From 1813552b5e58ef870e8196bab38770b3fcc2bb8c Mon Sep 17 00:00:00 2001
From: Eric House <xwords@eehouse.org>
Date: Wed, 10 Feb 2021 13:21:28 -0800
Subject: [PATCH] use native js for idle (timers next)

---
 xwords4/wasm/Makefile |  2 +-
 xwords4/wasm/main.c   | 44 ++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/xwords4/wasm/Makefile b/xwords4/wasm/Makefile
index f973ffa3a..dd327cb5e 100644
--- a/xwords4/wasm/Makefile
+++ b/xwords4/wasm/Makefile
@@ -48,7 +48,7 @@ main.html: ${INPUTS} $(MAKEFILE) shell_minimal.html
 		--preload-file assets_dir --shell-file shell_minimal.html \
 		-s USE_SDL_TTF=2 -s USE_SDL_IMAGE=2 -s SDL2_IMAGE_FORMATS='["png"]' \
 		-s "EXTRA_EXPORTED_RUNTIME_METHODS=['ccall']" \
-		-s EXPORTED_FUNCTIONS='["_main", "_button", "_newgame", "_gotMQTTMsg"]' -s WASM=0 \
+		-s EXPORTED_FUNCTIONS='["_main", "_button", "_newgame", "_gotMQTTMsg", "_jscallback"]' \
 		-s WASM=1 \
 		${INPUTS} -o $@
 
diff --git a/xwords4/wasm/main.c b/xwords4/wasm/main.c
index 8cd13db4c..6cbdbc0da 100644
--- a/xwords4/wasm/main.c
+++ b/xwords4/wasm/main.c
@@ -69,6 +69,15 @@ EM_JS(bool, call_mqttSend, (const char* topic, const uint8_t* ptr, int len), {
         return mqttSend(topStr, buffer);
 });
 
+typedef void (*JSCallback)(void* closure);
+
+EM_JS(void, jscallback_set, (JSCallback proc, void* closure, int inMS), {
+        let timerproc = function(closure) {
+            ccall('jscallback', null, ['number', 'number'], [proc, closure]);
+        };
+        setTimeout( timerproc, inMS, closure );
+    });
+
 static void updateScreen( Globals* globals, bool doSave );
 
 static Globals* sGlobals;
@@ -388,12 +397,34 @@ main_alert( Globals* globals, const XP_UCHAR* msg )
     call_alert( msg );
 }
 
+typedef struct _IdleClosure {
+    Globals* globals;
+    IdleProc proc;
+    void* closure;
+} IdleClosure;
+
+static void
+onIdleFired( void* closure )
+{
+    LOG_FUNC();
+    IdleClosure* ic = (IdleClosure*)closure;
+    XP_Bool draw = (*ic->proc)(ic->closure);
+    if ( draw ) {
+        updateScreen( ic->globals, true );
+    }
+    XP_FREE( ic->globals->mpool, ic );
+}
+
 void
 main_set_idle( Globals* globals, IdleProc proc, void* closure )
 {
-    XP_ASSERT( !globals->idleProc || globals->idleProc == proc );
-    globals->idleProc = proc;
-    globals->idleClosure = closure;
+    LOG_FUNC();
+    IdleClosure* ic = XP_MALLOC( globals->mpool, sizeof(*ic) );
+    ic->globals = globals;
+    ic->proc = proc;
+    ic->closure = closure;
+
+    jscallback_set( onIdleFired, ic, 0 );
 }
 
 static XP_Bool
@@ -615,6 +646,13 @@ gotMQTTMsg( void* closure, int len, const uint8_t* msg )
     dvc_parseMQTTPacket( globals->dutil, NULL, msg, len );
 }
 
+void
+jscallback( JSCallback proc, void* closure )
+{
+    LOG_FUNC();
+    (*proc)(closure);
+}
+
 int
 main( int argc, const char** argv )
 {