Class: DTAS::Tracklist

Inherits:
Object
  • Object
show all
Includes:
Serialize
Defined in:
lib/dtas/tracklist.rb

Overview

the a tracklist object for -player this is inspired by the MPRIS 2.0 TrackList spec

Constant Summary collapse

TL_DEFAULTS = 
{
  'pos' => -1,
  'repeat' => false,
  'max' => 20_000,
  'consume' => false,
}
SIVS = 
TL_DEFAULTS.keys

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Serialize

#ivars_to_hash

Constructor Details

#initialize ⇒ Tracklist

Returns a new instance of Tracklist.



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# File 'lib/dtas/tracklist.rb', line 61

def initialize
  TL_DEFAULTS.each { |k,v| instance_variable_set("@#{k}", v) }
  @list = []
  @goto_off = @goto_pos = nil
  @track_nr = 0
  @shuffle = false
end

Instance Attribute Details

#consume ⇒ Object

boolean



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# File 'lib/dtas/tracklist.rb', line 15

def consume
  @consume
end

#max ⇒ Object

integer



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# File 'lib/dtas/tracklist.rb', line 14

def max
  @max
end

#repeat ⇒ Object

true, false, 1



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# File 'lib/dtas/tracklist.rb', line 12

def repeat
  @repeat
end

#shuffle ⇒ Object

false or shuffled @list



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# File 'lib/dtas/tracklist.rb', line 13

def shuffle
  @shuffle
end

Class Method Details

.load(hash) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 25

def self.load(hash)
  obj = new
  obj.instance_eval do
    list = hash['list'] and @list.replace(list.map { |s| new_track(s) })
    SIVS.each do |k|
      instance_variable_set("@#{k}", hash[k] || TL_DEFAULTS[k])
    end

    # n.b.: we don't check @list.size against max here in case people
    # are migrating

    if hash['shuffle']
      @shuffle = @list.shuffle
      @pos = _idx_of(@shuffle, @list[@pos].track_id) if @pos >= 0
    end
  end
  obj
end

Instance Method Details

#_idx_of(list, track_id) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 193

def _idx_of(list, track_id)
  list.index { |t| t.track_id == track_id }
end

#_update_pos(pos, prev, list) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 95

def _update_pos(pos, prev, list)
  old = prev[pos]
  _idx_of(list, old.track_id)
end

#add_track(track, after_track_id = nil, set_as_current = false) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 146

def add_track(track, after_track_id = nil, set_as_current = false)
  return false if @list.size >= @max

  track = new_track(track)
  if after_track_id
    idx = _idx_of(@list, after_track_id) or
                                raise ArgumentError, 'after_track_id invalid'
    if @shuffle
      _idx_of(@shuffle, after_track_id) or
                                raise ArgumentError, 'after_track_id invalid'
    end
    @list[idx, 1] = [ @list[idx], track ]

    # add into random position if shuffling
    if @shuffle
      idx = rand(@shuffle.size)
      @shuffle[idx, 1] = [ @shuffle[idx], track ]
    end

    if set_as_current
      @pos = idx + 1
    else
      @pos += 1 if @pos > idx
    end
  else # nil = first_track
    @list.unshift(track)

    if @shuffle
      if @shuffle.empty?
        @shuffle << track
        @pos = 0 if set_as_current
      else
        idx = rand(@shuffle.size)
        @shuffle[idx, 1] = [ @shuffle[idx], track ]
        @pos = idx + 1 if set_as_current
      end
    else
      if set_as_current
        @pos = 0
      else
        @pos += 1 if @pos >= 0
      end
    end
  end
  track.track_id
end

