Maemo 5 DBus 初探

DBus 在Maemo 5系統中是很重要的 IPC 功能,透過DBus可以控制許多硬體如LED, Keypad,甚至是撥電話及發簡訊.現在我想要在程式執行時LCD panel不要進入power saving而關閉也需要透過DBus.

1.Reference

http://wiki.maemo.org/Documentation/Maemo_5_Developer_Guide/DBus/DBus_Basics

http://maemo.org/api_refs/5.0/5.0-final/mce-dev/dbus-names_8h.html#c9f233f336f9be78f223a31866455b80

http://www.mail-archive.com/maemo-developers@maemo.org/msg01889.html


2.以下的程式碼片段就是我想要的囉

    DBusConnection *conn;
    DBusMessage    *msg = NULL;
    DBusError       dbus_error;
    dbus_bool_t     dresult;    

#define MCE_SERVICE                     "com.nokia.mce"
#define MCE_REQUEST_PATH                "/com/nokia/mce/request"
#define MCE_REQUEST_IF                  "com.nokia.mce.request"
#define MCE_PREVENT_BLANK_REQ           "req_display_blanking_pause"

    dbus_error_init(&dbus_error);
    
    conn = dbus_bus_get (DBUS_BUS_SYSTEM, &dbus_error);

    msg = dbus_message_new_method_call(MCE_SERVICE, 
                                       MCE_REQUEST_PATH,
                                       MCE_REQUEST_IF, 
                                       MCE_PREVENT_BLANK_REQ);
    if (msg == NULL)
        return;
    
    dresult = dbus_connection_send (conn, msg, NULL);

    if (!dresult) 
    {
        dbus_message_unref(msg);
        return;
    }
   
    dbus_connection_flush(conn);
    dbus_message_unref(msg);