GH-1227: World import using drag and drop - zip files and folders

15 files changed, 336 insertions, 112 deletions

diff --git a/application/GuiUtil.cpp b/application/GuiUtil.cpp
index 922d38fa..edfe9951 100644
--- a/application/GuiUtil.cpp
+++ b/application/GuiUtil.cpp
@@ -51,14 +51,13 @@ void GuiUtil::setClipboardText(const QString &text)
 	QApplication::clipboard()->setText(text);
 }
 
-QStringList GuiUtil::BrowseForMods(QString context, QString caption, QString filter,
-								   QWidget *parentWidget)
+
+QStringList GuiUtil::BrowseForFiles(QString context, QString caption, QString filter, QString defaultPath, QWidget *parentWidget)
 {
 	static QMap<QString, QString> savedPaths;
 
 	QFileDialog w(parentWidget, caption);
 	QSet<QString> locations;
-	QString modsFolder = MMC->settings()->get("CentralModsDir").toString();
 	auto f = [&](QStandardPaths::StandardLocation l)
 	{
 		QString location = QStandardPaths::writableLocation(l);
@@ -76,19 +75,30 @@ QStringList GuiUtil::BrowseForMods(QString context, QString caption, QString fil
 	{
 		urls.append(QUrl::fromLocalFile(location));
 	}
-	urls.append(QUrl::fromLocalFile(modsFolder));
+	urls.append(QUrl::fromLocalFile(defaultPath));
 
 	w.setFileMode(QFileDialog::ExistingFiles);
 	w.setAcceptMode(QFileDialog::AcceptOpen);
 	w.setNameFilter(filter);
+
+	QString pathToOpen;
 	if(savedPaths.contains(context))
 	{
-		w.setDirectory(savedPaths[context]);
+		pathToOpen = savedPaths[context];
 	}
 	else
 	{
-		w.setDirectory(modsFolder);
+		pathToOpen = defaultPath;
 	}
+	if(!pathToOpen.isEmpty())
+	{
+		QFileInfo finfo(pathToOpen);
+		if(finfo.exists() && finfo.isDir())
+		{
+			w.setDirectory(finfo.absoluteFilePath());
+		}
+	}
+
 	w.setSidebarUrls(urls);
 
 	if (w.exec())
diff --git a/application/GuiUtil.h b/application/GuiUtil.h
index 4c8bdaa7..381683e4 100644
--- a/application/GuiUtil.h
+++ b/application/GuiUtil.h
@@ -6,5 +6,5 @@ namespace GuiUtil
 {
 void uploadPaste(const QString &text, QWidget *parentWidget);
 void setClipboardText(const QString &text);
-QStringList BrowseForMods(QString context, QString caption, QString filter, QWidget *parentWidget);
+QStringList BrowseForFiles(QString context, QString caption, QString filter, QString defaultPath, QWidget *parentWidget);
 }
diff --git a/application/pages/LegacyJarModPage.cpp b/application/pages/LegacyJarModPage.cpp
index 92977de9..87a9f3b5 100644
--- a/application/pages/LegacyJarModPage.cpp
+++ b/application/pages/LegacyJarModPage.cpp
@@ -100,7 +100,7 @@ bool LegacyJarModPage::eventFilter(QObject *obj, QEvent *ev)
 
 void LegacyJarModPage::on_addJarBtn_clicked()
 {
-	auto list = GuiUtil::BrowseForMods("jarmod", tr("Select jar mods"), tr("Minecraft.jar mods (*.zip *.jar)"), this->parentWidget());
+	auto list = GuiUtil::BrowseForFiles("jarmod", tr("Select jar mods"), tr("Minecraft.jar mods (*.zip *.jar)"), MMC->settings()->get("CentralModsDir").toString(), this->parentWidget());
 	if(!list.empty())
 	{
 		m_jarmods->stopWatching();
diff --git a/application/pages/ModFolderPage.cpp b/application/pages/ModFolderPage.cpp
index a70c1620..9a2a43a4 100644
--- a/application/pages/ModFolderPage.cpp
+++ b/application/pages/ModFolderPage.cpp
@@ -131,12 +131,13 @@ bool ModFolderPage::eventFilter(QObject *obj, QEvent *ev)
 
