUED_EVENTS   65535
 
@@ -87,32 +85,53 @@
 } SDL_EventQ = { NULL, { 1 }, { 0 }, 0, NULL, NULL, NULL, NULL, NULL };
 
 
-#ifdef SDL_DEBUG_EVENTS
+/* 0 (default) means no logging, 1 means logging, 2 means logging with mouse and finger motion */
+static int SDL_DoEventLogging = 0;
 
-/* this is to make printf() calls cleaner. */
-#define uint unsigned int
+static void SDLCALL
+SDL_EventLoggingChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
+{
+    SDL_DoEventLogging = (hint && *hint) ? SDL_max(SDL_min(SDL_atoi(hint), 2), 0) : 0;
+}
 
 static void
-SDL_DebugPrintEvent(const SDL_Event *event)
+SDL_LogEvent(const SDL_Event *event)
 {
-    /* !!! FIXME: This code is kinda ugly, sorry. */
-    printf("SDL EVENT: ");
+    char name[32];
+    char details[128];
 
-    if ((event->type >= SDL_USEREVENT) && (event->type <= SDL_LASTEVENT)) {
-        printf("SDL_USEREVENT");
-        if (event->type > SDL_USEREVENT) {
-            printf("+%u", ((uint) event->type) - SDL_USEREVENT);
-        }
-        printf(" (timestamp=%u windowid=%u code=%d data1=%p data2=%p)",
-                (uint) event->user.timestamp, (uint) event->user.windowID,
-                (int) event->user.code, event->user.data1, event->user.data2);
+    /* mouse/finger motion are spammy, ignore these if they aren't demanded. */
+    if ( (SDL_DoEventLogging < 2) &&
+            ( (event->type == SDL_MOUSEMOTION) ||
+              (event->type == SDL_FINGERMOTION) ) ) {
         return;
     }
 
+    /* this is to make SDL_snprintf() calls cleaner. */
+    #define uint unsigned int
+
+    name[0] = '\0';
+    details[0] = '\0';
+
+    /* !!! FIXME: This code is kinda ugly, sorry. */
+
+    if ((event->type >= SDL_USEREVENT) && (event->type <= SDL_LASTEVENT)) {
+        char plusstr[16];
+        SDL_strlcpy(name, "SDL_USEREVENT", sizeof (name));
+        if (event->type > SDL_USEREVENT) {
+            SDL_snprintf(plusstr, sizeof (plusstr), "+%u", ((uint) event->type) - SDL_USEREVENT);
+        } else {
+            plusstr[0] = '\0';
+        }
+        SDL_snprintf(details, sizeof (details), "%s (timestamp=%u windowid=%u code=%d data1=%p data2=%p)",
+                plusstr, (uint) event->user.timestamp, (uint) event->user.windowID,
+                (int) event->user.code, event->user.data1, event->user.data2);
+    }
+
     switch (event->type) {
-        #define SDL_EVENT_CASE(x) case x: printf("%s", #x);
-        SDL_EVENT_CASE(SDL_FIRSTEVENT) printf("(THIS IS PROBABLY A BUG!)"); break;
-        SDL_EVENT_CASE(SDL_QUIT) printf("(timestamp=%u)", (uint) event->quit.timestamp); break;
+        #define SDL_EVENT_CASE(x) case x: SDL_strlcpy(name, #x, sizeof (name));
+        SDL_EVENT_CASE(SDL_FIRSTEVENT) SDL_strlcpy(details, " (THIS IS PROBABLY A BUG!)", sizeof (details)); break;
+        SDL_EVENT_CASE(SDL_QUIT) SDL_snprintf(details, sizeof (details), " (timestamp=%u)", (uint) event->quit.timestamp); break;
         SDL_EVENT_CASE(SDL_APP_TERMINATING) break;
         SDL_EVENT_CASE(SDL_APP_LOWMEMORY) break;
         SDL_EVENT_CASE(SDL_APP_WILLENTERBACKGROUND) break;
@@ -123,15 +142,12 @@
         SDL_EVENT_CASE(SDL_CLIPBOARDUPDATE) break;
         SDL_EVENT_CASE(SDL_RENDER_TARGETS_RESET) break;
         SDL_EVENT_CASE(SDL_RENDER_DEVICE_RESET) break;
-        #undef SDL_EVENT_CASE
 
