Add format string support.

8 files changed, 163 insertions, 10 deletions

diff --git a/NEWS b/NEWS
index 9b556c2..3f56359 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,8 @@ Version 0.14, released XXXXXXXXXX
 * A method for printing error messages is provided. They are printed to
   the standard error.
 * The `PercentDone` class handles zero total amounts better now.
+* Widgets may now be added using a simple format string. See
+  `ttystatus.TerminalStatus.format` method.
 
 Version 0.13, released 2011-08-18
 ---------------------------------
diff --git a/doc/index.rst b/doc/index.rst
index 5f671bf..7119d5d 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -25,11 +25,8 @@ Here's an example program that searches for symlinks in a directory tree::
     import ttystatus
 
     ts = ttystatus.TerminalStatus(period=0.1)
-    ts.add(ttystatus.ElapsedTime())
-    ts.add(ttystatus.Literal(' Looking for files: '))
-    ts.add(ttystatus.Counter('pathname'))
-    ts.add(ttystatus.Literal(' found, currently in '))
-    ts.add(ttystatus.Pathname('dirname'))
+    ts.format('%ElapsedTime() Looking for files: %Counter(pathname) found, '
+              'currently in %Pathname(dirname)')
     
     pathnames = []
     for dirname, subdirs, basenames in os.walk(sys.argv[1]):
diff --git a/example.py b/example.py
index 909ce46..5814fbc 100644
--- a/example.py
+++ b/example.py
@@ -25,11 +25,8 @@ import ttystatus
 
 def main():
     ts = ttystatus.TerminalStatus(period=0.1)
-    ts.add(ttystatus.ElapsedTime())
-    ts.add(ttystatus.Literal(' Looking for files: '))
-    ts.add(ttystatus.Counter('pathname'))
-    ts.add(ttystatus.Literal(' found, currently in '))
-    ts.add(ttystatus.Pathname('dirname'))
+    ts.format('%ElapsedTime() Looking for files: %Counter(pathname) found, '
+              'currently in %Pathname(dirname)')
     
     pathnames = []
     for dirname, subdirs, basenames in os.walk(sys.argv[1]):
diff --git a/ttystatus/__init__.py b/ttystatus/__init__.py
index 794f0ee..c2cfebc 100644
--- a/ttystatus/__init__.py
+++ b/ttystatus/__init__.py
@@ -33,4 +33,6 @@ from remtime import RemainingTime
 from elapsed import ElapsedTime
 from bytespeed import ByteSpeed
 
