1 files changed, 135 insertions, 0 deletions
diff --git a/ranger/ext/direction.py b/ranger/ext/direction.py
new file mode 100644
index 00000000..0b3f55f7
--- /dev/null
+++ b/ranger/ext/direction.py
@@ -0,0 +1,135 @@
+# Copyright (C) 2009, 2010  Roman Zimbelmann <romanz@lavabit.com>
+#
+# 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/>.
+
+"""
+Directions provide convenience methods for movement operations.
+
+Direction objects are handled just like dicts but provide
+methods like up() and down() which give you the correct value
+for the vertical direction, even if only the "up" or "down" key
+has been defined.
+
+Example application:
+d = Direction(down=5)
+print(d.up()) # prints -5
+print(bool(d.horizontal())) # False, since no horizontal direction is defined
+"""
+
+class Direction(dict):
+	__doc__ = __doc__  # for nicer pydoc
+
+	def __init__(self, dictionary=None, **keywords):
+		if dictionary is not None:
+			dict.__init__(self, dictionary)
+		else:
+			dict.__init__(self, keywords)
+		if 'to' in self:
+			self['down'] = self['to']
+			self['absolute'] = True
+
+	def copy(self):
+		return Direction(**self)
+
+	def _get_bool(self, first, second, fallback=None):
+		try: return self[first]
+		except:
+			try: return not self[second]
+			except: return fallback
+
+	def _get_direction(self, first, second, fallback=0):
+		try: return self[first]
+		except:
+			try: return -self[second]
+			except: return fallback
+
+	def up(self):
+		return -Direction.down(self)
+
+	def down(self):
+		return Direction._get_direction(self, 'down', 'up')
+
+	def right(self):
+		return Direction._get_direction(self, 'right', 'left')
+
+	def absolute(self):
+		return Direction._get_bool(self, 'absolute', 'relative')
+
+	def left(self):
+		return -Direction.right(self)
+
+	def relative(self):
+		return not Direction.absolute(self)
+
+	def vertical_direction(self):
+		down = Direction.down(self)
+		return (down > 0) - (down < 0)
+
+	def horizontal_direction(self):
+		right = Direction.right(self)
+		return (right > 0) - (right < 0)
+
+	def vertical(self):
+		return set(self) & set(['up', 'down'])
+
+	def horizontal(self):
+		return set(self) & set(['left', 'right'])
+
+	def pages(self):
+		return 'pages' in self and self['pages']
+
+	def percentage(self):
+		return 'percentage' in self and self['percentage']
+
+	def multiply(self, n):
+		for key in ('up', 'right', 'down', 'left'):
+			try:
+				self[key] *= n
+			except:
+				pass
+
+	def set(self, n):
+		for key in ('up', 'right', 'down', 'left'):
+			if key in self:
+				self[key] = n
+
+	def move(self, direction, override=None, minimum=0, maximum=9999,
+			current=0, pagesize=1, offset=0):
+		"""
+		Calculates the new position in a given boundary.
+
+		Example:
+		d = Direction(pages=True)
+		d.move(direction=3) # = 3
+		d.move(direction=3, current=2) # = 5
+		d.move(direction=3, pagesize=5) # = 15
+		d.move(direction=3, pagesize=5, maximum=10) # = 10
+		d.move(direction=9, override=2) # = 18
+		"""
+		pos = direction
+		if override is not None:
+			if self.absolute():
+				pos = override
+			else:
+				pos *= override
+		if self.pages():
+			pos *= pagesize
+		elif self.percentage():
+			pos *= maximum / 100.0
+		if self.absolute():
+			if pos < minimum:
+				pos += maximum
+		else:
+			pos += current
+		return int(max(min(pos, maximum + offset - 1), minimum))