text: #!/usr/bin/env python
  
  
  #############################################################################
  ##
  ## Copyright (C) 2013 Riverbank Computing Limited.
  ## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  ## All rights reserved.
  ##
  ## This file is part of the examples of PyQt.
  ##
  ## $QT_BEGIN_LICENSE:BSD$
  ## You may use this file under the terms of the BSD license as follows:
  ##
  ## "Redistribution and use in source and binary forms, with or without
  ## modification, are permitted provided that the following conditions are
  ## met:
  ##   * Redistributions of source code must retain the above copyright
  ##     notice, this list of conditions and the following disclaimer.
  ##   * Redistributions in binary form must reproduce the above copyright
  ##     notice, this list of conditions and the following disclaimer in
  ##     the documentation and/or other materials provided with the
  ##     distribution.
  ##   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
  ##     the names of its contributors may be used to endorse or promote
  ##     products derived from this software without specific prior written
  ##     permission.
  ##
  ## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  ## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  ## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  ## $QT_END_LICENSE$
  ##
  #############################################################################
  
  
  import math
  
  from PyQt5.QtCore import (pyqtProperty, QDirIterator, QEasingCurve, QEvent,
          QEventTransition, QHistoryState, QParallelAnimationGroup, QPointF,
          QPropertyAnimation, QRectF, QSequentialAnimationGroup, QSize, QState,
          QStateMachine, Qt)
  from PyQt5.QtGui import (QBrush, QColor, QFont, QLinearGradient, QPainter,
          QPalette, QPen, QPixmap, QTransform)
  from PyQt5.QtWidgets import (QApplication, QGraphicsItem, QGraphicsObject,
          QGraphicsProxyWidget, QGraphicsRotation, QGraphicsScene, QGraphicsView,
          QKeyEventTransition, QWidget)
  from PyQt5.QtOpenGL import QGL, QGLFormat, QGLWidget
  
  import padnavigator_rc
  from ui_form import Ui_Form
  
  
  class PadNavigator(QGraphicsView):
      def __init__(self, size, parent=None):
          super(PadNavigator, self).__init__(parent)
  
          self.form = Ui_Form()
  
          splash = SplashItem()
          splash.setZValue(1)
  
          pad = FlippablePad(size)
          flipRotation = QGraphicsRotation(pad)
          xRotation = QGraphicsRotation(pad)
          yRotation = QGraphicsRotation(pad)
          flipRotation.setAxis(Qt.YAxis)
          xRotation.setAxis(Qt.YAxis)
          yRotation.setAxis(Qt.XAxis)
          pad.setTransformations([flipRotation, xRotation, yRotation])
  
          backItem = QGraphicsProxyWidget(pad)
          widget = QWidget()
          self.form.setupUi(widget)
          self.form.hostName.setFocus()
          backItem.setWidget(widget)
          backItem.setVisible(False)
          backItem.setFocus()
          backItem.setCacheMode(QGraphicsItem.ItemCoordinateCache)
          r = backItem.rect()
          backItem.setTransform(QTransform().rotate(180, Qt.YAxis).translate(-r.width()/2, -r.height()/2))
  
          selectionItem = RoundRectItem(QRectF(-60, -60, 120, 120),
                  QColor(Qt.gray), pad)
          selectionItem.setZValue(0.5)
  
          smoothSplashMove = QPropertyAnimation(splash, b'y')
          smoothSplashOpacity = QPropertyAnimation(splash, b'opacity')
          smoothSplashMove.setEasingCurve(QEasingCurve.InQuad)
          smoothSplashMove.setDuration(250)
          smoothSplashOpacity.setDuration(250)
  
          smoothXSelection = QPropertyAnimation(selectionItem, b'x')
          smoothYSelection = QPropertyAnimation(selectionItem, b'y')
          smoothXRotation = QPropertyAnimation(xRotation, b'angle')
          smoothYRotation = QPropertyAnimation(yRotation, b'angle')
          smoothXSelection.setDuration(125)
          smoothYSelection.setDuration(125)
          smoothXRotation.setDuration(125)
          smoothYRotation.setDuration(125)
          smoothXSelection.setEasingCurve(QEasingCurve.InOutQuad)
          smoothYSelection.setEasingCurve(QEasingCurve.InOutQuad)
          smoothXRotation.setEasingCurve(QEasingCurve.InOutQuad)
          smoothYRotation.setEasingCurve(QEasingCurve.InOutQuad)
  
