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ruby--ruby/ext/tk/sample/demos-en/knightstour.rb
nobu 287a34ae0d * {ext,lib,test}/**/*.rb: removed trailing spaces.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@22784 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2009-03-06 03:56:38 +00:00

271 lines
8.7 KiB
Ruby

# Based on the widget demo of Tcl/Tk8.5.2
# The following is the original copyright text.
#----------------------------------------------------------------------------
# Copyright (C) 2008 Pat Thoyts <patthoyts@users.sourceforge.net>
#
# Calculate a Knight's tour of a chessboard.
#
# This uses Warnsdorff's rule to calculate the next square each
# time. This specifies that the next square should be the one that
# has the least number of available moves.
#
# Using this rule it is possible to get to a position where
# there are no squares available to move into. In this implementation
# this occurs when the starting square is d6.
#
# To solve this fault an enhancement to the rule is that if we
# have a choice of squares with an equal score, we should choose
# the one nearest the edge of the board.
#
# If the call to the Edgemost function is commented out you can see
# this occur.
#
# You can drag the knight to a specific square to start if you wish.
# If you let it repeat then it will choose random start positions
# for each new tour.
#----------------------------------------------------------------------------
require 'tk'
class Knights_Tour
# Return a list of accessible squares from a given square
def valid_moves(square)
moves = []
[
[-1,-2], [-2,-1], [-2,1], [-1,2], [1,2], [2,1], [2,-1], [1,-2]
].each{|col_delta, row_delta|
col = (square % 8) + col_delta
row = (square.div(8)) + row_delta
moves << (row * 8 + col) if row > -1 && row < 8 && col > -1 && col < 8
}
moves
end
# Return the number of available moves for this square
def check_square(square)
valid_moves(square).find_all{|pos| ! @visited.include?(pos)}.length
end
# Select the next square to move to. Returns -1 if there are no available
# squares remaining that we can move to.
def next_square(square)
minimum = 9
nxt = -1
valid_moves(square).each{|pos|
unless @visited.include?(pos)
cnt = check_square(pos)
if cnt < minimum
minimum = cnt
nxt = pos
elsif cnt == minimum
nxt = edgemost(nxt, pos)
end
end
}
nxt
end
# Select the square nearest the edge of the board
def edgemost(nxt, pos)
col_A = 3 - ((3.5 - nxt % 8).abs.to_i)
col_B = 3 - ((3.5 - pos % 8).abs.to_i)
row_A = 3 - ((3.5 - nxt.div(8)).abs.to_i)
row_B = 3 - ((3.5 - pos.div(8)).abs.to_i)
(col_A * row_A < col_B * row_B)? nxt : pos
end
# Display a square number as a standard chess square notation.
def _N(square)
'%c%d' % [(97 + square % 8), (square.div(8) + 1)]
end
# Perform a Knight's move and schedule the next move.
def move_piece(last, square)
@log.insert(:end, "#{@visited.length}. #{_N last} -> #{_N square}\n", '')
@log.see(:end)
@board.itemconfigure(1+last, :state=>:normal, :outline=>'black')
@board.itemconfigure(1+square, :state=>:normal, :outline=>'red')
@knight.coords(@board.coords(1+square)[0..1])
@visited << square
if (nxt = next_square(square)) != -1
@after_id = Tk.after(@delay.numeric){move_piece(square, nxt) rescue nil}
else
@start_btn.state :normal
if @visited.length == 64
if @initial == square
@log.insert :end, 'Closed tour!'
