[mutter] backends: Force 2-finger scroll by default if available

[Bastien Nocera <hadess src gnome org>]

commit a27b2597b962fe3fba1e79df134be4ebb2c39055
Author: Bastien Nocera <hadess hadess net>
Date:   Fri Dec 11 12:32:46 2015 +0100

    backends: Force 2-finger scroll by default if available
    
    When the touchpad is two-finger scrolling capable, always enable it.
    
    When the touchpad only supports edge scrolling (usually older devices, and
    usually smaller devices), allow disabling the edge scrolling.
    
    This requires a newer gsettings-desktop-schemas as the scroll-method key
    was removed, and the edge-scroll-enabled key added.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=759304

 configure.ac                                     |    2 +-
 src/backends/meta-input-settings-private.h       |    6 ++--
 src/backends/meta-input-settings.c               |   26 ++++++++--------
 src/backends/native/meta-input-settings-native.c |   34 ++++++++++----------
 src/backends/x11/meta-input-settings-x11.c       |   35 +++++++++------------
 5 files changed, 49 insertions(+), 54 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 1ee3d09..6278369 100644
--- a/configure.ac
+++ b/configure.ac
@@ -63,7 +63,7 @@ MUTTER_PC_MODULES="
    gio-unix-2.0 >= 2.35.1
    pango >= 1.2.0
    cairo >= 1.10.0
-   gsettings-desktop-schemas >= 3.15.92
+   gsettings-desktop-schemas >= 3.19.3
    $CLUTTER_PACKAGE >= 1.25.1
    cogl-1.0 >= 1.17.1
    upower-glib >= 0.99.0
diff --git a/src/backends/meta-input-settings-private.h b/src/backends/meta-input-settings-private.h
index 18c1edb..ec207f2 100644
--- a/src/backends/meta-input-settings-private.h
+++ b/src/backends/meta-input-settings-private.h
@@ -63,9 +63,9 @@ struct _MetaInputSettingsClass
   void (* set_invert_scroll) (MetaInputSettings  *settings,
                               ClutterInputDevice *device,
                               gboolean            inverted);
-  void (* set_scroll_method) (MetaInputSettings            *settings,
-                              ClutterInputDevice           *device,
-                              GDesktopTouchpadScrollMethod  mode);
+  void (* set_edge_scroll)   (MetaInputSettings  *settings,
+                              ClutterInputDevice *device,
+                              gboolean            enabled);
   void (* set_scroll_button) (MetaInputSettings  *settings,
                               ClutterInputDevice *device,
                               guint               button);
diff --git a/src/backends/meta-input-settings.c b/src/backends/meta-input-settings.c
index 2f8ed77..5c509fa 100644
--- a/src/backends/meta-input-settings.c
+++ b/src/backends/meta-input-settings.c
@@ -395,11 +395,11 @@ update_touchpad_tap_enabled (MetaInputSettings  *input_settings,
 }
 
 static void
-update_touchpad_scroll_method (MetaInputSettings *input_settings,
-                               ClutterInputDevice *device)
+update_touchpad_edge_scroll (MetaInputSettings *input_settings,
+                             ClutterInputDevice *device)
 {
   MetaInputSettingsClass *input_settings_class;
-  GDesktopTouchpadScrollMethod method;
+  gboolean edge_scroll_enabled;
   MetaInputSettingsPrivate *priv;
 
   if (device &&
@@ -408,19 +408,19 @@ update_touchpad_scroll_method (MetaInputSettings *input_settings,
 
   priv = meta_input_settings_get_instance_private (input_settings);
   input_settings_class = META_INPUT_SETTINGS_GET_CLASS (input_settings);
-  method = g_settings_get_enum (priv->touchpad_settings, "scroll-method");
+  edge_scroll_enabled = g_settings_get_boolean (priv->touchpad_settings, "edge-scrolling-enabled");
 
   if (device)
     {
-      settings_device_set_uint_setting (input_settings, device,
-                                        input_settings_class->set_scroll_method,
-                                        method);
+      settings_device_set_bool_setting (input_settings, device,
+                                        input_settings_class->set_edge_scroll,
+                                        edge_scroll_enabled);
     }
   else
     {
-      settings_set_uint_setting (input_settings, CLUTTER_TOUCHPAD_DEVICE,
-                                 (ConfigUintFunc) input_settings_class->set_scroll_method,
-                                 method);
+      settings_set_bool_setting (input_settings, CLUTTER_TOUCHPAD_DEVICE,
+                                 (ConfigBoolFunc) input_settings_class->set_edge_scroll,
+                                 edge_scroll_enabled);
     }
 }
 
