[C++ Options] Begin Implementation for basic and validated options.

libgnucash/app-utils/gnc-option.cpp

@@ -0,0 +1,103 @@
+/********************************************************************\
+ * gnc-option.cpp -- Application options system                     *
+ * Copyright (C) 2019 John Ralls <jralls@ceridwen.us>               *
+ *                                                                  *
+ * This program is free software; you can redistribute it and/or    *
+ * modify it under the terms of the GNU General Public License as   *
+ * published by the Free Software Foundation; either version 2 of   *
+ * the License, or (at your option) any later version.              *
+ *                                                                  *
+ * This program is distributed in the hope that it will be useful,  *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
+ * GNU General Public License for more details.                     *
+ *                                                                  *
+ * You should have received a copy of the GNU General Public License*
+ * along with this program; if not, contact:                        *
+ *                                                                  *
+ * Free Software Foundation           Voice:  +1-617-542-5942       *
+ * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
+ * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
+ *                                                                  *
+\********************************************************************/
+
+//#include "options.h"
+#include "gnc-option.hpp"
+
+template<> SCM
+scm_from_value<std::string>(std::string value)
+{
+    return scm_from_utf8_string(value.c_str());
+}
+
+template<> SCM
+scm_from_value<bool>(bool value)
+{
+    return value ? SCM_BOOL_T : SCM_BOOL_F;
+}
+
+template<> SCM
+scm_from_value<int64_t>(int64_t value)
+{
+    return scm_from_int64(value);
+}
+
+template<> SCM
+scm_from_value<QofInstance*>(QofInstance* value)
+{
+    auto guid = guid_to_string(qof_instance_get_guid(value));
+    auto scm_guid = scm_from_utf8_string(guid);
+    g_free(guid);
+    return scm_guid;
+}
+
+std::shared_ptr<GncOptionValue<std::string>>
+gnc_make_string_option(const char* section, const char* name,
+                       const char* key, const char* doc_string,
+                       std::string value)
+{
+    return std::make_shared<GncOptionValue<std::string>>(
+        section, name, key, doc_string, value);
+}
+
+std::shared_ptr<GncOptionValue<std::string>>
+gnc_make_text_option(const char* section, const char* name,
+                     const char* key, const char* doc_string,
+                     std::string value)
+{
+    return gnc_make_string_option(section, name, key, doc_string, value);
+}
+
+std::shared_ptr<GncOptionValue<QofInstance*>>
+gnc_make_budget_option(const char* section, const char* name,
+                       const char* key, const char* doc_string,
+                       GncBudget *value)
+{
+    return std::make_shared<GncOptionValue<QofInstance*>>(
+        section, name, key, doc_string, QOF_INSTANCE(value));
+}
+
+std::shared_ptr<GncOptionValue<QofInstance*>>
+gnc_make_commodity_option(const char* section, const char* name,
+                     const char* key, const char* doc_string,
+                         gnc_commodity *value)
+{
+    return std::make_shared<GncOptionValue<QofInstance*>>(
+        section, name, key, doc_string, QOF_INSTANCE(value));
+}
+
+
+std::shared_ptr<GncOptionValidatedValue<QofInstance*>>
+gnc_make_currency_option(const char* section, const char* name,
+                         const char* key, const char* doc_string,
+                         gnc_commodity *value)
+{
+    return std::make_shared<GncOptionValidatedValue<QofInstance*>>(
+        section, name, key, doc_string, QOF_INSTANCE(value),
+        [](QofInstance* new_value) -> bool
+            {
+                return GNC_IS_COMMODITY (new_value) &&
+                    gnc_commodity_is_currency(GNC_COMMODITY(new_value));
+            }
+        );
+}

