diff -r 68443f5be176 -r 44679e468ba9 src/libraries.cpp
--- a/src/libraries.cpp	Sat Oct 05 23:47:03 2019 +0300
+++ b/src/libraries.cpp	Sun Nov 03 12:17:41 2019 +0200
@@ -1,22 +1,39 @@
 #include <QSettings>
 #include "libraries.h"
 
+/**
+ * @brief Constructs a new library manager
+ * @param parent Parent object
+ */
 LibraryManager::LibraryManager(QObject* parent):
 	QAbstractTableModel{parent}
 {
 }
 
+/**
+ * @brief Constructs a library manager from settings
+ * @param settings Settings to construct from
+ * @param parent Parent object
+ */
 LibraryManager::LibraryManager(QSettings* settings, QObject* parent) :
 	QAbstractTableModel{parent}
 {
 	this->restoreFromSettings(settings);
 }
 
+/**
+ * @brief Yields a begin-terator for the libraries
+ * @return iterator
+ */
 QVector<Library>::const_iterator LibraryManager::begin() const
 {
 	return this->libraries.begin();
 }
 
+/**
+ * @brief Yields an end-iterator for the libraries
+ * @return iterator
+ */
 QVector<Library>::const_iterator LibraryManager::end() const
 {
 	return this->libraries.end();
@@ -46,6 +63,10 @@
 	return path;
 }
 
+/**
+ * @brief Adds a new library to the end of the libraries list.
+ * @param library Library to add
+ */
 void LibraryManager::addLibrary(const Library& library)
 {
 	emit layoutAboutToBeChanged();
@@ -53,11 +74,38 @@
 	emit layoutChanged();
 }
 
+/**
+ * @brief Removes a library by index. Does nothing if the index is not valid.
+ * @param libraryIndex Index of the library
+ */
+void LibraryManager::removeLibrary(const int libraryIndex)
+{
+	Q_ASSERT(isValidIndex(libraryIndex));
+	if (isValidIndex(libraryIndex))
+	{
+		emit layoutAboutToBeChanged();
+		libraries.remove(libraryIndex);
+		emit layoutChanged();
+	}
+}
+
+/**
+ * @brief Gets a library by index.
+ * @warning Index is assumed to be valid.
+ * @param libraryIndex Index of the library
+ * @return const reference
+ */
 const Library& LibraryManager::library(int libraryIndex) const
 {
+	Q_ASSERT(isValidIndex(libraryIndex));
 	return this->libraries[libraryIndex];
 }
 
+/**
+ * @brief Changes the path of the specified library
+ * @param libraryIndex Index of the library
+ * @param path New path
+ */
 void LibraryManager::setLibraryPath(int libraryIndex, const QDir& path)
 {
 	if (this->isValidIndex(libraryIndex))
@@ -67,6 +115,11 @@
 	}
 }
 
+/**
+ * @brief Changes the role of the specified library
+ * @param libraryIndex Index of the library
+ * @param role New role
+ */
 void LibraryManager::setLibraryRole(int libraryIndex, const Library::Role role)
 {
 	if (this->isValidIndex(libraryIndex))
@@ -76,27 +129,71 @@
 	}
 }
 
+/**
+ * @brief Restores the libraries from the specified settings object. All unsaved
+ * changes are lost.
+ * @param settings Settings object to restore from.
+ */
 void LibraryManager::restoreFromSettings(QSettings* settings)
 {
 	this->libraries = settings->value("libraries").value<Libraries>();
 }
 
+/**
+ * @brief Saves the libraries to the specified settings object.
+ * @param settings Settings object to modify.
+ */
 void LibraryManager::storeToSettings(QSettings* settings)
 {
 	QVariant librariesValue = QVariant::fromValue(this->libraries);
 	settings->setValue("libraries", librariesValue);
 }
 
+/**
+ * @returns the amount of libraries
+ */
 int LibraryManager::count() const
 {
 	return this->libraries.size();
 }
 
