[gtk+/gtk-3-22] Settings: Reflect resurrected middleclick in Range

[Daniel Boles <dboles src gnome org>]

commit 694686d2ed24a6bd9ea85b05a8bf271ed7af2f02
Author: Daniel Boles <dboles src gmail com>
Date:   Wed Oct 11 21:23:20 2017 +0100

    Settings: Reflect resurrected middleclick in Range
    
    and while here, make the explanation more explicit as to which values do
    what, & use general Range terminology instead of focussing on scrollbars
    
    https://bugzilla.gnome.org/show_bug.cgi?id=787669

 gtk/gtksettings.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtksettings.c b/gtk/gtksettings.c
index f6d7283..0ebf422 100644
--- a/gtk/gtksettings.c
+++ b/gtk/gtksettings.c
@@ -1273,8 +1273,13 @@ gtk_settings_class_init (GtkSettingsClass *class)
   /**
    * GtkSettings:gtk-primary-button-warps-slider:
    *
-   * Whether a click in a #GtkRange trough should scroll to the click position or
-   * scroll by a single page in the respective direction.
+   * If the value of this setting is %TRUE, clicking the primary button in a
+   * #GtkRange trough will move the slider, and hence set the range’s value, to
+   * the point that you clicked. If it is %FALSE, a primary click will cause the
+   * slider/value to move by the range’s page-size towards the point clicked.
+   *
+   * Whichever action you choose for the primary button, the other action will
+   * be available by clicking the middle mouse button (since GTK+ 3.22.25).
    *
    * Since: 3.6
    */