Expressions: Added App::BooleanExpression class.

src/App/Application.cpp

@@ -1139,7 +1139,7 @@ void Application::initTypes(void)
     App ::ConditionalExpression     ::init();
     App ::StringExpression          ::init();
     App ::FunctionExpression        ::init();
-
+    App ::BooleanExpression         ::init();
 }
 
 void Application::initConfig(int argc, char ** argv)

src/App/Expression.cpp

@@ -1262,6 +1262,18 @@ Expression *ConstantExpression::copy() const
     return new ConstantExpression(owner, name.c_str(), quantity);
 }
 
+TYPESYSTEM_SOURCE_ABSTRACT(App::BooleanExpression, App::NumberExpression);
+
+BooleanExpression::BooleanExpression(const DocumentObject *_owner, bool _value)
+    : NumberExpression(owner, _value ? 1.0 : 0.0)
+{
+}
+
+Expression *BooleanExpression::copy() const
+{
+    return new BooleanExpression(owner, getValue() > 0.5 ? true : false);
+}
+
 namespace App {
 
 namespace ExpressionParser {

src/App/Expression.h

@@ -190,6 +190,15 @@ protected:
     std::string name; /**< Constant's name */
 };
 
+class AppExport BooleanExpression : public NumberExpression {
+    TYPESYSTEM_HEADER();
+public:
+    BooleanExpression(const App::DocumentObject *_owner = 0, bool _value = false);
+
+    virtual Expression * copy() const;
+
+};
+
 
 /**
   * Class implementing an infix expression.