diff --git a/atpbar/callback.py b/atpbar/callback.py
index f889da1..6ed4be7 100644
--- a/atpbar/callback.py
+++ b/atpbar/callback.py
@@ -1,12 +1,9 @@
 from collections.abc import Iterator
 from contextlib import contextmanager
-from multiprocessing import Queue
 from threading import Lock, current_thread, main_thread
 
 from .machine import StateMachine
-from .presentation import create_presentation
-from .progress_report import ProgressReporter, ProgressReportPickup, Report
-from .stream import StreamQueue, StreamRedirection, register_stream_queue
+from .progress_report import ProgressReporter
 
 
 class CallbackImp:
@@ -17,41 +14,12 @@ def __init__(self) -> None:
         self._lock: Lock  # to be set by the StateMachine
 
     def on_active(self) -> None:
-
-        self.queue: Queue[Report] = Queue()
-        self.notices_from_sub_processes: Queue[bool] = Queue()
-        self.stream_queue: StreamQueue = Queue()
-        self.reporter = ProgressReporter(
-            queue=self.queue,
-            notices_from_sub_processes=self.notices_from_sub_processes,
-            stream_queue=self.stream_queue,
-        )
-
-        self._start_pickup()
-
-        if self.stream_redirection.disabled:
-            self.reporter.stream_redirection_enabled = False
-
-    def _start_pickup(self) -> None:
-        presentation = create_presentation()
-        self.pickup = ProgressReportPickup(self.queue, presentation)
-
-        self.stream_redirection = StreamRedirection(
-            queue=self.stream_queue, presentation=presentation
-        )
-        self.stream_redirection.start()
-
-    def _end_pickup(self) -> None:
-        self.pickup.end()
-
-        self.stream_redirection.end()
-
-    def _restart_pickup(self) -> None:
-        self._end_pickup()
-        self._start_pickup()
+        self.reporter = ProgressReporter()
+        self.reporter.start_pickup()
 
     @contextmanager
     def fetch_reporter_in_active(self) -> Iterator[ProgressReporter | None]:
+        assert self.reporter
 
         if not in_main_thread():
             self.to_restart_pickup = False
@@ -59,10 +27,7 @@ def fetch_reporter_in_active(self) -> Iterator[ProgressReporter | None]:
             return
 
         self.to_restart_pickup = True
-
-        while not self.notices_from_sub_processes.empty():
-            _ = self.notices_from_sub_processes.get()
-
+        self.reporter.empty_notices()
         self._machine.on_yielded()
 
         try:
@@ -70,21 +35,22 @@ def fetch_reporter_in_active(self) -> Iterator[ProgressReporter | None]:
         finally:
             self._machine.on_resumed()
 
-            while not self.notices_from_sub_processes.empty():
-                _ = self.notices_from_sub_processes.get()
+            if self.reporter.empty_notices():
                 self.to_restart_pickup = False
 
             if not self.to_restart_pickup:
                 return
 
-            with self._lock:
-                self._restart_pickup()
+            with self._lock:  # NOTE: This lock is probably unnecessary
+                self.reporter.restart_pickup()
 
     def flush_in_active(self) -> None:
-        self._restart_pickup()
+        assert self.reporter
+        self.reporter.restart_pickup()
 
     def shutdown_in_active(self) -> None:
-        self._end_pickup()
+        assert self.reporter
+        self.reporter.end_pickup()
 
     @contextmanager
     def fetch_reporter_in_yielded(self) -> Iterator[ProgressReporter | None]:
@@ -100,8 +66,7 @@ def on_registered(self, reporter: ProgressReporter | None) -> None:
         self.reporter = reporter
         if reporter is None:
             return
-        if reporter.stream_redirection_enabled:
-            register_stream_queue(reporter.stream_queue)
+        reporter.register()
 
     @contextmanager
     def fetch_reporter_in_registered(self) -> Iterator[ProgressReporter | None]:
@@ -109,7 +74,7 @@ def fetch_reporter_in_registered(self) -> Iterator[ProgressReporter | None]:
             yield self.reporter
             return
 
-        self.reporter.notices_from_sub_processes.put(True)
+        self.reporter.notice()
         yield self.reporter
 
     def on_disabled(self) -> None:
diff --git a/atpbar/progress_report/reporter.py b/atpbar/progress_report/reporter.py
index b99a11f..90c745a 100755
--- a/atpbar/progress_report/reporter.py
+++ b/atpbar/progress_report/reporter.py
@@ -1,19 +1,21 @@
 import time
 from multiprocessing import Queue
-from typing import TYPE_CHECKING
 from uuid import UUID
 
+from atpbar.presentation import create_presentation
+from atpbar.stream import StreamQueue, StreamRedirection, register_stream_queue
+
 from .complement import ProgressReportComplementer
+from .pickup import ProgressReportPickup
 from .report import Report
 
-if TYPE_CHECKING:
-    from atpbar.stream import StreamQueue
-
 DEFAULT_INTERVAL = 0.1  # [second]
 
 
 class ProgressReporter:
-    '''A progress reporter
+    '''A progress reporter.
+
+    NOTE: This docstring is outdated.
 
