From 3471ef34411a00c3d19a8363b0daee1bfad0f250 Mon Sep 17 00:00:00 2001
From: Carlos Garnacho <carlosg@gnome.org>
Date: Wed, 11 Feb 2015 17:04:13 +0100
Subject: [PATCH] backend: Update cursor visibility based on device
 availability

On startup, the cursor is kept hidden if there's any touchscreen available.
If the device that was last interacted is removed, we check on available
pointing devices though, so we don't possibly hide the pointer if there are
further mice/touchpads/etc.

Devices being added don't update cursor visibility, we wait for the user
interacting with those instead.

https://bugzilla.gnome.org/show_bug.cgi?id=712775
---
 src/backends/meta-backend.c | 81 +++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/src/backends/meta-backend.c b/src/backends/meta-backend.c
index 474184aae..f55a4a02a 100644
--- a/src/backends/meta-backend.c
+++ b/src/backends/meta-backend.c
@@ -137,6 +137,55 @@ on_device_added (ClutterDeviceManager *device_manager,
   create_device_monitor (backend, device_id);
 }
 
+static inline gboolean
+device_is_slave_touchscreen (ClutterInputDevice *device)
+{
+  return (clutter_input_device_get_device_mode (device) != CLUTTER_INPUT_MODE_MASTER &&
+          clutter_input_device_get_device_type (device) == CLUTTER_TOUCHSCREEN_DEVICE);
+}
+
+static inline gboolean
+check_has_pointing_device (ClutterDeviceManager *manager)
+{
+  const GSList *devices;
+
+  devices = clutter_device_manager_peek_devices (manager);
+
+  for (; devices; devices = devices->next)
+    {
+      ClutterInputDevice *device = devices->data;
+
+      if (clutter_input_device_get_device_mode (device) == CLUTTER_INPUT_MODE_MASTER)
+        continue;
+      if (clutter_input_device_get_device_type (device) == CLUTTER_TOUCHSCREEN_DEVICE ||
+          clutter_input_device_get_device_type (device) == CLUTTER_KEYBOARD_DEVICE)
+        continue;
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static inline gboolean
+check_has_slave_touchscreen (ClutterDeviceManager *manager)
+{
+  const GSList *devices;
+
+  devices = clutter_device_manager_peek_devices (manager);
+
+  for (; devices; devices = devices->next)
+    {
+      ClutterInputDevice *device = devices->data;
+
+      if (clutter_input_device_get_device_mode (device) != CLUTTER_INPUT_MODE_MASTER &&
+          clutter_input_device_get_device_type (device) == CLUTTER_TOUCHSCREEN_DEVICE)
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
 static void
 on_device_removed (ClutterDeviceManager *device_manager,
                    ClutterInputDevice   *device,
@@ -146,6 +195,32 @@ on_device_removed (ClutterDeviceManager *device_manager,
   int device_id = clutter_input_device_get_device_id (device);
 
   destroy_device_monitor (backend, device_id);
+
+  /* If the device the user last interacted goes away, check again pointer
+   * visibility.
+   */
+  if (backend->current_device_id == device_id)
+    {
+      MetaCursorTracker *cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+      gboolean has_touchscreen, has_pointing_device;
+      ClutterInputDeviceType device_type;
+
+      device_type = clutter_input_device_get_device_type (device);
+      has_touchscreen = check_has_slave_touchscreen (device_manager);
+
+      if (device_type == CLUTTER_TOUCHSCREEN_DEVICE && has_touchscreen)
+        {
+          /* There's more touchscreens left, keep the pointer hidden */
+          meta_cursor_tracker_set_pointer_visible (cursor_tracker, FALSE);
+        }
+      else if (device_type != CLUTTER_KEYBOARD_DEVICE)
+        {
+          has_pointing_device = check_has_pointing_device (device_manager);
+          meta_cursor_tracker_set_pointer_visible (cursor_tracker,
+                                                   has_pointing_device &&
+                                                   !has_touchscreen);
+        }
+    }
 }
 
 static MetaMonitorManager *
@@ -178,7 +253,9 @@ meta_backend_real_post_init (MetaBackend *backend)
                                                     NULL, (GDestroyNotify) g_object_unref);
 
   {
+    MetaCursorTracker *cursor_tracker;
     ClutterDeviceManager *manager;
+    gboolean has_touchscreen = FALSE;
     GSList *devices, *l;
 
     /* Create the core device monitor. */
@@ -196,8 +273,12 @@ meta_backend_real_post_init (MetaBackend *backend)
       {
         ClutterInputDevice *device = l->data;
         on_device_added (manager, device, backend);
+        has_touchscreen |= device_is_slave_touchscreen (device);
       }
 
+    cursor_tracker = meta_cursor_tracker_get_for_screen (NULL);
+    meta_cursor_tracker_set_pointer_visible (cursor_tracker, !has_touchscreen);
+
     g_slist_free (devices);
   }