 void ModFolderPage::on_addModBtn_clicked()
 {
-	auto list = GuiUtil::BrowseForMods(
+	auto list = GuiUtil::BrowseForFiles(
 		m_helpName,
 		tr("Select %1",
 		   "Select whatever type of files the page contains. Example: 'Loader Mods'")
 			.arg(m_displayName),
-		m_filter.arg(m_displayName), this->parentWidget());
+		m_filter.arg(m_displayName), MMC->settings()->get("CentralModsDir").toString(),
+		this->parentWidget());
 	if (!list.empty())
 	{
 		m_mods->stopWatching();
@@ -146,8 +147,8 @@ void ModFolderPage::on_addModBtn_clicked()
 		}
 		m_mods->startWatching();
 	}
-
 }
+
 void ModFolderPage::on_rmModBtn_clicked()
 {
 	int first, last;
diff --git a/application/pages/VersionPage.cpp b/application/pages/VersionPage.cpp
index d56bbd28..36091630 100644
--- a/application/pages/VersionPage.cpp
+++ b/application/pages/VersionPage.cpp
@@ -180,7 +180,7 @@ void VersionPage::on_jarmodBtn_clicked()
 			nagShown = true;
 		}
 	}
-	auto list = GuiUtil::BrowseForMods("jarmod", tr("Select jar mods"), tr("Minecraft.jar mods (*.zip *.jar)"), this->parentWidget());
+	auto list = GuiUtil::BrowseForFiles("jarmod", tr("Select jar mods"), tr("Minecraft.jar mods (*.zip *.jar)"), MMC->settings()->get("CentralModsDir").toString(), this->parentWidget());
 	if(!list.empty())
 	{
 		m_version->installJarMods(list);
diff --git a/application/pages/WorldListPage.cpp b/application/pages/WorldListPage.cpp
index 8b95b2b0..be1d58b8 100644
--- a/application/pages/WorldListPage.cpp
+++ b/application/pages/WorldListPage.cpp
@@ -25,6 +25,7 @@
 
 
 #include "MultiMC.h"
+#include <GuiUtil.h>
 
 WorldListPage::WorldListPage(BaseInstance *inst, std::shared_ptr<WorldList> worlds, QString id,
 							 QString iconName, QString displayName, QString helpPage,
@@ -67,8 +68,6 @@ WorldListPage::~WorldListPage()
 
 bool WorldListPage::shouldDisplay() const
 {
-	if (m_inst)
-		return !m_inst->isRunning();
 	return true;
 }
 
