Improve handling of XI2 wheel movement

* src/xterm.c (handle_one_xevent): Process movement in all
directions and send it as a single event.

1 files changed, 50 insertions, 57 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 57e06f6c7e1..b0d3adca0e2 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10968,13 +10968,12 @@ handle_one_xevent (struct x_display_info *dpyinfo,
           case XI_Motion:
             {
               struct xi_device_t *device;
-              bool touch_end_event_seen = false;
 
               states = &xev->valuators;
               values = states->values;
               device = xi_device_from_id (dpyinfo, xev->deviceid);
 
-              if (!device || !device->master_p)
+              if (!device)
                 goto XI_OTHER;
 
 #ifdef XI_TouchBegin
@@ -10988,6 +10987,8 @@ handle_one_xevent (struct x_display_info *dpyinfo,
               double xv_total_x = 0.0;
               double xv_total_y = 0.0;
 #endif
+              double total_x = 0.0;
+              double total_y = 0.0;
 
               for (int i = 0; i < states->mask_len * 8; i++)
                 {
@@ -11029,7 +11030,8 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                             }
 #endif
 
-                          found_valuator = true;
+                          if (delta == 0.0)
+                            found_valuator = true;
 
                           if (signbit (delta) != signbit (val->emacs_value))
                             val->emacs_value = 0;
@@ -11041,26 +11043,6 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                               && (fabs (delta) > 0))
                             continue;
 
-                          bool s = signbit (val->emacs_value);
-                          inev.ie.kind = (fabs (delta) > 0
-                                          ? (val->horizontal
-                                             ? HORIZ_WHEEL_EVENT
-                                             : WHEEL_EVENT)
-                                          : TOUCH_END_EVENT);
-                          inev.ie.timestamp = xev->time;
-
-                          XSETINT (inev.ie.x, lrint (xev->event_x));
-                          XSETINT (inev.ie.y, lrint (xev->event_y));
-                          XSETFRAME (inev.ie.frame_or_window, f);
-
-                          if (fabs (delta) > 0)
-                            {
-                              inev.ie.modifiers = !s ? up_modifier : down_modifier;
-                              inev.ie.modifiers
-                                |= x_x_to_emacs_modifiers (dpyinfo,
-                                                           xev->mods.effective);
-                            }
-
                           window = window_from_coordinates (f, xev->event_x,
                                                             xev->event_y, NULL,
                                                             false, false);
@@ -11078,40 +11060,15 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                           if (NUMBERP (Vx_scroll_event_delta_factor))
                             scroll_unit *= XFLOATINT (Vx_scroll_event_delta_factor);
 
-                          if (fabs (delta) > 0)
-                            {
-                              if (val->horizontal)
-                                {
-                                  inev.ie.arg
-                                    = list3 (Qnil,
-                                             make_float (val->emacs_value
-                                                         * scroll_unit),
-                                             make_float (0));
-                                }
-                              else
-                                {
-                                  inev.ie.arg = list3 (Qnil, make_float (0),
-                                                       make_float (val->emacs_value
-                                                                   * scroll_unit));
-                                }
-                            }
+                          if (val->horizontal)
+                            total_x += delta * scroll_unit;
                           else
-                            {
-                              inev.ie.arg = Qnil;
-                            }
-
-                          if (inev.ie.kind != TOUCH_END_EVENT
-                              || !touch_end_event_seen)
-                            {
-                              kbd_buffer_store_event_hold (&inev.ie, hold_quit);
-                              touch_end_event_seen = inev.ie.kind == TOUCH_END_EVENT;
-                            }
+                            total_y += delta * scroll_unit;
 
+                          found_valuator = true;
                           val->emacs_value = 0;
                         }
                     }
-
-                  inev.ie.kind = NO_EVENT;
                 }
 
 #ifdef HAVE_XWIDGETS
@@ -11141,15 +11098,51 @@ handle_one_xevent (struct x_display_info *dpyinfo,
 
                   goto XI_OTHER;
                 }
-#endif
-              if (found_valuator)
+              else
                 {
+#endif
+                  if (found_valuator)
+                    {
+                      if (fabs (total_x) > 0 || fabs (total_y) > 0)
+                        {
+                          inev.ie.kind = (fabs (total_y) >= fabs (total_x)
+                                          ? WHEEL_EVENT : HORIZ_WHEEL_EVENT);
+                          inev.ie.timestamp = xev->time;
+
+                          XSETINT (inev.ie.x, lrint (xev->event_x));
+                          XSETINT (inev.ie.y, lrint (xev->event_y));
+                          XSETFRAME (inev.ie.frame_or_window, f);
+
+                          inev.ie.modifiers = (signbit (fabs (total_y) >= fabs (total_x)
+                                                        ? total_y : total_x)
+                                               ? down_modifier : up_modifier);
+                          inev.ie.modifiers
+                            |= x_x_to_emacs_modifiers (dpyinfo,
+                                                       xev->mods.effective);
+                          inev.ie.arg = list3 (Qnil,
+                                               make_float (total_x),
+                                               make_float (total_y));
+
 #ifdef USE_GTK
-                  if (f && xg_event_is_for_scrollbar (f, event))
-                    *finish = X_EVENT_DROP;
+                          if (f && xg_event_is_for_scrollbar (f, event))
+                            *finish = X_EVENT_DROP;
 #endif
-                  goto XI_OTHER;
+                        }
+                      else
+                        {
+                          inev.ie.kind = TOUCH_END_EVENT;
+                          inev.ie.timestamp = xev->time;
+
+                          XSETINT (inev.ie.x, lrint (xev->event_x));
+                          XSETINT (inev.ie.y, lrint (xev->event_y));
+                          XSETFRAME (inev.ie.frame_or_window, f);
+                        }
+
+                      goto XI_OTHER;
+                    }
+#ifdef HAVE_XWIDGETS
                 }
+#endif
 
               ev.x = lrint (xev->event_x);
               ev.y = lrint (xev->event_y);