Added 'filter' support to position function; Made sure sort script can depend on the value of the field itself.

Cleaned up some things, why is a blank image not thread safe?

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@548 0fc631ac-6414-0410-93d0-97cfa31319b6

src/data/field.cpp

@@ -37,6 +37,10 @@ Field::Field()
 
 Field::~Field() {}
 
+void Field::initDependencies(Context& ctx, const Dependency& dep) const {
+	sort_script.initDependencies(ctx, dep);
+}
+
 IMPLEMENT_REFLECTION(Field) {
 	REFLECT_IF_NOT_READING {
 		String type = typeName();
@@ -215,6 +219,18 @@ bool Value::equals(const Value* that) {
 	return this == that;
 }
 
+bool Value::update(Context& ctx) {
+	updateAge();
+	updateSortValue(ctx);
+	return false;
+}
+void Value::updateAge() {
+	last_script_update.update();
+}
+void Value::updateSortValue(Context& ctx) {
+	sort_value = fieldP->sort_script.invoke(ctx)->toString();
+}
+
 void init_object(const FieldP& field, ValueP& value) {
 	if (!value)
 		value = field->newValue(field);