distinguish touch screen and pointer dnd in client

Data device interface in client just handle with pointer's dnd.
If a touch screen trigger dnd, it will use pointer struct like i
nput->sx, input->sy, input->pointer_focus. So if pointer is moving
when touch screen trigeer a dnd, wrong behaviore will occur.
Before touch screen start dnd, system call touch_grab()
to mark the following drag and drop operation is generated by
touch screen.
Defined some common variables in struct input to track dnd.

Note, touch screen and pointer can't generate drag and drop at the
same time, becuae data device protocol can't identify the drag
and drop event is generated by touch screen or pointer.

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Reviewed-by: Kristian Hogsberg <hoegsberg@gmail.com>

clients/dnd.c

@@ -483,7 +483,8 @@ dnd_touch_down_handler(struct widget *widget,
 
 	int_x = (int32_t)x;
 	int_y = (int32_t)y;
-	create_drag_source(dnd, input, time, int_x, int_y);
+	if (create_drag_source(dnd, input, time, int_x, int_y) == 0)
+		touch_grab(input, 0);
 }
 
 static int

clients/window.c

@@ -320,6 +320,11 @@ struct input {
 	struct wl_data_device *data_device;
 	struct data_offer *drag_offer;
 	struct data_offer *selection_offer;
+	uint32_t touch_grab;
+	int32_t touch_grab_id;
+	float drag_x, drag_y;
+	struct window *drag_focus;
+	uint32_t drag_enter_serial;
 
 	struct {
 		struct xkb_keymap *keymap;
@@ -2545,6 +2550,31 @@ input_set_focus_widget(struct input *input, struct widget *focus,
 	}
 }
 
+void
+touch_grab(struct input  *input, int32_t touch_id)
+{
+	input->touch_grab = 1;
+	input->touch_grab_id = touch_id;
+}
+
+void
+touch_ungrab(struct input *input)
+{
+	struct touch_point *tp, *tmp;
+
+	input->touch_grab = 0;
+
+	wl_list_for_each_safe(tp, tmp,
+			&input->touch_point_list, link) {
+		if (tp->id != input->touch_grab_id)
+			continue;
+		wl_list_remove(&tp->link);
+		free(tp);
+
+		return;
+	}
+}
+
 void
 input_grab(struct input *input, struct widget *widget, uint32_t button)
 {
@@ -3245,11 +3275,14 @@ data_device_enter(void *data, struct wl_data_device *data_device,
 	float y = wl_fixed_to_double(y_w);
 	char **p;
 
-	input->pointer_enter_serial = serial;
 	window = wl_surface_get_user_data(surface);
-	input->pointer_focus = window;
-	input->sx = x;
-	input->sy = y;
+	input->drag_enter_serial = serial;
+	input->drag_focus = window,
+	input->drag_x = x;
+	input->drag_y = y;
+
+	if (!input->touch_grab)
+		input->pointer_enter_serial = serial;
 
 	if (offer) {
 		input->drag_offer = wl_data_offer_get_user_data(offer);
@@ -3263,7 +3296,6 @@ data_device_enter(void *data, struct wl_data_device *data_device,
 		types_data = NULL;
 	}
 
-	window = input->pointer_focus;
 	if (window->data_handler)
 		window->data_handler(window, input, x, y, types_data,
 				     window->user_data);
@@ -3285,13 +3317,13 @@ data_device_motion(void *data, struct wl_data_device *data_device,
 		   uint32_t time, wl_fixed_t x_w, wl_fixed_t y_w)
 {
 	struct input *input = data;
-	struct window *window = input->pointer_focus;
+	struct window *window = input->drag_focus;
 	float x = wl_fixed_to_double(x_w);
 	float y = wl_fixed_to_double(y_w);
 	void *types_data;
 
-	input->sx = x;
-	input->sy = y;
+	input->drag_x = x;
+	input->drag_y = y;
 
 	if (input->drag_offer)
 		types_data = input->drag_offer->types.data;
@@ -3307,11 +3339,18 @@ static void
 data_device_drop(void *data, struct wl_data_device *data_device)
 {
 	struct input *input = data;
-	struct window *window = input->pointer_focus;
+	struct window *window = input->drag_focus;
+	float x, y;
+
+	x = input->drag_x;
+	y = input->drag_y;
 
 	if (window->drop_handler)
 		window->drop_handler(window, input,
-				     input->sx, input->sy, window->user_data);
+				     x, y, window->user_data);
+
+	if (input->touch_grab)
+		touch_ungrab(input);
 }
 
 static void
@@ -3480,7 +3519,7 @@ void
 input_accept(struct input *input, const char *type)
 {
 	wl_data_offer_accept(input->drag_offer->offer,
-			     input->pointer_enter_serial, type);
+			     input->drag_enter_serial, type);
 }
 
 static void
@@ -3528,8 +3567,8 @@ input_receive_drag_data(struct input *input, const char *mime_type,
 			data_func_t func, void *data)
 {
 	data_offer_receive_data(input->drag_offer, mime_type, func, data);
-	input->drag_offer->x = input->sx;
-	input->drag_offer->y = input->sy;
+	input->drag_offer->x = input->drag_x;
+	input->drag_offer->y = input->drag_y;
 }
 
 int

clients/window.h

@@ -522,6 +522,12 @@ input_get_position(struct input *input, int32_t *x, int32_t *y);
 uint32_t
 input_get_modifiers(struct input *input);
 
+void
+touch_grab(struct input *input, int32_t touch_id);
+
+void
+touch_ungrab(struct input *input);
+
 void
 input_grab(struct input *input, struct widget *widget, uint32_t button);