Redesign uncaught exception handling to allow external reporters

[libs/core.git] / source / core / application.h

diff --git a/source/core/application.h b/source/core/application.h
index 38df732f1a5779782566d249b701a19ca99011a2..e1d3a8b5e2be95d0c2fd0ffce151a1347264f080 100644 (file)
--- a/source/core/application.h
+++ b/source/core/application.h
@@ -1,70 +1,98 @@
-/* $Id$
-
-This file is part of libmspcore
-Copyright © 2006-2008, 2011  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_CORE_APPLICATION_H_
 #define MSP_CORE_APPLICATION_H_
 
+#include <stdexcept>
+
 namespace Msp {
 
 /**
-Base class for applications.  Inherit the main class from this and add a static
-member of type RegApp<MainClass>.
+Base class for applications.  See also RegisteredApplication.
 */
 class Application
 {
 protected:
-       class RegBase
+       class Starter
        {
-       public:
-               virtual Application *create_app(int, char **)=0;
-               virtual void usage(const char *, const char *, bool)=0;
-               virtual ~RegBase() { }
        protected:
-               RegBase();
-       };
-
-       template<typename T>
-       class RegApp: public RegBase
-       {
+               Starter();
        public:
-               Application *create_app(int argc, char **argv) { return new T(argc, argv); }
-               void usage(const char *r, const char *a, bool b) { T::usage(r, a, b); }
+               virtual ~Starter() { }
+
+               virtual Application *create_app(int, char **) = 0;
        };
 
        bool done;
        int exit_code;
 
 private:
-       static RegBase *reg_app_;
+       static Starter *starter_;
        static Application *app_;
        static void *data_;
 
+       Application(const Application &);
+       Application &operator=(const Application &);
 protected:
        Application();
 public:
        virtual ~Application() { }
 
+       /** Constructs an instance of the registered application class and runs it.
+       If the application throws a usage_error, a help message is printed.  The
+       GetOpt class will throw such exceptions automatically in error conditions.
+
+       This function can only be called once.  The global main() function provided
+       by the library normally does it automatically at program startup. */
        static int run(int, char **, void * =0);
-       static void usage(const char *, const char *, bool);
+
        static void *get_data() { return data_; }
 
 protected:
+       /** Default main loop.  Calls tick() repeatedly until exit() is called.  A
+       custom main loop should monitor the done member variable and return
+       exit_code. */
        virtual int main();
+
+       /** Sets the specified signal to be delivered to the sighandler member
+       function. */
        void catch_signal(int);
+
+       /** Causes the application to exit gracefully with the given exit code. */
        void exit(int);
+
        virtual void tick() { }
        virtual void sighandler(int) { }
+
 private:
+       /** Static wrapper function to call a member function of the Application
+       instance. */
        static void sighandler_(int);
+};
 
-       Application(const Application &);
-       Application &operator=(const Application &);
+
+/**
+Registers the class to be used for program startup.  The main application class
+should be derived from this.
+*/
+template<typename T>
+class RegisteredApplication: public Application
+{
+private:
+       class Starter: public Application::Starter
+       {
+       public:
+               Application *create_app(int argc, char **argv) { return new T(argc, argv); }
+       };
+
+       static Starter starter_;
+
+protected:
+       // Force the starter into existence
+       RegisteredApplication() { (void)starter_; }
 };
 
+template<typename T>
+typename RegisteredApplication<T>::Starter RegisteredApplication<T>::starter_;
+
 } // namespace Msp
 
 #endif