* \sa JoinLayer */GHANDLE GUIAPI GetLayerInfo (const char* layer_name, RECT* max_rect,                 int* nr_clients, BOOL* is_topmost, int* cli_active);/**  * \fn BOOL GUIAPI BringLayer2Topmost (GHANDLE handle) * \brief Brings a layer to be the topmost one. * * This function brings the specified layer \a handle to be the topmost layer. * * \param handle The handle to the layer. * \return TRUE on success, otherwise FALSE. * * \sa SetActiveClient */BOOL GUIAPI BringLayer2Topmost (GHANDLE handle);/**  * \fn BOOL GUIAPI SetActiveClient (int active) * \brief Sets a client as the ative one. * * This function sets the specified client \a active to be the active one. * It also bring the layer in which the client lays to be the topmost as well. * * \param active The identifier of the client. * \return TRUE on success, otherwise FALSE. * * \sa BringLayer2Topmost */BOOL GUIAPI SetActiveClient (int active);    /** @} end of lite_layer_fns */    /**     * \defgroup lite_server_fns Server-only operations     *     * MiniGUI provides some server-only functions for you to create a     * customized server for MiniGUI-Lite, i.e. \a mginit.     *     * Example:     *     * \include server_startup.c     *     * @{     */#define LCO_NEW_CLIENT      1#define LCO_DEL_CLIENT      2/** * \var typedef void (* ON_NEW_DEL_CLIENT) (int op, int cli) * \brief Client event callback. * * \sa OnNewDelClient, OnChangeLayer */typedef void (* ON_NEW_DEL_CLIENT) (int op, int cli);#define LCO_NEW_LAYER       1#define LCO_DEL_LAYER       2#define LCO_JOIN_CLIENT     3#define LCO_REMOVE_CLIENT   4#define LCO_TOPMOST_CHANGED 5#define LCO_ACTIVE_CHANGED  6/** * \var typedef void (* ON_CHANGE_LAYER) (int op, MG_Layer* layer, MG_Client* client) * \brief Layer event callback. * * \sa OnNewDelClient, OnChangeLayer */typedef void (* ON_CHANGE_LAYER) (int op, MG_Layer* layer, MG_Client* client);/** * \var ON_NEW_DEL_CLIENT OnNewDelClient * \brief Sets to a function to handle a comming in/going away connection of client. * * When a client is connecting to or disconnecting from the server, MiniGUI * will call this function to tell you the event and the client identifier.  * The event could be one of the following: * *  - LCO_NEW_CLIENT\n *    A new client is connecting to the server. *  - LCO_DEL_CLIENT\n *    A new client is disconnecting from the server. * * The event will be passed through the argument of \a op, and the client * identifier will be passed through the argument of \a cli. * You can get the information of the client by accessing \a mgClients with \a cli. * * \note Only available for the server of MiniGUI-Lite. *  * \sa ON_NEW_DEL_CLIENT, mgClients */extern ON_NEW_DEL_CLIENT OnNewDelClient;/** * \var ON_CHANGE_LAYER OnChangeLayer * \brief Sets to a function to handle events of layers. * * When a layer is changing, MiniGUI will call this function to tell  * you the event and the layer or the client which leads to the event. * The event could be one of the following: * *  - LCO_NEW_LAYER\n *    A new layer is creating. *  - LCO_DEL_LAYER\n *    A new layer is deleting. *  - LCO_JOIN_CLIENT\n *    A client is joining to the layer. *  - LCO_REMOVE_CLIENT\n *    A client is removing from the layer. *  - LCO_TOPMOST_CHANGED\n *    The topmost layer changed, the layer will be the topmost one. *  - LCO_ACTIVE_CHANGED\n *    The active client changed, the client will be the active one. * * The event will be passed through the argument of \a op, and the pointers to the relevant * layer and client will be passed through the argument of \a layer and \a client respectively. * * \note Only available for the server of MiniGUI-Lite. *  * \sa ON_NEW_DEL_CLIENT, mgClients */extern ON_CHANGE_LAYER OnChangeLayer;/**  * \fn BOOL GUIAPI ServerStartup (void) * \brief Initializes the server of MiniGUI-Lite. * * This function initializes the server, i.e. \a mginit. It creates * the shared resource, the listening socket, and other internal objects. * Your costomized \a mginit program should call this function before calling * any other function. * * \return TRUE on success, otherwise FALSE. * * \note Server-only function, i.e. \em only can be called by \a mginit. */BOOL GUIAPI ServerStartup (void);/**  * \fn BOOL