gnome-gps: a simple GTK+ GPS monitor
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I intended this more as a learning experience, but as it corrects several defects in other gps/gis programs, I am turning it loose on the world under same terms as gpsd, i.e. under the BSD license. Readers may find it useful for studying GTK+ programming (or not…) as well as libgps programming (again, or not…).
I use this as I travel to keep an eye on altitude, speed and quality of the fix, none of which is readily available in other GPS display programs I use. Here, "readily available" means in large enough font that I can glance at the laptop and read it without squinting.
Requirements
This version is designed to work with gpsd 3.0, gps protocol version 4.1, once the gpsd folks turn that loose. Until then, you will likely want the head version of gpsd from the git repo. This version identifies itself like so:
ccurley@white:~$ ~/projects/gnome-gps/src/gnome-gps -V Time-stamp: <2010-05-09 12:01:44 ccurley gnome-gps.c>, Compiled for gpsd API version 4.1. Usage: gnome-gps [-d d] [-m] [-k] [-p port] [-u] [-v] [-V] [host] ccurley@white:~$
Running it in verbose mode reveals, among other things, GPSD version: 2.95~dev Rev: 2010-05-09T14:01:40, Protocol 3.2. There is a compile time check for gpsd API 4.1 or greater.
I compile and run this on Ubuntu 9.10, "Karmic Koala". Ubuntu 10.04 "Good Buddy", er, "Lucid Lynx", has gpsd version 2.92-4 available. That version should work for everything except possibly replugging the gps receiver.
Features
There are several features common to gps display programs, like the ability to display data in various units. The program can save settings to a resource file, a dot file named after the program. (If you rename the executable, you change the name of the dot file that executable will look for.)
One thing that is unusual about this program is that most of the time it uses a progress bar to show the relative proportion of visible satellites and the number used in the fix. It also uses the progress bar for user information, such as announcing when it makes a connection to gpsd.
The program doesn't display the quality of the fix as text. Rather, it changes the background color:
- Red, no fix or other problem.
- Yellow, two dimensional fix.
- Green, three dimensional fix.
The code detects the loss of a connection to gpsd, and puts an appropriate message into the progress bar. It also will detect when gpsd has lost contact with the gps receiver, and places a different appropriate message in the progress bar. It will recover once the fault is repaired. These features rely on code in the 4.1 protocol.
You can specify a font from the GUI. You can also force the program to attempt to reconnect to gpsd, or to another gpsd. Since recovery from loss of a connection should be automatic, the resynch option should be useful mainly to change the host and/or port of the gpsd connection. The defaults are "localhost" and the port indicated by the gpsd code at compile time, TCP port 2947.
No ./configure or ./autogen folderol. The compile line is near the top of the file.
Bugs
The window will expand nicely if the user selects a larger font. However, I haven't found out how to make it shrink when the user selects a smaller font. Workaround: manually resize it. Volunteers?
It would be nice if one could preserve the location of the window on the screen in the resource file. Volunteers?
Options
A somewhat more detailed look at the options:
- [-d d] ("degrees") Specify display of lat and long in one of d: degrees and decimal degrees (ddd.ddddd), m: degrees, minutes and decimal minutes (ddd mm.mmmm), s: degrees, minutes, seconds, and decimal seconds (dd mm ss.ss).
- [-m] ("metric") Set metric units.
- [-k] ("knots") Set the speed unit to knots, others to appropriate US measurements.
- [-p port] Specify the port at which to attach. The default is the gpsd standard, as provided by the gpsd code at compilation.
- [-u] ("US") Set units to US units, including statutory miles.
- [-v] ("Verbose") Set verbose mode: print lots of stuff to stdout, including fixes.
- [-V] ("Version") Print out the version and other information, and exit.
- [host] Specify an optional host. The default is "localhost".
Once you have set these options, using command line switches as above, or from the menus, you can preserve them with control s, or, using the mouse, File -> Save.
The Code
char *versionString = "Time-stamp: <2010-06-27 06:39:28 ccurley gnome-gps.c>"; /* A GTK program for showing the latest gps data using libgps. */ /* Compile: gcc -Wall gnome-gps.c -o gnome-gps $(pkg-config --cflags --libs gtk+-2.0 libgps) add: -ggdb for debug (gdb) output. */ #include <gps.h> /* Not the same as gpsd.h */ /* Do we recognize the current libgps API? */ #if ( GPSD_API_MAJOR_VERSION < 4 ) #error Unknown gps API protocol version; see gps.h for the current value of GPSD_API_MAJOR_VERSION #endif /* We'll take 4.1 or 4.2. */ #if ( GPSD_API_MINOR_VERSION < 1 ) #error Unknown gps API protocol version; see gps.h for the current value of GPSD_API_MINOR_VERSION #endif #include <gtk/gtk.h> #include <math.h> /* For isnan (), modf (), fabs () */ #include <string.h> /* For strcpy (), etc. */ #include <unistd.h> /* getopt stuff */ #include <errno.h> #include <ctype.h> /* tolower () */ /* prototypes */ inline