/** * @file lllivefile.h * @brief Automatically reloads a file whenever it changes or is removed. * * $LicenseInfo:firstyear=2006&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #ifndef LL_LLLIVEFILE_H #define LL_LLLIVEFILE_H extern const F32 DEFAULT_CONFIG_FILE_REFRESH; class LL_COMMON_API LLLiveFile { public: LLLiveFile(const std::string& filename, const F32 refresh_period = 5.f); virtual ~LLLiveFile(); /** * @brief Check to see if this live file should reload. * * Call this before using anything that was read & cached * from the file. * * This method calls the <code>loadFile()</code> method if * any of: * file has a new modify time since the last check * file used to exist and now does not * file used to not exist but now does * @return Returns true if the file was reloaded. */ bool checkAndReload(); std::string filename() const; /** * @brief Add this live file to an automated recheck. * * Normally, just calling checkAndReload() is enough. In some * cases though, you may need to let the live file periodically * check itself. */ void addToEventTimer(); void setRefreshPeriod(F32 seconds); protected: /** * @breif Implement this to load your file if it changed. * * This method is called automatically by <code>checkAndReload()</code>, * so though you must implement this in derived classes, you do * not need to call it manually. * @return Returns true if the file was successfully loaded. */ virtual bool loadFile() = 0; /** * @brief Implement this method if you want to get a change callback. * * This virtual function will be called automatically at the end * of <code>checkAndReload()</code> if a new configuration was * loaded. This does not track differences between the current and * newly loaded file, so any successful load event will trigger a * <code>changed()</code> callback. Default is to do nothing. */ virtual void changed() {} private: class Impl; Impl& impl; }; #endif //LL_LLLIVEFILE_H