libgnucash/app-utils/gnc-option.hpp

@@ -0,0 +1,215 @@
+/********************************************************************\
+ * gnc-option.hpp -- Application options system                     *
+ * Copyright (C) 2019 John Ralls <jralls@ceridwen.us>               *
+ *                                                                  *
+ * This program is free software; you can redistribute it and/or    *
+ * modify it under the terms of the GNU General Public License as   *
+ * published by the Free Software Foundation; either version 2 of   *
+ * the License, or (at your option) any later version.              *
+ *                                                                  *
+ * This program is distributed in the hope that it will be useful,  *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
+ * GNU General Public License for more details.                     *
+ *                                                                  *
+ * You should have received a copy of the GNU General Public License*
+ * along with this program; if not, contact:                        *
+ *                                                                  *
+ * Free Software Foundation           Voice:  +1-617-542-5942       *
+ * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
+ * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
+ *                                                                  *
+\********************************************************************/
+
+#ifndef GNC_OPTION_HPP_
+#define GNC_OPTION_HPP_
+
+extern "C"
+{
+#include <config.h>
+#include <qof.h>
+#include <gnc-budget.h>
+#include <gnc-commodity.h>
+}
+#include <libguile.h>
+#include <string>
+
+/*
+ * Unused base class to document the structure of the current Scheme option
+ * vector, re-expressed in C++. The comment-numbers on the right indicate which
+ * item in the Scheme vector each item implements.
+ *
+ * Not everything here needs to be implemented, nor will it necessarily be
+ * implemented the same way. For example, part of the purpose of this redesign
+ * is to convert from saving options as strings of Scheme code to some form of
+ * key-value pair in the book options, so generate_restore_form() will likely be
+ * supplanted with save_to_book().
+
+template <typename ValueType>
+class GncOptionBase
+{
+public:
+    virtual ~GncOption = default;
+    virtual ValueType get_value() const = 0;                             //5
+    virtual ValueType get_default_value() = 0;
+    virtual SCM get_SCM_value() = 0;
+    virtual SCM get_SCM_default_value() const = 0;                       //7
+    virtual void set_value(ValueType) = 0;                               //6
+// generate_restore_form outputs a Scheme expression (a "form") that finds an
+// option and sets it to the current value. e.g.:
+//(let ((option (gnc:lookup-option options
+//                                 "Display"
+//                                 "Amount")))
+//  ((lambda (option) (if option ((gnc:option-setter option) 'none))) option))
+// it uses gnc:value->string to generate the "'none" (or whatever the option's
+// value would be as input to the scheme interpreter).
+
+    virtual std::string generate_restore_form();                         //8
+    virtual void save_to_book(QofBook*) const noexcept;                  //9
+    virtual void read_from_book(QofBook*);                               //10
+    virtual std::vector<std::string> get_option_strings();               //15
+    virtual set_changed_callback(std::function<void(void*)>);            //14
+protected:
+    const std::string m_section;                                         //0
+    const std::string m_name;                                            //1
+    const std::string m_sort_tag;                                        //2
+    const std::type_info m_kvp_type;                                     //3
+    const std::string m_doc_string;                                      //4
+    std::function<void(void*)> m_changed_callback;   //Part of the make-option closure
+    std::function<void(void*)>m_option_widget_changed_callback;          //16
+};
+*/
+
+struct OptionClassifier
+{
+    const std::string m_section;
+    const std::string m_name;
+    const std::string m_sort_tag;
+//    const std::type_info m_kvp_type;
+    const std::string m_doc_string;
+};
+
+template <typename ValueType>
+SCM scm_from_value(ValueType);
+
+/* This design pattern is called the Curiously Recursive Template Pattern, or
+ * CRTP. See https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern
+ * for a detailed explanation.
+ */
+template <typename ValueType, class ValueClass>
+class GncOption
+{
+public:
+    ValueType get_value() const
+    {
+        return static_cast<ValueClass const&>(*this).get_value();
+    }
+    void set_value(ValueType value)
+    {
+        static_cast<ValueClass&>(*this).set_value(value);
+    }
+    ValueType get_default_value() const
+    {
+        return static_cast<ValueClass const&>(*this).get_default_value();
+    }
+    SCM get_scm_value()
+    {
+        ValueType value{static_cast<ValueClass const&>(*this).get_value()};
+        return scm_from_value<ValueType>(value);
+    }
+    SCM get_scm_default_value()
+    {
+        ValueType value{static_cast<ValueClass const&>(*this).get_default_value()};
+        return scm_from_value<ValueType>(value);
+    }
+};
+
+template <typename ValueType>
+class GncOptionValue :
+    public OptionClassifier,
+    public GncOption<ValueType, GncOptionValue<ValueType>>
+{
+public:
+    GncOptionValue<ValueType>(const char* section, const char* name,
+                              const char* key, const char* doc_string,
+                              ValueType value) :
+        OptionClassifier{section, name, key, doc_string},
+        m_value{value}, m_default_value{value} {}
+    ValueType get_value() const { return m_value; }
+    ValueType get_default_value() const { return m_default_value; }
+    void set_value(ValueType new_value) { m_value = new_value; }
+protected:
+    ValueType m_value;
+    ValueType m_default_value;
+};
+
+template <typename ValueType>
+class GncOptionValidatedValue :
+    public OptionClassifier,
+    public GncOption<ValueType, GncOptionValidatedValue<ValueType>>
+{
+public:
+    GncOptionValidatedValue<ValueType>(const char* section, const char* name,
+                                       const char* key, const char* doc_string,
+                                       ValueType value,
+                                      std::function<bool(ValueType)>validator) :
+        OptionClassifier{section, name, key, doc_string},
+        m_value{value}, m_default_value{value}, m_validator{validator}
+        {
+            if (!this->validate(value))
+            throw std::invalid_argument("Attempt to create GncValidatedOption with bad value.");
+        }
+    GncOptionValidatedValue<ValueType>(const char* section, const char* name,
+                                       const char* key, const char* doc_string,
+                                       ValueType value,
+                                       std::function<bool(ValueType)>validator,
+                                       ValueType val_data) :
+        OptionClassifier{section, name, key, doc_string}, m_value{value},
+        m_default_value{value}, m_validator{validator}, m_validation_data{val_data}
+    {
+            if (!this->validate(value))
+            throw std::invalid_argument("Attempt to create GncValidatedOption with bad value.");
+    }
+    ValueType get_value() const { return m_value; }
+    ValueType get_default_value() const { return m_default_value; }
+    bool validate(ValueType value) { return m_validator(value); }
+    void set_value(ValueType value)
+    {
+        if (this->validate(value))
+            m_value = value;
+        else
+            throw std::invalid_argument("Validation failed, value not set.");
+    }
+private:
+    ValueType m_value;
+    ValueType m_default_value;
+    std::function<bool(ValueType)> m_validator;                         //11
+    ValueType m_validation_data;
+};
+
+std::shared_ptr<GncOptionValue<std::string>>
+gnc_make_string_option(const char* section, const char* name,
+                       const char* key, const char* doc_string,
+                       std::string value);
+
+std::shared_ptr<GncOptionValue<std::string>>
+gnc_make_text_option(const char* section, const char* name,
+                     const char* key, const char* doc_string,
+                     std::string value);
+
+std::shared_ptr<GncOptionValue<QofInstance*>>
+gnc_make_budget_option(const char* section, const char* name,
+                       const char* key, const char* doc_string,
+                       GncBudget* value);
+
+std::shared_ptr<GncOptionValue<QofInstance*>>
+gnc_make_commodity_option(const char* section, const char* name,
+                          const char* key, const char* doc_string,
+                          gnc_commodity* value);
+
+std::shared_ptr<GncOptionValidatedValue<QofInstance*>>
+gnc_make_currency_option(const char* section, const char* name,
+                         const char* key, const char* doc_string,
+                         gnc_commodity* value);
+
+#endif //GNC_OPTION_HPP_

