Add the shell for a multitouch-compatible touchpad implementation

Doesn't do anything but initialize and destroy. This is not a permanent
separate implementation, it's just easier to start this way and then switch
over than to add to the current one.

Temporary measure: LIBINPUT_NEW_TOUCHPAD_DRIVER environment variable can be
used to enable the new driver

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

src/Makefile.am

@@ -11,6 +11,7 @@ libinput_la_SOURCES =			\
 	libinput-util.h			\
 	evdev.c				\
 	evdev.h				\
+	evdev-mt-touchpad.c		\
 	evdev-touchpad.c		\
 	filter.c			\
 	filter.h			\

src/evdev-mt-touchpad.c

@@ -0,0 +1,76 @@
+/*
+ * Copyright © 2014 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission.  The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "evdev.h"
+
+struct touchpad_dispatch {
+	struct evdev_dispatch base;
+	struct evdev_device *device;
+};
+
+static void
+touchpad_process(struct evdev_dispatch *dispatch,
+		 struct evdev_device *device,
+		 struct input_event *e,
+		 uint32_t time)
+{
+}
+
+static void
+touchpad_destroy(struct evdev_dispatch *dispatch)
+{
+	free(dispatch);
+}
+
+static struct evdev_dispatch_interface touchpad_interface = {
+	touchpad_process,
+	touchpad_destroy
+};
+
+static int
+touchpad_init(struct touchpad_dispatch *touchpad,
+	      struct evdev_device *device)
+{
+	touchpad->base.interface = &touchpad_interface;
+	touchpad->device = device;
+
+	return 0;
+}
+
+struct evdev_dispatch *
+evdev_mt_touchpad_create(struct evdev_device *device)
+{
+	struct touchpad_dispatch *touchpad;
+
+	touchpad = zalloc(sizeof *touchpad);
+	if (!touchpad)
+		return NULL;
+
+	if (touchpad_init(touchpad, device) != 0) {
+		free(touchpad);
+		return NULL;
+	}
+
+	return  &touchpad->base;
+}

src/evdev.c

@@ -600,7 +600,10 @@ evdev_configure_device(struct evdev_device *device)
 		if (libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOOL_FINGER) &&
 		    !libevdev_has_event_code(device->evdev, EV_KEY, BTN_TOOL_PEN) &&
 		    (has_abs || has_mt)) {
-			device->dispatch = evdev_touchpad_create(device);
+			if (getenv("LIBINPUT_NEW_TOUCHPAD_DRIVER") && has_mt)
+				device->dispatch = evdev_mt_touchpad_create(device);
+			else
+				device->dispatch = evdev_touchpad_create(device);
 		}
 		for (i = KEY_ESC; i < KEY_MAX; i++) {
 			if (i >= BTN_MISC && i < KEY_OK)

src/evdev.h

@@ -118,6 +118,9 @@ evdev_device_create(struct libinput_seat *seat,
 struct evdev_dispatch *
 evdev_touchpad_create(struct evdev_device *device);
 
+struct evdev_dispatch *
+evdev_mt_touchpad_create(struct evdev_device *device);
+
 void
 evdev_device_proces_event(struct libinput_event *event);