@@ -200,3 +199,20 @@ void WorldListPage::worldChanged(const QModelIndex &current, const QModelIndex &
 	ui->mcEditBtn->setEnabled(enable);
 	ui->rmWorldBtn->setEnabled(enable);
 }
+
+void WorldListPage::on_addBtn_clicked()
+{
+	auto list = GuiUtil::BrowseForFiles(
+		m_helpName,
+		tr("Select a Minecraft world zip"),
+		tr("Minecraft World Zip File (*.zip)"), QString(), this->parentWidget());
+	if (!list.empty())
+	{
+		m_worlds->stopWatching();
+		for (auto filename : list)
+		{
+			m_worlds->installWorld(QFileInfo(filename));
+		}
+		m_worlds->startWatching();
+	}
+}
\ No newline at end of file
diff --git a/application/pages/WorldListPage.h b/application/pages/WorldListPage.h
index c79f1be6..f3111f93 100644
--- a/application/pages/WorldListPage.h
+++ b/application/pages/WorldListPage.h
@@ -81,6 +81,7 @@ private slots:
 	void on_copySeedBtn_clicked();
 	void on_mcEditBtn_clicked();
 	void on_rmWorldBtn_clicked();
+	void on_addBtn_clicked();
 	void on_viewFolderBtn_clicked();
 	void worldChanged(const QModelIndex &current, const QModelIndex &previous);
 };
diff --git a/application/pages/WorldListPage.ui b/application/pages/WorldListPage.ui
index 9d396fa6..ecd9709f 100644
--- a/application/pages/WorldListPage.ui
+++ b/application/pages/WorldListPage.ui
@@ -48,7 +48,7 @@
           <bool>true</bool>
          </property>
          <property name="dragDropMode">
-          <enum>QAbstractItemView::DropOnly</enum>
+          <enum>QAbstractItemView::DragDrop</enum>
          </property>
          <property name="sortingEnabled">
           <bool>true</bool>
@@ -64,23 +64,33 @@
        <item row="0" column="1">
         <layout class="QVBoxLayout" name="verticalLayout_2">
          <item>
-          <widget class="QPushButton" name="mcEditBtn">
+          <widget class="QPushButton" name="addBtn">
            <property name="text">
-            <string>MCEdit</string>
+            <string>Add</string>
            </property>
           </widget>
          </item>
          <item>
-          <widget class="QPushButton" name="copySeedBtn">
+          <widget class="QPushButton" name="rmWorldBtn">
            <property name="text">
-            <string>Copy Seed</string>
+            <string>&amp;Remove</string>
            </property>
           </widget>
          </item>
          <item>
-          <widget class="QPushButton" name="rmWorldBtn">
+          <widget class="LineSeparator" name="separator" native="true"/>
+         </item>
+         <item>
+          <widget class="QPushButton" name="mcEditBtn">
            <property name="text">
-            <string>&amp;Remove</string>
+            <string>MCEdit</string>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QPushButton" name="copySeedBtn">
+           <property name="text">
+            <string>Copy Seed</string>
            </property>
           </widget>
          </item>
@@ -112,12 +122,21 @@
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>LineSeparator</class>
+   <extends>QWidget</extends>
+   <header>widgets/LineSeparator.h</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
  <tabstops>
   <tabstop>tabWidget</tabstop>
   <tabstop>worldTreeView</tabstop>
+  <tabstop>addBtn</tabstop>
+  <tabstop>rmWorldBtn</tabstop>
   <tabstop>mcEditBtn</tabstop>
   <tabstop>copySeedBtn</tabstop>
-  <tabstop>rmWorldBtn</tabstop>
   <tabstop>viewFolderBtn</tabstop>
  </tabstops>
  <resources/>
diff --git a/depends/util/include/pathutils.h b/depends/util/include/pathutils.h
index f31b96d1..82d55cd7 100644
--- a/depends/util/include/pathutils.h
+++ b/depends/util/include/pathutils.h
@@ -54,7 +54,7 @@ LIBUTIL_EXPORT bool ensureFolderPathExists(QString filenamepath);
 /**
  * Copy a folder recursively
  */
-LIBUTIL_EXPORT bool copyPath(QString src, QString dst, bool follow_symlinks = true);
+LIBUTIL_EXPORT bool copyPath(const QString &src, const QString &dst, bool follow_symlinks = true);
 
 /**
  * Delete a folder recursively
diff --git a/depends/util/src/pathutils.cpp b/depends/util/src/pathutils.cpp
index ce9138be..35c7f901 100644
--- a/depends/util/src/pathutils.cpp
+++ b/depends/util/src/pathutils.cpp
@@ -81,16 +81,24 @@ QString RemoveInvalidFilenameChars(QString string, QChar replaceWith)
 QString DirNameFromString(QString string, QString inDir)
 {
 	int num = 0;
-	QString dirName = RemoveInvalidFilenameChars(string, '-');
-	while (QFileInfo(PathCombine(inDir, dirName)).exists())
+	QString baseName = RemoveInvalidFilenameChars(string, '-');
+	QString dirName;
+	do
 	{
-		num++;
-		dirName = RemoveInvalidFilenameChars(dirName, '-') + QString::number(num);
+		if(num == 0)
+		{
+			dirName = baseName;
+		}
+		else
+		{
+			dirName = baseName + QString::number(num);;
+		}
 
 		// If it's over 9000
 		if (num > 9000)
 			return "";
-	}
+		num++;
+	} while (QFileInfo(PathCombine(inDir, dirName)).exists());
 	return dirName;
 }
 
@@ -112,7 +120,7 @@ bool ensureFolderPathExists(QString foldernamepath)
 	return success;
 }
 
-bool copyPath(QString src, QString dst, bool follow_symlinks)
+bool copyPath(const QString &src, const QString &dst, bool follow_symlinks)
 {
 	//NOTE always deep copy on windows. the alternatives are too messy.
 	#if defined Q_OS_WIN32
@@ -127,21 +135,26 @@ bool copyPath(QString src, QString dst, bool follow_symlinks)
 
 	bool OK = true;
 
