[PATCH xwayland 2/2] xwayland: Implement tablet_tool_wheel for scrolling

[Jason Gerecke]

The 'tablet_tool_wheel' function for tablet scrolling was added back in
8a1defcc634 but left unimplemented. This commit fills in the necessary
details, using the "clicks" count as the number of discrete scroll up/down
events to send.

Signed-off-by: Jason Gerecke <jason.gerecke at wacom.com>
---
 hw/xwayland/xwayland-input.c | 24 ++++++++++++++++++++++++
 hw/xwayland/xwayland.h       |  2 ++
 2 files changed, 26 insertions(+)

diff --git a/hw/xwayland/xwayland-input.c b/hw/xwayland/xwayland-input.c
index c2801fa70..ffdb25dfd 100644
--- a/hw/xwayland/xwayland-input.c
+++ b/hw/xwayland/xwayland-input.c
@@ -1560,6 +1560,13 @@ static void
 tablet_tool_wheel(void *data, struct zwp_tablet_tool_v2 *tool,
                   wl_fixed_t degrees, int32_t clicks)
 {
+    struct xwl_tablet_tool *xwl_tablet_tool = data;
+    struct xwl_seat *xwl_seat = xwl_tablet_tool->seat;
+
+    if (!xwl_seat->focus_window)
+        return;
+
+    xwl_tablet_tool->wheel_clicks = clicks;
 }
 
 static void
@@ -1671,6 +1678,23 @@ tablet_tool_frame(void *data, struct zwp_tablet_tool_v2 *tool, uint32_t time)
     }
 
     xwl_tablet_tool->buttons_prev = xwl_tablet_tool->buttons_now;
+
+    while (xwl_tablet_tool->wheel_clicks) {
+            if (xwl_tablet_tool->wheel_clicks < 0) {
+                button = 4;
+                xwl_tablet_tool->wheel_clicks++;
+            }
+            else {
+                button = 5;
+                xwl_tablet_tool->wheel_clicks--;
+            }
+
+            QueuePointerEvents(xwl_tablet_tool->xdevice,
+                               ButtonPress, button, 0, &mask);
+            QueuePointerEvents(xwl_tablet_tool->xdevice,
+                               ButtonRelease, button, 0, &mask);
+
+    }
 }
 
 static const struct zwp_tablet_tool_v2_listener tablet_tool_listener = {
diff --git a/hw/xwayland/xwayland.h b/hw/xwayland/xwayland.h
index b37e73b94..ccab93b33 100644
--- a/hw/xwayland/xwayland.h
+++ b/hw/xwayland/xwayland.h
@@ -216,6 +216,8 @@ struct xwl_tablet_tool {
     uint32_t buttons_now,
              buttons_prev;
 
+    int32_t wheel_clicks;
+
     struct xwl_cursor cursor;
 };
 
-- 
2.13.0