@@ -645,8 +645,8 @@ meta_input_settings_changed_cb (GSettings  *settings,
         update_touchpad_tap_enabled (input_settings, NULL);
       else if (strcmp (key, "send-events") == 0)
         update_touchpad_send_events (input_settings, NULL);
-      else if (strcmp (key, "scroll-method") == 0)
-        update_touchpad_scroll_method (input_settings, NULL);
+      else if (strcmp (key, "edge-scrolling-enabled") == 0)
+        update_touchpad_edge_scroll (input_settings, NULL);
       else if (strcmp (key, "click-method") == 0)
         update_touchpad_click_method (input_settings, NULL);
     }
@@ -771,7 +771,7 @@ apply_device_settings (MetaInputSettings  *input_settings,
   update_device_natural_scroll (input_settings, device);
   update_touchpad_tap_enabled (input_settings, device);
   update_touchpad_send_events (input_settings, device);
-  update_touchpad_scroll_method (input_settings, device);
+  update_touchpad_edge_scroll (input_settings, device);
   update_touchpad_click_method (input_settings, device);
 
   update_trackball_scroll_button (input_settings, device);
diff --git a/src/backends/native/meta-input-settings-native.c 
b/src/backends/native/meta-input-settings-native.c
index fd2f80b..4b4e8c2 100644
--- a/src/backends/native/meta-input-settings-native.c
+++ b/src/backends/native/meta-input-settings-native.c
@@ -154,30 +154,30 @@ device_set_click_method (struct libinput_device            *libinput_device,
 }
 
 static void
-meta_input_settings_native_set_scroll_method (MetaInputSettings            *settings,
-                                              ClutterInputDevice           *device,
-                                              GDesktopTouchpadScrollMethod  mode)
+meta_input_settings_native_set_edge_scroll (MetaInputSettings            *settings,
+                                            ClutterInputDevice           *device,
+                                            gboolean                      edge_scrolling_enabled)
 {
   enum libinput_config_scroll_method scroll_method = 0;
   struct libinput_device *libinput_device;
+  enum libinput_config_scroll_method supported;
 
   libinput_device = clutter_evdev_input_device_get_libinput_device (device);
+  supported = libinput_device_config_scroll_get_methods (libinput_device);
 
-  switch (mode)
+  if (supported & LIBINPUT_CONFIG_SCROLL_2FG)
     {
-    case G_DESKTOP_TOUCHPAD_SCROLL_METHOD_DISABLED:
-      scroll_method = LIBINPUT_CONFIG_SCROLL_NO_SCROLL;
-      break;
-    case G_DESKTOP_TOUCHPAD_SCROLL_METHOD_EDGE_SCROLLING:
-      scroll_method = LIBINPUT_CONFIG_SCROLL_EDGE;
-      break;
-    case G_DESKTOP_TOUCHPAD_SCROLL_METHOD_TWO_FINGER_SCROLLING:
       scroll_method = LIBINPUT_CONFIG_SCROLL_2FG;
-      break;
-    default:
-      g_assert_not_reached ();
-      return;
-  }
+    }
+  else if (supported & LIBINPUT_CONFIG_SCROLL_EDGE &&
+           edge_scrolling_enabled)
+    {
+      scroll_method = LIBINPUT_CONFIG_SCROLL_EDGE;
+    }
+  else
+    {
+      scroll_method = LIBINPUT_CONFIG_SCROLL_NO_SCROLL;
+    }
 
