2 files changed, 31 insertions, 0 deletions

diff --git a/include/utouch/frame.h b/include/utouch/frame.h
index 5b5f4d2..03a44aa 100644
--- a/include/utouch/frame.h
+++ b/include/utouch/frame.h
@@ -250,6 +250,17 @@ struct utouch_contact *utouch_frame_get_current_slot(utouch_frame_handle fh);
 int utouch_frame_set_current_slot(utouch_frame_handle fh, int slot);
 
 /**
+ * utouch_frame_set_current_id - set the current slot by touch id
+ * @fh: the frame engine in use
+ * @id: the touch id
+ *
+ * Sets the slot currently being modified, by touch id. If the id is
+ * not currently in use (does not have an active slot), a new slot is
+ * assigned. Returns zero if successful, negative error otherwise.
+ */
+int utouch_frame_set_current_id(utouch_frame_handle fh, int id);
+
+/**
  * utouch_frame_sync - synchronize and return new frame
  * @fh: the frame engine in use
  * @time: the frame synchronization time (ms)
diff --git a/src/frame.c b/src/frame.c
index e722adf..061b170 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -205,6 +205,26 @@ int utouch_frame_set_current_slot(utouch_frame_handle fh, int slot)
         return 0;
 }
 
+int utouch_frame_set_current_id(utouch_frame_handle fh, int id)
+{
+        struct utouch_contact *t;
+        int i;
+
+        for (i = 0; i < fh->num_slots; i++) {
+                t = fh->next->slots[i];
+                if (t->id == id)
+                        return utouch_frame_set_current_slot(fh, i);
+        }
+        for (i = 0; i < fh->num_slots; i++) {
+                t = fh->next->slots[i];
+                if (t->id < 0) {
+                        t->id = id;
+                        return utouch_frame_set_current_slot(fh, i);
+                }
+        }
+        return -ENOMEM;
+}
+
 static void transform_slot(struct utouch_contact *slot,
                            const struct utouch_surface *s)
 {