libgimpwidgets: New API to check system animation status

Ports the animation code started in e13cc635
to an independent gimp_widget_animation_enabled()
function. This allows plug-in authors to
also conditionally turn off animations if
the user's system settings say to do so.

The function is applied to the About
Dialogue animation as well as two Easter
Egg animations:
* Wilber's eyes blinking after 23 minutes
on an empty canvas
* Wilber's eyes following the mouse after
a certain sequence of tools is clicked

app/dialogs/about-dialog.c

@@ -42,14 +42,6 @@
 
 #include "gimp-intl.h"
 
-#ifdef PLATFORM_OSX
-#import <Cocoa/Cocoa.h>
-#endif
-
-#ifdef G_OS_WIN32
-#include <windows.h>
-#endif
-
 
 /* The first authors are the creators and maintainers, don't shuffle
  * them
@@ -141,22 +133,7 @@ about_dialog_create (Gimp           *gimp,
        * list. This is redundant anyway as the full list is available in
        * the Credits tab.
        */
-      g_object_get (gtk_settings_get_default (),
-                    "gtk-enable-animations", &dialog.use_animation,
-                    NULL);
-
-      /* gtk-enable-animation does not currently respect system settings by
-       * different operating systems. This check can be removed once that
-       * support is added in GTK.
-       */
-#ifdef PLATFORM_OSX
-      dialog.use_animation =
-        ! ([[NSWorkspace sharedWorkspace] accessibilityDisplayShouldReduceMotion]);
-#endif
-#ifdef G_OS_WIN32
-      SystemParametersInfo (SPI_GETCLIENTAREAANIMATION, 0x00,
-                            &dialog.use_animation, 0x00);
-#endif
+      dialog.use_animation = gimp_widget_animation_enabled ();
 
       pixbuf = about_dialog_load_logo ();
 

app/display/gimpdisplayshell.c

@@ -1504,9 +1504,12 @@ gimp_display_shell_empty (GimpDisplayShell *shell)
   if (shell->display == gimp_context_get_display (user_context))
     gimp_ui_manager_update (shell->popup_manager, shell->display);
 
+  if (gimp_widget_animation_enabled ())
+    {
       shell->blink_timeout_id =
         g_timeout_add (1403230, (GSourceFunc) gimp_display_shell_blink, shell);
     }
+}
 
 static gboolean
 gimp_display_shell_fill_idle (GimpDisplayShell *shell)

app/tools/tool_manager.c

@@ -23,6 +23,7 @@
 #include <gtk/gtk.h>
 
 #include "libgimpconfig/gimpconfig.h"
+#include "libgimpwidgets/gimpwidgets.h"
 
 #include "tools-types.h"
 
@@ -776,9 +777,12 @@ tool_manager_tool_changed (GimpContext     *user_context,
 
   g_object_unref (new_tool);
 
+  if (gimp_widget_animation_enabled ())
+    {
       /* ??? */
       tool_manager_cast_spell (tool_info);
     }
+}
 
 static void
 tool_manager_copy_tool_options (GObject *src,

libgimpwidgets/gimpwidgets.def

@@ -501,6 +501,7 @@ EXPORTS
 	gimp_unit_store_set_pixel_values
 	gimp_unit_store_set_resolution
 	gimp_unit_store_set_resolutions
+	gimp_widget_animation_enabled
 	gimp_widget_get_color_profile
 	gimp_widget_get_color_transform
 	gimp_widget_get_monitor

libgimpwidgets/gimpwidgetsutils.c

@@ -46,6 +46,9 @@
 #include <ApplicationServices/ApplicationServices.h>
 #include <CoreServices/CoreServices.h>
 #endif
+#ifdef PLATFORM_OSX
+#import <Cocoa/Cocoa.h>
+#endif
 
 #include "libgimpcolor/gimpcolor.h"
 #include "libgimpconfig/gimpconfig.h"
@@ -1159,6 +1162,43 @@ gimp_widget_set_native_handle (GtkWidget  *widget,
     gimp_widget_set_handle_on_mapped (widget, NULL, handle);
 }
 
+/**
+ * gimp_widget_animation_enabled:
+ *
+ * This function attempts to read the user's system preference for
+ * showing animation. It can be used to turn off or hide unnecessary
+ * animations such as the scrolling credits or Easter Egg animations.
+ *
+ * Returns: %TRUE if the user has animations enabled on their system
+ *
+ * Since: 3.0
+ */
+gboolean
+gimp_widget_animation_enabled (void)
+{
+  gboolean animation_enabled = TRUE;
+
+  /* Per Luca Bacci, KDE syncs their animation setting with GTK. See
+   * https://invent.kde.org/plasma/kde-gtk-config/-/blob/v6.0.90/kded/gtkconfig.cpp?ref_type=tags#L232
+   */
+  g_object_get (gtk_settings_get_default (),
+                "gtk-enable-animations", &animation_enabled,
+                NULL);
+
+#ifdef PLATFORM_OSX
+  /* The MacOS setting is TRUE if the user wants animations turned off, so
+   * we invert it to match the format of the other platforms */
+  animation_enabled =
+    ! ([[NSWorkspace sharedWorkspace] accessibilityDisplayShouldReduceMotion]);
+#endif
+#ifdef G_OS_WIN32
+  SystemParametersInfo (SPI_GETCLIENTAREAANIMATION, 0x00, &animation_enabled,
+                        0x00);
+#endif
+
+  return animation_enabled;
+}
+
 
 /* Internal functions */
 

libgimpwidgets/gimpwidgetsutils.h

@@ -70,6 +70,8 @@ const Babl         * gimp_widget_get_render_space    (GtkWidget       *widget,
 void                 gimp_widget_set_native_handle   (GtkWidget        *widget,
                                                       GBytes          **handle);
 
+gboolean             gimp_widget_animation_enabled   (void);
+
 /* Internal use */
 
 G_GNUC_INTERNAL void _gimp_widget_get_profiles       (GtkWidget         *widget,