+	qDebug() << "Looking at " << dir.absolutePath();
 	foreach(QString f, dir.entryList(QDir::Files | QDir::Dirs | QDir::NoDotAndDotDot | QDir::Hidden | QDir::System))
 	{
 		QString inner_src = src + QDir::separator() + f;
 		QString inner_dst = dst + QDir::separator() + f;
+		qDebug() << f << "translates to"<< inner_src << "to" << inner_dst;
 		QFileInfo fileInfo(inner_src);
 		if(!follow_symlinks && fileInfo.isSymLink())
 		{
+			qDebug() << "creating symlink" << inner_src << " - " << inner_dst;
 			OK &= QFile::link(fileInfo.symLinkTarget(),inner_dst);
 		}
 		else if (fileInfo.isDir())
 		{
+			qDebug() << "recursing" << inner_src << " - " << inner_dst;
 			OK &= copyPath(inner_src, inner_dst, follow_symlinks);
 		}
 		else if (fileInfo.isFile())
 		{
+			qDebug() << "copying file" << inner_src << " - " << inner_dst;
 			OK &= QFile::copy(inner_src, inner_dst);
 		}
 		else
diff --git a/logic/minecraft/ModList.cpp b/logic/minecraft/ModList.cpp
index a77c5890..8f1bc041 100644
--- a/logic/minecraft/ModList.cpp
+++ b/logic/minecraft/ModList.cpp
@@ -539,6 +539,7 @@ QMimeData *ModList::mimeData(const QModelIndexList &indexes) const
 	data->setText(params.join('|'));
 	return data;
 }
+
 bool ModList::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column,
 						   const QModelIndex &parent)
 {
diff --git a/logic/minecraft/World.cpp b/logic/minecraft/World.cpp
index 977a03cf..3b66f113 100644
--- a/logic/minecraft/World.cpp
+++ b/logic/minecraft/World.cpp
@@ -20,10 +20,13 @@
 #include <pathutils.h>
 
 #include "GZip.h"
+#include <MMCZip.h>
 #include <sstream>
 #include <io/stream_reader.h>
 #include <tag_string.h>
 #include <tag_primitive.h>
+#include <quazip.h>
+#include <quazipfile.h>
 
 World::World(const QFileInfo &file)
 {
@@ -32,8 +35,20 @@ World::World(const QFileInfo &file)
 
 void World::repath(const QFileInfo &file)
 {
-	m_file = file;
+	m_containerFile = file;
 	m_folderName = file.fileName();
+	if(file.isFile() && file.suffix() == "zip")
+	{
+		readFromZip(file);
+	}
+	else if(file.isDir())
+	{
+		readFromFS(file);
+	}
+}
+
+void World::readFromFS(const QFileInfo &file)
+{
 	QDir worldDir(file.filePath());
 	is_valid = file.isDir() && worldDir.exists("level.dat");
 	if(!is_valid)
@@ -48,66 +63,123 @@ void World::repath(const QFileInfo &file)
 	{
 		return;
 	}
+	QFileInfo finfo(fullFilePath);
+	levelDatTime = finfo.lastModified();
+	parseLevelDat(f.readAll());
+}
 
-	QByteArray output;
-	is_valid = GZip::inflate(f.readAll(), output);
-	if(!is_valid)
+void World::readFromZip(const QFileInfo &file)
+{
+	QuaZip zip(file.absoluteFilePath());
+	is_valid = zip.open(QuaZip::mdUnzip);
+	if (!is_valid)
+	{
+		return;
+	}
+	QuaZipFile zippedFile(&zip);
+	// read the install profile
+	is_valid = zip.setCurrentFile("level.dat");
+	if (!is_valid)
 	{
 		return;
 	}
-	f.close();
+	is_valid = zippedFile.open(QIODevice::ReadOnly);
+	QuaZipFileInfo64 levelDatInfo;
+	zippedFile.getFileInfo(&levelDatInfo);
+	auto modTime = levelDatInfo.getNTFSmTime();
+	if(!modTime.isValid())
+	{
+		modTime = levelDatInfo.dateTime;
+	}
+	levelDatTime = modTime;
+	if (!is_valid)
+	{
+		return;
+	}
+	parseLevelDat(zippedFile.readAll());
+	zippedFile.close();
+}
 
