Added UserSelection class.

Makefile

@@ -64,6 +64,7 @@ profiles:
 # List in order to be tested
 UNITTESTS = \
 	test-testing \
+	test-Utils \
 	test-Action \
 	test-Bitfield \
 	test-Cards \

pyPoker/Utils.py

@@ -1,6 +1,8 @@
 """Internal utility functions"""
 
+import collections
 import itertools
+import sys
 
 def assertInstance(obj, cls):
     if obj is None:
@@ -49,4 +51,69 @@ def combinations(set, n):
     else:
         for comb in itertools.combinations(set, n):
             yield set.__class__(comb)
-
+
+class UserSelection(object):
+    """Present a user with a menu of options, each selectable with a single
+    keystroke. Get and return the user's selection."""
+
+    _Option = collections.namedtuple('_Option', "description return_value")
+
+    def __init__(self,
+                 input_stream=None,
+                 output_stream=None,
+                 prompt="Selection?",
+                 selection_format="({})"):
+        """input_stream is the stream from which to receive input
+        from the user.
+
+        output_stream is the stream to which to send output to the user.
+
+        prompt is the string presented to the user to prompt for
+        their selection.
+
+        selection_format is the string used to present the selection
+        format to the user. It must include one '{}' string which will
+        be replaced by the selection character.
+        """
+        self.input_stream = input_stream \
+            if input_stream is not None else sys.stdin
+        self.output_stream = output_stream \
+            if output_stream is not None else sys.stdout
+        self.prompt = prompt
+        self.selection_format = selection_format
+        self.options = {}
+
+    def add_option(self, char, description, return_value):
+        """Add an option.
+
+        char is the character the user should use to select the option.
+
+        description is the string displayed to the user for the option.
+
+        return_value is the value returned if the user selects the option.
+        """
+        if char in self.options.keys():
+            raise ValueError(\
+                "Selection character \"{}\" already in use".format(char))
+        self.options[char] = self._Option(description=description,
+                                          return_value=return_value)
+
+    def get_user_selection(self):
+        """Present user with options and get their selection.
+
+        Returns selection's associated return_value."""
+        for char, option in self.options.items():
+            self.output_stream.write(\
+                self.selection_format.format(char) +
+                " {}\n".format(option.description))
+        self.output_stream.write(self.prompt)
+        self.output_stream.flush()
+        while True:
+            selection = self.input_stream.read(1)
+            if selection in self.options.keys():
+                break
+            # Just ignore non-legal selections
+        self.output_stream.write("\n")
+        self.output_stream.flush()
+        return self.options[selection].return_value
+

unittests/test-Utils.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+"""Unittests for Utils module"""
+
+import StringIO
+
+import testing
+
+from pyPoker.Utils import UserSelection
+
+class TestSequenceFunctions(testing.TestCase):
+
+    def test_UserSelection(self):
+        """Test basic UserSelction functionality"""
+        with self.pipe_to_stdin() as input:
+            with self.stdout_to_pipe() as output:
+                user_selection = UserSelection()
+                self.assertIsNotNone(user_selection)
+                user_selection.add_option('p',
+                                          description="Play",
+                                          return_value=0)
+                user_selection.add_option('q',
+                                          description="Quit",
+                                          return_value=1)
+                user_selection.add_option('r',
+                                          description="Reset",
+                                          return_value=2)
+                input.write("pyrq")
+                # 'p' should return 0
+                self.assertEqual(user_selection.get_user_selection(), 0)
+                # 'y' should be ignored, 'r' should return 2
+                self.assertEqual(user_selection.get_user_selection(), 2)
+                # 'q' should return 1
+                self.assertEqual(user_selection.get_user_selection(), 1)
+        lines = output.readlines()
+        # (Three options plus prompt) times 3 calls to get_user_selection()
+        # meands we should have 12 lines in output buffer.
+        self.assertEqual(len(lines), 12)
+
+    def test_UserSelection_with_streams(self):
+        """Test basic UserSelction with specified streams"""
+        input_buffer = StringIO.StringIO("pyrq")
+        output_buffer = StringIO.StringIO()
+        user_selection = UserSelection(input_stream=input_buffer,
+                                       output_stream=output_buffer)
+        self.assertIsNotNone(user_selection)
+        user_selection.add_option('p', description="Play", return_value=0)
+        user_selection.add_option('q', description="Quit", return_value=1)
+        user_selection.add_option('r', description="Reset", return_value=2)
+        # 'p' should return 0
+        self.assertEqual(user_selection.get_user_selection(), 0)
+        output_buffer.seek(0)
+        lines = output_buffer.readlines()
+        self.assertEqual(len(lines), 4)  # 3 options plus prompt
+        # 'y' should be ignored, 'r' should return 2
+        self.assertEqual(user_selection.get_user_selection(), 2)
+        # 'q' should return 1
+        self.assertEqual(user_selection.get_user_selection(), 1)
+
+if __name__ == "__main__":
+    testing.main()