rostopic echo: Show stat when --noarr/nostr

tools/rostopic/src/rostopic/__init__.py

@@ -608,14 +608,16 @@ class CallbackEcho(object):
     def __init__(self, topic, msg_eval, plot=False, filter_fn=None,
                  echo_clear=False, echo_all_topics=False,
                  offset_time=False, count=None,
-                 field_filter_fn=None, fixed_numeric_width=None):
+                 field_filter_fn=None, value_transform_fn=None,
+                 fixed_numeric_width=None):
         """
         :param plot: if ``True``, echo in plotting-friendly format, ``bool``
         :param filter_fn: function that evaluates to ``True`` if message is to be echo'd, ``fn(topic, msg)``
         :param echo_all_topics: (optional) if ``True``, echo all messages in bag, ``bool``
         :param offset_time: (optional) if ``True``, display time as offset from current time, ``bool``
         :param count: number of messages to echo, ``None`` for infinite, ``int``
         :param field_filter_fn: filter the fields that are strified for Messages, ``fn(Message)->iter(str)``
+        :param value_transform_fn: transform the values of Messages, ``fn(Message)->Message``
         :param fixed_numeric_width: fixed width for numeric values, ``None`` for automatic, ``int``
         """
         if topic and topic[-1] == '/':
@@ -649,6 +651,7 @@ def __init__(self, topic, msg_eval, plot=False, filter_fn=None,
                 self.prefix = '\033[2J\033[;H'
 
         self.field_filter=field_filter_fn
+        self.value_transform=value_transform_fn
 
         # first tracks whether or not we've printed anything yet. Need this for printing plot fields.
         self.first = True
@@ -657,11 +660,19 @@ def __init__(self, topic, msg_eval, plot=False, filter_fn=None,
         self.last_topic = None
         self.last_msg_eval = None
 
-    def custom_strify_message(self, val, indent='', time_offset=None, current_time=None, field_filter=None, type_information=None, fixed_numeric_width=None):
+    def custom_strify_message(self, val, indent='', time_offset=None, current_time=None, field_filter=None, value_transform=None,
+                              type_information=None, fixed_numeric_width=None):
         # ensure to print uint8[] as array of numbers instead of string
         if type_information and type_information.startswith('uint8['):
             val = [ord(x) for x in val]
-        return genpy.message.strify_message(val, indent=indent, time_offset=time_offset, current_time=current_time, field_filter=field_filter, fixed_numeric_width=fixed_numeric_width)
+        if value_transform:
+            val, value_untransform_fn = value_transform(val)
+        text = genpy.message.strify_message(val, indent=indent, time_offset=time_offset, current_time=current_time, field_filter=field_filter, fixed_numeric_width=fixed_numeric_width)
+        if value_transform:
+            # this operation is necessary because value_transform does change the type of message
+            # and that causes not strified values next time
+            val = value_untransform_fn(val)
+        return text
 
     def callback(self, data, callback_args, current_time=None):
         """
@@ -714,12 +725,14 @@ def callback(self, data, callback_args, current_time=None):
                 if self.offset_time:
                     sys.stdout.write(self.prefix+\
                                      self.str_fn(data, time_offset=rospy.get_rostime(),
-                                                 current_time=current_time, field_filter=self.field_filter, type_information=type_information, fixed_numeric_width=self.fixed_numeric_width) + \
+                                                 current_time=current_time, field_filter=self.field_filter, value_transform=self.value_transform,
+                                                 type_information=type_information, fixed_numeric_width=self.fixed_numeric_width) + \
                                      self.suffix + '\n')
                 else:
                     sys.stdout.write(self.prefix+\
                                      self.str_fn(data,
-                                                 current_time=current_time, field_filter=self.field_filter, type_information=type_information, fixed_numeric_width=self.fixed_numeric_width) + \
+                                                 current_time=current_time, field_filter=self.field_filter, value_transform=self.value_transform,
+                                                 type_information=type_information, fixed_numeric_width=self.fixed_numeric_width) + \
                                      self.suffix + '\n')
 
                 # we have to flush in order before piping to work
@@ -1145,25 +1158,44 @@ def eval_fn(m):
         parser.error("NUM_WIDTH must be an integer")
 
     field_filter_fn = create_field_filter(options.nostr, options.noarr)
+    value_transform_fn = create_value_transform(options.nostr, options.noarr)
     callback_echo = CallbackEcho(topic, None, plot=options.plot,
                                  filter_fn=filter_fn,
                                  echo_clear=options.clear, echo_all_topics=options.all_topics,
                                  offset_time=options.offset_time, count=msg_count,
-                                 field_filter_fn=field_filter_fn, fixed_numeric_width=fixed_numeric_width)
+                                 field_filter_fn=field_filter_fn, value_transform_fn=value_transform_fn,
+                                 fixed_numeric_width=fixed_numeric_width)
     try:
         _rostopic_echo(topic, callback_echo, bag_file=options.bag)
     except socket.error:
         sys.stderr.write("Network communication failed. Most likely failed to communicate with master.\n")
 
-def create_field_filter(echo_nostr, echo_noarr):
-    def field_filter(val):
+def create_value_transform(echo_nostr, echo_noarr):
+    def value_transform(val):
         fields = val.__slots__
         field_types = val._slot_types
-        for f, t in zip(val.__slots__, val._slot_types):
+        transformed_arrays = []
+        for f, t in zip(fields, field_types):
             if echo_noarr and '[' in t:
-                continue
+                val.__setattr__(f, '<array type: %s, length: %s>' %
+                                (t.rstrip('[]'), len(val.__getattribute__(f))))
+                index = fields.index(f)
+                val._slot_types[index] = 'string'
+                transformed_arrays.append((index, t))
             elif echo_nostr and 'string' in t:
-                continue
+                val.__setattr__(f, '<string length: %s>' % len(val.__getattribute__(f)))
+        def untransform_fn(val):
+            for index, type in transformed_arrays:
+                val._slot_types[index] = type
+            return val
+        return val, untransform_fn
+    return value_transform
+
+def create_field_filter(echo_nostr, echo_noarr):
+    def field_filter(val):
+        fields = val.__slots__
+        field_types = val._slot_types
+        for f, t in zip(fields, field_types):
             yield f
     return field_filter