[mutter] virtual-input/evdev: Translate from button internal codes to evdev

[Jonas Ådahl <jadahl src gnome org>]

commit 24aef44baf5d9dddf0e459e0a38cfb67d8457a88
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Aug 6 21:00:23 2018 +0200

    virtual-input/evdev: Translate from button internal codes to evdev
    
    Sending button events to a ClutterVirtualInputDevice, the API expects
    button codes to be of the internal clutter type. The evdev
    implementation incorrectly assumed it was already prepared evdev event
    codes, which was not the case. Fix the evdev implementation to translate
    from the internal representation to evdev before passing it along to
    ClutterSeatEvdev.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/190

 .../evdev/clutter-virtual-input-device-evdev.c     | 35 ++++++++++++++++++----
 1 file changed, 29 insertions(+), 6 deletions(-)
---
diff --git a/clutter/clutter/evdev/clutter-virtual-input-device-evdev.c 
b/clutter/clutter/evdev/clutter-virtual-input-device-evdev.c
index fe628da85..ab4ddaa14 100644
--- a/clutter/clutter/evdev/clutter-virtual-input-device-evdev.c
+++ b/clutter/clutter/evdev/clutter-virtual-input-device-evdev.c
@@ -185,6 +185,26 @@ clutter_virtual_input_device_evdev_notify_absolute_motion (ClutterVirtualInputDe
                                              NULL);
 }
 
+static int
+translate_to_evdev_button (int clutter_button)
+{
+  switch (clutter_button)
+    {
+    case CLUTTER_BUTTON_PRIMARY:
+      return BTN_LEFT;
+    case CLUTTER_BUTTON_SECONDARY:
+      return BTN_RIGHT;
+    case CLUTTER_BUTTON_MIDDLE:
+      return BTN_MIDDLE;
+    default:
+      /*
+       * For compatibility reasons, all additional buttons go after the old
+       * 4-7 scroll ones.
+       */
+      return clutter_button + (BTN_LEFT - 1) - 4;
+    }
+}
+
 static void
 clutter_virtual_input_device_evdev_notify_button (ClutterVirtualInputDevice *virtual_device,
                                                   uint64_t                   time_us,
@@ -194,30 +214,33 @@ clutter_virtual_input_device_evdev_notify_button (ClutterVirtualInputDevice *vir
   ClutterVirtualInputDeviceEvdev *virtual_evdev =
     CLUTTER_VIRTUAL_INPUT_DEVICE_EVDEV (virtual_device);
   int button_count;
+  int evdev_button;
 
   if (time_us == CLUTTER_CURRENT_TIME)
     time_us = g_get_monotonic_time ();
 
-  if (get_button_type (button) != EVDEV_BUTTON_TYPE_BUTTON)
+  evdev_button = translate_to_evdev_button (button);
+
+  if (get_button_type (evdev_button) != EVDEV_BUTTON_TYPE_BUTTON)
     {
       g_warning ("Unknown/invalid virtual device button 0x%x pressed",
-                 button);
+                 evdev_button);
       return;
     }
 
-  button_count = update_button_count (virtual_evdev, button, button_state);
+  button_count = update_button_count (virtual_evdev, evdev_button, button_state);
   if (button_count < 0 || button_count > 1)
     {
-      g_warning ("Received multiple virtual 0x%x button %s (ignoring)", button,
+      g_warning ("Received multiple virtual 0x%x button %s (ignoring)", evdev_button,
                  button_state == CLUTTER_BUTTON_STATE_PRESSED ? "presses" : "releases");
-      update_button_count (virtual_evdev, button, 1 - button_state);
+      update_button_count (virtual_evdev, evdev_button, 1 - button_state);
       return;
     }
 
   clutter_seat_evdev_notify_button (virtual_evdev->seat,
                                     virtual_evdev->device,
                                     time_us,
-                                    button,
+                                    evdev_button,
                                     button_state);
 }