-        #define SDL_EVENT_CASE(x) case x: printf("%s ", #x);
-
-        SDL_EVENT_CASE(SDL_WINDOWEVENT)
-            printf("(timestamp=%u windowid=%u event=", (uint) event->window.timestamp, (uint) event->window.windowID);
+        SDL_EVENT_CASE(SDL_WINDOWEVENT) {
+            char name2[64];
             switch(event->window.event) {
-                case SDL_WINDOWEVENT_NONE: printf("none(THIS IS PROBABLY A BUG!)"); break;
-                #define SDL_WINDOWEVENT_CASE(x) case x: printf("%s", #x); break
+                case SDL_WINDOWEVENT_NONE: SDL_strlcpy(name2, "SDL_WINDOWEVENT_NONE (THIS IS PROBABLY A BUG!)", sizeof (name2)); break;
+                #define SDL_WINDOWEVENT_CASE(x) case x: SDL_strlcpy(name2, #x, sizeof (name2)); break
                 SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_SHOWN);
                 SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_HIDDEN);
                 SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_EXPOSED);
@@ -149,18 +165,20 @@
                 SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_TAKE_FOCUS);
                 SDL_WINDOWEVENT_CASE(SDL_WINDOWEVENT_HIT_TEST);
                 #undef SDL_WINDOWEVENT_CASE
-                default: printf("UNKNOWN(bug? fixme?)"); break;
+                default: SDL_strlcpy(name2, "UNKNOWN (bug? fixme?)", sizeof (name2)); break;
             }
-            printf(" data1=%d data2=%d)", (int) event->window.data1, (int) event->window.data2);
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u event=%s data1=%d data2=%d)",
+                        (uint) event->window.timestamp, (uint) event->window.windowID, name2, (int) event->window.data1, (int) event->window.data2);
             break;
+        }
 
         SDL_EVENT_CASE(SDL_SYSWMEVENT)
-            printf("(timestamp=%u)", (uint) event->syswm.timestamp);
             /* !!! FIXME: we don't delve further at the moment. */
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u)", (uint) event->syswm.timestamp);
             break;
 
         #define PRINT_KEY_EVENT(event) \
-            printf("(timestamp=%u windowid=%u state=%s repeat=%s scancode=%u keycode=%u mod=%u)", \
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u state=%s repeat=%s scancode=%u keycode=%u mod=%u)", \
                 (uint) event->key.timestamp, (uint) event->key.windowID, \
                 event->key.state == SDL_PRESSED ? "pressed" : "released", \
                 event->key.repeat ? "true" : "false", \
@@ -172,18 +190,18 @@
         #undef PRINT_KEY_EVENT
 
         SDL_EVENT_CASE(SDL_TEXTEDITING)
-            printf("(timestamp=%u windowid=%u text='%s' start=%d length=%d)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u text='%s' start=%d length=%d)",
                 (uint) event->edit.timestamp, (uint) event->edit.windowID,
                 event->edit.text, (int) event->edit.start, (int) event->edit.length);
             break;
 
         SDL_EVENT_CASE(SDL_TEXTINPUT)
-            printf("(timestamp=%u windowid=%u text='%s')", (uint) event->text.timestamp, (uint) event->text.windowID, event->text.text);
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u text='%s')", (uint) event->text.timestamp, (uint) event->text.windowID, event->text.text);
             break;
 
 
         SDL_EVENT_CASE(SDL_MOUSEMOTION)
-            printf("(timestamp=%u windowid=%u which=%u state=%u x=%d y=%d xrel=%d yrel=%d)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u which=%u state=%u x=%d y=%d xrel=%d yrel=%d)",
                     (uint) event->motion.timestamp, (uint) event->motion.windowID,
                     (uint) event->motion.which, (uint) event->motion.state,
                     (int) event->motion.x, (int) event->motion.y,
@@ -191,7 +209,7 @@
             break;
 
