modem-helpers: add utility function to split DTMF runs

Split into groups of non-pause characters and single pause characters
by themselves and return as an array of strings.

Signed-off-by: Dan Williams <dan@ioncontrol.co>

src/mm-base-call.h

@@ -41,8 +41,6 @@ typedef struct _MMBaseCallPrivate MMBaseCallPrivate;
 #define MM_CALL_NUMBER             "number"
 #define MM_CALL_DTMF_TONE_DURATION "dtmf-tone-duration"
 
-#define MM_CALL_DTMF_PAUSE_CHAR ','
-
 #define MM_BASE_CALL_PATH                        "call-path"
 #define MM_BASE_CALL_CONNECTION                  "call-connection"
 #define MM_BASE_CALL_IFACE_MODEM_VOICE           "call-iface-modem-voice"

src/mm-modem-helpers.c

@@ -5887,3 +5887,37 @@ mm_dtmf_duration_normalize (guint duration_ms)
 
     return CLAMP (duration_ms, 100, 1000);
 }
+
+GPtrArray *
+mm_dtmf_split (const gchar *dtmf)
+{
+    GPtrArray   *array;
+    const gchar *p = dtmf;
+    GString     *cur = NULL;
+
+    array = g_ptr_array_new ();
+
+    while (*p) {
+        if (*p == MM_CALL_DTMF_PAUSE_CHAR) {
+            if (cur) {
+                g_ptr_array_add (array, g_string_free (cur, FALSE));
+                cur = NULL;
+            }
+            g_ptr_array_add (array, g_strdup (","));
+        } else {
+            if (!cur)
+                cur = g_string_new (NULL);
+            g_string_append_c (cur, *p);
+        }
+        p++;
+    }
+    if (cur)
+        g_ptr_array_add (array, g_string_free (cur, FALSE));
+
+    if (array->len == 0) {
+        g_ptr_array_free (array, TRUE);
+        return NULL;
+    }
+
+    return array;
+}

src/mm-modem-helpers.h

@@ -648,4 +648,8 @@ MMModemLock mm_parse_cpin_response (const gchar *response,
 /* Helper to clamp duration and round to next 100ms */
 guint mm_dtmf_duration_normalize (guint duration_ms);
 
+#define MM_CALL_DTMF_PAUSE_CHAR ','
+
+GPtrArray *mm_dtmf_split (const gchar *dtmf);
+
 #endif  /* MM_MODEM_HELPERS_H */

src/tests/test-modem-helpers.c

@@ -5120,6 +5120,44 @@ test_cpin_response (void)
 
 /*****************************************************************************/
 
+typedef struct {
+    const char *desc;
+    const char *dtmf;
+    const char *expected[5];
+} DtmfTestData;
+
+static const DtmfTestData test_dtmf_data[] = {
+    { "/MM/ModemHelpers/DTMF/empty",     "",         { NULL } },
+    { "/MM/ModemHelpers/DTMF/one",       "1",        { "1", NULL } },
+    { "/MM/ModemHelpers/DTMF/no-pause",  "1234",     { "1234", NULL } },
+    { "/MM/ModemHelpers/DTMF/mid-pause", "123,,456", { "123", ",", ",", "456", NULL } },
+    { "/MM/ModemHelpers/DTMF/end-pause", "123,,",    { "123", ",", ",", NULL } },
+};
+
+static void
+test_dtmf_split (gpointer user_data)
+{
+    DtmfTestData *td = user_data;
+    GPtrArray *split;
+    guint expected_len;
+    guint i;
+
+    split = mm_dtmf_split (td->dtmf);
+
+    expected_len = g_strv_length ((gchar **) td->expected);
+    if (expected_len == 0)
+        g_assert_true (split == NULL);
+    else {
+        g_assert_true (split != NULL);
+        g_assert_cmpint (split->len, ==, expected_len);
+    }
+
+    for (i = 0; i < expected_len; i++)
+        g_assert_cmpstr (td->expected[i], ==, g_ptr_array_index (split, i));
+}
+
+/*****************************************************************************/
+
 #define TESTCASE(t, d) g_test_create_case (#t, 0, d, NULL, (GTestFixtureFunc) t, NULL)
 
 int main (int argc, char **argv)
@@ -5128,6 +5166,7 @@ int main (int argc, char **argv)
     RegTestData *reg_data;
     gint result;
     DevidItem *item = &devids[0];
+    guint i;
 
     g_test_init (&argc, &argv, NULL);
 
@@ -5384,6 +5423,12 @@ int main (int argc, char **argv)
 
     g_test_suite_add (suite, TESTCASE (test_cpin_response, NULL));
 
+    for (i = 0; i < G_N_ELEMENTS (test_dtmf_data); i++) {
+        g_test_add_data_func (test_dtmf_data[i].desc,
+                              &test_dtmf_data[i],
+                              (GTestDataFunc) test_dtmf_split);
+    }
+
     result = g_test_run ();
 
     reg_test_data_free (reg_data);