options: fix 2 issues

1. Calling valueChanged didn't invoke machinery in
   value<t>, only base_value aka value_.

   There's a fast path in value<t>::type() despite the
   pessimization.

2. Split global scope stuff into options::globals from
   the options::globals stuff

3. Adjust usages

3 files changed, 27 insertions, 25 deletions

diff --git a/migration/20160906_00-mappings.cpp b/migration/20160906_00-mappings.cpp
index 0019d0ef..f94f8290 100644
--- a/migration/20160906_00-mappings.cpp
+++ b/migration/20160906_00-mappings.cpp
@@ -19,6 +19,7 @@
 #include <QDebug>
 
 using namespace options;
+using namespace options::globals;
 using namespace migrations;
 
 static const char* const old_names[] =
@@ -44,7 +45,7 @@ static QList<QList<QPointF>> get_old_splines()
 {
     QList<QList<QPointF>> ret;
 
-    return group::with_settings_object([&](QSettings& settings) {
+    return with_settings_object([&](QSettings& settings) {
         for (const char* name : old_names)
         {
             const int max = settings.value("point-count", 0).toInt();
@@ -96,7 +97,7 @@ struct mappings_from_2_3_0_rc11 : migration
 
     void run() override
     {        
-        group::with_settings_object([this](QSettings&) {
+        with_settings_object([](QSettings&) {
             const QList<QList<QPointF>> old_mappings = get_old_splines();
 
             for (int i = 0; i < 12; i++)
diff --git a/migration/20180102_00-process-detector-separator.cpp b/migration/20180102_00-process-detector-separator.cpp
index ddb01cb4..6c3a2b58 100644
--- a/migration/20180102_00-process-detector-separator.cpp
+++ b/migration/20180102_00-process-detector-separator.cpp
@@ -2,6 +2,7 @@
 #include "options/options.hpp"
 
 using namespace options;
+using namespace options::globals;
 using namespace migrations;
 
 static constexpr auto OLD_RECORD_SEPARATOR  = QChar('|');
@@ -26,7 +27,7 @@ struct process_detector_record_separator : migration
 
     bool should_run() const override
     {
-        return group::with_global_settings_object([](const QSettings& s)
+        return with_global_settings_object([](const QSettings& s)
         {
             const QString old_value = s.value(KEY_NAME).toString();
             return old_value.contains(OLD_RECORD_SEPARATOR);
@@ -35,7 +36,7 @@ struct process_detector_record_separator : migration
 
     void run() override
     {
-        return group::with_global_settings_object([](QSettings& s)
+        return with_global_settings_object([](QSettings& s)
         {
             QString value = s.value(KEY_NAME).toString();
             value.replace(OLD_UNIT_SEPARATOR,   NEW_UNIT_SEPARATOR);
diff --git a/migration/migration.cpp b/migration/migration.cpp
index 8e5fea5e..386fde9b 100644
--- a/migration/migration.cpp
+++ b/migration/migration.cpp
@@ -20,6 +20,8 @@
 
 #include <memory>
 
+using namespace options::globals;
+
 // individual migrations are run in the UI thread. they can be interactive if necessary.
 
 namespace migrations {
@@ -105,7 +107,7 @@ QString migrator::last_migration_time()
 {
     QString ret;
 
-    options::group::with_settings_object([&](QSettings& s) {
+    with_settings_object([&](QSettings& s) {
         s.beginGroup("migrations");
         ret = s.value("last-migration-at", "19700101_00").toString();
         s.endGroup();
@@ -129,13 +131,13 @@ QString migrator::time_after_migrations()
 
 void migrator::set_last_migration_time(const QString& val)
 {
-    options::group::with_settings_object([&](QSettings& s) {
+    with_settings_object([&](QSettings& s) {
         s.beginGroup("migrations");
         const QString old_value = s.value("last-migration-at", "").toString();
         if (val != old_value)
         {
             s.setValue("last-migration-at", val);
-            options::group::mark_ini_modified();
+            mark_ini_modified();
         }
         s.endGroup();
     });
@@ -155,26 +157,24 @@ std::vector<QString> migrator::run()
 
     const QString last_migration = last_migration_time();
 
-    options::group::with_global_settings_object([&](QSettings&) {
-        options::group::with_settings_object([&](QSettings&) {
-            for (mptr m : migrations())
+    with_global_settings_object([&](QSettings&) {
+        for (mptr const& m : migrations())
+        {
+            const QString date = m->unique_date();
+
+            if (date <= last_migration)
+                continue;
+
+            if (m->should_run())
             {
-                const QString date = m->unique_date();
-
-                if (date <= last_migration)
-                    continue;
-
-                if (m->should_run())
-                {
-                    const QByteArray name = m->name().toUtf8();
-                    const QByteArray date = m->unique_date().toUtf8();
-                    qDebug() << "migrate:" << date.constData() << name.constData();
-                    m->run();
-                    done.push_back(m->name());
-                }
+                const QByteArray name = m->name().toUtf8();
+                const QByteArray date = m->unique_date().toUtf8();
+                qDebug() << "migrate:" << date.constData() << name.constData();
+                m->run();
+                done.push_back(m->name());
             }
-            mark_config_as_not_needing_migration();
-        });
+        }
+        mark_config_as_not_needing_migration();
     });
 
     return done;