Prepare for queued event handling

The current grail operates via callbacks. In order to make grail work
as a pipe, where input and output can be controlled externally, add
the missing event queue for gestures, and align the code to simplify a
switch.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 60 insertions, 0 deletions

diff --git a/src/grailbuf.h b/src/grailbuf.h
new file mode 100644
index 0000000..b319d24
--- /dev/null
+++ b/src/grailbuf.h
@@ -0,0 +1,60 @@
+/*****************************************************************************
+ *
+ * grail - Gesture Recognition And Instantiation Library
+ *
+ * Copyright (C) 2010 Canonical Ltd.
+ * Copyright (C) 2010 Henrik Rydberg <rydberg@bitmath.org>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ****************************************************************************/
+
+#ifndef _GRAIL_BUFFER_H
+#define _GRAIL_BUFFER_H
+
+#include <grail.h>
+
+#define DIM_GRAIL_EVENTS 512
+
+struct grailbuf {
+        int head;
+        int tail;
+        struct grail_event buffer[DIM_GRAIL_EVENTS];
+};
+
+static inline void grailbuf_clear(struct grailbuf *buf)
+{
+        buf->head = buf->tail = 0;
+}
+
+static inline int grailbuf_empty(const struct grailbuf *buf)
+{
+        return buf->head == buf->tail;
+}
+
+static inline void grailbuf_put(struct grailbuf *buf,
+                                const struct grail_event *ev)
+{
+        buf->buffer[buf->head++] = *ev;
+        buf->head &= DIM_GRAIL_EVENTS - 1;
+}
+
+static inline void grailbuf_get(struct grailbuf *buf,
+                                struct grail_event *ev)
+{
+        *ev = buf->buffer[buf->tail++];
+        buf->tail &= DIM_GRAIL_EVENTS - 1;
+}
+
+#endif