Fix use_sim_time not modifying clock (#88)

Previously, when attaching a node that has 'use_sim_time' set to true, we
were not setting ROS time on any previously attached clocks or creating a
subscription to the /clock topic. This change fixes that by calling the
TimeSource setter.

Added unit tests that fail without this fix.

Signed-off-by: Jacob Perron <jacob@openrobotics.org>

Author: jacobperron

rcljava/src/main/java/org/ros2/rcljava/time/TimeSource.java

@@ -152,7 +152,7 @@ public void attachNode(Node node) {
     ParameterType useSimTimeType = useSimTime.getType();
     if (useSimTimeType != ParameterType.PARAMETER_NOT_SET) {
       if (useSimTimeType == ParameterType.PARAMETER_BOOL) {
-        this.rosTimeIsActive = useSimTime.asBool();
+        this.setRosTimeIsActive(useSimTime.asBool());
       } else {
         logger.warn("The 'use_sim_time' parameter must be a boolean");
       }

rcljava/src/test/java/org/ros2/rcljava/time/TimeSourceTest.java

@@ -78,19 +78,28 @@ public final void testConstructorWithNode() {
   @Test
   public final void testAttachNodeUseSimTimeFalse() {
     when(mockedNode.getParameter("use_sim_time")).thenReturn(new ParameterVariant("use_sim_time", false));
+    when(mockedClock.getClockType()).thenReturn(ClockType.ROS_TIME);
 
     TimeSource timeSource = new TimeSource();
+    // An attached clock should be notified of the 'use_sim_time' value
+    timeSource.attachClock(mockedClock);
     timeSource.attachNode(mockedNode);
     assertFalse(timeSource.getRosTimeIsActive());
+    verify(mockedClock).setRosTimeIsActive(false);
   }
 
   @Test
   public final void testAttachNodeUseSimTimeTrue() {
     when(mockedNode.getParameter("use_sim_time")).thenReturn(new ParameterVariant("use_sim_time", true));
+    when(mockedClock.getClockType()).thenReturn(ClockType.ROS_TIME);
 
     TimeSource timeSource = new TimeSource();
+    // An attached clock should be notified of the 'use_sim_time' value
+    timeSource.attachClock(mockedClock);
     timeSource.attachNode(mockedNode);
     assertTrue(timeSource.getRosTimeIsActive());
+
+    verify(mockedClock).setRosTimeIsActive(true);
   }
 
   @Test