From 4c79075b4d396ba009b0f0e70d05c1c253cc3da6 Mon Sep 17 00:00:00 2001
From: Kristian Rietveld <kris@lanedo.com>
Date: Fri, 24 Aug 2012 12:12:04 +0200
Subject: [PATCH 07/68] Implement gtk-enable-overlay-scrollbars GtkSetting

And set this up such that on OS X
NSPreferredScrollerDidChangeNotification is followed.
---
 gdk/quartz/gdkevents-quartz.c |   56 ++++++++++++++++++++++++++++++++++++++++-
 gtk/gtksettings.c             |   20 ++++++++++++++-
 2 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/gdk/quartz/gdkevents-quartz.c b/gdk/quartz/gdkevents-quartz.c
index 53f1962..c99a2c9 100644
--- a/gdk/quartz/gdkevents-quartz.c
+++ b/gdk/quartz/gdkevents-quartz.c
@@ -85,6 +85,10 @@ gdk_quartz_ns_notification_callback (CFNotificationCenterRef  center,
                        CFSTR("AppleNoRedisplayAppearancePreferenceChanged"),
                        0) == kCFCompareEqualTo)
     new_event.setting.name = "gtk-primary-button-warps-slider";
+  else if (CFStringCompare (name,
+                            CFSTR("NSPreferredScrollerStyleDidChangeNotification"),
+                            0) == kCFCompareEqualTo)
+    new_event.setting.name = "gtk-enable-overlay-scrollbars";

   if (!new_event.setting.name)
     return;
@@ -114,6 +118,20 @@ gdk_quartz_events_init_notifications (void)
                                    CFSTR ("AppleNoRedisplayAppearancePreferenceChanged"),
                                    NULL,
                                    CFNotificationSuspensionBehaviorDeliverImmediately);
+
+  /* The preferred scroller notification and property are only available on Lion
+   * and higher. Also, beware that the notification will only start working after the
+   * property has been queried for the first time!.
+   */
+  if (gdk_quartz_osx_version () >= GDK_OSX_LION)
+    {
+      CFNotificationCenterAddObserver (CFNotificationCenterGetLocalCenter (),
+                                       NULL,
+                                       &gdk_quartz_ns_notification_callback,
+                                       CFSTR ("NSPreferredScrollerStyleDidChangeNotification"),
+                                       NULL,
+                                       CFNotificationSuspensionBehaviorDeliverImmediately);
+    }
 }

 void
@@ -1686,7 +1704,43 @@ gdk_screen_get_setting (GdkScreen   *screen,

       return TRUE;
     }
-
+  else if (strcmp (name, "gtk-enable-overlay-scrollbars") == 0)
+    {
+      gboolean enabled = FALSE;
+
+      GDK_QUARTZ_ALLOC_POOL;
+
+      if (gdk_quartz_osx_version () >= GDK_OSX_LION)
+        {
+          /* Use an integer instead of NSScrollerStyle to allow things to be compiled
+           * on < 10.7 systems.
+           */
+          int setting = (int)[NSScroller preferredScrollerStyle];
+
+          if (setting == 1)
+            /* 1 == NSScrollerStyleOverlay */
+            enabled = TRUE;
+          else
+            enabled = FALSE;
+        }
+      else
+        {
+          /* On systems prior to Lion, default to legacy scrolling. */
+          enabled = FALSE;
+        }
+
+      g_value_set_boolean (value, enabled);
+
+      /* Initialize after quering the property for the first theme,
+       * notifications are otherwise not received!
+       */
+      gdk_quartz_events_init_notifications ();
+
+      GDK_QUARTZ_RELEASE_POOL;
+
+      return TRUE;
+    }
+
   /* FIXME: Add more settings */

   return FALSE;
diff --git a/gtk/gtksettings.c b/gtk/gtksettings.c
index 3fbbf00..1455db1 100644
--- a/gtk/gtksettings.c
+++ b/gtk/gtksettings.c
@@ -139,7 +139,8 @@ enum {
   PROP_LABEL_SELECT_ON_FOCUS,
   PROP_COLOR_PALETTE,
   PROP_IM_PREEDIT_STYLE,
-  PROP_IM_STATUS_STYLE
+  PROP_IM_STATUS_STYLE,
+  PROP_ENABLE_OVERLAY_SCROLLBARS
 };

 /* --- prototypes --- */
@@ -1205,6 +1206,23 @@ gtk_settings_class_init (GtkSettingsClass *class)
                                                                 GTK_PARAM_READWRITE),
                                              gtk_rc_property_parse_enum);
   g_assert (result == PROP_IM_STATUS_STYLE);
+
+  /**
+   * GtkSettings:gtk-enable-overlay-scrollbars:
+   *
+   * Whether overlay scrollbars should be enabled.
+   *
+   * Since: Xamarin specific API.
+   */
+  result = settings_install_property_parser (class,
+                                             g_param_spec_boolean ("gtk-enable-overlay-scrollbars",
+                                                                   P_("Enable Overlay Scrollbars"),
+                                                                   P_("Whether to enable overlay scrollbars."),
+                                                                   FALSE,
+                                                                   GTK_PARAM_READWRITE),
+                                             NULL);
+
+  g_assert (result == PROP_ENABLE_OVERLAY_SCROLLBARS);
 }

 static void
--
1.7.10.2 (Apple Git-33)