     This class sends progress reports. The reports will be picked up
     by the pickup (`ProgressReportPickup`), which uses the reports,
@@ -45,24 +47,49 @@ class ProgressReporter:
         The queue through which this class sends progress reports.
     '''
 
-    def __init__(
-        self,
-        queue: 'Queue[Report]',
-        notices_from_sub_processes: 'Queue[bool]',
-        stream_queue: 'StreamQueue',
-    ) -> None:
-        self.queue = queue
+    def __init__(self) -> None:
+        self.queue: Queue[Report] = Queue()
+        self.notices_from_sub_processes: Queue[bool] = Queue()
+        self.stream_queue: StreamQueue = Queue()
         self.interval = DEFAULT_INTERVAL  # [second]
         self.last_time = dict[UUID, float]()
         self.complete_report = ProgressReportComplementer()
-        self.notices_from_sub_processes = notices_from_sub_processes
-        self.stream_queue = stream_queue
         self.stream_redirection_enabled = True
 
     def __repr__(self) -> str:
-        return '{}(queue={!r}, interval={!r})'.format(
-            self.__class__.__name__, self.queue, self.interval
+        return f'{self.__class__.__name__}(queue={self.queue!r}, interval={self.interval!r})'
+
+    def start_pickup(self) -> None:
+        presentation = create_presentation()
+        self.pickup = ProgressReportPickup(self.queue, presentation)
+
+        self.stream_redirection = StreamRedirection(
+            queue=self.stream_queue, presentation=presentation
         )
+        self.stream_redirection.start()
+        self.stream_redirection_enabled = not self.stream_redirection.disabled
+
+    def end_pickup(self) -> None:
+        self.pickup.end()
+        self.stream_redirection.end()
+
+    def restart_pickup(self) -> None:
+        self.end_pickup()
+        self.start_pickup()
+
+    def notice(self) -> None:
+        self.notices_from_sub_processes.put(True)
+
+    def empty_notices(self) -> bool:
+        ret = False
+        while not self.notices_from_sub_processes.empty():
+            _ = self.notices_from_sub_processes.get()
+            ret = True
+        return ret
+
+    def register(self) -> None:
+        if self.stream_redirection_enabled:
+            register_stream_queue(self.stream_queue)
 
     def report(self, report: Report) -> None:
         '''send ``report`` to a progress monitor
diff --git a/tests/progress_report/test_reporter.py b/tests/progress_report/test_reporter.py
index 80d46d6..13b177e 100644
--- a/tests/progress_report/test_reporter.py
+++ b/tests/progress_report/test_reporter.py
@@ -24,9 +24,8 @@ def mock_time(monkeypatch: pytest.MonkeyPatch) -> mock.Mock:
 
 @pytest.fixture()
 def obj(mock_queue: mock.Mock, mock_time: mock.Mock) -> ProgressReporter:
-    ret = ProgressReporter(
-        mock_queue, notices_from_sub_processes=mock.Mock(), stream_queue=mock.Mock()
-    )
+    ret = ProgressReporter()
+    ret.queue = mock_queue
     return ret
 
 
diff --git a/tests/scenarios/test_utils.py b/tests/scenarios/test_utils.py
index 187bb29..bc9d6a4 100644
--- a/tests/scenarios/test_utils.py
+++ b/tests/scenarios/test_utils.py
@@ -1,4 +1,4 @@
-from atpbar import callback, funcs
+from atpbar import funcs
 from atpbar.progress_report import reporter
 
 from .utils import mock_presentations
@@ -11,12 +11,12 @@ class MockException(Exception):
 
     func_machine = funcs._machine
     interval = reporter.DEFAULT_INTERVAL
-    create_presentation = callback.create_presentation
+    create_presentation = reporter.create_presentation
     try:
         with mock_presentations() as presentations:
             assert func_machine is not funcs._machine
             assert interval != reporter.DEFAULT_INTERVAL
-            assert create_presentation is not callback.create_presentation
+            assert create_presentation is not reporter.create_presentation
             presentations
             raise MockException()
     except MockException:
@@ -24,4 +24,4 @@ class MockException(Exception):
     finally:
         assert func_machine is funcs._machine
         assert interval == reporter.DEFAULT_INTERVAL
-        assert create_presentation is callback.create_presentation
+        assert create_presentation is reporter.create_presentation
diff --git a/tests/scenarios/utils.py b/tests/scenarios/utils.py
index af050e9..c0fd96c 100644
--- a/tests/scenarios/utils.py
+++ b/tests/scenarios/utils.py
@@ -88,7 +88,7 @@ def monkeypatch_reporter_interval() -> Iterator[None]:
 def mock_create_presentation() -> Iterator[MockCreatePresentation]:
     y = MockCreatePresentation()
     with MonkeyPatch.context() as m:
-        m.setattr(callback, 'create_presentation', y)
+        m.setattr(reporter, 'create_presentation', y)
         yield y