         #define PRINT_MBUTTON_EVENT(event) \
-            printf("(timestamp=%u windowid=%u which=%u button=%u state=%s clicks=%u x=%d y=%d)", \
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u which=%u button=%u state=%s clicks=%u x=%d y=%d)", \
                     (uint) event->button.timestamp, (uint) event->button.windowID, \
                     (uint) event->button.which, (uint) event->button.button, \
                     event->button.state == SDL_PRESSED ? "pressed" : "released", \
@@ -202,65 +220,65 @@
 
 
         SDL_EVENT_CASE(SDL_MOUSEWHEEL)
-            printf("(timestamp=%u windowid=%u which=%u x=%d y=%d direction=%s)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u windowid=%u which=%u x=%d y=%d direction=%s)",
                     (uint) event->wheel.timestamp, (uint) event->wheel.windowID,
                     (uint) event->wheel.which, (int) event->wheel.x, (int) event->wheel.y,
                     event->wheel.direction == SDL_MOUSEWHEEL_NORMAL ? "normal" : "flipped");
             break;
 
         SDL_EVENT_CASE(SDL_JOYAXISMOTION)
-            printf("(timestamp=%u which=%d axis=%u value=%d)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d axis=%u value=%d)",
                 (uint) event->jaxis.timestamp, (int) event->jaxis.which,
                 (uint) event->jaxis.axis, (int) event->jaxis.value);
             break;
 
         SDL_EVENT_CASE(SDL_JOYBALLMOTION)
-            printf("(timestamp=%u which=%d ball=%u xrel=%d yrel=%d)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d ball=%u xrel=%d yrel=%d)",
                 (uint) event->jball.timestamp, (int) event->jball.which,
                 (uint) event->jball.ball, (int) event->jball.xrel, (int) event->jball.yrel);
             break;
 
         SDL_EVENT_CASE(SDL_JOYHATMOTION)
-            printf("(timestamp=%u which=%d hat=%u value=%u)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d hat=%u value=%u)",
                 (uint) event->jhat.timestamp, (int) event->jhat.which,
                 (uint) event->jhat.hat, (uint) event->jhat.value);
             break;
 
         #define PRINT_JBUTTON_EVENT(event) \
-            printf("(timestamp=%u which=%d button=%u state=%s)", \
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d button=%u state=%s)", \
                 (uint) event->jbutton.timestamp, (int) event->jbutton.which, \
                 (uint) event->jbutton.button, event->jbutton.state == SDL_PRESSED ? "pressed" : "released")
         SDL_EVENT_CASE(SDL_JOYBUTTONDOWN) PRINT_JBUTTON_EVENT(event); break;
         SDL_EVENT_CASE(SDL_JOYBUTTONUP) PRINT_JBUTTON_EVENT(event); break;
         #undef PRINT_JBUTTON_EVENT
 
-        #define PRINT_JOYDEV_EVENT(event) printf("(timestamp=%u which=%d)", (uint) event->jdevice.timestamp, (int) event->jdevice.which)
+        #define PRINT_JOYDEV_EVENT(event) SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d)", (uint) event->jdevice.timestamp, (int) event->jdevice.which)
         SDL_EVENT_CASE(SDL_JOYDEVICEADDED) PRINT_JOYDEV_EVENT(event); break;
         SDL_EVENT_CASE(SDL_JOYDEVICEREMOVED) PRINT_JOYDEV_EVENT(event); break;
         #undef PRINT_JOYDEV_EVENT
 
         SDL_EVENT_CASE(SDL_CONTROLLERAXISMOTION)
-            printf("(timestamp=%u which=%d axis=%u value=%d)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d axis=%u value=%d)",
                 (uint) event->caxis.timestamp, (int) event->caxis.which,
                 (uint) event->caxis.axis, (int) event->caxis.value);
             break;
 
