[gimp] app: add GimpWaitable interface

[Ell <ell src gnome org>]

commit 0fe066890ef6bebaf1d67a2f148a879397cfbe35
Author: Ell <ell_se yahoo com>
Date:   Sun May 27 09:53:33 2018 -0400

    app: add GimpWaitable interface
    
    ... which provides methods for waiting on an object.

 app/core/Makefile.am    |  4 ++-
 app/core/core-types.h   |  1 +
 app/core/gimpwaitable.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++
 app/core/gimpwaitable.h | 53 +++++++++++++++++++++++++++++
 4 files changed, 147 insertions(+), 1 deletion(-)
---
diff --git a/app/core/Makefile.am b/app/core/Makefile.am
index 495ad0667b..7b8f524959 100644
--- a/app/core/Makefile.am
+++ b/app/core/Makefile.am
@@ -446,7 +446,9 @@ libappcore_a_sources = \
        gimpundostack.c                         \
        gimpundostack.h                         \
        gimpviewable.c                          \
-       gimpviewable.h
+       gimpviewable.h                          \
+       gimpwaitable.c                          \
+       gimpwaitable.h
 
 libappcore_a_built_sources = \
        core-enums.c    \
diff --git a/app/core/core-types.h b/app/core/core-types.h
index fb1680ea87..bbda2209b5 100644
--- a/app/core/core-types.h
+++ b/app/core/core-types.h
@@ -202,6 +202,7 @@ typedef struct _GimpPickable        GimpPickable;    /* dummy typedef */
 typedef struct _GimpProgress        GimpProgress;    /* dummy typedef */
 typedef struct _GimpProjectable     GimpProjectable; /* dummy typedef */
 typedef struct _GimpTagged          GimpTagged;      /* dummy typedef */
+typedef struct _GimpWaitable        GimpWaitable;    /* dummy typedef */
 
 
 /*  non-object types  */
diff --git a/app/core/gimpwaitable.c b/app/core/gimpwaitable.c
new file mode 100644
index 0000000000..93e57be0e3
--- /dev/null
+++ b/app/core/gimpwaitable.c
@@ -0,0 +1,90 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpwaitable.c
+ * Copyright (C) 2018 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "config.h"
+
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#include <gegl.h>
+
+#include "core-types.h"
+
+#include "gimpwaitable.h"
+
+
+G_DEFINE_INTERFACE (GimpWaitable, gimp_waitable, G_TYPE_OBJECT)
+
+
+/*  private functions  */
+
+
+static void
+gimp_waitable_default_init (GimpWaitableInterface *iface)
+{
+}
+
+
+/*  public functions  */
+
+
+void
+gimp_waitable_wait (GimpWaitable *waitable)
+{
+  GimpWaitableInterface *iface;
+
+  g_return_if_fail (GIMP_IS_WAITABLE (waitable));
+
+  iface = GIMP_WAITABLE_GET_INTERFACE (waitable);
+
+  if (iface->wait)
+    iface->wait (waitable);
+}
+
+gboolean
+gimp_waitable_wait_until (GimpWaitable *waitable,
+                          gint64        end_time)
+{
+  GimpWaitableInterface *iface;
+
+  g_return_val_if_fail (GIMP_IS_WAITABLE (waitable), FALSE);
+
+  iface = GIMP_WAITABLE_GET_INTERFACE (waitable);
+
+  if (iface->wait_until)
+    {
+      return iface->wait_until (waitable, end_time);
+    }
+  else
+    {
+      gimp_waitable_wait (waitable);
+
+      return TRUE;
+    }
+}
+
+gboolean
+gimp_waitable_wait_for (GimpWaitable *waitable,
+                        gint64        wait_duration)
+{
+  g_return_val_if_fail (GIMP_IS_WAITABLE (waitable), FALSE);
+
+  return gimp_waitable_wait_until (waitable,
+                                   g_get_monotonic_time () + wait_duration);
+}
diff --git a/app/core/gimpwaitable.h b/app/core/gimpwaitable.h
new file mode 100644
index 0000000000..5b52308a1e
--- /dev/null
+++ b/app/core/gimpwaitable.h
@@ -0,0 +1,53 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995-1997 Spencer Kimball and Peter Mattis
+ *
+ * gimpwaitable.h
+ * Copyright (C) 2018 Ell
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_WAITABLE_H__
+#define __GIMP_WAITABLE_H__
+
+
+#define GIMP_TYPE_WAITABLE               (gimp_waitable_get_type ())
+#define GIMP_IS_WAITABLE(obj)            (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_WAITABLE))
+#define GIMP_WAITABLE(obj)               (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_WAITABLE, 
GimpWaitable))
+#define GIMP_WAITABLE_GET_INTERFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), GIMP_TYPE_WAITABLE, 
GimpWaitableInterface))
+
+
+typedef struct _GimpWaitableInterface GimpWaitableInterface;
+
+struct _GimpWaitableInterface
+{
+  GTypeInterface base_iface;
+
+  /*  virtual functions  */
+  void       (* wait)       (GimpWaitable *waitable);
+  gboolean   (* wait_until) (GimpWaitable *waitable,
+                             gint64        end_time);
+};
+
+
+GType      gimp_waitable_get_type   (void) G_GNUC_CONST;
+
+void       gimp_waitable_wait       (GimpWaitable *waitable);
+gboolean   gimp_waitable_wait_until (GimpWaitable *waitable,
+                                     gint64        end_time);
+gboolean   gimp_waitable_wait_for   (GimpWaitable *waitable,
+                                     gint64        wait_duration);
+
+
+#endif  /* __GIMP_WAITABLE_H__ */