          smoothFlipRotation = QPropertyAnimation(flipRotation, b'angle')
          smoothFlipScale = QPropertyAnimation(pad, b'scale')
          smoothFlipXRotation = QPropertyAnimation(xRotation, b'angle')
          smoothFlipYRotation = QPropertyAnimation(yRotation, b'angle')
          flipAnimation = QParallelAnimationGroup(self)
          smoothFlipScale.setDuration(500)
          smoothFlipRotation.setDuration(500)
          smoothFlipXRotation.setDuration(500)
          smoothFlipYRotation.setDuration(500)
          smoothFlipScale.setEasingCurve(QEasingCurve.InOutQuad)
          smoothFlipRotation.setEasingCurve(QEasingCurve.InOutQuad)
          smoothFlipXRotation.setEasingCurve(QEasingCurve.InOutQuad)
          smoothFlipYRotation.setEasingCurve(QEasingCurve.InOutQuad)
          smoothFlipScale.setKeyValueAt(0, 1.0)
          smoothFlipScale.setKeyValueAt(0.5, 0.7)
          smoothFlipScale.setKeyValueAt(1, 1.0)
          flipAnimation.addAnimation(smoothFlipRotation)
          flipAnimation.addAnimation(smoothFlipScale)
          flipAnimation.addAnimation(smoothFlipXRotation)
          flipAnimation.addAnimation(smoothFlipYRotation)
  
          setVariablesSequence = QSequentialAnimationGroup()
          setFillAnimation = QPropertyAnimation(pad, b'fill')
          setBackItemVisibleAnimation = QPropertyAnimation(backItem, b'visible')
          setSelectionItemVisibleAnimation = QPropertyAnimation(selectionItem, b'visible')
          setFillAnimation.setDuration(0)
          setBackItemVisibleAnimation.setDuration(0)
          setSelectionItemVisibleAnimation.setDuration(0)
          setVariablesSequence.addPause(250)
          setVariablesSequence.addAnimation(setBackItemVisibleAnimation)
          setVariablesSequence.addAnimation(setSelectionItemVisibleAnimation)
          setVariablesSequence.addAnimation(setFillAnimation)
          flipAnimation.addAnimation(setVariablesSequence)
  
          stateMachine = QStateMachine(self)
          splashState = QState(stateMachine)
          frontState = QState(stateMachine)
          historyState = QHistoryState(frontState)
          backState = QState(stateMachine)
  
          frontState.assignProperty(pad, "fill", False)
          frontState.assignProperty(splash, "opacity", 0.0)
          frontState.assignProperty(backItem, "visible", False)
          frontState.assignProperty(flipRotation, "angle", 0.0)
          frontState.assignProperty(selectionItem, "visible", True)
  
          backState.assignProperty(pad, "fill", True)
          backState.assignProperty(backItem, "visible", True)
          backState.assignProperty(xRotation, "angle", 0.0)
          backState.assignProperty(yRotation, "angle", 0.0)
          backState.assignProperty(flipRotation, "angle", 180.0)
          backState.assignProperty(selectionItem, "visible", False)
  
          stateMachine.addDefaultAnimation(smoothXRotation)
          stateMachine.addDefaultAnimation(smoothYRotation)
          stateMachine.addDefaultAnimation(smoothXSelection)
          stateMachine.addDefaultAnimation(smoothYSelection)
          stateMachine.setInitialState(splashState)
  
          anyKeyTransition = QEventTransition(self, QEvent.KeyPress, splashState)
          anyKeyTransition.setTargetState(frontState)
          anyKeyTransition.addAnimation(smoothSplashMove)
          anyKeyTransition.addAnimation(smoothSplashOpacity)
  
          enterTransition = QKeyEventTransition(self, QEvent.KeyPress,
                  Qt.Key_Enter, backState)
          returnTransition = QKeyEventTransition(self, QEvent.KeyPress,
                  Qt.Key_Return, backState)
          backEnterTransition = QKeyEventTransition(self, QEvent.KeyPress,
                  Qt.Key_Enter, frontState)
          backReturnTransition = QKeyEventTransition(self, QEvent.KeyPress,
                  Qt.Key_Return, frontState)
          enterTransition.setTargetState(historyState)
          returnTransition.setTargetState(historyState)
          backEnterTransition.setTargetState(backState)
          backReturnTransition.setTargetState(backState)
          enterTransition.addAnimation(flipAnimation)
          returnTransition.addAnimation(flipAnimation)
          backEnterTransition.addAnimation(flipAnimation)
          backReturnTransition.addAnimation(flipAnimation)
  
