Check settings at launch to avoid crashing

Some settings were changed between v1.02 and 1.10 (current), and some
of these changes cause OpenBoard to crash at launch. This commit adds
a function to check for these specific new settings, and wipe the old
values if they are found.
This avoids problems when the user upgrades from 1.02 without deleting
their configuration file.

(This is an alternative to having a post-install script, which would be
ineffective in a multi-user configuration)

src/core/UBSetting.h

@@ -62,6 +62,11 @@ class UBSetting : public QObject
             return mPath;
         }
 
+        virtual QVariant defaultValue() const
+        {
+            return mDefaultValue;
+        }
+
     public slots:
 
         void setBool(bool pValue);

src/core/UBSettings.cpp

@@ -226,13 +226,13 @@ void UBSettings::init()
     appPreferredLanguage = new UBSetting(this,"App","PreferredLanguage", "");
 
     rightLibPaletteBoardModeWidth = new UBSetting(this, "Board", "RightLibPaletteBoardModeWidth", 270);
-    rightLibPaletteBoardModeIsCollapsed = new UBSetting(this,"Board", "RightLibPaletteBoardModeIsCollapsed",false);
+    rightLibPaletteBoardModeIsCollapsed = new UBSetting(this,"Board", "RightLibPaletteBoardModeIsCollapsed",true);
     rightLibPaletteDesktopModeWidth = new UBSetting(this, "Board", "RightLibPaletteDesktopModeWidth", 270);
-    rightLibPaletteDesktopModeIsCollapsed = new UBSetting(this,"Board", "RightLibPaletteDesktopModeIsCollapsed",false);
+    rightLibPaletteDesktopModeIsCollapsed = new UBSetting(this,"Board", "RightLibPaletteDesktopModeIsCollapsed",true);
     leftLibPaletteBoardModeWidth = new UBSetting(this, "Board", "LeftLibPaletteBoardModeWidth",270);
-    leftLibPaletteBoardModeIsCollapsed = new UBSetting(this,"Board","LeftLibPaletteBoardModeIsCollapsed",false);
+    leftLibPaletteBoardModeIsCollapsed = new UBSetting(this,"Board","LeftLibPaletteBoardModeIsCollapsed",true);
     leftLibPaletteDesktopModeWidth = new UBSetting(this, "Board", "LeftLibPaletteDesktopModeWidth",270);
-    leftLibPaletteDesktopModeIsCollapsed = new UBSetting(this,"Board","LeftLibPaletteDesktopModeIsCollapsed",false);
+    leftLibPaletteDesktopModeIsCollapsed = new UBSetting(this,"Board","LeftLibPaletteDesktopModeIsCollapsed",true);
 
     appIsInSoftwareUpdateProcess = new UBSetting(this, "App", "IsInSoftwareUpdateProcess", false);
     appLastSessionDocumentUUID = new UBSetting(this, "App", "LastSessionDocumentUUID", "");
@@ -268,11 +268,11 @@ void UBSettings::init()
     pageDpi = new UBSetting(this, "Board", "pageDpi", 0);
 
     QStringList penLightBackgroundColors;
-    penLightBackgroundColors << "#000000" << "#FF0000" <<"#004080" << "#008000" << "#FFDD00" << "#C87400" << "#800040" << "#008080"  << "#5F2D0A";
+    penLightBackgroundColors << "#000000" << "#FF0000" <<"#004080" << "#008000" << "#FFDD00" << "#C87400" << "#800040" << "#008080"  << "#5F2D0A" << "#FFFFFF";
     boardPenLightBackgroundColors = new UBColorListSetting(this, "Board", "PenLightBackgroundColors", penLightBackgroundColors, 1.0);
 
