Improve behaviour for empty modpacks and when no mods at all are installed:

Only show enable all / disable all buttons for all add-ons when at
least one add-on is installed. When no add-on ist installed, don't
show any buttons or checkboxes.

Added is_modpack flag to ModSpec to distinguish empty modpacks from
normal mods and check this flag in mod selection gui so that empty
modpacks are not treated like mods that can be enabled or disabled.

src/guiConfigureWorld.cpp

@@ -69,15 +69,13 @@ GUIConfigureWorld::GUIConfigureWorld(gui::IGUIEnvironment* env,
 	m_worldmods = flattenModTree(getModsInPath(worldmods_path));
 
 	// fill m_addontree with add-on mods
-	ModSpec addons("Add-Ons");
 	std::set<std::string> paths = m_gspec.addon_mods_paths;
 	for(std::set<std::string>::iterator it=paths.begin();
 		it != paths.end(); ++it)
 	{
 		std::map<std::string,ModSpec> mods = getModsInPath(*it);
-		addons.modpack_content.insert(mods.begin(), mods.end());
+		m_addontree.insert(mods.begin(), mods.end());
 	}
-	m_addontree.insert(std::make_pair(addons.name,addons));
 
 	// expand modpacks
 	m_addonmods = flattenModTree(m_addontree);
@@ -116,7 +114,7 @@ GUIConfigureWorld::GUIConfigureWorld(gui::IGUIEnvironment* env,
 		ModSpec mod = (*it).second;
 		// a mod is new if it is not a modpack, and does not occur in
 		// mod_names
-		if(mod.modpack_content.empty() &&
+		if(!mod.is_modpack &&
 		   mod_names.count(modname) == 0)
 			m_new_mod_names.insert(modname);
 	}
@@ -253,7 +251,9 @@ void GUIConfigureWorld::regenerateGui(v2u32 screensize)
 		rect += v2s32(220, 0) + topleft;
 		m_treeview = Environment->addTreeView(rect, this,
 											  GUI_ID_MOD_TREEVIEW,true);
-		buildTreeView(m_addontree, m_treeview->getRoot());
+		gui::IGUITreeViewNode* node 
+			= m_treeview->getRoot()->addChildBack(L"Add-Ons");
+		buildTreeView(m_addontree, node);
 	}
 	{
 		core::rect<s32> rect(0, 0, 120, 30);
@@ -407,7 +407,11 @@ bool GUIConfigureWorld::OnEvent(const SEvent& event)
 				return true;
 			}
 			case GUI_ID_ENABLEALL: {
-				if(selected_node != NULL && selected_node->getText() != NULL)
+				if(selected_node != NULL && selected_node->getParent() == m_treeview->getRoot())
+				{  
+					enableAllMods(m_addonmods,true);
+				} 
+				else if(selected_node != NULL && selected_node->getText() != NULL)
 				{  
 					std::string modname = wide_to_narrow(selected_node->getText());
 					ModSpec mod = m_addonmods[modname];
@@ -416,6 +420,10 @@ bool GUIConfigureWorld::OnEvent(const SEvent& event)
 				return true;
 			}
 			case GUI_ID_DISABLEALL: {
+				if(selected_node != NULL && selected_node->getParent() == m_treeview->getRoot())
+				{
+					enableAllMods(m_addonmods,false);
+				} 
 				if(selected_node != NULL && selected_node->getText() != NULL)
 				{
 					std::string modname = wide_to_narrow(selected_node->getText());
@@ -517,7 +525,7 @@ void GUIConfigureWorld::buildTreeView(std::map<std::string, ModSpec> mods,
 		gui::IGUITreeViewNode* new_node = 
 			node->addChildBack(narrow_to_wide(modname).c_str());
 		m_nodes.insert(std::make_pair(modname, new_node));
-		if(!mod.modpack_content.empty())
+		if(mod.is_modpack)
 			buildTreeView(mod.modpack_content, new_node);
 		else
 		{
@@ -552,9 +560,19 @@ void GUIConfigureWorld::adjustSidebar()
 		modname_w = L"N/A";
 	std::string modname = wide_to_narrow(modname_w);
 
+	// if no mods installed, don't show buttons or checkbox on the sidebar
+	if(node->getParent() == m_treeview->getRoot() && !node->hasChilds())
+	{
+		m_disableall->setVisible(false);
+		m_enableall->setVisible(false);
+		m_enabled_checkbox->setVisible(false);
+	} 
+	else
+	{
 		// if modpack, show enable/disable all buttons. otherwise, show
 		// enabled checkbox
-	if(node->hasChilds())
+		if(node->getParent() == m_treeview->getRoot() ||
+		   m_addonmods[modname].is_modpack)
 		{
 			m_enabled_checkbox->setVisible(false);
 			m_disableall->setVisible(true);
@@ -568,7 +586,7 @@ void GUIConfigureWorld::adjustSidebar()
 			m_enabled_checkbox->setVisible(true);
 			m_modname_text->setText((L"Mod: "+modname_w).c_str());
 		}
-
+	}
 	// the mod is enabled unless it is disabled in the world.mt settings. 
 	bool mod_enabled = true;
 	if(m_settings.exists("load_mod_"+modname))
@@ -616,7 +634,7 @@ void GUIConfigureWorld::enableAllMods(std::map<std::string, ModSpec> mods,bool e
 		it != mods.end(); ++it)
 	{
 		ModSpec mod = (*it).second;
-		if(!mod.modpack_content.empty()) 
+		if(mod.is_modpack) 
 			// a modpack, recursively enable all mods in it
 			enableAllMods(mod.modpack_content,enable);
 		else // not a modpack

src/mods.cpp

@@ -46,6 +46,7 @@ std::map<std::string, ModSpec> getModsInPath(std::string path)
 			modpack_is.close(); // We don't actually need the file
 			ModSpec spec(modname,modpath);
 			spec.modpack_content = getModsInPath(modpath);
+			spec.is_modpack = true;
 			result.insert(std::make_pair(modname,spec));
 		}
 		else // not a modpack, add the modspec
@@ -76,7 +77,7 @@ std::map<std::string, ModSpec> flattenModTree(std::map<std::string, ModSpec> mod
 		it != mods.end(); ++it)
 	{
 		ModSpec mod = (*it).second;
-		if(!mod.modpack_content.empty()) //is a modpack
+		if(mod.is_modpack)
 		{
 			std::map<std::string, ModSpec> content = 
 				flattenModTree(mod.modpack_content);
@@ -98,7 +99,7 @@ std::vector<ModSpec> flattenMods(std::map<std::string, ModSpec> mods)
 		it != mods.end(); ++it)
 	{
 		ModSpec mod = (*it).second;
-		if(!mod.modpack_content.empty()) //is a modpack
+		if(mod.is_modpack)
 		{
 			std::vector<ModSpec> content = flattenMods(mod.modpack_content);
 			result.reserve(result.size() + content.size());

src/mods.h

@@ -53,6 +53,8 @@ struct ModSpec
 	//if normal mod:
 	std::set<std::string> depends;
 	std::set<std::string> unsatisfied_depends;
+
+	bool is_modpack;
 	// if modpack:
 	std::map<std::string,ModSpec> modpack_content;
 	ModSpec(const std::string name_="", const std::string path_="",
@@ -61,6 +63,7 @@ struct ModSpec
 		path(path_),
 		depends(depends_),
 		unsatisfied_depends(depends_),
+		is_modpack(false),	
 		modpack_content()	
 	{}
 };