Class: Kamelopard::CoordinateList

Inherits:
Object
  • Object
show all
Defined in:
lib/kamelopard/classes.rb

Overview

Helper class for KML objects which need to know about several points at once

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(coords = nil) ⇒ CoordinateList

Accepts an optional array of coordinates in any format add_element accepts



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# File 'lib/kamelopard/classes.rb', line 169

def initialize(coords = nil)
    # Internally we store coordinates as an array of three-element
    # arrays
    @coordinates = []
    if not coords.nil? then
        add_element coords
    else
        @coordinates = []
    end
end

Instance Attribute Details

#coordinates ⇒ Object (readonly)

Returns the value of attribute coordinates.



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# File 'lib/kamelopard/classes.rb', line 165

def coordinates
  @coordinates
end

Instance Method Details

#<<(a) ⇒ Object

Alias for add_element



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# File 'lib/kamelopard/classes.rb', line 194

def <<(a)
    add_element a
end

#add_element(a) ⇒ Object

Adds one or more elements to this CoordinateList. The argument can be in any of several formats:

  • An array of arrays of numeric objects, in the form [ longitude, latitude, altitude (optional) ]

  • A Point, or some other object that response to latitude, longitude, and altitude methods

  • An array of the above

  • Another CoordinateList, to append to this on

Note that this will not accept a one-dimensional array of numbers to add a single point. Instead, create a Point with those numbers, and pass it to add_element



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# File 'lib/kamelopard/classes.rb', line 207

def add_element(a)
    if a.kind_of? Enumerable then
        # We've got some sort of array or list. It could be a list of
        # floats, to become one coordinate, or it could be several
        # coordinates
        t = a.to_a.first
        if t.kind_of? Enumerable then
            # At this point we assume we've got an array of float-like
            # objects. The second-level arrays need to have two or three
            # entries -- long, lat, and (optionally) alt
            a.each do |i|
                if i.size < 2 then
                    raise "There aren't enough objects here to make a 2- or 3-element coordinate"
                elsif i.size >= 3 then
                    @coordinates << [ i[0].to_f, i[1].to_f, i[2].to_f ]
                else
                    @coordinates << [ i[0].to_f, i[1].to_f ]
                end
            end
        elsif t.respond_to? 'longitude' and
            t.respond_to? 'latitude' and
            t.respond_to? 'altitude' then
            # This object can cough up a set of coordinates
            a.each do |i|
                @coordinates << [i.longitude, i.latitude, i.altitude]
            end
        else
            # I dunno what it is
            raise "Kamelopard can't understand this object as a coordinate"
        end
    elsif a.kind_of? CoordinateList then
        # Append this coordinate list
        @coordinates << a.coordinates
    else
        # This is one element. It better know how to make latitude, longitude, etc.
        if a.respond_to? 'longitude' and
            a.respond_to? 'latitude' and
            a.respond_to? 'altitude' then
            @coordinates << [a.longitude, a.latitude, a.altitude]
        else
            raise "Kamelopard can't understand this object as a coordinate"
        end
    end
end

#to_kml(elem = nil) ⇒ Object 



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# File 'lib/kamelopard/classes.rb', line 180

def to_kml(elem = nil)
    e = REXML::Element.new 'coordinates'
    t = ''
    @coordinates.each do |a|
        t << "#{ a[0] },#{ a[1] }"
        t << ",#{ a[2] }" if a.size > 2
        t << ' '
    end
    e.text = t.chomp(' ')
    elem.elements.add e unless elem.nil?
    e
end