     QStringList penDarkBackgroundColors;
-    penDarkBackgroundColors << "#FFFFFF" << "#FF3400" <<"#66C0FF" << "#81FF5C" << "#FFFF00" << "#B68360" << "#FF497E" << "#8D69FF";
+    penDarkBackgroundColors << "#FFFFFF" << "#FF3400" <<"#66C0FF" << "#81FF5C" << "#FFFF00" << "#B68360" << "#FF497E" << "#8D69FF" << "#000000";
     boardPenDarkBackgroundColors = new UBColorListSetting(this, "Board", "PenDarkBackgroundColors", penDarkBackgroundColors, 1.0);
 
     boardMarkerAlpha = new UBSetting(this, "Board", "MarkerAlpha", 0.5);
@@ -421,6 +421,7 @@ void UBSettings::init()
     useSystemOnScreenKeyboard = new UBSetting(this, "App", "UseSystemOnScreenKeyboard", true);
 
     cleanNonPersistentSettings();
+    checkNewSettings();
 }
 
 
@@ -1339,3 +1340,76 @@ void UBSettings::cleanNonPersistentSettings()
         youTubeUserEMail->set(QVariant(""));
     }
 }
+
+/**
+ * @brief Permanently remove a setting, from local memory and config files
+ * @param setting The setting to remove
+ */
+void UBSettings::removeSetting(const QString &setting)
+{
+    if (sAppSettings->contains(setting))
+        sAppSettings->remove(setting);
+
+    if (mUserSettings->contains(setting))
+        mUserSettings->remove(setting);
+
+    if (mSettingsQueue.contains(setting))
+        mSettingsQueue.remove(setting);
+}
+
+void UBSettings::checkNewSettings()
+{
+    /*
+     * Some settings were modified in new versions and OpenBoard can crash
+     * if an old settings file is used. This function checks these settings and
+     * if necessary, resets them to the values initialized in UBSettings::init().
+     *
+     * Thus this method can be removed when it is no longer deemed useful.
+     */
+
+    // OB 1.10 introduced an extra pen color;  for simplicity, if the old settings
+    // are still present (i.e only 4 selected pen colors), we just reset all color settings.
+    // Having too few colors actually causes OpenBoard to crash, hence these measures.
+
+    QList<UBColorListSetting*> colorSettings;
+    colorSettings << boardPenDarkBackgroundSelectedColors
+                  << boardPenLightBackgroundSelectedColors
+                  << boardMarkerDarkBackgroundSelectedColors
+                  << boardMarkerLightBackgroundSelectedColors;
+
+    foreach (UBColorListSetting* setting, colorSettings) {
+        if (setting->colors().size() < 5)
+            setting->reset(); // Make sure that there are 5 selected colors
+    }
+
+    colorSettings.clear();
+
+    // Next we check whether all the new colors were added; i.e if some default
+    // colors are not also in the config file, we add them to it.
+
+    // This is not nearly as critical as the above issue, but the users (or admins) seemingly
+    // can't be trusted to delete or modify their own config file when upgrading, so they might
+    // wonder why they don't have the new colors in their app.
+
+    colorSettings << boardPenDarkBackgroundColors
+                  << boardPenLightBackgroundColors
+                  << boardMarkerDarkBackgroundColors
+                  << boardMarkerLightBackgroundColors;
+
+    foreach (UBColorListSetting* setting, colorSettings) {
+        QStringList defaultColors = qvariant_cast<QStringList>(setting->defaultValue());
+        QStringList currentColors(qvariant_cast<QStringList>(setting->get())); // copy
+
+        foreach (QString c, defaultColors) {
+            if (!currentColors.contains(c))
+                currentColors.append(QString(c));
+        }
+
+        setting->set(currentColors);
+    }
+
+
+    // A typo was corrected in version 1.10
+    removeSetting("Board/useSystemOnScreenKeybard");
+
+}

src/core/UBSettings.h

@@ -425,6 +425,9 @@ class UBSettings : public QObject
         static bool checkDirectory(QString& dirPath);
         static QString replaceWildcard(QString& path);
 
+        void removeSetting(const QString& setting);
+        void checkNewSettings();
+
 };