From a3b5a5f2db5bc0404a4b3f7e7afd8a6cb8919e5d Mon Sep 17 00:00:00 2001
From: "Andrew M. Kuchling" <amk@amk.ca>
Date: Wed, 13 Dec 2000 03:50:20 +0000
Subject: Check in README file and one demo program

---
 Demo/curses/README  |   3 +
 Demo/curses/life.py | 223 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 226 insertions(+)
 create mode 100644 Demo/curses/README
 create mode 100755 Demo/curses/life.py

diff --git a/Demo/curses/README b/Demo/curses/README
new file mode 100644
index 0000000..7de5c96
--- /dev/null
+++ b/Demo/curses/README
@@ -0,0 +1,3 @@
+Sample programs that use the curses package:
+
+life.py		Simple game of Life
diff --git a/Demo/curses/life.py b/Demo/curses/life.py
new file mode 100755
index 0000000..b4797bf
--- /dev/null
+++ b/Demo/curses/life.py
@@ -0,0 +1,223 @@
+#!/usr/bin/env python
+# life.py -- A curses-based version of Conway's Game of Life.
+# Contributed by A.M. Kuchling <amk1@bigfoot.com>
+#
+# An empty board will be displayed, and the following commands are available:
+#  E : Erase the board
+#  R : Fill the board randomly
+#  S : Step for a single generation
+#  C : Update continuously until a key is struck
+#  Q : Quit
+#  Cursor keys :  Move the cursor around the board
+#  Space or Enter : Toggle the contents of the cursor's position
+#
+# TODO : 
+#   Support the mouse
+#   Use colour if available
+#   Make board updates faster
+#
+
+class LifeBoard:
+    """Encapsulates a Life board
+
+    Attributes:
+    X,Y : horizontal and vertical size of the board
+    state : dictionary mapping (x,y) to 0 or 1
+    
+    Methods:
+    display(update_board) -- If update_board is true, compute the 
+                             next generation.  Then display the state
+			     of the board and refresh the screen.
+    erase() -- clear the entire board
+    makeRandom() -- fill the board randomly
+    set(y,x) -- set the given cell to Live; doesn't refresh the screen
+    toggle(y,x) -- change the given cell from live to dead, or vice
+                   versa, and refresh the screen display
+
+    """
+    def __init__(self, scr, char=ord('*')):
+	"""Create a new LifeBoard instance.
+
+	scr -- curses screen object to use for display
+	char -- character used to render live cells (default: '*')
+	"""
+	self.state={} ; self.scr=scr
+	Y, X = self.scr.getmaxyx()
+	self.X, self.Y = X-2, Y-2-1
+	self.char = char
+	self.scr.clear()	
+
+	# Draw a border around the board
+	border_line='+'+(self.X*'-')+'+'
+	self.scr.addstr(0, 0, border_line)
+	self.scr.addstr(self.Y+1,0, border_line)
+	for y in range(0, self.Y): 
+	    self.scr.addstr(1+y, 0, '|') 
+	    self.scr.addstr(1+y, self.X+1, '|')
+	self.scr.refresh()
+
+    def set(self, y, x): 
+	"""Set a cell to the live state"""
+	if x<0 or self.X<=x or y<0 or self.Y<=y:
+	    raise ValueError, "Coordinates out of range %i,%i"% (y,x)
+	self.state[x,y] = 1
+
+    def toggle(self, y, x): 
+	"""Toggle a cell's state between live and dead"""
+	if x<0 or self.X<=x or y<0 or self.Y<=y:
+	    raise ValueError, "Coordinates out of range %i,%i"% (y,x)
+	if self.state.has_key( (x,y) ): 
+	    del self.state[x,y]
+	    self.scr.addch(y+1, x+1, ' ')
+	else:
+	    self.state[x,y]=1
+	    self.scr.addch(y+1, x+1, self.char)
+	self.scr.refresh()
+
+    def erase(self):
+	"""Clear the entire board and update the board display"""
+	self.state={}
+	self.display(update_board=0)
+
+    def display(self, update_board=1):
+	"""Display the whole board, optionally computing one generation"""
+	M,N = self.X, self.Y 
+	if not update_board:
+	    for i in range(0, M):
+		for j in range(0, N):
+			if self.state.has_key( (i,j) ): 
+			    self.scr.addch(j+1, i+1, self.char)
+			else:
+			    self.scr.addch(j+1, i+1, ' ')
+	    self.scr.refresh()
+	    return
+
+	d={} ; self.boring=1
+	for i in range(0, M):
+	    L=range( max(0, i-1), min(M, i+2) )
+	    for j in range(0, N):
+		s=0
+		live=self.state.has_key( (i,j) )
+		for k in range( max(0, j-1), min(N, j+2) ):
+		    for l in L:
+			if self.state.has_key( (l,k) ):
+			    s=s+1
+		s=s-live
+		if s==3: 
+		    # Birth
+		    d[i,j]=1 
+		    self.scr.addch(j+1, i+1, self.char)
+		    if not live: self.boring=0  
+		elif s==2 and live: d[i,j]=1       # Survival
+		elif live: 
+		    # Death
+		    self.scr.addch(j+1, i+1, ' ')
+		    self.boring=0
+	self.state=d
+	self.scr.refresh()
+
+    def makeRandom(self):
+	"Fill the board with a random pattern"
+	import whrandom
+	self.state={}
+	for i in range(0, self.X): 
+            for j in range(0, self.Y):
+		if whrandom.random()*10>5.0: self.set(j,i)
+
+
+def erase_menu(stdscr, menu_y):
+    "Clear the space where the menu resides"
+    stdscr.move(menu_y, 0) ; stdscr.clrtoeol()
+    stdscr.move(menu_y+1, 0) ; stdscr.clrtoeol()
+
+def display_menu(stdscr, menu_y):
+    "Display the menu of possible keystroke commands"
+    erase_menu(stdscr, menu_y)
+    stdscr.addstr(menu_y, 4,
+                  'Use the cursor keys to move, and space or Enter to toggle a cell.')
