[gtk/gtk-3-24: 1/2] quartz: mimic source device axes

[Emmanuele Bassi <ebassi src gnome org>]

commit 4b953dee70cd7e2b4d2dd50bdce427163273e7fb
Author: Biggio <biggio 8c85904c918c ant amazon com>
Date:   Wed Jul 8 15:26:06 2020 +0200

    quartz: mimic source device axes
    
    Input devices such as stylus pens have additional axes besides (x,y)
    coordinates. In order for these devices to work properly, their additional
    axes need to be mimicked from the physical device to the associated
    virtual pointer when they become active.

 gdk/quartz/gdkdevicemanager-core-quartz.c | 46 +++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
---
diff --git a/gdk/quartz/gdkdevicemanager-core-quartz.c b/gdk/quartz/gdkdevicemanager-core-quartz.c
index 44ff25e4c6..782323c16a 100644
--- a/gdk/quartz/gdkdevicemanager-core-quartz.c
+++ b/gdk/quartz/gdkdevicemanager-core-quartz.c
@@ -197,6 +197,50 @@ create_core_device (GdkDeviceManager *device_manager,
   return device;
 }
 
+static void
+mimic_device_axes (GdkDevice *logical,
+                   GdkDevice *physical)
+{
+  double axis_min, axis_max, axis_resolution;
+  GdkAtom axis_label;
+  GdkAxisUse axis_use;
+  int axis_count;
+  int i;
+
+  axis_count = gdk_device_get_n_axes (physical);
+
+  for (i = 0; i < axis_count; i++)
+    {
+      _gdk_device_get_axis_info (physical, i, &axis_label, &axis_use, &axis_min,
+                                 &axis_max, &axis_resolution);
+      _gdk_device_add_axis (logical, axis_label, axis_use, axis_min,
+                            axis_max, axis_resolution);
+    }
+}
+
+static void
+translate_device_axes (GdkDevice *source_device,
+                       gboolean   active)
+{
+  GdkSeat *seat = gdk_display_get_default_seat (_gdk_display);
+  GdkDevice *core_pointer = gdk_seat_get_pointer (seat);
+
+  g_object_freeze_notify (G_OBJECT (core_pointer));
+
+  _gdk_device_reset_axes (core_pointer);
+  if (active && source_device)
+    {
+      mimic_device_axes (core_pointer, source_device);
+    }
+  else
+    {
+      _gdk_device_add_axis (core_pointer, GDK_NONE, GDK_AXIS_X, 0, 0, 1);
+      _gdk_device_add_axis (core_pointer, GDK_NONE, GDK_AXIS_Y, 0, 0, 1);
+    }
+
+  g_object_thaw_notify (G_OBJECT (core_pointer));
+}
+
 void
 _gdk_quartz_device_manager_register_device_for_ns_event (GdkDeviceManager *device_manager,
                                                          NSEvent          *nsevent)
@@ -290,6 +334,8 @@ _gdk_quartz_device_manager_register_device_for_ns_event (GdkDeviceManager *devic
         }
     }
 
+  translate_device_axes (device, [nsevent isEnteringProximity]);
+
   if (self->num_active_devices)
     [NSEvent setMouseCoalescingEnabled: FALSE];
   else