[GTK] Only autoscroll viewport if accessibility is disabled

This is a followup to https://github.com/mono/bockbuild/pull/126 and
https://github.com/xamarin/AtkCocoa/pull/9

We want to keep the GTK patch because it improves the experience when
accessibility is not enabled. But in cases where it is enabled we
don't want viewport autoscrolling potentially happening from both
GTK and from AtkCocoa.

2 files changed, 120 insertions, 1 deletions

diff --git a/packages/gtk+.py b/packages/gtk+.py
index ff42b5f..85b8ec0 100644
--- a/packages/gtk+.py
+++ b/packages/gtk+.py
@@ -226,7 +226,8 @@ class GtkPackage (GitHubPackage):
                 'patches/gtk/nsview-embedding-skip-hidden-subviews.patch',
                 'patches/gtk/0001-gtk-combo-box-native-menu-hook.patch',
 
-                'patches/gtk/gtkviewport-autoscroll.patch'
+                'patches/gtk/gtkviewport-autoscroll.patch',
+                'packages/patches/gtk/only-scroll-autoviewport-if-accessibility-is-disabled.patch'
             ])
 
     def prep(self):
diff --git a/packages/patches/gtk/only-scroll-autoviewport-if-accessibility-is-disabled.patch b/packages/patches/gtk/only-scroll-autoviewport-if-accessibility-is-disabled.patch
new file mode 100644
index 0000000..b393339
--- /dev/null
+++ b/packages/patches/gtk/only-scroll-autoviewport-if-accessibility-is-disabled.patch
@@ -0,0 +1,118 @@
+diff --git a/gdk/gdk.h b/gdk/gdk.h
+index 3f0b1acf6..094f2fee7 100644
+--- a/gdk/gdk.h
++++ b/gdk/gdk.h
+@@ -221,6 +221,8 @@ guint    gdk_threads_add_timeout_seconds      (guint          interval,
+                                                GSourceFunc    function,
+                                                gpointer       data);
+ 
++gboolean gdk_accessibility_is_enabled         (void);
++
+ #ifdef	G_THREADS_ENABLED
+ #  define GDK_THREADS_ENTER()	G_STMT_START {	\
+       if (gdk_threads_lock)                 	\
+diff --git a/gdk/quartz/gdkmain-quartz.c b/gdk/quartz/gdkmain-quartz.c
+index 6e82478ea..6db6d5a88 100644
+--- a/gdk/quartz/gdkmain-quartz.c
++++ b/gdk/quartz/gdkmain-quartz.c
+@@ -22,18 +22,55 @@
+ #include <dlfcn.h>
+ 
+ #include "gdk.h"
++#include <Cocoa/Cocoa.h>
+ #include <ApplicationServices/ApplicationServices.h>
+ 
++@interface AccessibilityNotificationReceiver : NSObject
++{
++  @public gboolean atk_cocoa_enabled;
++}
++
++- (void) accessibilityEnabled:(id)sender;
++- (void) accessibilityDisabled:(id)sender;
++
++@end
++
+ const GOptionEntry _gdk_windowing_args[] = {
+   { NULL }
+ };
+ 
++static AccessibilityNotificationReceiver *receiver = NULL;
++
++@implementation AccessibilityNotificationReceiver
++
++- (void) accessibilityEnabled:(id)sender
++{
++  g_return_if_fail (receiver != NULL);
++
++  g_print ("a11y ENABLED!\n");
++
++  receiver->atk_cocoa_enabled = TRUE;
++}
++
++- (void) accessibilityDisabled:(id)sender
++{
++  g_return_if_fail (receiver != NULL);
++
++  g_print ("a11y DISABLED\n");
++
++  receiver->atk_cocoa_enabled = FALSE;
++}
++
++@end
++
+ void
+ _gdk_windowing_init (void)
+ {
+   ProcessSerialNumber psn = { 0, kCurrentProcess };
+   void (*_gtk_quartz_framework_init_ptr) (void);
+ 
++  receiver = [[AccessibilityNotificationReceiver alloc] init];
++
+   /* Make the current process a foreground application, i.e. an app
+    * with a user interface, in case we're not running from a .app bundle
+    */
+@@ -43,6 +80,30 @@ _gdk_windowing_init (void)
+   _gtk_quartz_framework_init_ptr = dlsym (RTLD_DEFAULT, "_gtk_quartz_framework_init");
+   if (_gtk_quartz_framework_init_ptr)
+     _gtk_quartz_framework_init_ptr ();
++
++  [[NSNotificationCenter defaultCenter] addObserver:receiver
++                                        selector:@selector(accessibilityEnabled:)
++                                        name:@"AtkCocoaAccessibilityEnabled"
++                                        object: [NSApplication sharedApplication]];
++
++  [[NSNotificationCenter defaultCenter] addObserver:receiver
++                                        selector:@selector(accessibilityDisabled:)
++                                        name:@"AtkCocoaAccessibilityDisabled"
++                                        object: [NSApplication sharedApplication]];
++}
++
++gboolean
++gdk_accessibility_is_enabled (void)
++{
++  g_return_val_if_fail (receiver != NULL, FALSE);
++
++  return receiver->atk_cocoa_enabled;
++}
++
++void
++_gdk_windowing_exit (void)
++{
++  [receiver release];
+ }
+ 
+ void
+diff --git a/gtk/gtkviewport.c b/gtk/gtkviewport.c
+index 24dd9f099..38659dbaa 100644
+--- a/gtk/gtkviewport.c
++++ b/gtk/gtkviewport.c
+@@ -829,6 +829,9 @@ gtk_viewport_set_focus_child (GtkContainer *container,
+   if (child == NULL)
+     return;
+ 
++  if (gdk_accessibility_is_enabled ())
++    return;
++
+   g_idle_add (set_focus_child_cb, container);
+ }
+