[mutter] ClutterSeatEvdev: Keep track of button count

[Carlos Garnacho <carlosg src gnome org>]

commit e928370bf06d2c31fc6be1ccb9b484ba4809cfbe
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Jun 22 17:55:58 2016 +0800

    ClutterSeatEvdev: Keep track of button count
    
    libinput does it for us, but only for physical devices. When we add
    virtual devices to the same seat, we need to track button press count
    ourself.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=765009

 clutter/clutter/evdev/clutter-seat-evdev.c |   37 ++++++++++++++++++++++++++++
 clutter/clutter/evdev/clutter-seat-evdev.h |    2 +
 2 files changed, 39 insertions(+), 0 deletions(-)
---
diff --git a/clutter/clutter/evdev/clutter-seat-evdev.c b/clutter/clutter/evdev/clutter-seat-evdev.c
index 30e205d..6835980 100644
--- a/clutter/clutter/evdev/clutter-seat-evdev.c
+++ b/clutter/clutter/evdev/clutter-seat-evdev.c
@@ -205,6 +205,25 @@ queue_event (ClutterEvent *event)
   _clutter_event_push (event, FALSE);
 }
 
+static int
+update_button_count (ClutterSeatEvdev *seat,
+                     uint32_t          button,
+                     uint32_t          state)
+{
+  if (state)
+    {
+      return ++seat->button_count[button];
+    }
+  else
+    {
+      /* Handle cases where we newer saw the initial pressed event. */
+      if (seat->button_count[button] == 0)
+        return 0;
+
+      return --seat->button_count[button];
+    }
+}
+
 void
 clutter_seat_evdev_notify_key (ClutterSeatEvdev   *seat,
                                ClutterInputDevice *device,
@@ -217,6 +236,16 @@ clutter_seat_evdev_notify_key (ClutterSeatEvdev   *seat,
   ClutterEvent *event = NULL;
   enum xkb_state_component changed_state;
 
+  if (state != AUTOREPEAT_VALUE)
+    {
+      /* Drop any repeated button press (for example from virtual devices. */
+      int count = update_button_count (seat, key, state);
+      if (state && count > 1)
+        return;
+      if (!state && count != 0)
+        return;
+    }
+
   /* We can drop the event on the floor if no stage has been
    * associated with the device yet. */
   stage = _clutter_input_device_get_stage (device);
@@ -410,6 +439,14 @@ clutter_seat_evdev_notify_button (ClutterSeatEvdev   *seat,
       CLUTTER_BUTTON1_MASK, CLUTTER_BUTTON3_MASK, CLUTTER_BUTTON2_MASK,
       CLUTTER_BUTTON4_MASK, CLUTTER_BUTTON5_MASK, 0, 0, 0
     };
+  int button_count;
+
+  /* Drop any repeated button press (for example from virtual devices. */
+  button_count = update_button_count (seat, button, state);
+  if (state && button_count > 1)
+    return;
+  if (!state && button_count != 0)
+    return;
 
   /* We can drop the event on the floor if no stage has been
    * associated with the device yet. */
diff --git a/clutter/clutter/evdev/clutter-seat-evdev.h b/clutter/clutter/evdev/clutter-seat-evdev.h
index f246434..35f4ea2 100644
--- a/clutter/clutter/evdev/clutter-seat-evdev.h
+++ b/clutter/clutter/evdev/clutter-seat-evdev.h
@@ -28,6 +28,7 @@
 #define __CLUTTER_SEAT_EVDEV_H__
 
 #include <libinput.h>
+#include <linux/input.h>
 
 #include "clutter-input-device.h"
 #include "clutter-device-manager-evdev.h"
@@ -58,6 +59,7 @@ struct _ClutterSeatEvdev
   xkb_led_index_t num_lock_led;
   xkb_led_index_t scroll_lock_led;
   uint32_t button_state;
+  int button_count[KEY_CNT];
 
   /* keyboard repeat */
   gboolean repeat;