[ion/simulator/web] Implement a custom journal with callbacks

This journal adds two new callbacks:
 - onIonEvent
 - onEpsilonIdle

ion/src/simulator/web/Makefile

@@ -16,6 +16,7 @@ LDFLAGS += --pre-js ion/src/simulator/web/preamble_env.js
 ion_src += $(addprefix ion/src/simulator/web/, \
   clipboard_helper.cpp \
   exports.cpp \
+  journal.cpp \
   keyboard_callback.cpp \
   window_callback.cpp \
 )
@@ -24,7 +25,6 @@ ion_src += $(addprefix ion/src/simulator/shared/, \
   dummy/language.cpp \
   dummy/haptics_enabled.cpp \
   haptics.cpp \
-  journal.cpp \
 )
 
 ion_src += ion/src/shared/collect_registers.cpp

ion/src/simulator/web/journal.cpp

@@ -0,0 +1,58 @@
+#include "../shared/journal.h"
+#include "../shared/journal/queue_journal.h"
+#include <emscripten.h>
+
+namespace Ion {
+namespace Simulator {
+namespace Journal {
+
+using Ion::Events::Event;
+using Ion::Events::None;
+
+class LogJournal : public Ion::Events::Journal {
+public:
+  void pushEvent(Event e) override {
+    static bool lastEventWasNone = false;
+    if (e != None) {
+      EM_ASM({
+        if (typeof Module.onIonEvent === "function") {
+          Module.onIonEvent($0);
+        }
+      }, static_cast<uint8_t>(e));
+      lastEventWasNone = true;
+    } else {
+      if (!lastEventWasNone) {
+        EM_ASM({
+          if (typeof Module.onEpsilonIdle === "function") {
+            Module.onEpsilonIdle();
+          }
+        });
+      }
+      lastEventWasNone = true;
+    }
+  }
+  Event popEvent() override {
+    return None;
+  }
+  bool isEmpty() override {
+    return true;
+  }
+};
+
+void init() {
+  Events::logTo(logJournal());
+}
+
+Events::Journal * replayJournal() {
+  static QueueJournal journal;
+  return &journal;
+}
+
+Ion::Events::Journal * logJournal() {
+  static LogJournal journal;
+  return &journal;
+}
+
+}
+}
+}