SetClientScreen (int lx, int ty, int rx, int by) * \brief Sets the screen rectangle can be used by clients. * * This function sets the screen rectangle can be used by clients. * All clients' drawing will be clipped out of the rectangle. * * The rectangle set by this function should be a subrectangle of * the server's exclusive rectangle defined by \a SetDesktopRect. * * \param lx lx,ty,rx,by: Specifies the screen rectangle. * \param ty lx,ty,rx,by: Specifies the screen rectangle. * \param rx lx,ty,rx,by: Specifies the screen rectangle. * \param by lx,ty,rx,by: Specifies the screen rectangle. * \return TRUE on success, otherwise FALSE. * * \note Server-only function, i.e. \em ONLY can be called by \a mginit. * * \note This function do nothing in MiniGUI V 1.5.x. * * \sa JoinLayer */static inline BOOL SetClientScreen (int lx, int ty, int rx, int by){    return TRUE;}/**  * \fn BOOL GUIAPI OnlyMeCanDraw (void) * \brief Tells clients do not draw anything on screen. * * If the server want to output something out of its exclusive rectangle, * it can call this function to disable the clients' any drawing output. * When the server done, it can call \a ClientCanDrawNowEx function * to tell clients in the topmost layer to repaint themselves. * * Note that the clients is still running after the server calling  * this function. *  * \return TRUE on success, otherwise FALSE. * * \note Server-only function. * * \sa ClientCanDrawNowEx, ClientCanDrawNow */BOOL GUIAPI OnlyMeCanDraw (void);/**  * \fn BOOL GUIAPI ClientCanDrawNowEx (BOOL bRepaint, const RECT* invrc) * \brief Tells clients that they can output to screen now. * * \param bRepaint Whether to repaint the clients in the topmost layer. * \param invrc The invalid screen rect. It can be NULL,  *        indicates the whole desktop of clients should be repainted. * \return TRUE on success, otherwise FALSE. * * \note Server-only function. * * \sa OnlyMeCanDraw, ClientCanDrawNow */BOOL GUIAPI ClientCanDrawNowEx (BOOL bRepaint, const RECT* invrc);/**  * \def ClientCanDrawNow() * \brief Tells clients that they can output to screen now, and  *        notify clients to repaint the whole desktop. * * \return TRUE on success, otherwise FALSE. * * \note Server-only function, and defined as a macro  *       calling \a ClientCanDrawNowEx with \a bRepaint is TRUE and \a invrc is NULL. * * \sa ClientCanDrawNowEx */#define ClientCanDrawNow()    ClientCanDrawNowEx (TRUE, NULL)/** * \fn void GUIAPI UpdateTopmostLayer (const RECT* dirty_rc) * \brief Tells the clients in the topmost layer to update their windows. * * \param dirty_rc The dirty rectangle in screen coordinate system. * * \note Server-only function. * * \sa OnlyMeCanDraw, ClientCanDrawNowEx */void GUIAPI UpdateTopmostLayer (const RECT* dirty_rc);/**  * \fn BOOL GUIAPI SetTopMostClient (int cli) * \brief Sets topmost layer by a client identifier. * * This function sets the topmost layer by the specified client identifier \a cli. * It will bring the layer contains the client to be the topmost one. * * \param cli The identifier of the client. * \return TRUE on success, otherwise FALSE. * * \note Server-only function. * * \sa SetTopMostLayer, BringLayer2Topmost */BOOL GUIAPI SetTopMostClient (int cli);/**  * \fn BOOL GUIAPI SetTopMostLayer (MG_Layer* layer) * \brief Sets topmost layer. * * This functions sets the specified layer \a layer to be the topmost layer. * * \param layer The pointer to the layer. * \return TRUE on success, otherwise FALSE. * * \note Server-only function. * * \sa SetTopMostClient, BringLayer2Topmost */BOOL GUIAPI SetTopMostLayer (MG_Layer* layer);/**  * \fn int GUIAPI GetClientByPID (int pid) * \brief Returns the client identifier from PID of a client. * * This function gets the identifier of the sepcified client from the PID of it. * * \param pid The process ID of the client. * \return The client identifier on success, less than 0 on error. * * \note Server-only function. */int GUIAPI GetClientByPID (int pid);    /** @} end of lite_server_fns */    /**     * \defgroup lite_request_fns Simple request/reply interfaces     *      * You can register a customized request handler to extend your server, i.e.      * \a mginit, of MiniGUI-Lite.     *     * A request consists of an identifier and the data associated with the request.     * The identifier is used by MiniGUI to determine which handler should be called     * when a request arrives. When MiniGUI finds one handler, it will call the handler     * and pass the socket fd connected to the client, the data associated with the request,     * and the length of the data. Eventually, the handler will sent the reply to     * the client.     *     * After register a customized request handler in your server, you can call      * \a cli_request function in the client to send a request to      * the server and wait for the reply. On the other hand, the request handler in the server     * will receive the request and call \a send_reply to send the reply to the client.     * In this way, you can create a simple IPC (inter-process conmmunication)      * mechanism between clients and the server.     *     * Example:     *     * \include request.c     *     * @{     *//** * \def MAX_SYS_REQID * \brief Maximal system reserved request identifier. * * \sa RegisterRequestHandler */#define MAX_SYS_REQID           0x0011/** * \def MAX_REQID * \brief Maximal request identifier. * * \sa RegisterRequestHandler */#define MAX_REQID               0x0018/** A request will be sent to the server of MiniGUI-Lite. */typedef struct _REQUEST {    /** The identifier of the type of the request. */    int id;    /** The data will be sent to the server. */    const void* data;    /** The length of the data. */    size_t len_data;} REQUEST;typedef REQUEST* PREQUEST;/**  * \fn cli_request (PREQUEST request, void* result, int len_rslt) * \brief Sends a request to the server and wait reply. * * If \a result is NULL or \a len_rslt is zero, the function will return  * immediately after sent the data to the server. * * \param request The pointer to REQUEST, which contains the data of the request. * \param result The buffer receives the reply. * \param len_rslt The lenght of the buffer. * \return Zero on success, no-zero on error. * * \note Only used by clients to send a request to the server of MiniGUI-Lite. * * \sa send_reply */int cli_request (PREQUEST request, void* result, int len_rslt);/**  * \fn int get_sock_fd2srv (void) * \brief Gets the file descriptor of the socket connected to the server. * * This function returns the file descriptor of the socket connected to the server, * i.e. \a mginit. * * \return The file descriptor of the socket connected to the server. * * \note Only used by clients, no meaning for the server. */int get_sock_fd2srv (void);/**  * \fn send_reply (int clifd, const void* reply, int len) * \brief Sends the reply to the client. * * This function sends a replay pointed to by \a reply which is  * \a len bytes long to the client. * * \note Only used by the server to send the reply to the client. * This function typically called in your customized request handler. * * \param clifd The fd connected to the client. * \param reply The buffer contains the reply data. * \param len The length of the reply data in bytes. * \return Zero on success, no-zero on error. * * \sa cli_request, RegisterRequestHandler */int send_reply (int clifd, const void* reply, int len);/** * \var typedef int (* REQ_HANDLER)(int cli, int clifd, void* buff, size_t len) * \brief Request handler. * * \sa RegisterRequestHandler */typedef int (* REQ_HANDLER) (int cli, int clifd, void* buff, size_t len);/**  * \fn BOOL GUIAPI RegisterRequestHandler (int req_id, REQ_HANDLER your_handler) * \brief Registers a customize request handler. * * This function registers a request handler to the server, i.e. \a mginit. * * \param req_id The identifier of the customized request. * \param your_handler The handler of the request. Being NULL to unregister the request handler. * \return TRUE on success, FALSE on error. * * \note Only used by the server to register a request handler. *       And the identifier should be larger than \a MAX_SYS_REQID and  *       less than or equal to \a MAX_REQID. * * \sa cli_request, send_reply, MAX_SYS_REQID, MAX_REQID */BOOL GUIAPI RegisterRequestHandler (int req_id, REQ_HANDLER your_handler);/**  * \fn EQ_HANDLER GUIAPI GetRequestHandler (int req_id) * \brief Gets the request handler by request identifier. *