Turn the pretty printer into a class.

This allows for other printer implementations, where a printer is a
transformation from a Todo item to a string.

topydo/lib/AddCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -21,7 +21,7 @@ import re
 
 from topydo.lib.Config import config
 from topydo.lib.Command import Command
-from topydo.lib.PrettyPrinter import pretty_print
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterNumbers
 from topydo.lib.RelativeDate import relative_date_to_date
 from topydo.lib.TodoListBase import InvalidTodoException
 
@@ -93,7 +93,9 @@ class AddCommand(Command):
             self.todo = self.todolist.add(self.text)
             self._postprocess_input_todo()
 
-            self.out(pretty_print(self.todo, [self.todolist.pp_number()]))
+            self.out(
+                self.printer.print_todo(self.todo,
+                [PrettyPrinterNumbers(self.todolist)]))
         else:
             self.error(self.usage())
 

topydo/lib/AppendCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from topydo.lib.Command import Command, InvalidCommandArgument
-from topydo.lib.PrettyPrinter import pretty_print
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterNumbers
 from topydo.lib.TodoListBase import InvalidTodoException
 
 class AppendCommand(Command):
@@ -37,7 +37,9 @@ class AppendCommand(Command):
             if text:
                 todo = self.todolist.todo(number)
                 self.todolist.append(todo, text)
-                self.out(pretty_print(todo, [self.todolist.pp_number()]))
+
+                self.out(self.printer.print_todo(todo,
+                    [PrettyPrinterNumbers(self.todolist)]))
             else:
                 self.error(self.usage())
         except InvalidCommandArgument:

topydo/lib/Command.py

@@ -16,6 +16,8 @@
 
 import getopt
 
+from topydo.lib.PrettyPrinter import PrettyPrinter
+
 class InvalidCommandArgument(Exception):
     pass
 
@@ -49,6 +51,9 @@ class Command(object):
         self.error = p_err
         self.prompt = p_prompt
 
+        # make pretty printer available
+        self.printer = PrettyPrinter()
+
     def execute(self):
         """
         Execute the command. Intercepts the help subsubcommand to show the help

topydo/lib/DCommand.py

@@ -17,7 +17,7 @@
 import re
 
 from topydo.lib.Command import Command
-from topydo.lib.PrettyPrinter import pretty_print, pretty_print_list
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterNumbers
 from topydo.lib.TodoListBase import InvalidTodoException
 
 class DCommand(Command):
@@ -72,8 +72,8 @@ class DCommand(Command):
         )
 
     def _print_list(self, p_todos):
-        filters = [self.todolist.pp_number()]
-        self.out("\n".join(pretty_print_list(p_todos, filters)))
+        filters = [PrettyPrinterNumbers(self.todolist)]
+        self.out("\n".join(self.printer.print_list(p_todos, filters)))
 
     def prompt_text(self):
         return "Yes or no? [y/N] "
@@ -93,7 +93,7 @@ class DCommand(Command):
             if not self.force and re.match('^y(es)?$', confirmation, re.I):
                 for child in children:
                     self.execute_specific_core(child)
-                    self.out(self.prefix() + pretty_print(child))
+                    self.out(self.prefix() + self.printer.print_todo(child))
 
     def _print_unlocked_todos(self, p_old, p_new):
         delta = [todo for todo in p_new if todo not in p_old]

topydo/lib/DeleteCommand.py

@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from topydo.lib.DCommand import DCommand
-from topydo.lib.PrettyPrinter import pretty_print
 
 class DeleteCommand(DCommand):
     def __init__(self, p_args, p_todolist,
@@ -35,7 +34,7 @@ class DeleteCommand(DCommand):
         self.todolist.delete(p_todo)
 
     def execute_specific(self, p_todo):
-        self.out(self.prefix() + pretty_print(p_todo))
+        self.out(self.prefix() + self.printer.print_todo(p_todo))
         self.execute_specific_core(p_todo)
 
     def usage(self):

topydo/lib/DepriCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from topydo.lib.Command import Command, InvalidCommandArgument
-from topydo.lib.PrettyPrinter import pretty_print
 from topydo.lib.TodoListBase import InvalidTodoException
 
 class DepriCommand(Command):
@@ -37,7 +36,7 @@ class DepriCommand(Command):
             if todo.priority() != None:
                 self.todolist.set_priority(todo, None)
                 self.out("Priority removed.")
-                self.out(pretty_print(todo))
+                self.out(self.printer.print_todo(todo))
         except InvalidCommandArgument:
             self.error(self.usage())
         except (InvalidTodoException):

topydo/lib/DoCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -17,7 +17,7 @@
 from datetime import date
 
 from topydo.lib.DCommand import DCommand
-from topydo.lib.PrettyPrinter import pretty_print
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterNumbers
 from topydo.lib.Recurrence import advance_recurring_todo, strict_advance_recurring_todo
 from topydo.lib.Utils import date_string_to_date
 