void preserve (GtkEntry *entry, gint index); inline void sendWatch (void); void setColor (GdkColor *color); static gboolean delete_event( GtkWidget *widget, GdkEvent *event, gpointer data); static void destroy( GtkWidget *widget, gpointer data ); void formatTrack (double track); void formatAngle (double theAngle, gchar *buffer); void formatLat (double latitude); void formatLong (double longitude); void formatTime (double time); void formatAltitude (double altitude); void formatSpeed (double speed); static void resynchWrapper ( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void resynch (void); static void hostOkCallback (GtkWidget *widget, gpointer data); static void hostCancelCallback (GtkWidget *widget, gpointer data); static void hostDialog( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void aboutDialog( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void setUnits( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void setDegrees( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void saveState( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void fontApplyCallback (GtkWidget *widget, gpointer data); static void fontOkCallback (GtkWidget *widget, gpointer data); static void setFont( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static GtkWidget *get_menubar_menu( GtkWidget *window ); static void setUnits( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); static void setDegrees( gpointer callback_data, guint callback_action, GtkWidget *menu_item ); /* libgps callback. */ void showData (struct gps_data_t *gpsdata, char *message, size_t len); static void buildPair (gint index, gchar *labelText, GtkWidget *table, gint left, gint top); gint gpsPoll (gpointer data); void saveKeyFile (GKeyFile *keyFile); void setActiveUnits (void); void setActiveAngle (void); int main ( int argc, char *argv[] ); /* end prototypes. */ /* Settings that go into the configuration file. */ typedef struct { gchar *port, *host, *angle, *units, *font; } settings; /* Table layout of the main window. */ #define ROWS 3 #define COLS 4 /* Display factors for the widgets in the table. */ #define XOPTIONS ((GtkAttachOptions) (GTK_FILL|GTK_EXPAND|GTK_SHRINK)) #define YOPTIONS ((GtkAttachOptions) (GTK_FILL|GTK_EXPAND|GTK_SHRINK)) #define XPADDING 5 #define YPADDING 2 /* Have we detected the loss of the GPS receiver? If so, when we get a * new DEVICE message, send a WATCH. */ bool gpsLost = false; gint tag = 0; /* GtkWidget is the storage type for widgets */ GtkWidget *window; /* The main window. */ GtkWidget *vbox; /* A vertical box, which goes in the * main window so we can divvy it * up. */ GtkWidget *menubar; /* Which goes in the top of the * vbox. */ GtkWidget *table; /* Which goes in the middle of the * vbox. */ GtkProgressBar *progress; /* Which goes into the bottom of the * vbox. */ GtkWidget *fontDialog = NULL; /* The font selector dialog */ GtkItemFactory *item_factory; GtkAccelGroup *accel_group; GtkWidget *hostDialogBox = NULL; /* The host/port dialog box. */ GtkWidget *hostEntry = NULL; /* And the two text entry boxes in it. */ GtkWidget *portEntry = NULL; GKeyFile *keyFile = NULL; struct gps_data_t *gpsdata = NULL; /* per gps.h */ /* Defaults, which the user may change later on. */ char *host = "localhost"; char *port = DEFAULT_GPSD_PORT; /* Option handling variables. */ extern char *optarg; extern int optind, opterr, optopt; gboolean verbose = false; gboolean haveHome = false; /* Do we have a home environmental * variable? */ enum unitsRadio { METRIC = 'm', US = 'u', KNOTS = 'k' } unitsRadio; char units = US; enum angleSpec {DEGREES = 'd', MINUTES = 'm', SECONDS = 's' } angleSpec; char angle = DEGREES; /* How to display the angles in lat * and long. */ #define STRINGBUFFSIZE 1024 gchar fixBuff[STRINGBUFFSIZE] = "No fix seen yet"; gchar timeString[STRINGBUFFSIZE] = "No time yet"; gchar latString[STRINGBUFFSIZE] = "No latitude yet"; gchar longString[STRINGBUFFSIZE] = "No longitude yet"; gchar altString[STRINGBUFFSIZE] = "No altitude yet"; gchar speedString[STRINGBUFFSIZE] = "No speed yet"; gchar trackString[STRINGBUFFSIZE] = "No track yet"; gchar keyFileName[STRINGBUFFSIZE]; char hostName[STRINGBUFFSIZE]; char hostPort[STRINGBUFFSIZE]; const gchar *baseName; /* So we can print out only the base name in the help. */ /* SIZE must be last as we use it to size the array and in related * code. */ enum entryNames { LAT, LONG, ALT, SPEED, TRACK, TIME, SIZE } entryNames; GtkEntry *entries[SIZE]; inline void preserve (GtkEntry *entry, gint index) { entries [index] = entry; } /* Some colors for various fix states */ GdkColor ThreeDFixColor = {0, 0, 0xffff, 0}; /* green */ GdkColor TwoDFixColor = {0, 0xff00, 0xff00, 0}; /* yellow */ GdkColor NoFixColor = {0, 0xff00, 0, 0}; /* red */ GdkColor *oldColor = NULL; /* sendWatch: tell the gps daemon that we'd like to connect and * receive data, thank you. Use this after making a socket * (re)connection to the daemon, or after determining that the daemon * has lost the gps. You have to resend this after loosing the daemon * because otherwise you may never get the notification that you have * a new gps. */ inline void sendWatch (void) { /* Tell libgps to keep shoveling data at us, and use JSON rather * than gpsd's corrected nmea. */ (void) gps_stream(gpsdata, WATCH_ENABLE | WATCH_JSON, NULL); } /* We have to change