-	auto read_string = [](nbt::value& parent, const char * name, const QString & fallback = QString()) -> QString
+bool World::install(QString to)
+{
+	auto finalPath = PathCombine(to, DirNameFromString(m_actualName, to));
+	if(!ensureFolderPathExists(finalPath))
 	{
-		try
-		{
-			auto &namedValue = parent.at(name);
-			if(namedValue.get_type() != nbt::tag_type::String)
-			{
-				return fallback;
-			}
-			auto & tag_str = namedValue.as<nbt::tag_string>();
-			return QString::fromStdString(tag_str.get());
-		}
-		catch(std::out_of_range e)
-		{
-			// fallback for old world formats
-			qWarning() << "String NBT tag" << name << "could not be found. Defaulting to" << fallback;
-			return fallback;
-		}
-		catch(std::bad_cast e)
-		{
-			// type mismatch
-			qWarning() << "NBT tag" << name << "could not be converted to string. Defaulting to" << fallback;
-			return fallback;
-		}
-	};
+		return false;
+	}
+	if(m_containerFile.isFile())
+	{
+		// FIXME: check if this is OK.
+		return !MMCZip::extractDir(m_containerFile.absoluteFilePath(), finalPath).isEmpty();
+	}
+	else if(m_containerFile.isDir())
+	{
+		QString from = m_containerFile.filePath();
+		return copyPath(from, finalPath);
+	}
+	return false;
+}
 
-	auto read_long = [](nbt::value& parent, const char * name, const int64_t & fallback = 0) -> int64_t
+static QString read_string (nbt::value& parent, const char * name, const QString & fallback = QString())
+{
+	try
 	{
-		try
-		{
-			auto &namedValue = parent.at(name);
-			if(namedValue.get_type() != nbt::tag_type::Long)
-			{
-				return fallback;
-			}
-			auto & tag_str = namedValue.as<nbt::tag_long>();
-			return tag_str.get();
-		}
-		catch(std::out_of_range e)
+		auto &namedValue = parent.at(name);
+		if(namedValue.get_type() != nbt::tag_type::String)
 		{
-			// fallback for old world formats
-			qWarning() << "Long NBT tag" << name << "could not be found. Defaulting to" << fallback;
 			return fallback;
 		}
-		catch(std::bad_cast e)
+		auto & tag_str = namedValue.as<nbt::tag_string>();
+		return QString::fromStdString(tag_str.get());
+	}
+	catch(std::out_of_range e)
+	{
+		// fallback for old world formats
+		qWarning() << "String NBT tag" << name << "could not be found. Defaulting to" << fallback;
+		return fallback;
+	}
+	catch(std::bad_cast e)
+	{
+		// type mismatch
+		qWarning() << "NBT tag" << name << "could not be converted to string. Defaulting to" << fallback;
+		return fallback;
+	}
+};
+
+static int64_t read_long (nbt::value& parent, const char * name, const int64_t & fallback = 0)
+{
+	try
+	{
+		auto &namedValue = parent.at(name);
+		if(namedValue.get_type() != nbt::tag_type::Long)
 		{
-			// type mismatch
-			qWarning() << "NBT tag" << name << "could not be converted to long. Defaulting to" << fallback;
 			return fallback;
 		}
-	};
+		auto & tag_str = namedValue.as<nbt::tag_long>();
+		return tag_str.get();
+	}
+	catch(std::out_of_range e)
+	{
+		// fallback for old world formats
+		qWarning() << "Long NBT tag" << name << "could not be found. Defaulting to" << fallback;
+		return fallback;
+	}
+	catch(std::bad_cast e)
+	{
+		// type mismatch
+		qWarning() << "NBT tag" << name << "could not be converted to long. Defaulting to" << fallback;
+		return fallback;
+	}
+};
+
+void World::parseLevelDat(QByteArray data)
+{
+	QByteArray output;
+	is_valid = GZip::inflate(data, output);
+	if(!is_valid)
+	{
+		return;
+	}
 