#advance_track(repeat_ok = true) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 118

def advance_track(repeat_ok = true)
  cur = @shuffle || @list
  return if cur.empty?
  prev = cur[@pos] if @consume && @pos >= 0
  # @repeat == 1 for single track repeat
  repeat = repeat_ok ? @repeat : false
  next_pos = @goto_pos || @pos + (repeat == 1 ? 0 : 1)
  next_off = @goto_off # nil by default
  @goto_pos = @goto_off = nil

  if nxt = cur[next_pos]
    @pos = next_pos
    remove_track(prev.track_id) if prev
  else
    remove_track(prev.track_id) if prev
    # reshuffle the tracklist when we've exhausted it
    cur.shuffle! if @shuffle
    return if !repeat || cur.empty?
    next_pos = @pos = 0
    nxt = cur[0]
  end
  [ nxt.to_path, next_off ]
end

#clear ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 214

def clear
  @list.clear
  @shuffle.clear if @shuffle
  reset
end

#cur_track ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 142

def cur_track
  @pos >= 0 ? (@shuffle || @list)[@pos] : nil
end

#get_tracks(track_ids) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 85

def get_tracks(track_ids)
  want = {}
  track_ids.each { |i| want[i] = i }
  rv = []
  @list.each do |t|
    i = want[t.track_id] and rv << [ i, t.to_path ]
  end
  rv
end

#go_to(track_id, offset_hhmmss = nil) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 220

def go_to(track_id, offset_hhmmss = nil)
  list = @shuffle || @list
  if idx = _idx_of(list, track_id)
    @goto_off = offset_hhmmss
    return list[@goto_pos = idx].to_path
  end
  @goto_pos = nil
  # noop if track_id is invalid
end

#new_track(path) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 69

def new_track(path)
  n = @track_nr += 1

  # nobody needs a billion tracks in their tracklist, right?
  # avoid promoting to Bignum on 32-bit
  @track_nr = n = 1 if n >= 0x3fffffff

  DTAS::Track.new(n, path)
end

#previous! ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 230

def previous!
  return if @list.empty?
  prev_idx = @pos - 1
  if prev_idx < 0
    # stop playback if nothing to go back to.
    prev_idx = @repeat ? @list.size - 1 : @list.size
  end
  @goto_pos = prev_idx
end

#remove_track(track_id) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 197

def remove_track(track_id)
  idx = _idx_of(@list, track_id) or return false
  track = @list.delete_at(idx)
  if @shuffle
    idx = _idx_of(@shuffle, track_id) or return false
    @shuffle.delete_at(idx)
  end
  len = @list.size
  if @pos >= len
    @pos = len - 1
  elsif idx <= @pos
    @pos -= 1
  end
  @goto_pos = @goto_off = nil # TODO: reposition?
  track.to_path
end

#reset ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 79

def reset
  @goto_off = @goto_pos = nil
  @pos = TL_DEFAULTS["pos"]
  @shuffle.shuffle! if @shuffle
end

#swap(a_id, b_id) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 240

def swap(a_id, b_id)
  ok = { a_id => a_idx = [], b_id => b_idx = [] }
  @list.each_with_index do |t,i|
    ary = ok.delete(t.track_id) or next
    ary[0] = i
    break if ok.empty?
  end
  a_idx = a_idx[0] or return
  b_idx = b_idx[0] or return
  @list[a_idx], @list[b_idx] = @list[b_idx], @list[a_idx]
  unless @shuffle
    [ :@goto_pos, :@pos ].each do |v|
      case instance_variable_get(v)
      when a_idx then instance_variable_set(v, b_idx)
      when b_idx then instance_variable_set(v, a_idx)
      end
    end
  end
  true
end

#to_hsh(full_list = true) ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 44

def to_hsh(full_list = true)
  h = ivars_to_hash(SIVS)
  h.delete_if { |k,v| TL_DEFAULTS[k] == v }
  unless @list.empty?
    if full_list
      h['list'] = @list.map(&:to_path)
    else
      h['size'] = @list.size
    end
  end
  if @shuffle
    h['shuffle'] = true
    h['pos'] = _idx_of(@list, @shuffle[@pos].track_id) if @pos >= 0
  end
  h
end

#tracks ⇒ Object 



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# File 'lib/dtas/tracklist.rb', line 114

def tracks
  @list.map(&:track_id)
end