showip.c

/*

=WHAT IT DOES

Will display eth0 IP in lxpanel widget, if eth0 is not connected will fallback to wlan0. 
If both are unconnected, will display blank.

=BUILD INSTRUCTIONS

$> make

or something like:

$> gcc -Wall `pkg-config --cflags gtk+-2.0 lxpanel` -shared -fPIC showip.c toolbox.c toolbox-char-array.c toolbox-line-parser.c toolbox-text-buffer-reader.c -o showip.so `pkg-config --libs lxpanel`


=INSTALL INSTRUCTIONS

$> python install.py

or 

sudo cp showip.so /usr/lib/arm-linux-gnueabihf/lxpanel/plugins/
reboot or restart lxpanel
then right click on top panel and add "showip"

*/

#include <lxpanel/plugin.h>

#include <stdio.h>  
#include <sys/types.h>
#include <ifaddrs.h>
#include <netinet/in.h> 
#include <arpa/inet.h>

#include "toolbox.h"

// internal to the plugin source, not used by the 'priv' variable
static int iInstanceCount = 0;


typedef struct 
{
	LXPanel *panel;
	gint iMyId;
	GtkWidget *gLabel;
	unsigned int timer;
} ShowIp;


static void update_display(ShowIp *pPlugin)
{
   GdkColor color;

   char ip[256];
   char which_interface[256] = "";
   struct ifaddrs * ifAddrStruct=NULL;
   struct ifaddrs * ifa=NULL;
   void * tmpAddrPtr=NULL;

   getifaddrs(&ifAddrStruct);

   // get eth0 first
   for (ifa = ifAddrStruct; ifa != NULL; ifa = ifa->ifa_next) 
   {
      if (!ifa->ifa_addr) 
      {
         continue;
      }
      
      if (ifa->ifa_addr->sa_family == AF_INET) // check it is IP4
      { 
         tmpAddrPtr=&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
         char addressBuffer[INET_ADDRSTRLEN];
         inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);
         printf("%s IP Address %s\n", ifa->ifa_name, addressBuffer);
         if (strcmp(ifa->ifa_name, "lo") != 0)
         {
            strncpy(ip, addressBuffer, sizeof(ip)-1);
            strcpy(which_interface, ifa->ifa_name);
	 }
	 
	 if (strcmp(ifa->ifa_name, "eth0") == 0)
         {
            break;
	 }
      }
   }
   
   // get eth0 first
   if (ip[0] == '\0') for (ifa = ifAddrStruct; ifa != NULL; ifa = ifa->ifa_next) 
   {
      if (!ifa->ifa_addr) 
      {
         continue;
      }
      if (ifa->ifa_addr->sa_family == AF_INET) // check it is IP4
      { 
         tmpAddrPtr=&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
         char addressBuffer[INET_ADDRSTRLEN];
         inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);
         printf("%s IP Address %s\n", ifa->ifa_name, addressBuffer);
         if (ifa->ifa_name[0] == 'w')
         {
            strncpy(ip, addressBuffer, sizeof(ip)-1); // get wireless lans
            strcpy(which_interface, ifa->ifa_name);
	 }
      }
   }
    
   // loop ipv6 if we couldnt find ipv4 eth0
   if (ip[0] == '\0') for (ifa = ifAddrStruct; ifa != NULL; ifa = ifa->ifa_next) 
   {
      if (!ifa->ifa_addr) 
      {
          continue;
      }

      if (ifa->ifa_addr->sa_family == AF_INET6) 
      {
         tmpAddrPtr=&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
         char addressBuffer[INET6_ADDRSTRLEN];
         inet_ntop(AF_INET6, tmpAddrPtr, addressBuffer, INET6_ADDRSTRLEN);
         printf("%s IP Address %s\n", ifa->ifa_name, addressBuffer); 
         if (strcmp(ifa->ifa_name, "lo") != 0)
         {
            strncpy(ip, addressBuffer, sizeof(ip)-1);
            strcpy(which_interface, ifa->ifa_name);
	    break;
         }
      } 
   }
    
   if (ifAddrStruct!=NULL) freeifaddrs(ifAddrStruct);
    
   printf("ip(%s)\n",ip);

   if (ip[0] == '\0')
   {
      strcpy(ip, "No IP found");	
   }
   
   //lxpanel_draw_label_text(pPlugin->panel, pPlugin->gLabel, ip, TRUE, 2, TRUE);
   gdk_color_parse("#FF80FF", &color);
   color.pixel = 1;
   color.green = 255;
   color.blue = 155;
   color.red = 100;
   lxpanel_draw_label_text_with_color(pPlugin->panel, pPlugin->gLabel, ip, TRUE, 1.3, &color);
   gtk_widget_set_tooltip_text(pPlugin->gLabel, which_interface);
}

static gboolean update_display_timeout(gpointer user_data)
{
   if (g_source_is_destroyed(g_main_current_source()))
      return FALSE;
   update_display(user_data);
   return TRUE; /* repeat later */
}

GtkWidget *showip_constructor(LXPanel *panel, config_setting_t *settings)
{
   /* panel is a pointer to the panel and
      settings is a pointer to the configuration data. */
   (void)settings;

   // allocate our private structure instance
   ShowIp *pPlugin = g_new0(ShowIp, 1);

   // update the instance count
   pPlugin->iMyId = ++iInstanceCount;
   pPlugin->panel = panel;

   // make a label out of the ID
   char cIdBuf[20];
   cIdBuf[sizeof(cIdBuf)-1] = '\0';
   snprintf(cIdBuf, sizeof(cIdBuf)-1, "IP %s", "127.0.0.1");

   // create a label widget instance 
   pPlugin->gLabel = gtk_label_new(cIdBuf);
	
   update_display(pPlugin);

   // set the label to be visible
   gtk_widget_show(pPlugin->gLabel);

   // need to create a container to be able to set a border
   GtkWidget *p = gtk_event_box_new();

   // our widget doesn't have a window...
   // it is usually illegal to call gtk_widget_set_has_window() from application but for GtkEventBox it doesn't hurt
   gtk_widget_set_has_window(p, FALSE);

   // bind private structure to the widget assuming it should be freed using g_free()
   lxpanel_plugin_set_data(p, pPlugin, g_free);

   // set border width
   gtk_container_set_border_width(GTK_CONTAINER(p), 1);

   // add the label to the container
   gtk_container_add(GTK_CONTAINER(p), pPlugin->gLabel);

   // set the size we want
   gtk_widget_set_size_request(p, 140, 25);
	
   pPlugin->timer = g_timeout_add_seconds(4, (GSourceFunc) update_display_timeout, (gpointer)pPlugin);

   return p;
}

FM_DEFINE_MODULE(lxpanel_gtk, showip)

/* Plugin descriptor. */
LXPanelPluginInit fm_module_init_lxpanel_gtk = {
   .name = "ShowIP",
   .description = "Display current IP address.",

   // assigning our functions to provided pointers.
   .new_instance = showip_constructor
};