 	try
 	{
@@ -138,8 +210,7 @@ void World::repath(const QFileInfo &file)
 		int64_t temp = read_long(val, "LastPlayed", 0);
 		if(temp == 0)
 		{
-			QFileInfo finfo(fullFilePath);
-			m_lastPlayed = finfo.lastModified();
+			m_lastPlayed = levelDatTime;
 		}
 		else
 		{
@@ -164,11 +235,11 @@ bool World::replace(World &with)
 {
 	if (!destroy())
 		return false;
-	bool success = copyPath(with.m_file.filePath(), m_file.path());
+	bool success = copyPath(with.m_containerFile.filePath(), m_containerFile.path());
 	if (success)
 	{
 		m_folderName = with.m_folderName;
-		m_file.refresh();
+		m_containerFile.refresh();
 	}
 	return success;
 }
@@ -176,18 +247,15 @@ bool World::replace(World &with)
 bool World::destroy()
 {
 	if(!is_valid) return false;
-	if (m_file.isDir())
+	if (m_containerFile.isDir())
 	{
-		QDir d(m_file.filePath());
-		if (d.removeRecursively())
-		{
-			return true;
-		}
-		return false;
+		QDir d(m_containerFile.filePath());
+		return d.removeRecursively();
 	}
-	else
+	else if(m_containerFile.isFile())
 	{
-		return false;
+		QFile file(m_containerFile.absoluteFilePath());
+		return file.remove();
 	}
 	return true;
 }
diff --git a/logic/minecraft/World.h b/logic/minecraft/World.h
index 91cb2a83..27184e05 100644
--- a/logic/minecraft/World.h
+++ b/logic/minecraft/World.h
@@ -48,15 +48,23 @@ public:
 	// change the world's filesystem path (used by world lists for *MAGIC* purposes)
 	void repath(const QFileInfo &file);
 
+	bool install(QString to);
+
 	// WEAK compare operator - used for replacing worlds
 	bool operator==(const World &other) const;
 	bool strongCompare(const World &other) const;
 
+private:
+	void readFromZip(const QFileInfo &file);
+	void readFromFS(const QFileInfo &file);
+	void parseLevelDat(QByteArray data);
+
 protected:
 
-	QFileInfo m_file;
+	QFileInfo m_containerFile;
 	QString m_folderName;
 	QString m_actualName;
+	QDateTime levelDatTime;
 	QDateTime m_lastPlayed;
 	int64_t m_randomSeed = 0;
 	bool is_valid = false;
diff --git a/logic/minecraft/WorldList.cpp b/logic/minecraft/WorldList.cpp
index 7066093c..1c25f3b1 100644
--- a/logic/minecraft/WorldList.cpp
+++ b/logic/minecraft/WorldList.cpp
@@ -62,40 +62,28 @@ void WorldList::stopWatching()
 	}
 }
 
-void WorldList::internalSort(QList<World> &what)
-{
-	auto predicate = [](const World &left, const World &right)
-	{
-		return left.folderName().localeAwareCompare(right.folderName()) < 0;
-	};
-	std::sort(what.begin(), what.end(), predicate);
-}
-
 bool WorldList::update()
 {
 	if (!isValid())
 		return false;
 
-	QList<World> orderedWorlds;
 	QList<World> newWorlds;
 	m_dir.refresh();
 	auto folderContents = m_dir.entryInfoList();
 	// if there are any untracked files...
-	if (folderContents.size())
+	for (QFileInfo entry : folderContents)
 	{
-		// the order surely changed!
-		for (auto entry : folderContents)
+		if(!entry.isDir())
+			continue;
+
+		World w(entry);
+		if(w.isValid())
 		{
-			World w(entry);
-			if(w.isValid()) {
-				newWorlds.append(w);
-			}
+			newWorlds.append(w);
 		}
-		internalSort(newWorlds);
-		orderedWorlds.append(newWorlds);
 	}
 	beginResetModel();
-	worlds.swap(orderedWorlds);
+	worlds.swap(newWorlds);
 	endResetModel();
 	return true;
 }
@@ -232,6 +220,7 @@ QStringList WorldList::mimeTypes() const
 {
 	QStringList types;
 	types << "text/plain";
+	types << "text/uri-list";
 	return types;
 }
 