+    stdscr.addstr(menu_y+1, 4,
+                  'E)rase the board, R)andom fill, S)tep once or C)ontinuously, Q)uit')
+
+def main(stdscr):
+    import string, curses
+
+    # Clear the screen and display the menu of keys
+    stdscr.clear()
+    stdscr_y, stdscr_x = stdscr.getmaxyx()
+    menu_y=(stdscr_y-3)-1
+    display_menu(stdscr, menu_y)
+
+    # Allocate a subwindow for the Life board and create the board object
+    subwin=stdscr.subwin(stdscr_y-3, stdscr_x, 0, 0) 
+    board=LifeBoard(subwin, char=ord('*'))
+    board.display(update_board=0)
+
+    # xpos, ypos are the cursor's position
+    xpos, ypos = board.X/2, board.Y/2
+
+    # Main loop:
+    while (1):
+	stdscr.move(1+ypos, 1+xpos)     # Move the cursor
+	c=stdscr.getch()		# Get a keystroke
+	if 0<c<256:
+	    c=chr(c)
+	    if c in ' \n':
+		board.toggle(ypos, xpos)
+	    elif c in 'Cc':
+		erase_menu(stdscr, menu_y)
+		stdscr.addstr(menu_y, 6, ' Hit any key to stop continuously '
+			      'updating the screen.')
+		stdscr.refresh()
+		# Activate nodelay mode; getch() will return -1
+		# if no keystroke is available, instead of waiting.
+		stdscr.nodelay(1)   
+		while (1):
+		    c=stdscr.getch()
+		    if c!=-1: break
+		    stdscr.addstr(0,0, '/'); stdscr.refresh()
+		    board.display()
+		    stdscr.addstr(0,0, '+'); stdscr.refresh()
+
+		stdscr.nodelay(0)	# Disable nodelay mode
+		display_menu(stdscr, menu_y)
+
+	    elif c in 'Ee': board.erase()
+	    elif c in 'Qq': break
+	    elif c in 'Rr': 
+		board.makeRandom()
+		board.display(update_board=0)
+	    elif c in 'Ss':
+		board.display()
+	    else: pass                  # Ignore incorrect keys
+	elif c==curses.KEY_UP and ypos>0: 	     ypos=ypos-1
+	elif c==curses.KEY_DOWN and ypos<board.Y-1:  ypos=ypos+1
+	elif c==curses.KEY_LEFT and xpos>0:          xpos=xpos-1
+	elif c==curses.KEY_RIGHT and xpos<board.X-1: xpos=xpos+1
+        else: pass			# Ignore incorrect keys
+
+if __name__=='__main__':
+    import curses, traceback
+    try:
+	# Initialize curses
+	stdscr=curses.initscr()
+	# Turn off echoing of keys, and enter cbreak mode,
+	# where no buffering is performed on keyboard input
+	curses.noecho() ; curses.cbreak()
+
+	# In keypad mode, escape sequences for special keys
+	# (like the cursor keys) will be interpreted and
+	# a special value like curses.KEY_LEFT will be returned
+	stdscr.keypad(1)
+	main(stdscr)			# Enter the main loop
+	# Set everything back to normal
+	stdscr.keypad(0)
+	curses.echo() ; curses.nocbreak()
+	curses.endwin()			# Terminate curses
+    except:
+        # In the event of an error, restore the terminal
+	# to a sane state.
+	stdscr.keypad(0)
+	curses.echo() ; curses.nocbreak()
+	curses.endwin()
+	traceback.print_exc()		# Print the exception
+
-- 
cgit v0.12