@@ -56,7 +56,8 @@ class DoCommand(DCommand):
                     self.completion_date)
 
             self.todolist.add_todo(new_todo)
-            self.out(pretty_print(new_todo, [self.todolist.pp_number()]))
+            self.out(self.printer.print_todo(new_todo,
+                [PrettyPrinterNumbers(self.todolist)]))
 
     def prompt_text(self):
         return "Also mark subtasks as done? [y/N] "
@@ -77,7 +78,7 @@ class DoCommand(DCommand):
         """ Actions specific to this command. """
         self._handle_recurrence(p_todo)
         self.execute_specific_core(p_todo)
-        self.out(self.prefix() + pretty_print(p_todo))
+        self.out(self.prefix() + self.printer.print_todo(p_todo))
 
     def execute_specific_core(self, p_todo):
         """

topydo/lib/ListCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -19,7 +19,7 @@ import re
 from topydo.lib.Command import Command
 from topydo.lib.Config import config
 from topydo.lib import Filter
-from topydo.lib.PrettyPrinter import pp_indent
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterIndentFilter
 from topydo.lib.Sorter import Sorter
 
 class ListCommand(Command):
@@ -83,7 +83,8 @@ class ListCommand(Command):
         sorter = Sorter(self.sort_expression)
         filters = self._filters()
 
-        pp_filters = [pp_indent(config().list_indent())]
+        indent = config().list_indent()
+        pp_filters = [PrettyPrinterIndentFilter(indent)]
         self.out(self.todolist.view(sorter, filters).pretty_print(pp_filters))
 
     def usage(self):

topydo/lib/PostponeCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -18,7 +18,7 @@ from datetime import date, timedelta
 
 from topydo.lib.Command import Command, InvalidCommandArgument
 from topydo.lib.Config import config
-from topydo.lib.PrettyPrinter import pretty_print
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterNumbers
 from topydo.lib.RelativeDate import relative_date_to_date
 from topydo.lib.TodoListBase import InvalidTodoException
 from topydo.lib.Utils import date_string_to_date
@@ -75,7 +75,8 @@ class PostponeCommand(Command):
                 todo.set_tag(config().tag_due(), new_due.isoformat())
 
                 self.todolist.set_dirty()
-                self.out(pretty_print(todo, [self.todolist.pp_number()]))
+                self.out(self.printer.print_todo(todo,
+                    [PrettyPrinterNumbers(self.todolist)]))
             else:
                 self.error("Invalid date pattern given.")
 

topydo/lib/PrettyPrinter.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -14,75 +14,54 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-""" Provides a function to pretty print a list of todo items. """
-
-import re
-
-from topydo.lib.Config import config
-
-PRIORITY_COLORS = {
-    'A': '\033[36m', # cyan
-    'B': '\033[33m', # yellow
-    'C': '\033[34m'  # blue
-}
-
-PROJECT_COLOR = '\033[31m' # red
-NEUTRAL_COLOR = '\033[0m'
-
-def pp_color(p_todo_str, p_todo):
+class Printer(object):
     """
-    Adds colors to the todo string by inserting ANSI codes.
+    An abstract class that turns todo items into strings.
 
-    Should be passed as a filter in the filter list of pretty_print()
+    Subclasses must at least implement the print_todo method.
     """
-
-    if config().colors():
-        color = NEUTRAL_COLOR
-        try:
-            color = PRIORITY_COLORS[p_todo.priority()]
-        except KeyError:
-            pass
-
-        p_todo_str = color + p_todo_str + NEUTRAL_COLOR
-
-        if config().highlight_projects_contexts():
-            p_todo_str = re.sub(
-                r'\B(\+|@)(\S*\w)',
-                PROJECT_COLOR + r'\g<0>' + color,
-                p_todo_str)
-
-        p_todo_str += NEUTRAL_COLOR
-
-    return p_todo_str
-
-def pp_indent(p_indent=0):
-    return lambda s, t: ' ' * p_indent + s
-
-def pretty_print(p_todo, p_filters=None):
+    def print_todo(self, p_todo):
+        """ Base implementation. Simply returns the string conversion. """
+        return str(p_todo)
+
+    def print_list(self, p_todos):
+        """
+        Given a list of todo items, pretty print it and return a list of
+        formatted strings.
+        """
+        return [self.print_todo(todo) for todo in p_todos]
+
+class PrettyPrinter(Printer):
     """
-    Given a todo item, pretty print it and return a list of formatted strings.
+    Prints todo items on a single line, decorated by the filters passed by
+    the caller.
 
