Class: GPX::Track

Inherits:
Base
  • Object
show all
Defined in:
lib/gpx/track.rb

Overview

In GPX, a single Track can hold multiple Segments, each of which hold multiple points (in this library, those points are instances of TrackPoint). Each instance of this class has its own meta-data, including low point, high point, and distance. Of course, each track references an array of the segments that comprise it, but additionally each track holds a reference to all of its points as one big array called “points”.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#instantiate_with_text_elements

Constructor Details

#initialize(opts = {}) ⇒ Track

Initialize a track from a XML::Node, or, if no :element option is passed, initialize a blank Track object.



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# File 'lib/gpx/track.rb', line 14

def initialize(opts = {})
  @gpx_file = opts[:gpx_file]
  @segments = []
  @points = []
  reset_meta_data

  return unless opts[:element]

  trk_element = opts[:element]
  @name = (begin
    trk_element.at('name').inner_text
  rescue StandardError
    ''
  end)
  @comment = (begin
    trk_element.at('cmt').inner_text
  rescue StandardError
    ''
  end)
  @description = (begin
    trk_element.at('desc').inner_text
  rescue StandardError
    ''
  end)
  trk_element.search('trkseg').each do |seg_element|
    seg = Segment.new(element: seg_element, track: self, gpx_file: @gpx_file)
    append_segment(seg)
  end
end

Instance Attribute Details

#bounds ⇒ Object (readonly)

Returns the value of attribute bounds.



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# File 'lib/gpx/track.rb', line 9

def bounds
  @bounds
end

#comment ⇒ Object

Returns the value of attribute comment.



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# File 'lib/gpx/track.rb', line 10

def comment
  @comment
end

#description ⇒ Object

Returns the value of attribute description.



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# File 'lib/gpx/track.rb', line 10

def description
  @description
end

#distance ⇒ Object (readonly)

Returns the value of attribute distance.



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# File 'lib/gpx/track.rb', line 9

def distance
  @distance
end

#gpx_file ⇒ Object

Returns the value of attribute gpx_file.



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# File 'lib/gpx/track.rb', line 10

def gpx_file
  @gpx_file
end

#highest_point ⇒ Object (readonly)

Returns the value of attribute highest_point.



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# File 'lib/gpx/track.rb', line 9

def highest_point
  @highest_point
end

#lowest_point ⇒ Object (readonly)

Returns the value of attribute lowest_point.



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# File 'lib/gpx/track.rb', line 9

def lowest_point
  @lowest_point
end

#moving_duration ⇒ Object (readonly)

Returns the value of attribute moving_duration.



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# File 'lib/gpx/track.rb', line 9

def moving_duration
  @moving_duration
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/gpx/track.rb', line 10

def name
  @name
end

#points ⇒ Object (readonly)

Returns the value of attribute points.



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# File 'lib/gpx/track.rb', line 9

def points
  @points
end

#segments ⇒ Object

Returns the value of attribute segments.



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# File 'lib/gpx/track.rb', line 10

def segments
  @segments
end

Instance Method Details

#append_segment(seg) ⇒ Object

Append a segment to this track, updating its meta data along the way.



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# File 'lib/gpx/track.rb', line 45

def append_segment(seg)
  return if seg.points.empty?
  update_meta_data(seg)
  @segments << seg
end

#closest_point(time) ⇒ Object

Finds the closest point (to “time”) within this track. Useful for correlating things like pictures, video, and other events, if you are working with a timestamp.



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# File 'lib/gpx/track.rb', line 62

def closest_point(time)
  segment = segments.select { |s| s.contains_time?(time) }
  segment.first
end

#contains_time?(time) ⇒ Boolean

Returns true if the given time occurs within any of the segments of this track.

Returns:

  • (Boolean) 


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# File 'lib/gpx/track.rb', line 52

def contains_time?(time)
  segments.each do |seg|
    return true if seg.contains_time?(time)
  end
  false
end

#crop(area) ⇒ Object

Removes all points outside of a given area and updates the meta data. The “area” paremeter is usually a Bounds object.



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# File 'lib/gpx/track.rb', line 69

def crop(area)
  reset_meta_data
  segments.each do |seg|
    seg.crop(area)
    update_meta_data(seg) unless seg.empty?
  end
  segments.delete_if(&:empty?)
end

#delete_area(area) ⇒ Object

Deletes all points within a given area and updates the meta data.



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# File 'lib/gpx/track.rb', line 79

def delete_area(area)
  reset_meta_data
  segments.each do |seg|
    seg.delete_area(area)
    update_meta_data(seg) unless seg.empty?
  end
  segments.delete_if(&:empty?)
end

#empty? ⇒ Boolean

Returns true if this track has no points in it. This should return true even when the track has empty segments.

Returns:

  • (Boolean) 


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# File 'lib/gpx/track.rb', line 90

def empty?
  (points.nil? || points.size.zero?)
end

#recalculate_distance ⇒ Object 



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# File 'lib/gpx/track.rb', line 112

def recalculate_distance
  @distance = 0
  @segments.each do |seg|
    @distance += seg.distance
  end
end

#to_s ⇒ Object

Prints out a friendly summary of this track (sans points). Useful for debugging and sanity checks.



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# File 'lib/gpx/track.rb', line 97

def to_s
  result = "Track \n"
  result << "\tName: #{name}\n"
  result << "\tComment: #{comment}\n"
  result << "\tDescription: #{description}\n"
  result << "\tSize: #{points.size} points\n"
  result << "\tSegments: #{segments.size} \n"
  result << "\tDistance: #{distance} km\n"
  result << "\tMoving duration: #{moving_duration} km\n"
  result << "\tLowest Point: #{lowest_point.elevation} \n"
  result << "\tHighest Point: #{highest_point.elevation}\n "
  result << "\tBounds: #{bounds}"
  result
end