Settings versioned independently from app version

src/QGCConfig.h

@@ -10,6 +10,10 @@
 #define MAVLINK_HEARTBEAT_DEFAULT_RATE 1
 #define WITH_TEXT_TO_SPEECH 1
 
+// If you need to make an incompatible changes to stored settings, bump this version number
+// up by 1. This will caused store settings to be cleared on next boot.
+#define QGC_SETTINGS_VERSION 1
+
 #define QGC_APPLICATION_NAME "QGroundControl"
 #define QGC_APPLICATION_VERSION_BASE "v2.0.3"
 

src/QGCCore.cc

@@ -55,6 +55,7 @@ This file is part of the QGROUNDCONTROL project
 #include "MAVLinkSimulationLink.h"
 #include "SerialLink.h"
 
+const char* QGCCore::_settingsVersionKey = "SettingsVersion";
 
 /**
  * @brief Constructor for the main application.
@@ -108,31 +109,25 @@ bool QGCCore::init(void)
     // Exit main application when last window is closed
     connect(this, SIGNAL(lastWindowClosed()), this, SLOT(quit()));
     
-    
-    // Show user an upgrade message if QGC got upgraded (see code below, after splash screen)
-    bool upgraded = false;
+    // Show user an upgrade message if the settings version has been bumped up
+    bool settingsUpgraded = false;
     enum MainWindow::CUSTOM_MODE mode = MainWindow::CUSTOM_MODE_PX4;
-    QString lastApplicationVersion("");
-    if (settings.contains("QGC_APPLICATION_VERSION"))
-    {
-        QString qgcVersion = settings.value("QGC_APPLICATION_VERSION").toString();
-        if (qgcVersion != QGC_APPLICATION_VERSION)
-        {
-            lastApplicationVersion = qgcVersion;
-            settings.clear(); // Clear settings from different version
-            // Write current application version
-            settings.setValue("QGC_APPLICATION_VERSION", QGC_APPLICATION_VERSION);
-            upgraded = true;
-        } else {
-            mode = (enum MainWindow::CUSTOM_MODE) settings.value("QGC_CUSTOM_MODE", (int)MainWindow::CUSTOM_MODE_PX4).toInt();
+    if (settings.contains(_settingsVersionKey)) {
+        if (settings.value(_settingsVersionKey).toInt() != QGC_SETTINGS_VERSION) {
+            settingsUpgraded = true;
         }
-    } else {
-        // If application version is not set, clear settings anyway
+    } else if (settings.allKeys().count()) {
+        // Settings version key is missing and there are settings. This is an upgrade scenario.
+        settingsUpgraded = true;
+    }
+    
+    if (settingsUpgraded) {
         settings.clear();
-        // Write current application version
-        settings.setValue("QGC_APPLICATION_VERSION", QGC_APPLICATION_VERSION);
+        settings.setValue(_settingsVersionKey, QGC_SETTINGS_VERSION);
     }
     
+    mode = (enum MainWindow::CUSTOM_MODE) settings.value("QGC_CUSTOM_MODE", (int)MainWindow::CUSTOM_MODE_PX4).toInt();
+    
     settings.sync();
     
     // Show splash screen
@@ -192,8 +187,11 @@ bool QGCCore::init(void)
     // Remove splash screen
     splashScreen->finish(_mainWindow);
     
-    if (upgraded) _mainWindow->showInfoMessage(tr("Default Settings Loaded"),
-                                              tr("qgroundcontrol has been upgraded from version %1 to version %2. Some of your user preferences have been reset to defaults for safety reasons. Please adjust them where needed.").arg(lastApplicationVersion).arg(QGC_APPLICATION_VERSION));
+    if (settingsUpgraded) {
+        _mainWindow->showInfoMessage(tr("Settings Cleared"),
+                                     tr("The format for QGroundControl saved settings has been modified. "
+                                        "Your saved settings have been reset to defaults."));
+    }
     
     // Check if link could be connected
     if (udpLink && !udpLink->connect())

src/QGCCore.h

@@ -72,7 +72,8 @@ protected:
     void startUASManager();
 
 private:
-    MainWindow*             _mainWindow;
+    MainWindow* _mainWindow;
+    static const char* _settingsVersionKey;
 };
 
 #endif /* _CORE_H_ */