#!/usr/bin/python

import sys
import math
import numpy as np
from PyQt5 import Qwt
from PyQt5.QtCore import Qt, QSize, QRectF
from PyQt5.QtGui import QPen, QBrush,  QPainter, QFont
from PyQt5.QtWidgets import QApplication, QFrame

Size = 27
CurvCnt = 6

xval = np.zeros(Size,float)
yval = np.zeros(Size,float)
xMap = Qwt.QwtScaleMap()
yMap = Qwt.QwtScaleMap()

class MainWin(QFrame):
    def __init__(self):
        QFrame.__init__(self)
        self.d_curves = [None]*CurvCnt
        xMap.setScaleInterval( -0.5, 10.5 )
        yMap.setScaleInterval( -1.1, 1.1 )
        # Frame style FIXME This doesn't seem to work properly
        self.setFrameStyle( QFrame.Box | QFrame.Raised )
        self.setLineWidth( 2 )
        self.setMidLineWidth( 3 )
        # Calculate values
        for i in range(Size):
            xval[i] = i * 10.0 / ( Size - 1.0 )
            yval[i] = math.sin( xval[i] ) * math.cos( 2.0 * xval[i] )
        #  define curve styles
        i = 0
        self.d_curves[i] = Qwt.QwtPlotCurve()
        self.d_curves[i].setSymbol( Qwt.QwtSymbol( Qwt.QwtSymbol.Cross, QBrush(Qt.NoBrush),
                                    QPen( Qt.black ), QSize( 5, 5 ) ) )
        self.d_curves[i].setPen( Qt.darkGreen )
        self.d_curves[i].setStyle( Qwt.QwtPlotCurve.Lines )
        self.d_curves[i].setCurveAttribute( Qwt.QwtPlotCurve.Fitted )
        i += 1
        self.d_curves[i] = Qwt.QwtPlotCurve()
        self.d_curves[i].setSymbol( Qwt.QwtSymbol( Qwt.QwtSymbol.Ellipse, Qt.yellow,
                                    QPen( Qt.blue ), QSize( 5, 5 ) ) )
        self.d_curves[i].setPen( Qt.red )
        self.d_curves[i].setStyle( Qwt.QwtPlotCurve.Sticks )
        i += 1
        self.d_curves[i] = Qwt.QwtPlotCurve()
        self.d_curves[i].setPen( Qt.darkBlue )
        self.d_curves[i].setStyle( Qwt.QwtPlotCurve.Lines )
        i += 1
        self.d_curves[i] = Qwt.QwtPlotCurve()
        self.d_curves[i].setPen( Qt.darkBlue )
        self.d_curves[i].setStyle( Qwt.QwtPlotCurve.Lines )
        self.d_curves[i].setRenderHint( Qwt.QwtPlotItem.RenderAntialiased )
        i += 1
        self.d_curves[i] = Qwt.QwtPlotCurve()
        self.d_curves[i].setPen( Qt.darkCyan )
        self.d_curves[i].setStyle( Qwt.QwtPlotCurve.Steps )
        i += 1
        self.d_curves[i] = Qwt.QwtPlotCurve()
        self.d_curves[i].setSymbol( Qwt.QwtSymbol( Qwt.QwtSymbol.XCross, QBrush(Qt.NoBrush),
                                    QPen( Qt.darkMagenta ), QSize( 5, 5 ) ) )
        self.d_curves[i].setStyle( Qwt.QwtPlotCurve.NoCurve )
        # attach data
        for i in range(CurvCnt):
            self.d_curves[i].setSamples( xval, yval )

    def shiftDown(self, rect, offset ):
        rect.translate( 0, offset )

    def paintEvent( self, event ):
        #QFrame.paintEvent( event )
        painter = QPainter( self )
        painter.setClipRect( self.contentsRect() )
        self.drawContents( painter )

    # REDRAW CONTENTS
    def drawContents( self, painter ):
        r = self.contentsRect()
        deltay = r.height() // CurvCnt - 1
        r.setHeight( deltay )
        #  draw curves
        for i in range( CurvCnt ):
            xMap.setPaintInterval( r.left(), r.right() )
            yMap.setPaintInterval( r.top(), r.bottom() )
            painter.setRenderHint( QPainter.Antialiasing,
                self.d_curves[i].testRenderHint( Qwt.QwtPlotItem.RenderAntialiased ) )
            self.d_curves[i].draw( painter, xMap, yMap, QRectF(r) )
            self.shiftDown( r, deltay )

        # draw titles
        r = self.contentsRect()     # reset r
        painter.setFont( QFont( "Helvetica", 8 ) )
        alignment = Qt.AlignTop | Qt.AlignHCenter
        painter.setPen( Qt.black )
        painter.drawText( 0, r.top(), r.width(), painter.fontMetrics().height(),
            alignment, "Style: Line/Fitted, Symbol: Cross" )
        self.shiftDown( r, deltay )
        painter.drawText( 0, r.top(), r.width(), painter.fontMetrics().height(),
            alignment, "Style: Sticks, Symbol: Ellipse" )
        self.shiftDown( r, deltay )
        painter.drawText( 0 , r.top(), r.width(), painter.fontMetrics().height(),
            alignment, "Style: Lines, Symbol: None" )
        self.shiftDown( r, deltay )
        painter.drawText( 0 , r.top(), r.width(), painter.fontMetrics().height(),
            alignment, "Style: Lines, Symbol: None, Antialiased" )
        self.shiftDown( r, deltay )
        painter.drawText( 0, r.top(), r.width(), painter.fontMetrics().height(),
            alignment, "Style: Steps, Symbol: None" )
        self.shiftDown( r, deltay )
        painter.drawText( 0, r.top(), r.width(), painter.fontMetrics().height(),
            alignment, "Style: NoCurve, Symbol: XCross" )


if __name__ == '__main__':
    a = QApplication(sys.argv)
    a.setStyle( "Windows" )
    w = MainWin()
    w.resize( 300, 600 )
    w.show()
    sys.exit(a.exec_())