the background of the window (which gets the * labels, since they don't have their own backgrounds), and the * individual text entry widgets, which do have their own * backgrounds. */ void setColor (GdkColor *color) { gint i; if ( color != oldColor ) { for ( i=0; i < SIZE; i++) { if (entries[i] != NULL) { gtk_widget_modify_bg (GTK_WIDGET (entries[i]), 0, color); } } gtk_widget_modify_bg (GTK_WIDGET (window), 0, color); gtk_widget_modify_bg (GTK_WIDGET (menubar), 0, color); gtk_widget_modify_bg (GTK_WIDGET (progress), 0, color); oldColor = color; } } static gboolean delete_event( GtkWidget *widget, GdkEvent *event, gpointer data) { /* If you return FALSE in the "delete_event" signal handler, GTK * will emit the "destroy" signal. Returning TRUE means you don't * want the window to be destroyed. This is useful for popping up * 'are you sure you want to quit?' type dialogs. */ return FALSE; } static void destroy( GtkWidget *widget, gpointer data ) { if (gpsdata != NULL) { (void) gps_stream(gpsdata, WATCH_DISABLE, NULL); gps_close(gpsdata); } if (tag != 0) { g_source_remove (tag); } gtk_main_quit (); } /* See http://en.wikipedia.org/wiki/Boxing_the_compass. This isn't the * same algorithm. We use scaled integer math, so it's faster and more * suitable for simpler devices. */ void formatTrack (double track) { char *dirString; int dir = (int) track * 10; dir += 112; /* handle inadvertent rounding due to * float to int conversion. */ dir /= 225; switch (dir) { case 0: dirString = "N"; break; case 1: dirString = "NNE"; break; case 2: dirString = "NE"; break; case 3: dirString = "ENE"; break; case 4: dirString = "E"; break; case 5: dirString = "ESE"; break; case 6: dirString = "SE"; break; case 7: dirString = "SSE"; break; case 8: dirString = "S"; break; case 9: dirString = "SSW"; break; case 10: dirString = "SW"; break; case 11: dirString = "WSW"; break; case 12: dirString = "W"; break; case 13: dirString = "WNW"; break; case 14: dirString = "NW"; break; case 15: dirString = "NNW"; break; case 16: dirString = "N"; break; default: dirString = "oops!"; } (void) snprintf (trackString, STRINGBUFFSIZE, "%03.0f° true %s", gpsdata->fix.track, dirString); gtk_entry_set_text(entries[TRACK], trackString ); } /* Factored from both formatLat and formatLong */ void formatAngle (double theAngle, gchar *buffer) { double minutes; double seconds; switch (angle) { /* Use the default to silently handle errors and fall through * to the substitute case. */ default: angle = DEGREES; case DEGREES: (void) snprintf (buffer, STRINGBUFFSIZE, "%.5f° ", theAngle); break; case MINUTES: minutes = modf (theAngle, &theAngle); (void) snprintf (buffer, STRINGBUFFSIZE, "%.f° %.4f' ", theAngle, minutes*60); break; case SECONDS: minutes = modf (theAngle, &theAngle); minutes *= 60; seconds = modf (minutes, &minutes); (void) snprintf (buffer, STRINGBUFFSIZE, "%.f° %.f' %.2f\" ", theAngle, minutes, seconds*60); break; } } void formatLat (double latitude) { double latAbs = fabs (latitude); formatAngle (latAbs, latString); (void) strcat (latString, latitude < 0 ? "S" : latitude > 0 ? "N" : "" ); gtk_entry_set_text(entries[LAT], latString ); } void formatLong (double longitude) { double longAbs = fabs (longitude); formatAngle (longAbs, longString); (void) strcat (longString, longitude < 0 ? "W" : longitude > 0 ? "E" : "" ); gtk_entry_set_text(entries[LONG], longString ); } void formatTime (double time) { if (isnan(time)==0) { (void) unix_to_iso8601(time, timeString, (int) sizeof(timeString)); } else { (void) strcpy(timeString,"n/a"); } gtk_entry_set_text(entries[TIME], timeString ); } void formatAltitude (double altitude) { if (units != METRIC) { altitude *= METERS_TO_FEET; } (void) snprintf (altString, STRINGBUFFSIZE, units != METRIC ? "%.0f feet" : "%.1f meters", altitude); gtk_entry_set_text(entries[ALT], altString ); } /* Speed in meters per second. */ void formatSpeed (double speed) { gchar *formatString = NULL; switch (units) { case KNOTS: speed *= MPS_TO_KNOTS; formatString = speed < 10.0 ? "%.1f knots" : "%f knots" ; break; case US: speed *= MPS_TO_MPH; formatString = speed < 10.0 ? "%.1f miles per hour" : "%.0f miles per hour" ; break; /* Use the default to silently handle errors and fall through * to the substitute case. */ default: units = METRIC; case METRIC: speed *= MPS_TO_KPH; formatString = speed < 10.0 ? "%.1f km per hour" : "%.0f km per hour"; break; } (void) snprintf (speedString, STRINGBUFFSIZE, formatString, speed); gtk_entry_set_text(entries[SPEED], speedString ); } /* This exists wo we can call resynch () from the menu. We don't * actually use the parameters at all. We call resynch () elsewhere in * the program. */ static void resynchWrapper ( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { resynch (); } static void resynch (void) { if (gpsdata != NULL) { (void) gps_stream(gpsdata, WATCH_DISABLE, NULL); gps_close (gpsdata); gpsdata = NULL; } setColor (&NoFixColor); gpsdata = gps_open(host, port); if (gpsdata == NULL) { if (errno < 1) { (void) fprintf (stderr, "%s: gpsd error: %s\n", baseName, gps_errstr(errno)); } else { perror (baseName); } gtk_progress_bar_set_fraction (progress, 0.0); gtk_progress_bar_set_text (progress, "No gpsd connection!"); } else { /* If we got here, we're good to go. */ gtk_progress_bar_set_text (progress, "Ahhh, a gpsd connection!"); gps_set_raw_hook (gpsdata, showData); gpsLost = false; sendWatch (); } } static void hostOkCallback (GtkWidget *widget, gpointer data) { const gchar *sandbox = NULL; /* look but don't touch */ /* Get the contents of the two entry widgets */ sandbox = gtk_entry_get_text (GTK_ENTRY (hostEntry)); if ((strlen (sandbox) < STRINGBUFFSIZE) && (sandbox != NULL)) { (void) strcpy (host, sandbox); } sandbox = gtk_entry_get_text (GTK_ENTRY (portEntry)); if ((strlen (sandbox) < STRINGBUFFSIZE) && (sandbox != NULL)) { (void) strcpy (port, sandbox); } gtk_widget_destroy (hostDialogBox); } static void hostCancelCallback (GtkWidget *widget, gpointer data) { gtk_widget_destroy (hostDialogBox); } static void hostDialog( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { GtkWidget *table = NULL; GtkWidget *child = NULL; GtkWidget *okButton = NULL; GtkWidget *cancelButton = NULL; hostDialogBox = gtk_dialog_new (); table = gtk_table_new( 2, 2, FALSE ); /* 2 rows, 2 cols */ /* Put the table in the vbox */ gtk_box_pack_start (GTK_BOX (GTK_DIALOG (hostDialogBox)->vbox), table, TRUE, TRUE, 0); { /* Creates a new right aligned label. */ child = gtk_label_new( "Host" ); gtk_misc_set_alignment(GTK_MISC(child), 1.0f, 0.5f); /* Instead of gtk_container_add, we pack this button into the * table, which has been packed into the window. */ gtk_table_attach(GTK_TABLE (table), child, 0, 1, 0, 1, XOPTIONS, YOPTIONS, XPADDING, YPADDING ); /* And now the non-editable text box to show it. */ hostEntry = gtk_entry_new (); gtk_editable_set_editable(GTK_EDITABLE (hostEntry), true); gtk_entry_set_text(GTK_ENTRY (hostEntry), host ); gtk_signal_connect (GTK_OBJECT(hostEntry), "activate", GTK_SIGNAL_FUNC(hostOkCallback), NULL); /* Instead of gtk_container_add, we pack this text entry into the * table, which has been packed into the window. */ gtk_table_attach(GTK_TABLE (table), hostEntry, 1, 2, 0, 1, XOPTIONS, YOPTIONS, XPADDING, YPADDING ); } { /* Creates a new right aligned label. */ child = gtk_label_new( "Port" ); gtk_misc_set_alignment(GTK_MISC(child), 1.0f, 0.5f); /* Instead of gtk_container_add, we pack this button into the * table, which has been packed into the window. */ gtk_table_attach(GTK_TABLE (table), child, 0, 1, 1, 2, XOPTIONS, YOPTIONS, XPADDING, YPADDING ); /* And now the non-editable text box to show it. */ portEntry = gtk_entry_new (); gtk_editable_set_editable(GTK_EDITABLE (portEntry), true); gtk_entry_set_text(GTK_ENTRY (portEntry), port ); gtk_signal_connect (GTK_OBJECT(portEntry), "activate", GTK_SIGNAL_FUNC(hostOkCallback), NULL); /* Instead of gtk_container_add, we pack this text entry into the * table, which has been packed into the window. */ gtk_table_attach(GTK_TABLE (table), portEntry, 1, 2, 1, 2, XOPTIONS, YOPTIONS, XPADDING, YPADDING ); } { okButton = gtk_button_new_from_stock (GTK_STOCK_OK); /* Connect the "clicked" signal of the button to our callback */ g_signal_connect (G_OBJECT (okButton), "clicked", G_CALLBACK (hostOkCallback), (gpointer) "OK"); gtk_box_pack_start (GTK_BOX (GTK_DIALOG (hostDialogBox)->action_area), okButton, TRUE, TRUE, 0); } { cancelButton = gtk_button_new_from_stock (GTK_STOCK_CANCEL); /* Connect the "clicked" signal of the button to our callback */ g_signal_connect (G_OBJECT (cancelButton), "clicked", G_CALLBACK (hostCancelCallback), (gpointer) "Cancel"); gtk_box_pack_start (GTK_BOX (GTK_DIALOG (hostDialogBox)->action_area), cancelButton, TRUE, TRUE, 0); } /* Always remember this step, this tells GTK that our preparation * for this window is complete, and it can now be displayed. */ gtk_widget_show_all (hostDialogBox); } /* Some properties string arrays for the About dialog. */ gchar *authors[2] = { "Charles Curley, http://www.charlescurley.com/", NULL }; gchar *documentors[2] = { "Charles Curley, http://www.charlescurley.com/", NULL }; static void aboutDialog( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { gtk_show_about_dialog (GTK_WINDOW (window), "authors", authors, "comments", "A simple GTK+ GPS monitor.\n\nRed: No fix.\nYellow: Two dimensional fix.\nGreen: Three dimensional fix.\n\"Save\" to save settings such as font and units.", "copyright", "Copyright © 2009-2010 Charles Curley.", "documenters", documentors, "license", "This program is released under the same terms as gpsd itself, i.e under the BSD License. See the file COPYING in the distribution.\nThis program comes with ABSOLUTELY NO WARRANTY.\n", "program-name", baseName, "translator-credits", "Your name here?", "website", "http://www.charlescurley.com/", "wrap-license", TRUE, NULL); } /* Build the menu */ static GtkItemFactoryEntry menu_items[] = { /* menu hierarchy Accel Function action Type */ { "/_File", NULL, NULL, 0, "<Branch>" }, { "/File/_Font", "<ctrl>f", setFont, 0, "<StockItem>", GTK_STOCK_SELECT_FONT }, { "/File/_Save", "<ctrl>s", saveState, 0, "<StockItem>", GTK_STOCK_SAVE }, { "/File/_Quit", "<ctrl>q", destroy, 0, "<StockItem>", GTK_STOCK_QUIT }, { "/_Units", NULL, NULL, 0, "<Branch>" }, { "/Units/_Metric", "<ctrl>m", setUnits, METRIC, "<RadioItem>" }, { "/Units/_US", "<ctrl>i", setUnits, US, "/Units/Metric" }, { "/Units/_Knots", "<ctrl>k", setUnits, KNOTS, "/Units/Metric" }, { "/_Degrees", NULL, NULL, 0, "<Branch>" }, { "/Degrees/_ddd.ddddd", "<ctrl>d", setDegrees, DEGREES, "<RadioItem>" }, { "/Degrees/ddd _mm.mmmm", "<ctrl>n", setDegrees, MINUTES, "/Degrees/ddd.ddddd" }, { "/Degrees/ddd