void JSEventDispatcher::EndSendEvent(Context* context, Object* sender, StringHash eventType, VariantMap& eventData)
{
if (!jsEvents_.Contains(eventType))
return;
JSVM* vm = JSVM::GetJSVM(NULL);
if (!vm)
return;
duk_context* ctx = vm->GetJSContext();
duk_push_global_stash(ctx);
duk_get_prop_index(ctx, -1, JS_GLOBALSTASH_VARIANTMAP_CACHE);
duk_push_pointer(ctx, (void*) &eventData);
duk_get_prop(ctx, -2);
// If this issue is addressed, revisit this to simply remove
// the variantmap object from the cache, if the user explicitly
// keeps the event object alive in a local closure, that is allowed
// (though, will keep object properties from being GC'd)
// https://github.com/svaarala/duktape/issues/229
// Ok, this is unfortunate, in an event callback it is possible
// to capture the Proxy object which represents the event VariantMap
// in a function() {} closure, which will keep the event data alive
// until the function happens to be gc'd (it is a member of the eventhandler)
// which will leave things like scenes up if there was a P_SCENE event data
// member, etc
// So, we need to check if we have an object in the variant map cache
// and thense call it's delete property method on the Proxy, which will clear
// all the data (the proxy can still be alive as a captured local, though
// the members won't be held
// This all makes it that much more important that the pointer to eventData
// is consistent across entire event, otherwise references may be held
// see note above about: https://github.com/svaarala/duktape/issues/229
if (duk_is_object(ctx, -1))
{
// deletes all properties, thus freeing references, even if
// the variant map object is held onto by script (it will be invalid, post
// event send)
// see JSAPI.cpp variantmap_property_deleteproperty
duk_del_prop_index(ctx, -1, 0);
duk_push_pointer(ctx, (void*) &eventData);
duk_push_undefined(ctx);
// clear the variant map object from the cache
duk_put_prop(ctx, -4);
}
duk_pop_3(ctx);
}
void JSEventHelper::HandleEvent(StringHash eventType, VariantMap& eventData)
{
if (object_.Null())
return;
JSVM* vm = JSVM::GetJSVM(0);
duk_context* ctx = vm->GetJSContext();
duk_idx_t top = duk_get_top(ctx);
js_push_class_object_instance(ctx, this);
duk_get_prop_string(ctx, -1, "__eventHelperFunctions");
assert(duk_is_object(ctx, -1));
duk_get_prop_string(ctx, -1, eventType.ToString().CString());
if (duk_is_function(ctx, -1))
{
// look in the variant map cache
duk_push_global_stash(ctx);
duk_get_prop_index(ctx, -1, JS_GLOBALSTASH_VARIANTMAP_CACHE);
duk_push_pointer(ctx, (void*) &eventData);
duk_get_prop(ctx, -2);
if (!duk_is_object(ctx, -1))
{
// pop result
duk_pop(ctx);
// we need to push a new variant map and store to cache
// the cache object will be cleared at the send end in the
// global listener above
js_push_variantmap(ctx, eventData);
duk_push_pointer(ctx, (void*) &eventData);
duk_dup(ctx, -2);
duk_put_prop(ctx, -4);
}
duk_remove(ctx, -2); // vmap cache
duk_remove(ctx, -2); // global stash
if (duk_pcall(ctx, 1) != 0)
{
vm->SendJSErrorEvent();
}
else
{
// For widget events, need to check return value
// and set whether handled
if (eventType == E_WIDGETEVENT)
{
if (duk_is_boolean(ctx, -1))
{
if (duk_to_boolean(ctx, -1))
{
eventData[WidgetEvent::P_HANDLED] = true;
}
}
}
}
}
duk_set_top(ctx, top);
}
