Class: Sortviz::Canvas

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/sortviz/canvas.rb

Overview

Canvas is the portion of the screen that contains the sorting bar charts. It displays the partially sorted list of numbers and redraws on every iteration marking the currently selected bar (current index in the partially sorted list)

Constant Summary collapse

MARGIN = 
5

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(title, cursor, screen_dim) ⇒ Canvas

Initializes a new instance with a title to display, the current cursor object (Sortviz::Cursor) and the modified screen dimensions from the parent window/screen (standard screen created in Sortviz::Visualizer)



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# File 'lib/sortviz/canvas.rb', line 14

def initialize(title, cursor, screen_dim)
  @screen_dim = screen_dim
  @cursor = cursor
  @title = title
  @red_highlight = Curses.color_pair(Curses.const_get("COLOR_RED"))
end

Instance Attribute Details

#window ⇒ Object (readonly)

Returns the value of attribute window.



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# File 'lib/sortviz/canvas.rb', line 9

def window
  @window
end

Instance Method Details

#draw(partially_sorted, selection) ⇒ Object

Draws the partially sorted list and highlights the current index It also attempts to center the graph in the display area, does well but not always, sometimes it’ll be shifted to the right a bit.



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# File 'lib/sortviz/canvas.rb', line 34

def draw(partially_sorted, selection)
  clear
  draw_title

  len = partially_sorted.join.center(4).length
  # We draw bottom up, this sets our y-position at the very bottom of
  # the canvas and our x-position half way through the canvas
  @cursor.move(@window.maxy - 1, (@window.maxx - len) / MARGIN)
  
  partially_sorted.each_with_index do |number, i|
    draw_number(number)
    draw_bar(number, i == selection)
    next_bar
  end
  
  Curses.doupdate
end

#setup ⇒ Object

Does the initial setup of creating an actual curses window, adding a border to it and setting up non-blocking Curses::Window#getch



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# File 'lib/sortviz/canvas.rb', line 23

def setup
  @window ||= Curses::Window.new(
    @screen_dim[:lines] - MARGIN, 
    @screen_dim[:cols] - MARGIN,
    @cursor.y, @cursor.x)
  @window.nodelay = 1 # Non-blocking mode for #getch
end