mm _ss.ss", "<ctrl>s", setDegrees, SECONDS, "/Degrees/ddd.ddddd" }, { "/_Host", NULL, NULL, 0, "<Branch>" }, { "/_Host/_Resynch", "<ctrl>r", resynchWrapper, 0, "<StockItem>", GTK_STOCK_REFRESH }, { "/_Host/_Host", "<ctrl>h", hostDialog, 0, "<StockItem>", GTK_STOCK_NETWORK }, { "/_Help", NULL, NULL, 0, "<Branch>" }, { "/_Help/_About", "<ctrl>a", aboutDialog, 0, "<StockItem>", GTK_STOCK_ABOUT }, }; /* Now some functions for the menu */ static void setUnits( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { units = callback_action; } /* Now some functions for the menu */ static void setDegrees( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { angle = callback_action; } /* Now some functions for the menu */ static void saveState( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { if (haveHome) { saveKeyFile (keyFile); } } static void fontApplyCallback (GtkWidget *widget, gpointer data) { gchar *theFont = NULL; theFont = gtk_font_selection_dialog_get_font_name (GTK_FONT_SELECTION_DIALOG (fontDialog)); if (theFont != NULL) { GtkRcStyle *style; GdkColor *color; gint i; style = gtk_rc_style_new (); pango_font_description_free (style->font_desc); style->font_desc = pango_font_description_from_string (theFont); for ( i=0; i < SIZE; i++) { if (entries[i] != NULL) { gtk_widget_modify_style (GTK_WIDGET (entries[i]), style); } } gtk_widget_modify_style (GTK_WIDGET (progress), style); g_free (theFont); /* Now fox the color setting code. It actually changes colors * only if the parameter color != the old color we saved last * time it ran. */ color = oldColor; oldColor = NULL; setColor (color); } } static void fontOkCallback (GtkWidget *widget, gpointer data) { fontApplyCallback (widget, data); gtk_widget_destroy (fontDialog); } static void setFont( gpointer callback_data, guint callback_action, GtkWidget *menu_item ) { gchar title[STRINGBUFFSIZE]; const gchar *fontName; GtkStyle *style; (void) snprintf (title, STRINGBUFFSIZE, "%s: Select a font", baseName); fontDialog = gtk_font_selection_dialog_new (title); /* Now we jump through some hoops to get the existing font so we * can set the default to it instead of the system default. We use * one of the text entry widgets because their fonts are set by * this dialog. */ style = gtk_widget_get_style (GTK_WIDGET (entries[TIME])); fontName = pango_font_description_to_string (style->font_desc); (void) gtk_font_selection_dialog_set_font_name (GTK_FONT_SELECTION_DIALOG (fontDialog), fontName); gtk_font_selection_dialog_set_preview_text ( GTK_FONT_SELECTION_DIALOG(fontDialog), timeString); g_signal_connect (GTK_FONT_SELECTION_DIALOG (fontDialog)->ok_button, "clicked", G_CALLBACK (fontOkCallback), NULL); g_signal_connect (GTK_FONT_SELECTION_DIALOG (fontDialog)->apply_button, "clicked", G_CALLBACK (fontApplyCallback), NULL); g_signal_connect_swapped (GTK_FONT_SELECTION_DIALOG (fontDialog)->cancel_button, "clicked", G_CALLBACK (gtk_widget_destroy), fontDialog); gtk_widget_show_all (fontDialog); } static gint nmenu_items = sizeof (menu_items) / sizeof (menu_items[0]); /* Returns a menubar widget from the menu */ static GtkWidget *get_menubar_menu( GtkWidget *window ) { /* Make an accelerator group (shortcut keys) */ accel_group = gtk_accel_group_new (); /* Make an ItemFactory (that makes a menubar) */ item_factory = gtk_item_factory_new (GTK_TYPE_MENU_BAR, "<main>", accel_group); /* This function generates the menu items. Pass the item factory, the number of items in the array, the array itself, and any callback data for the the menu items. */ gtk_item_factory_create_items (item_factory, nmenu_items, menu_items, NULL); /* Attach the new accelerator group to the window. */ gtk_window_add_accel_group (GTK_WINDOW (window), accel_group); /* Finally, return the actual menu bar created by the item factory. */ return gtk_item_factory_get_widget (item_factory, "<main>"); } /* The libgps callback function. */ void showData (struct gps_data_t *gpsdata, char *message, /* The string(s) from GPSd from which libgps reconstructs the data we use. */ size_t len) { /* I think this is the length of * message. */ char tmpBuff[STRINGBUFFSIZE]; /* generic temporary holding. */ char *fixStatus = "DGPS "; /* Default, if we even use it. */ /* Some things we ignore. */ if (gpsdata->set & POLICY_SET) { gpsdata->set &= ~(POLICY_SET); return; } /* Fill in receiver type. Detect missing gps receiver. */ if (gpsdata->set & (DEVICE_SET)) { if (gpsdata->dev.activated < 1.0) { sendWatch (); gpsLost = true; gtk_progress_bar_set_fraction (progress, 0.0); gtk_progress_bar_set_text (progress, "GPS lost!"); setColor (&NoFixColor); if (verbose) { (void) fprintf (stderr, "gps lost.\n"); (void) strcpy (tmpBuff, "driver = nil: subtype = nil: activated = 0.0"); } } else { gpsLost = false; /* Old versions of printf would break if presented with a string * of 0 length. OK, I'm paranoid, deal with it. */ if (strlen (gpsdata->dev.driver)) { (void) snprintf(tmpBuff, sizeof(tmpBuff), "%s GPS Found!", gpsdata->dev.driver); } else { (void) strcpy (tmpBuff, "GPS Found!"); } sendWatch (); gtk_progress_bar_set_text (progress, tmpBuff); if (verbose) { (void) snprintf(tmpBuff, sizeof(tmpBuff), "driver = %s: subtype = %s: activated = %f", gpsdata->dev.driver, gpsdata->dev.subtype, gpsdata->dev.activated); (void) printf ("gps found.