   device_set_scroll_method (libinput_device, scroll_method);
 }
@@ -252,7 +252,7 @@ meta_input_settings_native_class_init (MetaInputSettingsNativeClass *klass)
   input_settings_class->set_left_handed = meta_input_settings_native_set_left_handed;
   input_settings_class->set_tap_enabled = meta_input_settings_native_set_tap_enabled;
   input_settings_class->set_invert_scroll = meta_input_settings_native_set_invert_scroll;
-  input_settings_class->set_scroll_method = meta_input_settings_native_set_scroll_method;
+  input_settings_class->set_edge_scroll = meta_input_settings_native_set_edge_scroll;
   input_settings_class->set_scroll_button = meta_input_settings_native_set_scroll_button;
   input_settings_class->set_click_method = meta_input_settings_native_set_click_method;
   input_settings_class->set_keyboard_repeat = meta_input_settings_native_set_keyboard_repeat;
diff --git a/src/backends/x11/meta-input-settings-x11.c b/src/backends/x11/meta-input-settings-x11.c
index e582dfc..79d567b 100644
--- a/src/backends/x11/meta-input-settings-x11.c
+++ b/src/backends/x11/meta-input-settings-x11.c
@@ -199,9 +199,9 @@ meta_input_settings_x11_set_invert_scroll (MetaInputSettings  *settings,
 }
 
 static void
-meta_input_settings_x11_set_scroll_method (MetaInputSettings            *settings,
-                                           ClutterInputDevice           *device,
-                                           GDesktopTouchpadScrollMethod  mode)
+meta_input_settings_x11_set_edge_scroll (MetaInputSettings            *settings,
+                                         ClutterInputDevice           *device,
+                                         gboolean                      edge_scroll_enabled)
 {
   guchar values[3] = { 0 }; /* 2fg, edge, button. The last value is unused */
   guchar *available;
@@ -211,26 +211,21 @@ meta_input_settings_x11_set_scroll_method (MetaInputSettings            *setting
   if (!available)
     return;
 
-  switch (mode)
+  if (available[0])
     {
-    case G_DESKTOP_TOUCHPAD_SCROLL_METHOD_DISABLED:
-      break;
-    case G_DESKTOP_TOUCHPAD_SCROLL_METHOD_EDGE_SCROLLING:
-      values[1] = 1;
-      break;
-    case G_DESKTOP_TOUCHPAD_SCROLL_METHOD_TWO_FINGER_SCROLLING:
       values[0] = 1;
-      break;
-    default:
-      g_assert_not_reached ();
     }
-
-  if ((values[0] && !available[0]) || (values[1] && !available[1]))
-    g_warning ("Device '%s' does not support scroll mode %d\n",
-               clutter_input_device_get_device_name (device), mode);
+  else if (available[1] && edge_scroll_enabled)
+    {
+      values[1] = 1;
+    }
   else
-    change_property (device, "libinput Scroll Method Enabled",
-                     XA_INTEGER, 8, &values, 3);
+    {
+      /* Disabled */
+    }
+
+  change_property (device, "libinput Scroll Method Enabled",
+                   XA_INTEGER, 8, &values, 3);
 
   meta_XFree (available);
 }
@@ -321,7 +316,7 @@ meta_input_settings_x11_class_init (MetaInputSettingsX11Class *klass)
   input_settings_class->set_left_handed = meta_input_settings_x11_set_left_handed;
   input_settings_class->set_tap_enabled = meta_input_settings_x11_set_tap_enabled;
   input_settings_class->set_invert_scroll = meta_input_settings_x11_set_invert_scroll;
-  input_settings_class->set_scroll_method = meta_input_settings_x11_set_scroll_method;
+  input_settings_class->set_edge_scroll = meta_input_settings_x11_set_edge_scroll;
   input_settings_class->set_scroll_button = meta_input_settings_x11_set_scroll_button;
   input_settings_class->set_click_method = meta_input_settings_x11_set_click_method;
   input_settings_class->set_keyboard_repeat = meta_input_settings_x11_set_keyboard_repeat;