+import fmt
+
 __all__ = locals()
diff --git a/ttystatus/fmt.py b/ttystatus/fmt.py
new file mode 100644
index 0000000..bc0bbe8
--- /dev/null
+++ b/ttystatus/fmt.py
@@ -0,0 +1,66 @@
+# Copyright 2011  Lars Wirzenius
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import inspect
+import re
+
+import ttystatus
+
+
+def _find_widgets():
+    names = dir(ttystatus)
+    objs = [getattr(ttystatus, x) for x in names]
+    classes = [o for o in objs if inspect.isclass(o)]
+    widgets = [c for c in classes if issubclass(c, ttystatus.Widget)]
+    subclasses = [w for w in widgets if w != ttystatus.Widget]
+    return subclasses
+
+widgets = _find_widgets()
+              
+              
+def parse(fmt):
+    '''Parse format string.'''
+    
+    names = [x.__name__ for x in widgets]
+    namespat = '|'.join(names)
+    argspat = r'[0-9a-zA-Z,_-]*'
+    pat = r'%%(?P<class>%s)\((?P<args>%s)\)' % (namespat, argspat)
+    pat = re.compile(pat)
+    
+    result = []
+    prefix = ''
+    while fmt:
+        m = pat.match(fmt)
+        if m:
+            if prefix:
+                result.append(ttystatus.Literal(prefix))    
+                prefix = ''
+            klass = getattr(ttystatus, m.group('class'))
+            argnames = m.group('args').split(',')
+            argnames = [x for x in argnames if x]
+            result.append(klass(*argnames))
+            fmt = fmt[m.end():]
+        elif fmt.startswith('%%'):
+            prefix += '%'
+            fmt = fmt[2:]
+        else:
+            prefix += fmt[0]
+            fmt = fmt[1:]
+
+    if prefix:
+        result.append(ttystatus.Literal(prefix))    
+    return result
+
diff --git a/ttystatus/fmt_tests.py b/ttystatus/fmt_tests.py
new file mode 100644
index 0000000..af39948
--- /dev/null
+++ b/ttystatus/fmt_tests.py
@@ -0,0 +1,71 @@
+# Copyright 2011  Lars Wirzenius
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import unittest
+
+import ttystatus
+
+
+class FormatTests(unittest.TestCase):
+
+    def test_knows_widgets(self):
+        self.assertEqual(type(ttystatus.fmt.widgets), list)
+        self.assert_(len(ttystatus.fmt.widgets) > 0)
+        for widget in ttystatus.fmt.widgets:
+            self.assert_(issubclass(widget, ttystatus.Widget))
+            self.assertNotEqual(widget, ttystatus.Widget)
+
+    def test_parses_string_without_widgets(self):
+        x = ttystatus.fmt.parse('hello, world')
+        self.assertEqual(len(x), 1)
+        self.assertEqual(type(x[0]), ttystatus.Literal)
+        self.assertEqual(str(x[0]), 'hello, world')
+
+    def test_parses_escaped_pecent(self):
+        x = ttystatus.fmt.parse('%%')
+        self.assertEqual(len(x), 1)
+        self.assertEqual(type(x[0]), ttystatus.Literal)
+        self.assertEqual(str(x[0]), '%')
+
+    def test_parses_parameterless_widget(self):
+        x = ttystatus.fmt.parse('%ElapsedTime()')
+
+        self.assertEqual(len(x), 1)
+        self.assertEqual(type(x[0]), ttystatus.ElapsedTime)
+
+    def test_parses_widget_with_one_parameter(self):
+        x = ttystatus.fmt.parse('%String(name)')
+
+        self.assertEqual(len(x), 1)
+
+        self.assertEqual(type(x[0]), ttystatus.String)
+        self.assertEqual(x[0]._key, 'name')
+
+    def test_parses_some_widgets(self):
+        x = ttystatus.fmt.parse('hello, %String(name): %ElapsedTime()')
+
+        self.assertEqual(len(x), 4)
+
+        self.assertEqual(type(x[0]), ttystatus.Literal)
+        self.assertEqual(str(x[0]), 'hello, ')
+
+        self.assertEqual(type(x[1]), ttystatus.String)
+
+        self.assertEqual(type(x[2]), ttystatus.Literal)
+        self.assertEqual(str(x[2]), ': ')
+
+        self.assertEqual(type(x[3]), ttystatus.ElapsedTime)
+
diff --git a/ttystatus/status.py b/ttystatus/status.py
index b5d743a..24f369b 100644
--- a/ttystatus/status.py
+++ b/ttystatus/status.py
@@ -44,6 +44,18 @@ class TerminalStatus(object):
         else:
             for key in widget.interesting_keys:
                 self._interests[key] = self._interests.get(key, []) + [widget]
+
+    def format(self, format_string):
+        '''Add new widgets based on format string.
+        
+        The format string is taken literally, except that ``%%`` is a
+        literal percent character, and ``%Foo(a,b,c)`` is a widget
+        of type ``Foo`` with parameters a, b, and c. For example:
+        ``format("hello, %String(name)")``.
+        
+        '''
+        for widget in ttystatus.fmt.parse(format_string):
+            self.add(widget)
         
     def clear(self):
         '''Remove all widgets.'''
diff --git a/ttystatus/status_tests.py b/ttystatus/status_tests.py
index 9e6d0ac..3583028 100644
--- a/ttystatus/status_tests.py
+++ b/ttystatus/status_tests.py
@@ -78,6 +78,12 @@ class TerminalStatusTests(unittest.TestCase):
         w = W()
         self.ts.add(w)
         self.assert_(w in self.ts._wildcards)
+
+    def test_adds_widgets_from_format_string(self):
+        self.ts.format('hello, %String(name)')
+        self.assertEqual(len(self.ts._widgets), 2)
+        self.assertEqual(type(self.ts._widgets[0]), ttystatus.Literal)
+        self.assertEqual(type(self.ts._widgets[1]), ttystatus.String)
         
     def test_removes_all_widgets(self):
         self.ts.add(ttystatus.Literal('foo'))