Rev 3012: Add bzrlib.progress.DotsTaskDisplay. in http://people.ubuntu.com/~robertc/baz2.0/nested-pb

[Robert Collins]

At http://people.ubuntu.com/~robertc/baz2.0/nested-pb

------------------------------------------------------------
revno: 3012
revision-id:robertc at robertcollins.net-20071120000238-bitv7u6kda5lmv5w
parent: robertc at robertcollins.net-20071119235143-p3h8sxxd2tlw46ke
committer: Robert Collins <robertc at robertcollins.net>
branch nick: pb.simplify
timestamp: Tue 2007-11-20 11:02:38 +1100
message:
  Add bzrlib.progress.DotsTaskDisplay.
modified:
  bzrlib/progress.py             progress.py-20050610070202-df9faaab791964c0
  bzrlib/tests/test_progress.py  test_progress.py-20060308160359-978c397bc79b7fda
=== modified file 'bzrlib/progress.py'
--- a/bzrlib/progress.py	2007-11-19 23:51:43 +0000
+++ b/bzrlib/progress.py	2007-11-20 00:02:38 +0000
@@ -259,15 +259,37 @@
 _progress_bar_types['none'] = DummyProgress
 
 
-class SilentTaskDisplay(object):
-    """A TaskDisplay that performs no output."""
+class TaskDisplay(object):
+    """Display a task in some medium."""
 
     def __init__(self, task):
-        """Create a SilentTaskDisplay."""
+        """Create a TaskDisplay."""
         self._task = task
 
     def task_changed(self):
-        """Notify the display that the task has changed."""
+        """Update the display due to a change in the task."""
+        raise NotImplementedError(self.task_changed)
+
+
+class DotsTaskDisplay(TaskDisplay):
+    """Display the task on a file stream using dots to mark activity."""
+
+    def __init__(self, task, stream):
+        TaskDisplay.__init__(self, task)
+        self._stream = stream
+
+    def task_changed(self):
+        # When the task changes, a dots display should output each message it
+        # sees once, then dots until a new message is shown. Messages are shown
+        # at the beginning of a line.
+        self._stream.write(self._task.get_message() + ':')
+
+
+class SilentTaskDisplay(TaskDisplay):
+    """A TaskDisplay that performs no output."""
+
+    def task_changed(self):
+        pass
 
 
 class DotsProgressBar(_BaseProgressBar):

=== modified file 'bzrlib/tests/test_progress.py'
--- a/bzrlib/tests/test_progress.py	2007-11-19 23:51:43 +0000
+++ b/bzrlib/tests/test_progress.py	2007-11-20 00:02:38 +0000
@@ -22,6 +22,7 @@
         ChildProgress,
         CountedTask,
         DotsProgressBar,
+        DotsTaskDisplay,
         DummyProgress,
         ProgressBarStack,
         SilentTaskDisplay,
@@ -336,3 +337,20 @@
         display = SilentTaskDisplay(task)
         # We cannot really tell if anything is output, but the API should work.
         display.task_changed()
+
+
+class TestDotsTaskDisplay(TestCase):
+
+    def test_construct(self):
+        task = CountedTask('message')
+        output = StringIO()
+        display = DotsTaskDisplay(task, output)
+
+    def test_task_changed(self):
+        task = CountedTask('message')
+        output = StringIO()
+        display = DotsTaskDisplay(task, output)
+        # The first change will display the message
+        display.task_changed()
+        self.assertEqual('message:', output.getvalue())
+