BOOL remove_layer (MG_Layer* layer){#ifdef _DEBUG    printf ("Remove a layer: %s\n", layer->name);#endif    if (layer->prev)        layer->prev->next = layer->next;    if (layer->next)        layer->next->prev = layer->prev;    if (layer == mgLayers) {        mgLayers = layer->next;    }    // Notify that a layer will be deleted.    if (OnChangeLayer) OnChangeLayer (LCO_DEL_LAYER, layer, NULL);    EmptyClipRgn (layer->spare_rects);    free (layer->spare_rects);    free (layer);    if (mgTopmostLayer != layer)        return FALSE;    // set new topmost layer    mgTopmostLayer = mgLayers;    CHANGE_TOPMOST_LAYER (mgTopmostLayer);    if (mgTopmostLayer) {        MG_Client* client;        MSG msg = {HWND_DESKTOP, MSG_PAINT, 0, 0, __mg_timer_counter};#ifdef _DEBUG        printf ("New topmost layer: %s\n", mgTopmostLayer->name);#endif        client = mgTopmostLayer->cli_head;        while (client) {            my_send2client (&msg, client);            client->last_live_time = __mg_timer_counter;            client = client->next;        }        if (mgTopmostLayer->cli_active) {            MSG msg = {HWND_DESKTOP, MSG_SETFOCUS, 0, 0, __mg_timer_counter};            my_send2client (&msg, mgTopmostLayer->cli_active);        }    }    // Notify that a new topmost layer have been set.    if (OnChangeLayer) OnChangeLayer (LCO_TOPMOST_CHANGED, mgTopmostLayer, NULL);#ifdef _DEBUG    printf ("layer removed\n");#endif    return TRUE;}void set_active_client (MG_Client* client){    MG_Layer* layer;    if (client)        layer = client->layer;    else        layer = mgTopmostLayer;    if (layer == NULL || layer->cli_active == client)        return;    if (layer->cli_active) {        MSG msg = {HWND_DESKTOP, MSG_SETFOCUS, 0, 0, __mg_timer_counter};        my_send2client (&msg, layer->cli_active);    }    // Notify that active client changed.    if (OnChangeLayer) OnChangeLayer (LCO_ACTIVE_CHANGED, layer, client);    layer->cli_active = client;}void client_join_layer (int cli, const JOINLAYERINFO* info, JOINEDCLIENTINFO* joined_info){    PCLIPRECT spare, max = NULL;    RECT tmp;    unsigned int max_area = 0, area;    MG_Layer* layer = (MG_Layer*)(joined_info->layer_handle);    MG_Client* new_client = mgClients + cli;#ifdef _DEBUG    printf ("Join a client (%s) to layer %s\n", info->client_name, layer->name);#endif    strcpy (new_client->name, info->client_name);    SetRectEmpty (&joined_info->desktop_rc);        spare = layer->spare_rects->head;    while (spare) {        if (IntersectRect (&tmp, &info->desktop_rc, &spare->rc)) {            area = (RECTW (tmp) * RECTH (tmp));            if (area > max_area) {                max_area = area;                max = spare;            }        }        spare = spare->next;    }    if (max) {        IntersectRect (&joined_info->desktop_rc, &info->desktop_rc, &max->rc);        SubtractClipRect (layer->spare_rects, &joined_info->desktop_rc);        new_client->layer = layer;        // Notify that a new client joined to this layer.        if (OnChangeLayer) OnChangeLayer (LCO_JOIN_CLIENT, layer, new_client);    }    else {        new_client->layer = NULL;        if (layer->cli_head == NULL)            remove_layer (layer);        return;    }    new_client->prev = NULL;    new_client->next = layer->cli_head;    if (layer->cli_head)        layer->cli_head->prev = new_client;    layer->cli_head = new_client;    set_active_client (new_client);    // set rect of new client    new_client->rc = joined_info->desktop_rc;#ifdef _DEBUG    printf ("Rect of client (%s): (%d, %d, %d, %d)\n",                     new_client->name,                    new_client->rc.left, new_client->rc.top,                    new_client->rc.right, new_client->rc.bottom);#endif    if (layer == mgTopmostLayer) {        // tell desktop to exclude this client from background        SendMessage (HWND_DESKTOP, MSG_NEWCLIENT, (WPARAM)cli, (LPARAM)(&new_client->rc));    }}BOOL is_valid_layer (MG_Layer* layer){    MG_Layer* myLayer;    myLayer = mgLayers;    while (myLayer) {        if (layer == myLayer)            return TRUE;        myLayer = myLayer->next;    }    return FALSE;}/* send message to client(s) */int GUIAPI Send2Client (MSG* msg, int cli){	    int i, n;    MG_Client* client;    if (cli >= 0 && cli < mgClientSize && mgClients [cli].fd != -1) {        return my_send2client (msg, mgClients + cli);    }    else if (cli == CLIENT_ACTIVE) {   /* send to active client */        if (mgTopmostLayer && mgTopmostLayer->cli_active) {            return my_send2client (msg, mgTopmostLayer->cli_active);        }    }    else if (cli == CLIENTS_TOPMOST) {   /* send to topmost clients */        if (mgTopmostLayer) {            client = mgTopmostLayer->cli_head;            while (client) {                if ((n = my_send2client (msg, client)) < 0)                    return n;                client = client->next;            }        }    }    else if (cli == CLIENTS_EXCEPT_TOPMOST) {   /* send to all clients except topmost client */        client = mgClients;        for (i = 0; i < mgClientSize; i++, client++) {            if (client->layer != mgTopmostLayer) {                if ((n = my_send2client (msg, client)) < 0)                    return n;            }        }    }    else if (cli == CLIENTS_ALL) {    /* send to all clients */        client = mgClients;        for (i = 0; i < mgClientSize; i++, client++) {            if ((n = my_send2client (msg, client)) < 0)                return n;        }    }    else        return SOCKERR_INVARG;    return SOCKERR_OK;}BOOL GUIAPI Send2TopMostClients (int iMsg, WPARAM wParam, LPARAM lParam){    MSG msg = {HWND_DESKTOP, iMsg, wParam, lParam, __mg_timer_counter};    if (send2client (&msg, CLIENTS_TOPMOST) < 0)        return FALSE;    return TRUE;}BOOL GUIAPI Send2ActiveClient (int iMsg, WPARAM wParam, LPARAM lParam){    MSG msg = {HWND_DESKTOP, iMsg, wParam, lParam, __mg_timer_counter};    if (send2client (&msg, CLIENT_ACTIVE) < 0)        return FALSE;    return TRUE;}void GUIAPI UpdateTopmostLayer (const RECT* dirty_rc){    MSG msg = {HWND_DESKTOP, MSG_PAINT, 0, 0, __mg_timer_counter};    if (dirty_rc) {        RECT eff_rc;        IntersectRect (&eff_rc, dirty_rc, &g_rcScr);        msg.wParam = MAKELONG (eff_rc.left, eff_rc.top);        msg.lParam = MAKELONG (eff_rc.right, eff_rc.bottom);    }    send2client (&msg, CLIENTS_TOPMOST);}static int onlyme_count = 0;BOOL GUIAPI OnlyMeCanDraw (void){    MG_Client* client;    if (onlyme_count ++)        return TRUE;    CHANGE_TOPMOST_LAYER (NULL);    if (mgTopmostLayer == NULL             || (client = mgTopmostLayer->cli_head) == NULL)        return FALSE;    return TRUE;}BOOL GUIAPI ClientCanDrawNowEx (BOOL bRepaint, const RECT* invrc){    MG_Client* client;    MSG msg = {HWND_DESKTOP, MSG_PAINT, 0, 0, __mg_timer_counter};    if (--onlyme_count)        return TRUE;    if (bRepaint && invrc) {        msg.wParam = MAKELONG (invrc->left, invrc->top);        msg.lParam = MAKELONG (invrc->right, invrc->bottom);    }    CHANGE_TOPMOST_LAYER (mgTopmostLayer);    if (mgTopmostLayer == NULL             || (client = mgTopmostLayer->cli_head) == NULL)        return FALSE;    while (client) {        if (bRepaint) {            my_send2client (&msg, client);        }        client = client->next;    }    return TRUE;}BOOL GUIAPI SetTopMostLayer (MG_Layer* layer){    MG_Client* client;    MSG msg = {HWND_DESKTOP, MSG_PAINT, 0, 0, __mg_timer_counter};    if (layer == mgTopmostLayer)        return FALSE;    mgTopmostLayer = layer;    CHANGE_TOPMOST_LAYER (layer);    client = layer->cli_head;    while (client) {        my_send2client (&msg, client);        client->last_live_time = __mg_timer_counter;        client = client->next;    }    if (layer->cli_active) {        MSG msg = {HWND_DESKTOP, MSG_SETFOCUS, 0, 0, __mg_timer_counter};        my_send2client (&msg, layer->cli_active);    }    SendMessage (HWND_DESKTOP, MSG_TOPMOSTCHANGED, 0, 0);    PostMessage (HWND_DESKTOP, MSG_ERASEDESKTOP, 0, 0);    // Notify that a new topmost layer have been set.    if (OnChangeLayer) OnChangeLayer (LCO_TOPMOST_CHANGED, mgTopmostLayer, NULL);    return TRUE;}BOOL GUIAPI SetTopMostClient (int cli){    if (cli < 0 || cli >= mgClientSize || mgClients [cli].fd == -1)        return FALSE;                     return SetTopMostLayer (mgClients [cli].layer);}int GUIAPI GetClientByPID (int pid){    int i;    for (i = 0; i < mgClientSize; i++) {        if (mgClients[i].pid == pid) {            if (mgClients[i].fd == -1)                return -1;            return i;        }    }    return -1;}