display: get button number from helper input event function

src/core/display.c

@@ -1721,6 +1721,7 @@ event_callback (XEvent   *event,
     {
       Window xwindow = meta_input_event_get_window (display, event);
       Time evtime = meta_input_event_get_time (display, event);
+      guint n_button;
 
       if (window && !window->override_redirect &&
           ((evtype == KeyPress) || (evtype == ButtonPress)))
@@ -1759,16 +1760,18 @@ event_callback (XEvent   *event,
             filter_out_event = bypass_compositor = TRUE;
           break;
         case ButtonPress:
+          meta_input_event_get_button (display, event, &n_button);
+
           if (display->grab_op == META_GRAB_OP_COMPOSITOR)
             break;
 
-          if (event->xbutton.button == 4 || event->xbutton.button == 5)
+          if (n_button == 4 || n_button == 5)
             /* Scrollwheel event, do nothing and deliver event to compositor below */
             break;
 
           if ((window &&
                grab_op_is_mouse (display->grab_op) &&
-               display->grab_button != (int) event->xbutton.button &&
+               display->grab_button != (int) n_button &&
                display->grab_window == window) ||
               grab_op_is_keyboard (display->grab_op))
             {
@@ -1809,8 +1812,7 @@ event_callback (XEvent   *event,
                */
               unmodified = (event->xbutton.state & grab_mask) == 0;
 
-              if (unmodified ||
+              if (unmodified || n_button == 1)
-                  event->xbutton.button == 1)
                 {
                   /* don't focus if frame received, will be lowered in
                    * frames.c or special-cased if the click was on a
@@ -1831,7 +1833,7 @@ event_callback (XEvent   *event,
                         {
                           meta_topic (META_DEBUG_FOCUS,
                                       "Focusing %s due to unmodified button %u press (display.c)\n",
-                                      window->desc, event->xbutton.button);
+                                      window->desc, n_button);
                           meta_window_focus (window, evtime);
                         }
                       else
@@ -1847,7 +1849,7 @@ event_callback (XEvent   *event,
                   if (!unmodified)
                     begin_move = TRUE;
                 }
-              else if (!unmodified && event->xbutton.button == meta_prefs_get_mouse_button_resize())
+              else if (!unmodified && n_button == meta_prefs_get_mouse_button_resize())
                 {
                   if (window->has_resize_func)
                     {
@@ -1889,21 +1891,21 @@ event_callback (XEvent   *event,
                                                     op,
                                                     TRUE,
                                                     FALSE,
-                                                    event->xbutton.button,
+                                                    n_button,
                                                     0,
                                                     evtime,
                                                     event->xbutton.x_root,
                                                     event->xbutton.y_root);
                     }
                 }
-              else if (event->xbutton.button == meta_prefs_get_mouse_button_menu())
+              else if (n_button == meta_prefs_get_mouse_button_menu())
                 {
                   if (meta_prefs_get_raise_on_click ())
                     meta_window_raise (window);
                   meta_window_show_menu (window,
                                          event->xbutton.x_root,
                                          event->xbutton.y_root,
-                                         event->xbutton.button,
+                                         n_button,
                                          evtime);
                 }
 
@@ -1946,7 +1948,7 @@ event_callback (XEvent   *event,
                                               META_GRAB_OP_MOVING,
                                               TRUE,
                                               FALSE,
-                                              event->xbutton.button,
+                                              n_button,
                                               0,
                                               evtime,
                                               event->xbutton.x_root,

src/core/input-events.c

@@ -495,3 +495,48 @@ meta_input_event_get_keycode (MetaDisplay *display,
 
   return FALSE;
 }
+
+gboolean
+meta_input_event_get_button (MetaDisplay *display,
+                             XEvent      *ev,
+                             guint       *button)
+{
+#ifdef HAVE_XINPUT2
+  if (ev->type == GenericEvent &&
+      ev->xcookie.extension == display->xinput2_opcode)
+    {
+      XIEvent *xev;
+
+      g_assert (display->have_xinput2 == TRUE);
+
+      xev = (XIEvent *) ev->xcookie.data;
+
+      if (xev->evtype == XI_ButtonPress ||
+          xev->evtype == XI_ButtonRelease)
+        {
+          if (button)
+            {
+              /* The detail field contains
+               * button number for button events
+               */
+              *button = ((XIDeviceEvent *) xev)->detail;
+            }
+
+          return TRUE;
+        }
+    }
+  else
+#endif /* HAVE_XINPUT2 */
+    {
+      if (ev->type == ButtonPress ||
+          ev->type == ButtonRelease)
+        {
+          if (button)
+            *button = ev->xbutton.button;
+
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}

src/core/input-events.h

@@ -60,5 +60,8 @@ gboolean meta_input_event_get_state         (MetaDisplay *display,
 gboolean meta_input_event_get_keycode       (MetaDisplay *display,
                                              XEvent      *ev,
                                              guint       *keycode);
+gboolean meta_input_event_get_button        (MetaDisplay *display,
+                                             XEvent      *event,
+                                             guint       *button);
 
 #endif /* META_EVENT_H */