Improve the dive computer device selection

We try to identify devices that are connected and their matching device
names (and mount paths in the case of the Uemis Zurich). Those are
presented as a drop down menu to choose from. The user can still override
this by simply entering a different device / path name.

On Windows this is not functional. How do I find out which drive letter
corresponds to the USB device named "UEMISSDA"? Similarly we need code
that finds serial ports that are present. For now we once again default
to COM3 (so this isn't a step back, but of course it's far from what we
want).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 57 insertions, 2 deletions

diff --git a/linux.c b/linux.c
index b32bde8c1..45fb02da4 100644
--- a/linux.c
+++ b/linux.c
@@ -56,9 +56,64 @@ void subsurface_close_conf(void)
 	/* this is a no-op */
 }
 
-const char *subsurface_USB_name()
+int subsurface_fill_device_list(GtkListStore *store)
 {
-	return "/dev/ttyUSB0";
+	int i = 0;
+	int index = -1;
+	GtkTreeIter iter;
+	GDir *dev;
+	const char *name;
+	char *buffer;
+	gsize length;
+
+	dev = g_dir_open("/dev", 0, NULL);
+	while (dev && (name = g_dir_read_name(dev)) != NULL) {
+		if (strstr(name, "USB")) {
+			int len = strlen(name) + 6;
+			char *devicename = malloc(len);
+			snprintf(devicename, len, "/dev/%s", name);
+			gtk_list_store_append(store, &iter);
+			gtk_list_store_set(store, &iter,
+					0, devicename, -1);
+			if (is_default_dive_computer_device(devicename))
+				index = i;
+			i++;
+		}
+	}
+	if (dev)
+		g_dir_close(dev);
+	if (g_file_get_contents("/proc/mounts", &buffer, &length, NULL) &&
+		length > 0) {
+		char *ptr = strstr(buffer, "UEMISSDA");
+		if (ptr) {
+			char *end = ptr, *start = ptr;
+			while (start > buffer && *start != ' ')
+				start--;
+			if (*start == ' ')
+				start++;
+			while (*end != ' ' && *end != '\0')
+				end++;
+			*end = '\0';
+			name = strdup(start);
+			gtk_list_store_append(store, &iter);
+			gtk_list_store_set(store, &iter,
+					0, name, -1);
+			if (is_default_dive_computer_device(name))
+				index = i;
+			i++;
+			free((void *)name);
+		}
+		g_free(buffer);
+	}
+	if (i == 0) {
+		/* if we can't find anything, use the default */
+		gtk_list_store_append(store, &iter);
+		gtk_list_store_set(store, &iter,
+				0, "/dev/ttyUSB0", -1);
+		if (is_default_dive_computer_device("/dev/ttyUSB0"))
+			index = i;
+	}
+	return index;
 }
 
 const char *subsurface_icon_name()