-    p_filters is a list of functions that transform the output string, each
-    function accepting two arguments:
+    The caller can adjust the output by passing on a set of filters, that may
+    add colors, indentation, etc. These filters are found in the
+    PrettyPrinterFilter module.
+    """
+    def print_todo(self, p_todo, p_filters=None):
+        """
+        Given a todo item, pretty print it.
 
-    * the todo's text that has to be modified;
-    * the todo object itself which allows for obtaining relevant information.
+        p_filters is a list of PrettyPrinterFilter objects (typically
+        subclasses of it, see PrettyPrinterFilter module)
+        """
+        p_filters = p_filters or []
 
-    Example is pp_color in this fle.
-    """
-    p_filters = p_filters or []
+        todo_str = str(p_todo)
 
-    todo_str = str(p_todo)
+        for ppf in p_filters:
+            todo_str = ppf.filter(todo_str, p_todo)
 
-    for f in p_filters:
-        todo_str = f(todo_str, p_todo)
+        return todo_str
 
-    return todo_str
+    def print_list(self, p_todos, p_filters=None):
+        """
+        Given a list of todo items, pretty print it and return a list of
+        formatted strings.
 
-def pretty_print_list(p_todos, p_filters=None):
-    """
-    Given a list of todo items, pretty print it and return a list of
-    formatted strings.
-    """
-    p_filters = p_filters or []
-    return [pretty_print(todo, p_filters) for todo in p_todos]
+        This override also passes on filters.
+        """
+        p_filters = p_filters or []
+        return [self.print_todo(todo, p_filters) for todo in p_todos]

topydo/lib/PrettyPrinterFilter.py

+# Topydo - A todo.txt client written in Python.
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
+#
+# 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/>.
+
+""" Provides filters used for pretty printing. """
+
+import re
+
+from topydo.lib.Config import config
+
+class PrettyPrinterFilter(object):
+    """
+    Base class for a pretty printer filter.
+
+    Subclasses must reimplement the filter method.
+    """
+
+    def filter(self, p_todo_str, _):
+        """ Default implementation returns an unmodified todo string. """
+        return p_todo_str
+
+PRIORITY_COLORS = {
+    'A': '\033[36m', # cyan
+    'B': '\033[33m', # yellow
+    'C': '\033[34m'  # blue
+}
+
+PROJECT_COLOR = '\033[31m' # red
+NEUTRAL_COLOR = '\033[0m'
+
+class PrettyPrinterColorFilter(PrettyPrinterFilter):
+    """
+    Adds colors to the todo string by inserting ANSI codes.
+
+    Should be passed as a filter in the filter list of pretty_print()
+    """
+
+    def filter(self, p_todo_str, p_todo):
+        """ Applies the colors. """
+
+        if config().colors():
+            color = NEUTRAL_COLOR
+            try:
+                color = PRIORITY_COLORS[p_todo.priority()]
+            except KeyError:
+                pass
+
+            p_todo_str = color + p_todo_str + NEUTRAL_COLOR
+
+            if config().highlight_projects_contexts():
+                p_todo_str = re.sub(
+                    r'\B(\+|@)(\S*\w)',
+                    PROJECT_COLOR + r'\g<0>' + color,
+                    p_todo_str)
+
+            p_todo_str += NEUTRAL_COLOR
+
+        return p_todo_str
+
+class PrettyPrinterIndentFilter(PrettyPrinterFilter):
+    """ Adds indentation to the todo item. """
+    def __init__(self, p_indent=0):
+        super(PrettyPrinterIndentFilter, self).__init__()
+        self.indent = p_indent
+
+    def filter(self, p_todo_str, _):
+        """ Applies the indentation. """
+        return ' ' * self.indent + p_todo_str
+
+class PrettyPrinterNumbers(PrettyPrinterFilter):
+    """ Prepends the todo's number, retrieved from the todolist. """
+    def __init__(self, p_todolist):
+        super(PrettyPrinterNumbers, self).__init__()
+        self.todolist = p_todolist
+
+    def filter(self, p_todo_str, p_todo):
+        """ Prepends the number to the todo string. """
+        return "|{:>3}| {}".format(self.todolist.number(p_todo), p_todo_str)

topydo/lib/PriorityCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from topydo.lib.Command import Command, InvalidCommandArgument
-from topydo.lib.PrettyPrinter import pretty_print
 from topydo.lib.TodoListBase import InvalidTodoException
 from topydo.lib.Utils import is_valid_priority
 