else
@log.insert :end, "Success\n", {}
Tk.after(@delay.numeric * 2){tour(rand(64))} if @continuous.bool
end
else
@log.insert :end, "FAILED!\n", {}
end
end
end
# Begin a new tour of the board given a random start position
def tour(square = nil)
@visited.clear
@log.clear
@start_btn.state :disabled
1.upto(64){|n|
@board.itemconfigure(n, :state=>:disabled, :outline=>'black')
}
unless square
square = @board.find_closest(*(@knight.coords << 0 << 65))[0].to_i - 1
end
@initial = square
Tk.after_idle{ move_piece(@initial, @initial) rescue nil }
end
def _stop
Tk.after_cancel(@after_id) rescue nil
end
def _exit
_stop
$knightstour.destroy
end
def set_delay(new)
@delay.numeric = new.to_i
end
def drag_start(w, x, y)
w.dtag('selected')
w.addtag('selected', :withtag, 'current')
@dragging = [x, y]
end
def drag_motion(w, x, y)
return unless @dragging
w.move('selected', x - @dragging[0], y - @dragging[1])
@dragging = [x, y]
end
def drag_end(w, x, y)
square = w.find_closest(x, y, 0, 65)
w.coords('selected', w.coords(square)[0..1])
w.dtag('selected')
@dragging = nil
end
def make_SeeDismiss
## See Code / Dismiss
frame = Ttk::Frame.new($knightstour)
sep = Ttk::Separator.new(frame)
Tk.grid(sep, :columnspan=>4, :row=>0, :sticky=>'ew', :pady=>2)
TkGrid('x',
Ttk::Button.new(frame, :text=>'See Code',
:image=>$image['view'], :compound=>:left,
:command=>proc{showCode 'knightstour'}),
Ttk::Button.new(frame, :text=>'Dismiss',
:image=>$image['delete'], :compound=>:left,
:command=>proc{
$knightstour.destroy
$knightstour = nil
}),
:padx=>4, :pady=>4)
frame.grid_columnconfigure(0, :weight=>1)
frame
end
def create_gui(parent = nil)
$knightstour.destroy rescue nil
$knightstour = Tk::Toplevel.new(parent, :title=>"Knight's tour")
$knightstour.withdraw
base_f = Ttk::Frame.new($knightstour)
@board = Tk::Canvas.new(base_f, :width=>240, :height=>240)
@log = Tk::Text.new(base_f, :width=>12, :height=>1,
:font=>'Arial 8', :background=>'white')
scr = @log.yscrollbar(Ttk::Scrollbar.new(base_f))
@visited = []
@delay = TkVariable.new(600)
@continuous = TkVariable.new(false)
tool_f = Ttk::Frame.new($knightstour)
label = Ttk::Label.new(tool_f, :text=>'Speed')
scale = Ttk::Scale.new(tool_f, :from=>8, :to=>2000, :variable=>@delay,
:command=>proc{|n| set_delay(n)})
check = Ttk::Checkbutton.new(tool_f, :text=>'Repeat',
:variable=>@continuous)
@start_btn = Ttk::Button.new(tool_f, :text=>'Start',
:command=>proc{tour()})
@exit_btn = Ttk::Button.new(tool_f, :text=>'Exit',
:command=>proc{_exit()})
7.downto(0){|row|
0.upto(7){|col|
if ((col & 1) ^ (row & 1)).zero?
fill = 'bisque'
dfill = 'bisque3'
else
fill = 'tan3'
dfill = 'tan4'
end
coords = [col * 30 + 4, row * 30 + 4, col * 30 + 30, row * 30 + 30]
@board.create(TkcRectangle, coords,
:fill=>fill, :disabledfill=>dfill,
:width=>2, :state=>:disabled)
}
}
@knight_font = TkFont.new(:size=>-24)
@knight = TkcText.new(@board, 0, 0, :font=>@knight_font,
:text=>Tk::UTF8_String.new('\u265e'),
:anchor=>'nw', # :tags=>'knight',
:fill=>'black', :activefill=>'#600000')
@knight.coords(@board.coords(rand(64)+1)[0..1])
@knight.bind('ButtonPress-1', '%W %x %y'){|w,x,y| drag_start(w,x,y)}
@knight.bind('Motion', '%W %x %y'){|w,x,y| drag_motion(w,x,y)}
@knight.bind('ButtonRelease-1', '%W %x %y'){|w,x,y| drag_end(w,x,y)}
Tk.grid(@board, @log, scr, :sticky=>'news')
base_f.grid_rowconfigure(0, :weight=>1)
base_f.grid_columnconfigure(0, :weight=>1)
Tk.grid(base_f, '-', '-', '-', '-', '-', :sticky=>'news')
widgets = [label, scale, check, @start_btn]
sg = nil
unless $RubyTk_WidgetDemo
widgets << @exit_btn
if Tk.windowingsystem != 'aqua'
#widgets.unshift(Ttk::SizeGrip.new(tool_f))
Ttk::SizeGrip.new(tool_f).pack(:side=>:right, :anchor=>'se')
end
end
Tk.pack(widgets, :side=>:right)
if Tk.windowingsystem == 'aqua'
TkPack.configure(widgets, :padx=>[4, 4], :pady=>[12, 12])
TkPack.configure(widgets[0], :padx=>[4, 24])
TkPack.configure(widgets[-1], :padx=>[16, 4])
end
Tk.grid(tool_f, '-', '-', '-', '-', '-', :sticky=>'ew')
if $RubyTk_WidgetDemo
Tk.grid(make_SeeDismiss(), '-', '-', '-', '-', '-', :sticky=>'ew')
end
$knightstour.grid_rowconfigure(0, :weight=>1)
$knightstour.grid_columnconfigure(0, :weight=>1)
$knightstour.bind('Control-F2'){TkConsole.show}
$knightstour.bind('Return'){@start_btn.invoke}
$knightstour.bind('Escape'){@exit_btn.invoke}
$knightstour.bind('Destroy'){ _stop }
$knightstour.protocol('WM_DELETE_WINDOW'){ _exit }
$knightstour.deiconify
$knightstour.tkwait_destroy
end
def initialize(parent = nil)
create_gui(parent)
end
end
Tk.root.withdraw unless $RubyTk_WidgetDemo
Thread.new{Tk.mainloop} if __FILE__ == $0
Knights_Tour.new