Implement registering/unregistering/calling change callbacks.

Drives reloading the report when the Apply or OK button is pressed.

gnucash/gnome/gnc-plugin-page-report.cpp

@@ -79,6 +79,7 @@ extern "C"
 
 
 #include <memory>
+#include <gnc-optiondb-impl.hpp>
 
 /* NW: you can add GNC_MOD_REPORT to gnc-engine.h
 or simply define it locally. Any unique string with
@@ -111,14 +112,14 @@ typedef struct GncPluginPageReportPrivate
     SCM cur_report;
     /// The Option DB for this report.
     GncOptionDB *cur_odb;
-    SCM option_change_cb_id;
+    size_t option_change_cb_id = 0;
 
     /* initial_report is special; it's the one that's saved and
      * restored.  The name_change_callback only gets called when
      * the initial_report name is changed. */
     SCM          initial_report;
     GncOptionDB  * initial_odb;
-    SCM          name_change_cb_id;
+    size_t       name_change_cb_id;
 
     /* keep a list of edited reports so that we can destroy them when
      * the window is closed. */
@@ -550,7 +551,7 @@ gnc_plugin_page_report_setup( GncPluginPage *ppage )
     priv->cur_report        = SCM_BOOL_F;
     priv->initial_report    = SCM_BOOL_F;
     priv->edited_reports    = SCM_EOL;
-    priv->name_change_cb_id = SCM_BOOL_F;
+    priv->name_change_cb_id = 0;
 
     g_object_get( ppage, "report-id", &report_id, nullptr );
 
@@ -643,22 +644,17 @@ gnc_plugin_page_report_load_cb(GncHtml * html, URLType type,
         scm_call_2(set_needs_save, inst_report, SCM_BOOL_T);
 
         priv->initial_odb = gnc_get_report_optiondb(inst_report);
-/*
+
         priv->name_change_cb_id =
-            gnc_option_db_register_change_callback(priv->initial_odb,
-                    gnc_plugin_page_report_refresh,
-                    priv,
-                    "General", "Report name");
-*/
+            priv->initial_odb->register_callback(
+                gnc_plugin_page_report_refresh, priv);
+
     }
 
     if ((priv->cur_report != SCM_BOOL_F) && (priv->cur_odb != nullptr))
     {
-/*
-        gnc_option_db_unregister_change_callback_id(priv->cur_odb,
-                priv->option_change_cb_id);
-*/
-        gnc_option_db_destroy(priv->cur_odb);
+        priv->cur_odb->unregister_callback(priv->option_change_cb_id);
+        priv->option_change_cb_id = 0;
         priv->cur_odb = nullptr;
     }
 
@@ -668,12 +664,11 @@ gnc_plugin_page_report_load_cb(GncHtml * html, URLType type,
     scm_gc_protect_object(priv->cur_report);
 
     priv->cur_odb = gnc_get_report_optiondb(inst_report);
-/*
+
     priv->option_change_cb_id =
-        gnc_option_db_register_change_callback(priv->cur_odb,
-                gnc_plugin_page_report_option_change_cb,
-                report, nullptr, nullptr);
-*/
+        priv->cur_odb->register_callback(
+            gnc_plugin_page_report_option_change_cb, report);
+
     if (gnc_html_history_forward_p(gnc_html_get_history(priv->html)))
     {
         gnc_plugin_page_report_set_fwd_button(report, TRUE);

libgnucash/app-utils/gnc-optiondb-impl.hpp

@@ -63,6 +63,25 @@ public:
 };
 
 using GncOptionSectionPtr = std::shared_ptr<GncOptionSection>;
+using GncOptionDBChangeCallback = void (*)(void* user_data);
+
+struct GncOptionDBCallback
+{
+    GncOptionDBCallback(size_t id, GncOptionDBChangeCallback func,
+                              void* data) :
+        m_id{id}, m_func{func}, m_data{data} {}
+    ~GncOptionDBCallback() = default;
+    GncOptionDBCallback(const GncOptionDBCallback&) = delete;
+    GncOptionDBCallback(GncOptionDBCallback&&) = default;
+    GncOptionDBCallback& operator=(const GncOptionDBCallback&) = default;
+    GncOptionDBCallback& operator=(GncOptionDBCallback&&) = default;
+
+    size_t m_id;
+    GncOptionDBChangeCallback m_func;
+    void* m_data;
+};
+
+using GncCallbackVec = std::vector<GncOptionDBCallback>;
 
 class GncOptionDB
 {
@@ -138,10 +157,14 @@ public:
                                         const std::string& section,
                                         const std::string& name) const noexcept;
     std::istream& load_option_key_value(std::istream& iss);
+    size_t register_callback(GncOptionDBChangeCallback, void*);
+    void unregister_callback(size_t);
+    void run_callbacks();
 private:
     GncOptionSection* m_default_section;
     std::vector<GncOptionSectionPtr> m_sections;
     bool m_dirty = false;
+    GncCallbackVec m_callbacks{};
 
     std::function<GncOptionUIItem*()> m_get_ui_value;
     std::function<void(GncOptionUIItem*)> m_set_ui_value;

libgnucash/app-utils/gnc-optiondb.cpp

@@ -22,6 +22,7 @@
 \********************************************************************/
 
 #include <libguile.h>
+#include <functional>
 #include <string>
 #include <limits>
 #include <sstream>
@@ -666,6 +667,31 @@ GncOptionDB::load_from_key_value(std::istream& iss)
     return iss;
 }
 
+size_t
+GncOptionDB::register_callback(GncOptionDBChangeCallback cb, void* data)
+{
+    constexpr std::hash<GncOptionDBChangeCallback> cb_hash;
+    auto id{cb_hash(cb)};
+    if (std::find_if(m_callbacks.begin(), m_callbacks.end(),
+                     [id](auto&cb)->bool{ return cb.m_id == id; }) == m_callbacks.end())
+        m_callbacks.emplace_back(id, cb, data);
+    return id;
+}
+
+void
+GncOptionDB::unregister_callback(size_t id)
+{
+    std::remove_if(m_callbacks.begin(), m_callbacks.end(),
+                   [id](auto& cb)->bool { return cb.m_id == id; });
+}
+
+void
+GncOptionDB::run_callbacks()
+{
+    std::for_each(m_callbacks.begin(), m_callbacks.end(),
+                  [](auto& cb)->void { cb.m_func(cb.m_data); });
+}
+
 static inline void
 counter_option_path(const GncOption& option, GSList* list, std::string& name)
 {
@@ -1306,6 +1332,8 @@ gnc_option_db_commit(GncOptionDB* odb)
                                                 (void*)option.get_name().c_str());
                     } });
         });
+    if (!errors)
+        odb->run_callbacks();
     return errors;
 }
 

libgnucash/app-utils/gnc-optiondb.i

@@ -799,6 +799,7 @@ wrap_unique_ptr(GncOptionDBPtr, GncOptionDB);
     }
 
     %}
+%ignore GncOptionDBCallback;
 
 %include "gnc-option-date.hpp"
 %include "gnc-option.hpp"