-bool LibraryManager::isValidIndex(int libraryIndex)
+void LibraryManager::moveLibrary(const int libraryFromIndex, const int libraryToIndex)
+{
+	if (isValidIndex(libraryFromIndex) and
+		(isValidIndex(libraryToIndex) or libraryToIndex == count()) and
+		libraryFromIndex != libraryToIndex)
+	{
+		emit layoutAboutToBeChanged();
+		const Library library = this->library(libraryFromIndex);
+		if (libraryToIndex > libraryFromIndex)
+		{
+			this->libraries.insert(libraryToIndex, library);
+			this->libraries.removeAt(libraryFromIndex);
+		}
+		else if (libraryToIndex < libraryFromIndex)
+		{
+			this->libraries.removeAt(libraryFromIndex);
+			this->libraries.insert(libraryToIndex, library);
+		}
+		emit layoutChanged();
+	}
+}
+
+/**
+ * @brief Checks whether the specified index points to a valid library.
+ * @param libraryIndex Index to check
+ * @returns whether or not it is valid
+ */
+bool LibraryManager::isValidIndex(const int libraryIndex) const
 {
 	return libraryIndex >= 0 && libraryIndex < this->libraries.size();
 }
 
+/**
+ * @brief Gets a human-readable string for the specified role
+ * @param role Role to get a string for
+ * @returns string
+ */
 QString Library::libraryRoleName(const Role role)
 {
 	switch (role)
@@ -112,12 +209,24 @@
 	}
 }
 
+/**
+ * @brief Overload necessary to implement QAbstractTableModel
+ * @param index
+ * @return Item flags
+ */
 Qt::ItemFlags LibraryManager::flags(const QModelIndex& index) const
 {
 	Q_UNUSED(index);
 	return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
 }
 
+/**
+ * @brief Returns data needed to represent the libraries in a table. This function
+ * decides how data is represented in a table view.
+ * @param index Index to get data for
+ * @param role Role of the data (role as in Qt model-view role, not LDraw library role)
+ * @returns variant
+ */
 QVariant LibraryManager::data(const QModelIndex& index, int role) const
 {
 	if (role != Qt::DisplayRole)
@@ -140,6 +249,13 @@
 	}
 }
 
+/**
+ * @brief Returns header texts for a table view. We only implement column headers here.
+ * @param section Index of the column (can also be a row but we only have column headers)
+ * @param orientation Orientation (we only support horizontal orientation)
+ * @param role Role of the data (role as in Qt model-view role, not LDraw library role)
+ * @returns variant
+ */
 QVariant LibraryManager::headerData(int section, Qt::Orientation orientation, int role) const
 {
 	if (orientation == Qt::Horizontal and role == Qt::DisplayRole)
@@ -159,25 +275,44 @@
 	}
 }
 
-int LibraryManager::rowCount(const QModelIndex& parent) const
+/**
+ * @brief Overload necessary to implement QAbstractTableModel.
+ * @returns how many rows there are in the table. Since there is one row per library, this returns
+ * the amount of libraries.
+ */
+int LibraryManager::rowCount(const QModelIndex&) const
 {
-	Q_UNUSED(parent)
 	return this->count();
 }
 
-int LibraryManager::columnCount(const QModelIndex& parent) const
+/**
+ * @brief LibraryManager::columnCount
+ * @returns how many columns there are in the table.
+ */
+int LibraryManager::columnCount(const QModelIndex&) const
 {
-	Q_UNUSED(parent)
 	return 2;
 }
 
+/**
+ * @brief Signals view objects that the specified library has changed. This is necessary
+ * to update the table widget know when libraries are changed.
+ * @param libraryIndex Index of the library.
+ */
 void LibraryManager::signalLibraryChange(int libraryIndex)
 {
+	Q_ASSERT(isValidIndex(libraryIndex));
 	const QModelIndex topLeft = this->index(libraryIndex, 0);
-	const QModelIndex bottomRight = this->index(libraryIndex, columnCount() - 1);
+	const QModelIndex bottomRight = this->index(libraryIndex, columnCount({}) - 1);
 	emit dataChanged(topLeft, bottomRight);
 }
 
+/**
+ * @brief Overload for operator<< to allow serializing a library into the configuration file.
+ * @param stream Stream to write the library into
+ * @param library Library to write into the stream
+ * @returns the stream
+ */
 QDataStream& operator<<(QDataStream& stream, const Library& library)
 {
 	const QString path = library.path.absolutePath();
@@ -185,6 +320,12 @@
 	return stream << path << role;
 }
 
+/**
+ * @brief Overload for operator>> to allow serializing a library into the configuration file.
+ * @param stream Stream to read the library from
+ * @param library Library to obtain from the stream
+ * @returns the stream
+ */
 QDataStream& operator>>(QDataStream& stream, Library& library)
 {
 	QString path;