libgnucash/app-utils/test/CMakeLists.txt

@@ -1,3 +1,4 @@
+set(MODULEPATH ${CMAKE_SOURCE_DIR}/libgnucash/app-utils)
 
 set(APP_UTILS_TEST_INCLUDE_DIRS
   ${CMAKE_BINARY_DIR}/common # for config.h
@@ -28,6 +29,25 @@ gnc_add_test_with_guile(test-scm-query-string test-scm-query-string.cpp
 )
 add_app_utils_test(test-sx test-sx.cpp)
 
+set(gtest_gnc_option_SOURCES
+  ${MODULEPATH}/gnc-option.cpp
+  gtest-gnc-option.cpp)
+
+set(gtest_gnc_option_INCLUDES
+  ${MODULEPATH}
+  ${CMAKE_SOURCE_DIR}/libgnucash/engine
+  ${CMAKE_BINARY_DIR}/common # for config.h
+  ${GLIB2_INCLUDE_DIRS}
+  ${GUILE_INCLUDE_DIRS})
+
+set(gtest_gnc_option_LIBS
+  gncmod-engine
+  ${GLIB2_LDFLAGS}
+  ${GUILE_LDFLAGS}
+  gtest)
+
+gnc_add_test(test-gnc-option "${gtest_gnc_option_SOURCES}" gtest_gnc_option_INCLUDES gtest_gnc_option_LIBS)
+
 set(GUILE_DEPENDS
   scm-test-engine
   scm-app-utils