\n"); } } if (verbose) { (void) printf ("set 0x%08x, (device) GPS Driver: %s\n", gpsdata->set, tmpBuff); } return; } if ((gpsdata->set & DEVICELIST_SET) && verbose) { if (gpsdata->devices.ndevices == 1) { if (gpsdata->devices.list[0].activated < 1.0) { (void) strcpy (tmpBuff, "driver = nil: subtype = nil: activated = 0.0"); } else { (void) snprintf(tmpBuff, sizeof(tmpBuff), "driver = %s: subtype = %s: activated = %f", gpsdata->devices.list[0].driver, gpsdata->devices.list[0].subtype, gpsdata->devices.list[0].activated); } } else { /* We have multiple devices, which I've never seen, so * punt. */ (void) snprintf(tmpBuff, sizeof(tmpBuff), "%d devices", gpsdata->devices.ndevices); } (void) printf ("set 0x%08x, (Devices) GPS Driver: %s\n", gpsdata->set, tmpBuff); return; } if (gpsdata->set & TIME_SET) { formatTime (gpsdata->fix.time); } if (gpsdata->set & VERSION_SET && (verbose != false)) { (void) printf ("set 0x%08x, GPSD version: %s Rev: %s, Protocol %d.%d\n", gpsdata->set, gpsdata->version.release, gpsdata->version.rev, gpsdata->version.proto_major, gpsdata->version.proto_minor); } if (gpsdata->set & SPEED_SET) { formatSpeed (gpsdata->fix.speed); } if (gpsdata->set & TRACK_SET) { formatTrack (gpsdata->fix.track); } /* A nice and unusual use of a progress bar, if I say so * myself. */ if (gpsdata->set & SATELLITE_SET) { gchar banner[STRINGBUFFSIZE]; /* Guard against division of or by 0. */ if (gpsdata->satellites_visible > 0 && gpsdata->satellites_used > 0) { gtk_progress_bar_set_fraction (progress, (gdouble) gpsdata->satellites_used/ (gdouble) gpsdata->satellites_visible); (void) snprintf (banner, STRINGBUFFSIZE, "%2d satellites visible, %2d used in the fix.", gpsdata->satellites_visible, gpsdata->satellites_used); } else { gtk_progress_bar_set_fraction (progress, 0.0); (void) snprintf (banner, STRINGBUFFSIZE, "%2d satellites visible, no fix.", gpsdata->satellites_visible); } gtk_progress_bar_set_text (progress, banner); if (verbose) { (void) printf ("set 0x%08x, %s\n", gpsdata->set, banner); } } if (gpsdata->set & STATUS_SET) { switch (gpsdata->status) { case STATUS_NO_FIX: (void) strcpy (fixBuff, "No fix"); setColor (&NoFixColor); break; case STATUS_FIX: (void) strcpy (fixBuff, "No fix"); fixStatus = ""; case STATUS_DGPS_FIX: if (gpsdata->set & MODE_SET) { switch (gpsdata->fix.mode) { case MODE_NOT_SEEN: (void) strcpy (fixBuff, "Fix not yet seen"); setColor (&NoFixColor); break; case MODE_NO_FIX: (void) strcpy (fixBuff, "No fix yet"); setColor (&NoFixColor); break; case MODE_2D: if ((gpsdata->set & LATLON_SET)) { formatLat (gpsdata->fix.latitude); formatLong (gpsdata->fix.longitude); setColor (&TwoDFixColor); if (verbose) { (void) snprintf (fixBuff, STRINGBUFFSIZE, "2D %sFix, la %f, lo %f", fixStatus, gpsdata->fix.latitude, gpsdata->fix.longitude); } } break; case MODE_3D: if ((gpsdata->set & (LATLON_SET|ALTITUDE_SET))) { formatLat (gpsdata->fix.latitude); formatLong (gpsdata->fix.longitude); /* Only if we have a fix are the details of it useful. Altitude is only meaningful on a 3D fix. */ formatAltitude (gpsdata->fix.altitude); setColor (&ThreeDFixColor); if (verbose) { (void) snprintf (fixBuff, STRINGBUFFSIZE, "3D %sFix, la %f, lo %f, %f", fixStatus, gpsdata->fix.latitude, gpsdata->fix.longitude, gpsdata->fix.altitude); } } break; default: (void) fprintf (stderr, "%s: Catastrophic error: Invalid mode %d.\n", baseName, gpsdata->fix.mode); setColor (&NoFixColor); return; } /* fix.mode */ } /* MODE_SET */ break; default: (void) fprintf (stderr, "Catastrophic error: Invalid status %d.\n", gpsdata->status); setColor (&NoFixColor); return; } if (verbose) { (void) printf ("set 0x%08x, mode %d, %s, %s.\n", gpsdata->set, gpsdata->fix.mode, timeString, fixBuff); } } /* STATUS_SET */ } /* Build a pair of display widgets, a label followed by an entry * box. */ static void buildPair (gint index, gchar *labelText, GtkWidget *table, gint left, gint top) { GtkWidget *child; left <<= 1; /* Convert pair co-ordinates to row * co-ordinates by multiplying by * 2. */ /* Creates a new right aligned label. */ child = gtk_label_new( labelText ); gtk_misc_set_alignment(GTK_MISC(child), 1.0f, 0.5f); /* Instead of gtk_container_add, we pack this button into the * table, which has been packed into the window. */ gtk_table_attach(GTK_TABLE (table), child, left, left+1, top, top+1, XOPTIONS, YOPTIONS, XPADDING, YPADDING ); /* And now the non-editable text box to show it. */ child = gtk_entry_new (); gtk_editable_set_editable(GTK_EDITABLE (child), true); gtk_entry_set_text(GTK_ENTRY (child), "Not Yet Seen" ); /* Now ask for a slightly longer time widget. */ gtk_entry_set_width_chars (GTK_ENTRY (child), left ? 