#!/usr/bin/env python

# PyQt tutorial 8


import sys
from PyQt4 import QtCore, QtGui


class LCDRange(QtGui.QWidget):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)

        lcd = QtGui.QLCDNumber(2)
        self.slider = QtGui.QSlider(QtCore.Qt.Horizontal)
        self.slider.setRange(0, 99)
        self.slider.setValue(0)

        self.connect(self.slider, QtCore.SIGNAL("valueChanged(int)"),
                     lcd, QtCore.SLOT("display(int)"))
        self.connect(self.slider, QtCore.SIGNAL("valueChanged(int)"),
                     self, QtCore.SIGNAL("valueChanged(int)"))

        layout = QtGui.QVBoxLayout()
        layout.addWidget(lcd)
        layout.addWidget(self.slider)
        self.setLayout(layout)

        self.setFocusProxy(self.slider)

    def value(self):
        return self.slider.value()

    def setValue(self, value):
        self.slider.setValue(value)

    def setRange(self, minValue, maxValue):
        if minValue < 0 or maxValue > 99 or minValue > maxValue:
            QtCore.qWarning("LCDRange.setRange(%d, %d)\n"
                    "\tRange must be 0..99\n"
                    "\tand minValue must not be greater than maxValue" % (minValue, maxValue))
            return

        self.slider.setRange(minValue, maxValue)


class CannonField(QtGui.QWidget):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)

        self.currentAngle = 45
        self.setPalette(QtGui.QPalette(QtGui.QColor(250, 250, 200)))
        self.setAutoFillBackground(True)

    def angle(self):
        return self.currentAngle

    def setAngle(self, angle):
        if angle < 5:
            angle = 5
        if angle > 70:
            angle = 70;
        if self.currentAngle == angle:
            return
        self.currentAngle = angle
        self.update()
        self.emit(QtCore.SIGNAL("angleChanged(int)"), self.currentAngle)

    def paintEvent(self, event):
        painter = QtGui.QPainter(self)
        painter.drawText(200, 200, "Angle = " + QtCore.QString.number(self.currentAngle))


class MyWidget(QtGui.QWidget):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)

        quit = QtGui.QPushButton("Quit")
        quit.setFont(QtGui.QFont("Times", 18, QtGui.QFont.Bold))

        self.connect(quit, QtCore.SIGNAL("clicked()"),
                     QtGui.qApp, QtCore.SLOT("quit()"))

        angle = LCDRange()
        angle.setRange(5, 70)

        cannonField = CannonField()

        self.connect(angle, QtCore.SIGNAL("valueChanged(int)"),
                     cannonField.setAngle)
        self.connect(cannonField, QtCore.SIGNAL("angleChanged(int)"),
                     angle.setValue)

        gridLayout = QtGui.QGridLayout()
        gridLayout.addWidget(quit, 0, 0)
        gridLayout.addWidget(angle, 1, 0)
        gridLayout.addWidget(cannonField, 1, 1, 2, 1)
        gridLayout.setColumnStretch(1, 10)
        self.setLayout(gridLayout)

        angle.setValue(60)
        angle.setFocus()


app = QtGui.QApplication(sys.argv)
widget = MyWidget()
widget.setGeometry(100, 100, 500, 355)
widget.show()
sys.exit(app.exec_())