@@ -250,3 +239,90 @@ QMimeData *WorldList::mimeData(const QModelIndexList &indexes) const
 	data->setText(QString::number(row));
 	return data;
 }
+
+Qt::ItemFlags WorldList::flags(const QModelIndex &index) const
+{
+	Qt::ItemFlags defaultFlags = QAbstractListModel::flags(index);
+	if (index.isValid())
+		return Qt::ItemIsUserCheckable | Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled |
+			   defaultFlags;
+	else
+		return Qt::ItemIsDropEnabled | defaultFlags;
+}
+
+Qt::DropActions WorldList::supportedDragActions() const
+{
+	// move to other mod lists or VOID
+	return Qt::MoveAction;
+}
+
+Qt::DropActions WorldList::supportedDropActions() const
+{
+	// copy from outside, move from within and other mod lists
+	return Qt::CopyAction | Qt::MoveAction;
+}
+
+void WorldList::installWorld(QFileInfo filename)
+{
+	qDebug() << "installing: " << filename.absoluteFilePath();
+	World w(filename);
+	if(!w.isValid())
+	{
+		return;
+	}
+	w.install(m_dir.absolutePath());
+}
+
+bool WorldList::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column,
+							 const QModelIndex &parent)
+{
+	if (action == Qt::IgnoreAction)
+		return true;
+	// check if the action is supported
+	if (!data || !(action & supportedDropActions()))
+		return false;
+	// files dropped from outside?
+	if (data->hasUrls())
+	{
+		bool was_watching = is_watching;
+		if (was_watching)
+			stopWatching();
+		auto urls = data->urls();
+		for (auto url : urls)
+		{
+			// only local files may be dropped...
+			if (!url.isLocalFile())
+				continue;
+			QString filename = url.toLocalFile();
+
+			QFileInfo worldInfo(filename);
+			installWorld(worldInfo);
+		}
+		if (was_watching)
+			startWatching();
+		return true;
+	}
+	/*
+	else if (data->hasText())
+	{
+		QString sourcestr = data->text();
+		auto list = sourcestr.split('|');
+		if (list.size() != 2)
+			return false;
+		QString remoteId = list[0];
+		int remoteIndex = list[1].toInt();
+		qDebug() << "move: " << sourcestr;
+		// no moving of things between two lists
+		if (remoteId != m_list_id)
+			return false;
+		// no point moving to the same place...
+		if (row == remoteIndex)
+			return false;
+		// otherwise, move the mod :D
+		moveModTo(remoteIndex, row);
+		return true;
+	}
+	*/
+	return false;
+
+}
diff --git a/logic/minecraft/WorldList.h b/logic/minecraft/WorldList.h
index 7f119e81..90c7c6ed 100644
--- a/logic/minecraft/WorldList.h
+++ b/logic/minecraft/WorldList.h
@@ -19,6 +19,7 @@
 #include <QString>
 #include <QDir>
 #include <QAbstractListModel>
+#include <QMimeData>
 #include "minecraft/World.h"
 
 #include "multimc_logic_export.h"
@@ -71,16 +72,28 @@ public:
 	/// Reloads the mod list and returns true if the list changed.
 	virtual bool update();
 
+	/// Install a world from location
+	void installWorld(QFileInfo filename);
+
 	/// Deletes the mod at the given index.
 	virtual bool deleteWorld(int index);
 
 	/// Deletes all the selected mods
 	virtual bool deleteWorlds(int first, int last);
 
+	/// flags, mostly to support drag&drop
+	virtual Qt::ItemFlags flags(const QModelIndex &index) const;
 	/// get data for drag action
 	virtual QMimeData *mimeData(const QModelIndexList &indexes) const;
 	/// get the supported mime types
 	virtual QStringList mimeTypes() const;
+	/// process data from drop action
+	virtual bool dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent);
+	/// what drag actions do we support?
+	virtual Qt::DropActions supportedDragActions() const;
+
+	/// what drop actions do we support?
+	virtual Qt::DropActions supportedDropActions() const;
 
 	void startWatching();
 	void stopWatching();
@@ -97,8 +110,6 @@ public:
 		return worlds;
 	}
 
-private:
-	void internalSort(QList<World> &what);
 private slots:
 	void directoryChanged(QString path);