@@ -48,7 +47,7 @@ class PriorityCommand(Command):
                 elif not old_priority:
                     self.out("Priority set to {}.".format(priority))
 
-                self.out(pretty_print(todo))
+                self.out(self.printer.print_todo(todo))
             else:
                 self.error("Invalid priority given.")
         except InvalidCommandArgument:

topydo/lib/TagCommand.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -15,8 +15,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from topydo.lib.Command import Command, InvalidCommandArgument
+from topydo.lib.PrettyPrinterFilter import PrettyPrinterNumbers
 from topydo.lib.TodoListBase import InvalidTodoException
-from topydo.lib.PrettyPrinter import pretty_print
 
 class TagCommand(Command):
     def __init__(self, p_args, p_todolist,
@@ -60,7 +60,8 @@ class TagCommand(Command):
             self.value = ""
 
     def _print(self):
-        self.out(pretty_print(self.todo, [self.todolist.pp_number()]))
+        filters = [PrettyPrinterNumbers(self.todolist)]
+        self.out(self.printer.print_todo(self.todo, filters))
 
     def _choose(self):
         """

topydo/lib/TodoListBase.py

@@ -24,7 +24,7 @@ import re
 from topydo.lib.Config import config
 from topydo.lib import Filter
 from topydo.lib.HashListValues import hash_list_values
-from topydo.lib.PrettyPrinter import pretty_print_list
+from topydo.lib.PrettyPrinter import PrettyPrinter
 from topydo.lib.Todo import Todo
 from topydo.lib.View import View
 
@@ -242,14 +242,6 @@ class TodoListBase(object):
         except (ValueError, KeyError):
             raise InvalidTodoException
 
-    def pp_number(self):
-        """
-        A filter for the pretty printer to append the todo number to the
-        printed todo.
-        """
-        return lambda p_todo_str, p_todo: \
-                "|{:>3}| {}".format(self.number(p_todo), p_todo_str)
-
     def _update_todo_ids(self):
         # the idea is to have a hash that is independent of the position of the
         # todo. Use the text (without tags) of the todo to keep the id as stable
@@ -264,5 +256,6 @@ class TodoListBase(object):
             self._id_todo_map[uid] = todo
 
     def __str__(self):
-        return '\n'.join(pretty_print_list(self._todos))
+        printer = PrettyPrinter()
+        return '\n'.join(printer.print_list(self._todos))
 

topydo/lib/View.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # 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
@@ -16,7 +16,11 @@
 
 """ A view is a list of todos, sorted and filtered. """
 
-from topydo.lib.PrettyPrinter import pretty_print_list, pp_color
+from topydo.lib.PrettyPrinterFilter import (
+    PrettyPrinterColorFilter,
+    PrettyPrinterNumbers
+)
+from topydo.lib.PrettyPrinter import PrettyPrinter
 
 class View(object):
     """
@@ -29,6 +33,7 @@ class View(object):
         self._viewdata = []
         self._sorter = p_sorter
         self._filters = p_filters
+        self._printer = PrettyPrinter()
 
         self.update()
 
@@ -45,8 +50,14 @@ class View(object):
     def pretty_print(self, p_pp_filters=None):
         """ Pretty prints the view. """
         p_pp_filters = p_pp_filters or []
-        pp_filters = [self._todolist.pp_number(), pp_color] + p_pp_filters
-        return '\n'.join(pretty_print_list(self._viewdata, pp_filters))
+
+        pp_filters = [
+            PrettyPrinterNumbers(self._todolist),
+            PrettyPrinterColorFilter()
+        ]
+        pp_filters += p_pp_filters
+
+        return '\n'.join(self._printer.print_list(self._viewdata, pp_filters))
 
     def __str__(self):
-        return '\n'.join(pretty_print_list(self._viewdata))
+        return '\n'.join(self._printer.print_list(self._viewdata))