Add screenshots to online content browser

builtin/mainmenu/dlg_contentstore.lua

@@ -18,6 +18,13 @@
 local store = {}
 local package_dialog = {}
 
+-- Screenshot
+local screenshot_dir = os.tempfolder()
+assert(core.create_dir(screenshot_dir))
+local screenshot_downloading = {}
+local screenshot_downloaded = {}
+
+-- Filter
 local search_string = ""
 local cur_page = 1
 local num_per_page = 5
@@ -137,6 +144,58 @@ local function start_install(calling_dialog, package)
 	new_dlg:show()
 end
 
+local function get_screenshot(package)
+	if #package.screenshots == 0 then
+		return defaulttexturedir .. "no_screenshot.png"
+	elseif screenshot_downloading[package.screenshots[1]] then
+		return defaulttexturedir .. "loading_screenshot.png"
+	end
+
+	-- Get tmp screenshot path
+	local filepath = screenshot_dir .. DIR_DELIM ..
+		package.type .. "-" .. package.author .. "-" .. package.name .. ".png"
+
+	-- Return if already downloaded
+	local file = io.open(filepath, "r")
+	if file then
+		file:close()
+		return filepath
+	end
+
+	-- Show error if we've failed to download before
+	if screenshot_downloaded[package.screenshots[1]] then
+		return defaulttexturedir .. "error_screenshot.png"
+	end
+
+	-- Download
+
+	local function download_screenshot(params)
+		return core.download_file(params.url, params.dest)
+	end
+	local function callback(success)
+		screenshot_downloading[package.screenshots[1]] = nil
+		screenshot_downloaded[package.screenshots[1]] = true
+		if not success then
+			core.log("warning", "Screenshot download failed for some reason")
+		end
+
+		local ele = ui.childlist.store
+		if ele and not ele.hidden then
+			core.update_formspec(ele:formspec())
+		end
+	end
+	if core.handle_async(download_screenshot,
+			{ dest = filepath, url = package.screenshots[1] }, callback) then
+		screenshot_downloading[package.screenshots[1]] = true
+	else
+		core.log("error", "ERROR: async event failed")
+		return defaulttexturedir .. "error_screenshot.png"
+	end
+
+	return defaulttexturedir .. "loading_screenshot.png"
+end
+
+
 
 function package_dialog.get_formspec()
 	local package = package_dialog.package
@@ -315,8 +374,7 @@ function store.get_formspec()
 
 		-- image
 		formspec[#formspec + 1] = "image[-0.4,0;1.5,1;"
-		formspec[#formspec + 1] = defaulttexturedir
-		formspec[#formspec + 1] = "no_screenshot.png"
+		formspec[#formspec + 1] = get_screenshot(package)
 		formspec[#formspec + 1] = "]"
 
 		-- title

src/script/lua_api/l_mainmenu.cpp

@@ -1043,10 +1043,22 @@ int ModApiMainMenu::l_get_package_list(lua_State *L)
 		lua_pushstring(L, package.url.c_str());
 		lua_settable  (L, top_lvl2);
 
-		lua_pushstring(L, "release");
+		lua_pushstring (L, "release");
 		lua_pushinteger(L, package.release);
 		lua_settable   (L, top_lvl2);
 
+		lua_pushstring(L, "screenshots");
+		lua_newtable(L);
+		{
+			int top_screenshots = lua_gettop(L);
+			for (size_t i = 0; i < package.screenshots.size(); ++i) {
+				lua_pushnumber(L, i + 1);
+				lua_pushstring(L, package.screenshots[i].c_str());
+				lua_settable(L, top_screenshots);
+			}
+		}
+		lua_settable(L, top_lvl2);
+
 		lua_settable(L, top);
 		index++;
 	}