Renamed 32 to active view to better reflect the program

32-active-view/README.md

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+Style #32
+==============================
+
+Constraints:
+
+- Variables are updated automatically based on changing values of
+  other variables. Variable values possibly depend on data streams
+  (keyboard, mouse, etc.)
+
+Possible names:
+
+- Reactive
+- Data-to-data

32-active-view/tf-32.py

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+#!/usr/bin/env python
+import sys, operator, string, os, threading, re
+from util import getch, cls, get_input
+from time import sleep
+
+lock = threading.Lock()
+
+#
+# The active view
+#
+class FreqObserver(threading.Thread):
+    def __init__(self, freqs):
+        threading.Thread.__init__(self)
+        self.daemon = True
+        self._end = False
+        # freqs is the part of the model to be observed
+        self._freqs = freqs
+        self._freqs_0 = sorted(self._freqs.iteritems(), key=operator.itemgetter(1), reverse=True)
+        self.start()
+
+    def run(self):
+        while not self._end:
+            self._update_view()
+            sleep(0.1)
+
+    def stop(self):
+        self._end = True
+
+    def _update_view(self):
+        lock.acquire()
+        freqs_1 = sorted(self._freqs.iteritems(), key=operator.itemgetter(1), reverse=True)
+        lock.release()
+        if (freqs_1[0:25] != self._freqs_0[0:25]):
+            self._update_display(freqs_1[0:25])
+        self._freqs_0 = freqs_1
+
+    def _update_display(self, tuples):
+        def refresh_screen(data):
+            # clear screen
+            cls()
+            print data
+            sys.stdout.flush()
+
+        data_str = ""
+        for (w, c) in tuples:
+            data_str += str(w) + ' - ' + str(c) + '\n'
+        refresh_screen(data_str)
+
+#
+# The model
+#
+class WordsCounter:
+    freqs = {}
+    def count(self):
+        def non_stop_words():
+            stopwords = set(open('../stop_words.txt').read().split(',')  + list(string.ascii_lowercase))
+            for line in f:
+                yield [w for w in re.findall('[a-z]{2,}', line.lower()) if w not in stopwords]
+
+        words = non_stop_words().next()
+        lock.acquire()
+        for w in words:
+            self.freqs[w] = 1 if w not in self.freqs else self.freqs[w]+1
+        lock.release()
+
+#
+# The controller
+#
+print "Press space bar to fetch words from the file one by one"
+print "Press ESC to switch to automatic mode"
+model = WordsCounter()
+view = FreqObserver(model.freqs)
+with open(sys.argv[1]) as f:
+    while get_input():
+        try:
+            model.count()
+        except StopIteration:
+            # Let's wait for the view thread to die gracefully
+            view.stop()
+            sleep(1)
+            break
+
+

32-active-view/util.py

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+import sys, os
+
+#
+# getch in a platform-independent way
+# Credit: http://code.activestate.com/recipes/134892/
+#
+class _Getch:
+    """Gets a single character from standard input.  Does not echo to the
+    screen."""
+    def __init__(self):
+        try:
+            self.impl = _GetchWindows()
+        except ImportError:
+            try:
+                self.impl = _GetchMacCarbon()
+            except(AttributeError, ImportError):
+                self.impl = _GetchUnix()
+
+    def __call__(self): return self.impl()
+
+
+class _GetchUnix:
+    def __init__(self):
+        import tty, sys
+
+    def __call__(self):
+        import sys, tty, termios
+        fd = sys.stdin.fileno()
+        old_settings = termios.tcgetattr(fd)
+        try:
+            tty.setraw(sys.stdin.fileno())
+            ch = sys.stdin.read(1)
+        finally:
+            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+        return ch
+
+class _GetchWindows:
+    def __init__(self):
+        import msvcrt
+    def __call__(self):
+        import msvcrt
+        return msvcrt.getch()
+
+class _GetchMacCarbon:
+    def __init__(self):
+        import Carbon
+
+    def __call__(self):
+        import Carbon
+        if Carbon.Evt.EventAvail(0x0008)[0]==0: # 0x0008 is the keyDownMask
+            return ''
+        else:
+            (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
+            return chr(msg & 0x000000FF)
+
+getch = _Getch()
+
+def cls():
+    os.system(['clear','cls'][os.name == 'nt'])
+
+
+interactive = True
+def get_input():
+    global interactive
+    if not interactive:
+        return True
+
+    while True: 
+        key = ord(getch())
+        if key == 32: # space bar
+            return True
+        elif key == 27: # ESC
+            interactive = False
+            return True
+