timeline-element: make in-point and max-duration EXPLICIT_NOTIFY

As such, they only emit a signal if their value changes, either through
their _set_inpoint or _set_max_duration methods, or through
g_object_set, etc.

Also, we now require the ->set_max_duration method to be implemented.
This was added to GESGroup, which will only allow the max-duration to be
set to GST_CLOCK_TIME_NONE.

ges/ges-group.c

@@ -402,8 +402,24 @@ _set_start (GESTimelineElement * element, GstClockTime start)
 static gboolean
 _set_inpoint (GESTimelineElement * element, GstClockTime inpoint)
 {
+  if (inpoint != 0) {
+    GST_WARNING_OBJECT (element, "The in-point of a group has no meaning,"
+        " it can not be set to a non-zero value");
     return FALSE;
   }
+  return TRUE;
+}
+
+static gboolean
+_set_max_duration (GESTimelineElement * element, GstClockTime max_duration)
+{
+  if (GST_CLOCK_TIME_IS_VALID (max_duration)) {
+    GST_WARNING_OBJECT (element, "The max-duration of a group has no "
+        "meaning, it can not be set to a valid GstClockTime value");
+    return FALSE;
+  }
+  return TRUE;
+}
 
 static gboolean
 _set_duration (GESTimelineElement * element, GstClockTime duration)
@@ -762,6 +778,7 @@ ges_group_class_init (GESGroupClass * klass)
   element_class->trim = _trim;
   element_class->set_duration = _set_duration;
   element_class->set_inpoint = _set_inpoint;
+  element_class->set_max_duration = _set_max_duration;
   element_class->set_start = _set_start;
   element_class->set_priority = _set_priority;
   element_class->paste = _paste;

ges/ges-timeline-element.c

@@ -430,7 +430,7 @@ ges_timeline_element_class_init (GESTimelineElementClass * klass)
    */
   properties[PROP_INPOINT] =
       g_param_spec_uint64 ("in-point", "In-point", "The in-point", 0,
-      G_MAXUINT64, 0, G_PARAM_READWRITE);
+      G_MAXUINT64, 0, G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY);
 
   /**
    * GESTimelineElement:duration:
@@ -462,7 +462,7 @@ ges_timeline_element_class_init (GESTimelineElementClass * klass)
   properties[PROP_MAX_DURATION] =
       g_param_spec_uint64 ("max-duration", "Maximum duration",
       "The maximum duration of the object", 0, G_MAXUINT64, GST_CLOCK_TIME_NONE,
-      G_PARAM_READWRITE | G_PARAM_CONSTRUCT);
+      G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_EXPLICIT_NOTIFY);
 
   /**
    * GESTimelineElement:priority:
@@ -1113,8 +1113,11 @@ ges_timeline_element_set_inpoint (GESTimelineElement * self,
   g_return_val_if_fail (GES_IS_TIMELINE_ELEMENT (self), FALSE);
 
   GST_DEBUG_OBJECT (self, "current inpoint: %" GST_TIME_FORMAT
-      " new inpoint: %" GST_TIME_FORMAT, GST_TIME_ARGS (inpoint),
-      GST_TIME_ARGS (GES_TIMELINE_ELEMENT_INPOINT (self)));
+      " new inpoint: %" GST_TIME_FORMAT, GST_TIME_ARGS (self->inpoint),
+      GST_TIME_ARGS (inpoint));
+
+  if (G_UNLIKELY (inpoint == self->inpoint))
+    return TRUE;
 
   klass = GES_TIMELINE_ELEMENT_GET_CLASS (self);
 
@@ -1123,13 +1126,13 @@ ges_timeline_element_set_inpoint (GESTimelineElement * self,
      * duplicate notify signals? Rather than relying on the return value
      * being -1 for setting that succeeds but does not want a notify
      * signal because it will call this method on itself a second time. */
-    gint res = klass->set_inpoint (self, inpoint);
-    if (res == TRUE) {
+    if (!klass->set_inpoint (self, inpoint))
+      return FALSE;
+
     self->inpoint = inpoint;
     g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_INPOINT]);
-    }
 
-    return ! !res;
+    return TRUE;
   }
 
   GST_DEBUG_OBJECT (self, "No set_inpoint virtual method implementation"
@@ -1156,23 +1159,31 @@ ges_timeline_element_set_max_duration (GESTimelineElement * self,
 
   g_return_val_if_fail (GES_IS_TIMELINE_ELEMENT (self), FALSE);
 
+  GST_DEBUG_OBJECT (self, "current max-duration: %" GST_TIME_FORMAT
+      " new max-duration: %" GST_TIME_FORMAT,
+      GST_TIME_ARGS (self->maxduration), GST_TIME_ARGS (maxduration));
+
+  if (G_UNLIKELY (maxduration == self->maxduration))
+    return TRUE;
+
   klass = GES_TIMELINE_ELEMENT_GET_CLASS (self);
 
-  GST_DEBUG_OBJECT (self, "current duration: %" GST_TIME_FORMAT
-      " new duration: %" GST_TIME_FORMAT,
-      GST_TIME_ARGS (GES_TIMELINE_ELEMENT_MAX_DURATION (self)),
-      GST_TIME_ARGS (maxduration));
-
   if (klass->set_max_duration) {
-    if (klass->set_max_duration (self, maxduration) == FALSE)
+    if (!klass->set_max_duration (self, maxduration))
       return FALSE;
-  }
-
     self->maxduration = maxduration;
     g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MAX_DURATION]);
+
     return TRUE;
   }
 
+  GST_DEBUG_OBJECT (self, "No set_max_duration virtual method implementation"
+      " on class %s. Can not set max-duration  %" GST_TIME_FORMAT,
+      G_OBJECT_CLASS_NAME (klass), GST_TIME_ARGS (maxduration));
+
+  return FALSE;
+}
+
 /**
  * ges_timeline_element_set_duration:
  * @self: A #GESTimelineElement

ges/ges-timeline-element.h

@@ -175,11 +175,17 @@ struct _GESTimelineElement
  * subclass handled emitting the notify signal and the base class should
  * return %TRUE.
  * @set_inpoint: Method called just before the
- * #GESTimelineElement:in-point is set. A return of -1 means that the
- * subclass handled emitting the notify signal and the base class should
- * return %TRUE.
+ * #GESTimelineElement:in-point is set to a new value. This method should
+ * not set the #GESTimelineElement:in-point itself, but should check
+ * whether it can be changed to the new value and to otherwise prepare the
+ * element in response to what the new value will be. A return of %FALSE
+ * means that the property should not be set.
  * @set_max_duration: Method called just before the
- * #GESTimelineElement:max-duration is set.
+ * #GESTimelineElement:max-duration is set. This method should
+ * not set the #GESTimelineElement:max-duration itself, but should check
+ * whether it can be changed to the new value and to otherwise prepare the
+ * element in response to what the new value will be. A return of %FALSE
+ * means that the property should not be set.
  * @set_priority:  Method called just before the
  * #GESTimelineElement:in-point is set.
  * @ripple_end: Method to ripple an object on its #GES_EDGE_END edge.