lib/barometer/data/distance.rb in barometer-0.7.3 vs lib/barometer/data/distance.rb in barometer-0.8.0
- old
+ new
@@ -1,141 +1,141 @@
module Barometer
#
# A simple Distance class
- #
+ #
# Think of this like the Integer class. Enhancement
# is that you can create a number (in a certain unit), then
# get that number back already converted to another unit.
#
# All comparison operations will be done in metric
- #
+ #
# NOTE: this currently only supports the scale of
# kilometers (km) and miles (m). There is currently
# no way to scale to smaller units (eg km -> m -> mm)
#
class Data::Distance < Data::Units
-
+
METRIC_UNITS = "km"
IMPERIAL_UNITS = "m"
-
+
attr_accessor :kilometers, :miles
-
+
def initialize(metric=true)
@kilometers = nil
@miles = nil
super(metric)
end
-
+
def metric_default=(value); self.km = value; end
def imperial_default=(value); self.m = value; end
#
# CONVERTERS
#
-
+
def self.km_to_m(km)
return nil unless km && (km.is_a?(Integer) || km.is_a?(Float))
km.to_f * 0.622
end
-
+
def self.m_to_km(m)
return nil unless m && (m.is_a?(Integer) || m.is_a?(Float))
m.to_f * 1.609
end
-
+
#
# ACCESSORS
#
-
+
# store kilometers
#
def km=(km)
return if !km || !(km.is_a?(Integer) || km.is_a?(Float))
@kilometers = km.to_f
self.update_miles(km.to_f)
end
-
+
# store miles
#
def m=(m)
return if !m || !(m.is_a?(Integer) || m.is_a?(Float))
@miles = m.to_f
self.update_kilometers(m.to_f)
end
-
+
# return the stored kilometers or convert from miles
#
def km(as_integer=true)
km = (@kilometers || Data::Distance.m_to_km(@miles))
km ? (as_integer ? km.to_i : (100*km).round/100.0) : nil
end
-
+
# return the stored miles or convert from kilometers
#
def m(as_integer=true)
m = (@miles || Data::Distance.km_to_m(@kilometers))
m ? (as_integer ? m.to_i : (100*m).round/100.0) : nil
end
-
+
#
# OPERATORS
#
-
+
def <=>(other)
self.km <=> other.km
end
-
+
#
# HELPERS
#
-
+
# will just return the value (no units)
#
def to_i(metric=nil)
(metric || (metric.nil? && self.metric?)) ? self.km : self.m
end
-
+
# will just return the value (no units) with more precision
#
def to_f(metric=nil)
(metric || (metric.nil? && self.metric?)) ? self.km(false) : self.m(false)
end
-
+
# will return the value with units
#
def to_s(metric=nil)
(metric || (metric.nil? && self.metric?)) ? "#{self.km} #{METRIC_UNITS}" : "#{self.m} #{IMPERIAL_UNITS}"
end
-
+
# will just return the units (no value)
#
def units(metric=nil)
(metric || (metric.nil? && self.metric?)) ? METRIC_UNITS : IMPERIAL_UNITS
end
-
+
# when we set miles, it is possible the a non-equivalent value of
# kilometers remains. if so, clear it.
def update_kilometers(m)
return unless @kilometers
difference = Data::Distance.m_to_km(m.to_f) - @kilometers
# only clear kilometers if the stored kilometers is off be more then 1 unit
# then the conversion of miles
@kilometers = nil unless difference.abs <= 1.0
end
-
+
# when we set kilometers, it is possible the a non-equivalent value of
# miles remains. if so, clear it.
#
def update_miles(km)
return unless @miles
difference = Data::Distance.km_to_m(km.to_f) - @miles
# only clear miles if the stored miles is off be more then 1 unit
# then the conversion of kilometers
@miles = nil unless difference.abs <= 1.0
end
-
+
def nil?
(@kilometers || @miles) ? false : true
end
-
+
end
-end
\ No newline at end of file
+end