         #define PRINT_CBUTTON_EVENT(event) \
-            printf("(timestamp=%u which=%d button=%u state=%s)", \
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d button=%u state=%s)", \
                 (uint) event->cbutton.timestamp, (int) event->cbutton.which, \
                 (uint) event->cbutton.button, event->cbutton.state == SDL_PRESSED ? "pressed" : "released")
         SDL_EVENT_CASE(SDL_CONTROLLERBUTTONDOWN) PRINT_CBUTTON_EVENT(event); break;
         SDL_EVENT_CASE(SDL_CONTROLLERBUTTONUP) PRINT_CBUTTON_EVENT(event); break;
         #undef PRINT_CBUTTON_EVENT
 
-        #define PRINT_CONTROLLERDEV_EVENT(event) printf("(timestamp=%u which=%d)", (uint) event->cdevice.timestamp, (int) event->cdevice.which)
+        #define PRINT_CONTROLLERDEV_EVENT(event) SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%d)", (uint) event->cdevice.timestamp, (int) event->cdevice.which)
         SDL_EVENT_CASE(SDL_CONTROLLERDEVICEADDED) PRINT_CONTROLLERDEV_EVENT(event); break;
         SDL_EVENT_CASE(SDL_CONTROLLERDEVICEREMOVED) PRINT_CONTROLLERDEV_EVENT(event); break;
         SDL_EVENT_CASE(SDL_CONTROLLERDEVICEREMAPPED) PRINT_CONTROLLERDEV_EVENT(event); break;
         #undef PRINT_CONTROLLERDEV_EVENT
 
         #define PRINT_FINGER_EVENT(event) \
-            printf("(timestamp=%u touchid=%lld fingerid=%lld x=%f y=%f dx=%f dy=%f pressure=%f)", \
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u touchid=%lld fingerid=%lld x=%f y=%f dx=%f dy=%f pressure=%f)", \
                 (uint) event->tfinger.timestamp, (long long) event->tfinger.touchId, \
                 (long long) event->tfinger.fingerId, event->tfinger.x, event->tfinger.y, \
                 event->tfinger.dx, event->tfinger.dy, event->tfinger.pressure)
@@ -270,7 +288,7 @@
         #undef PRINT_FINGER_EVENT
 
         #define PRINT_DOLLAR_EVENT(event) \
-            printf("(timestamp=%u touchid=%lld gestureid=%lld numfingers=%u error=%f x=%f y=%f)", \
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u touchid=%lld gestureid=%lld numfingers=%u error=%f x=%f y=%f)", \
                 (uint) event->dgesture.timestamp, (long long) event->dgesture.touchId, \
                 (long long) event->dgesture.gestureId, (uint) event->dgesture.numFingers, \
                 event->dgesture.error, event->dgesture.x, event->dgesture.y);
@@ -279,20 +297,20 @@
         #undef PRINT_DOLLAR_EVENT
 
         SDL_EVENT_CASE(SDL_MULTIGESTURE)
-            printf("(timestamp=%u touchid=%lld dtheta=%f ddist=%f x=%f y=%f numfingers=%u)",
+            SDL_snprintf(details, sizeof (details), " (timestamp=%u touchid=%lld dtheta=%f ddist=%f x=%f y=%f numfingers=%u)",
                 (uint) event->mgesture.timestamp, (long long) event->mgesture.touchId,
                 event->mgesture.dTheta, event->mgesture.dDist,
                 event->mgesture.x, event->mgesture.y, (uint) event->mgesture.numFingers);
             break;
 
-        #define PRINT_DROP_EVENT(event) printf("(file='%s' timestamp=%u windowid=%u)", event->drop.file, (uint) event->drop.timestamp, (uint) event->drop.windowID)
+        #define PRINT_DROP_EVENT(event) SDL_snprintf(details, sizeof (details), " (file='%s' timestamp=%u windowid=%u)", event->drop.file, (uint) event->drop.timestamp, (uint) event->drop.windowID)
         SDL_EVENT_CASE(SDL_DROPFILE) PRINT_DROP_EVENT(event); break;
         SDL_EVENT_CASE(SDL_DROPTEXT) PRINT_DROP_EVENT(event); break;
         SDL_EVENT_CASE(SDL_DROPBEGIN) PRINT_DROP_EVENT(event); break;
         SDL_EVENT_CASE(SDL_DROPCOMPLETE) PRINT_DROP_EVENT(event); break;
         #undef PRINT_DROP_EVENT
 
