Add freeze feature

freeze.lua

@@ -0,0 +1,61 @@
+function classroom.is_frozen(player)
+	return minetest.is_yes(player:get_meta():get_string("classroom:frozen"))
+end
+
+minetest.register_entity("classroom:freeze", {
+	initial_properties = {
+		physical = true,
+		collisionbox = { -0.01, -0.01, -0.01, 0.01, 0.01, 0.01 },
+		visual = "sprite",
+		visual_size = { x = 0, y = 0 },
+		textures = { "blank.png" },
+		is_visible = true,
+		makes_footstep_sound = false,
+	},
+
+	on_step = function(self, dtime)
+		local player = self.pname and minetest.get_player_by_name(self.pname)
+		if not player or not classroom.is_frozen(player) then
+			self.object:remove()
+			return
+		end
+	end,
+
+	set_frozen_player = function(self, player)
+		self.pname = player:get_player_name()
+		player:set_attach(self.object, "", {x = 0, y = 0, z = 0 }, { x = 0, y = 0, z = 0 })
+	end,
+})
+
+function classroom.freeze(player)
+	player:get_meta():set_string("classroom:frozen", "true")
+
+	local parent = player:get_attach()
+	if parent and parent:get_luaentity() and
+			parent:get_luaentity().set_frozen_player then
+		-- Already attached
+		return
+	end
+
+	local obj = minetest.add_entity(player:get_pos(), "classroom:freeze")
+	obj:get_luaentity():set_frozen_player(player)
+end
+
+function classroom.unfreeze(player)
+	player:get_meta():set_string("classroom:frozen", "")
+
+	local pname = player:get_player_name()
+	local objects = minetest.get_objects_inside_radius(player:get_pos(), 2)
+	for i=1, #objects do
+		local entity = objects[i]:get_luaentity()
+		if entity and entity.set_frozen_player and entity.pname == pname then
+			objects[i]:remove()
+		end
+	end
+end
+
+minetest.register_on_joinplayer(function(player)
+	if classroom.is_frozen(player) then
+		classroom.freeze(player)
+	end
+end)

gui_dash.lua

@@ -258,8 +258,8 @@ local function get_formspec(player, context)
 
 		for _, action in pairs(classroom.get_actions()) do
 			btn.state = "active"
-			btn.name  = action.name
-			btn.text = minetest.formspec_escape(action.title)
+			btn.name  = "action_" .. action.name
+			btn.text  = minetest.formspec_escape(action.title)
 			btn.tooltip = minetest.formspec_escape(action.description)
 			fs[#fs + 1] = button(btn)
 

init.lua

@@ -13,6 +13,7 @@ end
 dofile(minetest.get_modpath("classroom") .. "/api.lua")
 dofile(minetest.get_modpath("classroom") .. "/gui_dash.lua")
 dofile(minetest.get_modpath("classroom") .. "/gui_group.lua")
+dofile(minetest.get_modpath("classroom") .. "/freeze.lua")
 dofile(minetest.get_modpath("classroom") .. "/actions.lua")
 
 -- Privileges