[mutter] tests/frame-clock: Add test that switches frame clock mid timeline

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit ca82cde6dddf0761d2b2aca03f19830393906bf0
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Mar 25 19:20:42 2020 +0100

    tests/frame-clock: Add test that switches frame clock mid timeline
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285

 src/tests/clutter/conform/frame-clock-timeline.c | 86 ++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
---
diff --git a/src/tests/clutter/conform/frame-clock-timeline.c 
b/src/tests/clutter/conform/frame-clock-timeline.c
index 66ef030f22..f00a938da1 100644
--- a/src/tests/clutter/conform/frame-clock-timeline.c
+++ b/src/tests/clutter/conform/frame-clock-timeline.c
@@ -108,6 +108,92 @@ frame_clock_timeline_basic (void)
   g_assert_null (frame_clock);
 }
 
+static void
+on_switch_reached (ClutterTimeline   *timeline,
+                   const char        *marker_name,
+                   unsigned int       frame_number,
+                   ClutterFrameClock *new_frame_clock)
+{
+  ClutterFrameClock *old_frame_clock;
+
+  old_frame_clock = clutter_timeline_get_frame_clock (timeline);
+  clutter_frame_clock_inhibit (old_frame_clock);
+
+  clutter_timeline_set_frame_clock (timeline, new_frame_clock);
+}
+
+static void
+frame_clock_timeline_switch (void)
+{
+  GMainLoop *main_loop;
+  ClutterFrameClock *frame_clock2;
+  ClutterFrameClock *frame_clock1;
+  ClutterTimeline *timeline;
+  int frame_counter;
+  int64_t before_us;
+  int64_t after_us;
+
+  main_loop = g_main_loop_new (NULL, FALSE);
+
+  frame_clock1 = clutter_frame_clock_new (refresh_rate,
+                                          &timeline_frame_listener_iface,
+                                          NULL);
+  g_object_add_weak_pointer (G_OBJECT (frame_clock1), (gpointer *) &frame_clock1);
+  frame_clock2 = clutter_frame_clock_new (refresh_rate,
+                                          &timeline_frame_listener_iface,
+                                          NULL);
+  g_object_add_weak_pointer (G_OBJECT (frame_clock2), (gpointer *) &frame_clock2);
+
+  timeline = g_object_new (CLUTTER_TYPE_TIMELINE,
+                           "duration", 1000,
+                           "frame-clock", frame_clock1,
+                           NULL);
+  g_object_add_weak_pointer (G_OBJECT (timeline), (gpointer *) &timeline);
+
+  clutter_timeline_add_marker_at_time (timeline, "switch", 500);
+
+  frame_counter = 0;
+
+  g_signal_connect (timeline, "marker-reached::switch",
+                    G_CALLBACK (on_switch_reached),
+                    frame_clock2);
+  g_signal_connect (timeline, "new-frame",
+                    G_CALLBACK (on_timeline_new_frame),
+                    &frame_counter);
+  g_signal_connect (timeline, "completed",
+                    G_CALLBACK (on_timeline_completed),
+                    main_loop);
+
+  clutter_timeline_start (timeline);
+
+  before_us = g_get_monotonic_time ();
+
+  g_main_loop_run (main_loop);
+
+  after_us = g_get_monotonic_time ();
+
+  g_assert_cmpint (after_us - before_us,
+                   >=,
+                   ms2us (clutter_timeline_get_duration (timeline)));
+
+  g_assert (clutter_timeline_get_frame_clock (timeline) == frame_clock2);
+
+  /* The duration is 1s, with a 60hz clock, and we switch after 0.5s. To verify
+   * we continued to get frames, check that we have a bit more than half of the
+   * frames accounted for.
+   */
+  g_assert_cmpint (frame_counter, >, 35);
+
+  g_main_loop_unref (main_loop);
+  g_object_unref (timeline);
+  g_assert_null (timeline);
+  g_object_unref (frame_clock1);
+  g_assert_null (frame_clock1);
+  g_object_unref (frame_clock2);
+  g_assert_null (frame_clock2);
+}
+
 CLUTTER_TEST_SUITE (
   CLUTTER_TEST_UNIT ("/frame-clock/timeline/basic", frame_clock_timeline_basic)
+  CLUTTER_TEST_UNIT ("/frame-clock/timeline/switch", frame_clock_timeline_switch)
 )