#
# PlotList: Widget to plot a list of points
# Gustavo Rodriguez-Rivera, Purdue University 
# grr@cs.purdue.edu
#

import string
from Tkinter import *

class PlotList( Canvas ):

	def __init__( self, points, master = None ):

		Canvas.__init__( self, master )
		self.pack()

		self._font = "-Adobe-Helvetica-Medium-R-Normal--*-140-*-*-*-*-*-*"
		self._points = points
		if ( self._points ):
			self.redraw( self._points )


	def redraw( self, points ):

		self.delete("all")

		self._points = points

		self._screenWidth = string.atoi( self.config( "width" )[ 4 ] )
		self._screenHeight = string.atoi( self.config( "height" )[ 4 ] )

		# Get max X and Y from list of points
		[ minX, minY] = self._points[ 0 ]
		[ maxX, maxY] = self._points[ 0 ]

		for point in self._points:
			if ( point[ 0 ] < minX ): minX = point[ 0 ]
			if ( point[ 1 ] < minY ): minY = point[ 1 ]
			if ( point[ 0 ] > maxX ): maxX = point[ 0 ]
			if ( point[ 1 ] > maxY ): maxY = point[ 1 ]

		if ( maxX == minX ):
			maxX = maxX + 1
			minX = minX - 1

		if ( maxY == minY ):
			maxY = maxY + 1
			minY = minY - 1

		( refX, refY ) = ( minX, minY )
		if ( minX <= 0 and maxX >= 0 ): refX = 0
		if ( minY <= 0 and maxY >= 0 ): refY = 0

		offsetScreen = 40

		maxXScreen  = self._screenWidth - offsetScreen
		minXScreen = offsetScreen

		maxYScreen = offsetScreen
		minYScreen = self._screenHeight - offsetScreen

		scaleX = ( 1.0 * maxXScreen - minXScreen )/(maxX-minX)
		scaleY = ( 1.0 * maxYScreen - minYScreen )/(maxY-minY)

		refXScreen = (refX - minX) * scaleX + minXScreen
    		refYScreen = (refY - minY) * scaleY + minYScreen

    		self.create_line( minXScreen, refYScreen,
			      maxXScreen, refYScreen, {"width": 2 } )

    		self.create_line( refXScreen, minYScreen,
			      refXScreen, maxYScreen, {"width": 2 } )

    		divisions = 5
		for i in range( 0, divisions + 1 ):
			x = 1.0 * i * (maxX - minX)/divisions + minX
			xScreen = (x - minX) * scaleX + minXScreen
			self.create_line( xScreen, refYScreen,
				xScreen, refYScreen - 5, { "width": 2 } )
			self.create_text( xScreen, refYScreen + 4,
				{ "text": "%5.2lf" % x, "anchor": "n",
				  "font": self._font } );

		for i in range( 0, divisions + 1 ):
			y = 1.0 * i * (maxY - minY)/divisions + minY
			yScreen = (y - minY) * scaleY + minYScreen
			self.create_line( refXScreen, yScreen,
				refXScreen + 5, yScreen, { "width": 2 } )
			self.create_text( refXScreen - 8, yScreen + 4,
				{ "text": "%5.2lf" % y, "anchor": "e",
				  "font": self._font} );

		[ lastX, lastY ] = self._points[0]
		lastXScreen = (lastX - minX) * scaleX + minXScreen
 		lastYScreen = (lastY - minY) * scaleY + minYScreen
	
		for point in self._points:
			[ x, y ] = point
			xScreen = (x - minX) * scaleX + minXScreen
			yScreen = (y - minY) * scaleY + minYScreen;
			self.create_line( lastXScreen, lastYScreen,
				xScreen, yScreen, { "width": 1, "fill":"red"} );
			lastXScreen = xScreen;
			lastYScreen = yScreen;

#To test uncomment next lines
#app = PlotList( [ [0,0], [3,3], [5,7] ] )
#app.mainloop()