GlobalSettings: Implement undo function for the "cancel" button

[pulseview.git] / pv / globalsettings.cpp

diff --git a/pv/globalsettings.cpp b/pv/globalsettings.cpp
index 5da89ceba030bf66df5757d4ef0a318a5dc61735..d24822413038c5a63be439c1d1038b53fd49d1e4 100644 (file)
--- a/pv/globalsettings.cpp
+++ b/pv/globalsettings.cpp
@@ -25,6 +25,8 @@ const QString GlobalSettings::Key_View_AlwaysZoomToFit = "View_AlwaysZoomToFit";
 const QString GlobalSettings::Key_View_ColouredBG = "View_ColouredBG";
 
 std::multimap< QString, std::function<void(QVariant)> > GlobalSettings::callbacks_;
+bool GlobalSettings::tracking_ = false;
+std::map<QString, QVariant> GlobalSettings::tracked_changes_;
 
 GlobalSettings::GlobalSettings() :
        QSettings()
@@ -40,6 +42,11 @@ void GlobalSettings::register_change_handler(const QString key,
 
 void GlobalSettings::setValue(const QString &key, const QVariant &value)
 {
+       // Save previous value if we're tracking changes,
+       // not altering an already-existing saved setting
+       if (tracking_)
+               tracked_changes_.emplace(key, QSettings::value(key));
+
        QSettings::setValue(key, value);
 
        // Call all registered callbacks for this key
@@ -49,5 +56,26 @@ void GlobalSettings::setValue(const QString &key, const QVariant &value)
                it->second(value);
 }
 
+void GlobalSettings::start_tracking()
+{
+       tracking_ = true;
+       tracked_changes_.clear();
+}
+
+void GlobalSettings::stop_tracking()
+{
+       tracking_ = false;
+       tracked_changes_.clear();
+}
+
+void GlobalSettings::undo_tracked_changes()
+{
+       tracking_ = false;
+
+       for (auto entry : tracked_changes_)
+               setValue(entry.first, entry.second);
+
+       tracked_changes_.clear();
+}
 
 } // namespace pv