-        #define PRINT_AUDIODEV_EVENT(event) printf("(timestamp=%u which=%u iscapture=%s)", (uint) event->adevice.timestamp, (uint) event->adevice.which, event->adevice.iscapture ? "true" : "false");
+        #define PRINT_AUDIODEV_EVENT(event) SDL_snprintf(details, sizeof (details), " (timestamp=%u which=%u iscapture=%s)", (uint) event->adevice.timestamp, (uint) event->adevice.which, event->adevice.iscapture ? "true" : "false");
         SDL_EVENT_CASE(SDL_AUDIODEVICEADDED) PRINT_AUDIODEV_EVENT(event); break;
         SDL_EVENT_CASE(SDL_AUDIODEVICEREMOVED) PRINT_AUDIODEV_EVENT(event); break;
         #undef PRINT_AUDIODEV_EVENT
@@ -300,14 +318,19 @@
         #undef SDL_EVENT_CASE
 
         default:
-            printf("UNKNOWN SDL EVENT #%u! (Bug? FIXME?)", (uint) event->type);
+            if (!name[0]) {
+                SDL_strlcpy(name, "UNKNOWN", sizeof (name));
+                SDL_snprintf(details, sizeof (details), " #%u! (Bug? FIXME?)", (uint) event->type);
+            }
             break;
     }
 
-    printf("\n");
+    if (name[0]) {
+        SDL_Log("SDL EVENT: %s%s", name, details);
+    }
+
+    #undef uint
 }
-#undef uint
-#endif
 
 
 
@@ -451,9 +474,9 @@
         SDL_EventQ.free = entry->next;
     }
 
-    #ifdef SDL_DEBUG_EVENTS
-    SDL_DebugPrintEvent(event);
-    #endif
+    if (SDL_DoEventLogging) {
+        SDL_LogEvent(event);
+    }
 
     entry->event = *event;
     if (event->type == SDL_SYSWMEVENT) {
@@ -975,4 +998,30 @@
     return SDL_SendAppEvent(SDL_KEYMAPCHANGED);
 }
 
+
+extern int SDL_QuitInit(void);
+extern void SDL_QuitQuit(void);
+
+int
+SDL_EventsInit(void)
+{
+    SDL_AddHintCallback(SDL_HINT_EVENT_LOGGING, SDL_EventLoggingChanged, NULL);
+    if (SDL_StartEventLoop() < 0) {
+        SDL_DelHintCallback(SDL_HINT_EVENT_LOGGING, SDL_EventLoggingChanged, NULL);
+        return -1;
+    }
+
+    SDL_QuitInit();
+
+    return 0;
+}
+
+void
+SDL_EventsQuit(void)
+{
+    SDL_QuitQuit();
+    SDL_StopEventLoop();
+    SDL_DelHintCallback(SDL_HINT_EVENT_LOGGING, SDL_EventLoggingChanged, NULL);
+}
+
 /* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/events/SDL_events_c.h b/src/events/SDL_events_c.h
index bd3e644..6d68096 100644
--- a/src/events/SDL_events_c.h
+++ b/src/events/SDL_events_c.h
@@ -47,9 +47,10 @@
 extern int SDL_SendSysWMEvent(SDL_SysWMmsg * message);
 extern int SDL_SendKeymapChangedEvent(void);
 
-extern int SDL_QuitInit(void);
 extern int SDL_SendQuit(void);
-extern void SDL_QuitQuit(void);
+
+extern int SDL_EventsInit(void);
+extern void SDL_EventsQuit(void);
 
 extern void SDL_SendPendingQuit(void);