22 : 17); /* Instead of gtk_container_add, we pack this text entry into the * table, which has been packed into the window. */ gtk_table_attach(GTK_TABLE (table), child, left+1, left+2, top, top+1, XOPTIONS, YOPTIONS, XPADDING, YPADDING ); /* Add it to the table so we can access it later to change its * text and color. */ preserve (GTK_ENTRY (child), index); } /* Return true so we get called forever. */ gint gpsPoll (gpointer data) { if (gpsdata == NULL ) { resynch (); return (true); } if (gps_waiting (gpsdata)) { errno = 0; if (gps_poll (gpsdata) == -1) { if (errno == 0) { gtk_progress_bar_set_text (progress, "Lost contact with gpsd."); } else { gtk_progress_bar_set_text (progress, "Something went wrong."); } gtk_progress_bar_set_fraction (progress, 0.0); resynch (); } } return (true); } /* Collect our changed settings and preserve them. */ void saveKeyFile (GKeyFile *keyFile) { FILE *file; gchar *string = NULL; gsize length = 0; gsize size = 0; gchar sandbox[128]; GtkStyle *style; const gchar *fontName; if (haveHome == false) { return; } g_key_file_set_value (keyFile, baseName, "host", host); g_key_file_set_value (keyFile, baseName, "port", port); sandbox [1] = '\0'; sandbox [0] = angle; g_key_file_set_value (keyFile, baseName, "angle", sandbox); sandbox [0] = units; g_key_file_set_value (keyFile, baseName, "units", sandbox); /* Now we jump through some hoops to get the existing font so we * save it. We use one of the text entry widgets because their * fonts are set by this dialog. */ style = gtk_widget_get_style (GTK_WIDGET (entries[TIME])); fontName = pango_font_description_to_string (style->font_desc); g_key_file_set_value (keyFile, baseName, "font", fontName); string = g_key_file_to_data (keyFile, &length, NULL); if (length > 0 && string != NULL) { if (verbose) { (void) printf ("Length: %d. Configuration string: '%s'\n", length, string); } file = fopen (keyFileName, "w"); if (file == NULL) { (void) fprintf (stderr, "Could not open file '%s'.\n", keyFileName); return; } size = fwrite (string, length, 1, file); if (size != 1) { (void) fprintf (stderr, "Failure writing to file '%s'.\n", keyFileName); return; } (void) fclose (file); } } /* Having initialized the angles, we had better set the menu entry to * selected as well. See the notes where 'units' is defined. */ void setActiveAngle (void) { switch (angle) { /* Use the default to silently handle errors and fall through * to the substitute case. */ default: angle = DEGREES; case DEGREES: gtk_check_menu_item_set_active( GTK_CHECK_MENU_ITEM (gtk_item_factory_get_item (item_factory, "/Degrees/ddd.ddddd")), TRUE); break; case MINUTES: gtk_check_menu_item_set_active( GTK_CHECK_MENU_ITEM (gtk_item_factory_get_item (item_factory, "/Degrees/ddd mm.mmmm")), TRUE); break; case SECONDS: gtk_check_menu_item_set_active( GTK_CHECK_MENU_ITEM (gtk_item_factory_get_item (item_factory, "/Degrees/ddd mm ss.ss")), TRUE); break; } } /* Having initialized the units, we had better set the menu entry to * selected as well. See the notes where 'units' is defined. */ void setActiveUnits (void) { switch (units) { /* Use the default to silently handle errors and fall through * to the substitute case. */ default: units = US; case US: gtk_check_menu_item_set_active( GTK_CHECK_MENU_ITEM (gtk_item_factory_get_item (item_factory, "/Units/US")), TRUE); break; case KNOTS: gtk_check_menu_item_set_active( GTK_CHECK_MENU_ITEM (gtk_item_factory_get_item (item_factory, "/Units/Knots")), TRUE); break; case METRIC: gtk_check_menu_item_set_active( GTK_CHECK_MENU_ITEM (gtk_item_factory_get_item (item_factory, "/Units/Metric")), TRUE); break; } } int main ( int argc, char *argv[] ) { int ret = 0; int i; /* gfile variables. Swiped from * http://www.gtkbook.com/tutorial.php?page=keyfile. I may have to * buy the book. */ GKeyFileFlags flags; GError *error = NULL; settings *conf = NULL; /* Clean out the list of entries so we can check for ones not * initialized. */ for ( i=0 ; i < SIZE; i++) { entries[i] = NULL; } baseName = g_get_application_name (); if (baseName == NULL) { baseName = g_path_get_basename (g_strdup (argv[0])); } (void) printf ("\n%s: Copyright © 2010 Charles Curley\n", baseName); (void) printf ("This program is released under the same terms as gpsd itself, i.e.\n"); (void) printf ("under the BSD License. See the file Copying in the gpsd distribution.\n"); (void) printf ("\nThis program comes with ABSOLUTELY NO WARRANTY.\n"); /* gfile setup. Do this first, then see if the user overrides with * command line options later. */ { const gchar *home = NULL; home = g_getenv ("HOME"); if (home == NULL) { (void) fprintf (stderr, "%s: HOME environment variable not set.\n", baseName); (void) fprintf (stderr, "%s needs it to find its configuration file.\n", baseName); } else { if (strlen (home) + strlen (baseName) + 2 >= STRINGBUFFSIZE) { (void) fprintf (stderr, "%s: resource file name is too long.\n", baseName); return (3); } haveHome = true; (void) strncpy (keyFileName, home, STRINGBUFFSIZE); (void) strcat (keyFileName, "/."); (void) strcat (keyFileName, baseName); keyFile = g_key_file_new (); flags = G_KEY_FILE_KEEP_COMMENTS | G_KEY_FILE_KEEP_TRANSLATIONS; /* Load the GKeyFile from keyfile.conf if it exists. If it * doesn't exist, punt. */ (void) g_key_file_load_from_file (keyFile, keyFileName, flags, &error); /* Create a new Settings object. If you are using GTK+ 2.8 or below, you should * use g_new() or g_malloc() instead! */ conf = g_slice_new (settings); conf->host = g_key_file_get_string ( keyFile, baseName, "host", NULL); if (conf->host != NULL && strlen (conf->host) > 0) { host = conf->host; } conf->port = g_key_file_get_string ( keyFile, baseName, "port", NULL); if (conf->port != NULL && strlen (conf->port) > 0) { port = conf->port; } conf->angle = g_key_file_get_string ( keyFile, baseName, "angle", NULL); if (conf->angle != NULL && strlen (conf->angle) > 0) { /* Assume some bozo will edit it. */ angle = tolower (conf->angle[0]); } conf->units = g_key_file_get_string ( keyFile, baseName, "units", NULL); if (conf->units != NULL && strlen (conf->units) > 0) { /* Assume some bozo will edit it. */ units = tolower (conf->units[0]); } conf->font = NULL; conf->font = g_key_file_get_string ( keyFile, baseName, "font", NULL); } } /* This is called in all GTK applications. Arguments are parsed * from the command line and are returned to the application. */ gtk_init (&argc, &argv); /* for option processing. */ char *optstring = "d:kmp:uvV"; int opt = 0; while (( opt = getopt (argc, argv, optstring)) != -1) { switch (opt) { case 'd': switch (tolower (*optarg)) { case DEGREES: angle = DEGREES; break; case MINUTES: angle = MINUTES; break; case SECONDS: angle = SECONDS; break; default: (void) fprintf (stderr, "\nDegrees must be one of 'd', ddd.ddddd;\n"); (void) fprintf (stderr, "'m', ddd mm.mmmm; or 's', dd mm ss.ss\n"); return (-2); } break; case US: units = opt; break; case KNOTS: units = opt; break; case METRIC: units = opt; break; case 'p': (void) strncpy (hostPort, optarg, STRINGBUFFSIZE); port = hostPort; break; case 'v': verbose = true; break; case 'V': /* N.b.: falls through to the default case! */ (void) fprintf (stderr, "%s,\nCompiled for gpsd API version %d.%d.\n", versionString, GPSD_API_MAJOR_VERSION, GPSD_API_MINOR_VERSION); default: /* '?' */ (void) fprintf(stderr, "Usage: %s [-d d] [-m] [-k] [-p port] [-u] [-v] [-V] [host]\n", baseName); return(-2); } } if (optind != argc) { /* we have a host name.... */ (void) strncpy (hostName, argv[optind], STRINGBUFFSIZE); host = hostName; } { /* create a new window */ window = gtk_window_new (GTK_WINDOW_TOPLEVEL); /* When the window is given the "delete_event" signal (this is * given by the window manager, usually by the "close" option, * or on the titlebar), we ask it to call the delete_event () * function as defined above. */ g_signal_connect (G_OBJECT (window), "delete_event", G_CALLBACK (delete_event), (gpointer) "Done"); /* Here we connect the "destroy" event to a signal handler. * This event occurs when we call gtk_widget_destroy() on the * window, or if we return FALSE in the "delete_event" * callback. */ g_signal_connect (G_OBJECT (window), "destroy", G_CALLBACK (destroy), (gpointer) "Destroy"); /* Sets the border width of the window. */ gtk_container_set_border_width (GTK_CONTAINER (window), 1); /* And a title */ char titleBuff[STRINGBUFFSIZE]; (void) snprintf (titleBuff, STRINGBUFFSIZE, "%s: a simple GTK+ GPS monitor", baseName); gtk_window_set_title (GTK_WINDOW (window), titleBuff); } /* Build a vertical box. Into it we will put the menu bar, and * then the table containing all the labels and entry widgets. */ { vbox = gtk_vbox_new (FALSE, 1); gtk_container_set_border_width (GTK_CONTAINER (vbox), 1); gtk_container_add (GTK_CONTAINER (window), vbox); } /* Build and show the menu bar */ { menubar = get_menubar_menu (window); gtk_box_pack_start (GTK_BOX (vbox), menubar, FALSE, TRUE, 0); } /* Build the table we'll stuff everything into. Heterogeneous * layout, please. */ { table = gtk_table_new( ROWS, COLS, FALSE ); /* Put the table in the vbox */ gtk_container_add (GTK_CONTAINER (vbox), table); } /* Build pairs of widgets: a label, followed by a text entry * box. The table size is ROWS x COLS, based on a count of widgets * in the row. Co-ordinates here are for pairs, so the column * numbers are half what they would be for widgets. 0,0 is the * upper left, as with widgets. */ buildPair (LAT, "Lat", table, 0, 0); buildPair (LONG, "Long", table, 1, 0); buildPair (SPEED, "Speed", table, 0, 1); buildPair (TRACK, "Track", table, 1, 1); buildPair (ALT, "Alt", table, 0, 2); buildPair (TIME, "Time", table, 1, 2); /* Set up the satellite progress bar. */ progress = (GtkProgressBar *) gtk_progress_bar_new (); gtk_progress_bar_set_fraction (progress, 0.0); gtk_progress_bar_set_text (progress, "We've seen no data yet."); gtk_box_pack_end (GTK_BOX (vbox), GTK_WIDGET (progress), FALSE, TRUE, 0); if (conf->font != NULL && strlen (conf->font) > 0) { GtkRcStyle *style; style = gtk_rc_style_new (); pango_font_description_free (style->font_desc); style->font_desc = pango_font_description_from_string (conf->font); for ( i=0; i < SIZE; i++) { if (entries[i] != NULL) { gtk_widget_modify_style (GTK_WIDGET (entries[i]), style); /* Reset the width of the widget. */ } } gtk_widget_modify_style (GTK_WIDGET (progress), style); } /* Always remember this step, this tells GTK that our preparation * for this window is complete, and it can now be displayed. */ gtk_widget_show_all (window); setColor (&NoFixColor); setActiveAngle (); setActiveUnits (); /* (void) printf ("Host is %s, port is %s\n", host, port); */ resynch (); /* Now set up our idle function. */ tag = g_timeout_add ((guint32)250, gpsPoll, NULL); /* All GTK applications must have a gtk_main(). Control ends here * and waits for an event to occur (like a key press or mouse * event). */ gtk_main (); if (baseName != NULL) { g_free((gpointer) baseName); } if (keyFile != NULL) { g_free(keyFile); } return (ret); }
Changes
2010-05-16: Added void casts where appropriate. Cleaned up the style a bit. Made error messaging when the GPS receiver goes away a bit clearer.
2010-06-27: Better detect a missing GPS receiver and a new GPS receiver. Prototypes for all functions. Better resych () factoring. Use the progress bar for more error messages, e.g. GPS receivers or gpsd going AWOL. Other cleanup.