          columns = size.width()
          rows = size.height()
          stateGrid = []
          for y in range(rows):
              stateGrid.append([QState(frontState) for _ in range(columns)])
  
          frontState.setInitialState(stateGrid[0][0])
          selectionItem.setPos(pad.iconAt(0, 0).pos())
  
          for y in range(rows):
              for x in range(columns):
                  state = stateGrid[y][x]
  
                  rightTransition = QKeyEventTransition(self, QEvent.KeyPress,
                          Qt.Key_Right, state)
                  leftTransition = QKeyEventTransition(self, QEvent.KeyPress,
                          Qt.Key_Left, state)
                  downTransition = QKeyEventTransition(self, QEvent.KeyPress,
                          Qt.Key_Down, state)
                  upTransition = QKeyEventTransition(self, QEvent.KeyPress,
                          Qt.Key_Up, state)
  
                  rightTransition.setTargetState(stateGrid[y][(x + 1) % columns])
                  leftTransition.setTargetState(stateGrid[y][((x - 1) + columns) % columns])
                  downTransition.setTargetState(stateGrid[(y + 1) % rows][x])
                  upTransition.setTargetState(stateGrid[((y - 1) + rows) % rows][x])
  
                  icon = pad.iconAt(x, y)
                  state.assignProperty(xRotation, "angle", -icon.x() / 6.0)
                  state.assignProperty(yRotation, "angle", icon.y() / 6.0)
                  state.assignProperty(selectionItem, "x", icon.x())
                  state.assignProperty(selectionItem, "y", icon.y())
                  frontState.assignProperty(icon, "visible", True)
                  backState.assignProperty(icon, "visible", False)
  
                  setIconVisibleAnimation = QPropertyAnimation(icon, b'visible')
                  setIconVisibleAnimation.setDuration(0)
                  setVariablesSequence.addAnimation(setIconVisibleAnimation)
  
          scene = QGraphicsScene(self)
          scene.setBackgroundBrush(QBrush(QPixmap(":/images/blue_angle_swirl.jpg")))
          scene.setItemIndexMethod(QGraphicsScene.NoIndex)
          scene.addItem(pad)
          scene.setSceneRect(scene.itemsBoundingRect())
          self.setScene(scene)
  
          sbr = splash.boundingRect()
          splash.setPos(-sbr.width() / 2, scene.sceneRect().top() - 2)
          frontState.assignProperty(splash, "y", splash.y() - 100.0)
          scene.addItem(splash)
  
          self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
          self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
          self.setMinimumSize(50, 50)
          self.setViewportUpdateMode(QGraphicsView.FullViewportUpdate)
          self.setCacheMode(QGraphicsView.CacheBackground)
          self.setRenderHints(QPainter.Antialiasing |
                  QPainter.SmoothPixmapTransform | QPainter.TextAntialiasing)
  
          if QGLFormat.hasOpenGL():
              self.setViewport(QGLWidget(QGLFormat(QGL.SampleBuffers)))
  
          stateMachine.start()
  
      def resizeEvent(self, event):
          super(PadNavigator, self).resizeEvent(event)
          self.fitInView(self.scene().sceneRect(), Qt.KeepAspectRatio)
  
  
  class RoundRectItem(QGraphicsObject):
      def __init__(self, bounds, color, parent=None):
          super(RoundRectItem, self).__init__(parent)
  
          self.fillRect = False
          self.bounds = QRectF(bounds)
          self.pix = QPixmap()
  
          self.gradient = QLinearGradient()
          self.gradient.setStart(self.bounds.topLeft())
          self.gradient.setFinalStop(self.bounds.bottomRight())
          self.gradient.setColorAt(0, color)
          self.gradient.setColorAt(1, color.darker(200))
  
          self.setCacheMode(QGraphicsItem.ItemCoordinateCache)
  
      def setFill(self, fill):
          self.fillRect = fill
          self.update()
  
      def fill(self):
          return self.fillRect
  
      fill = pyqtProperty(bool, fill, setFill)
  
      def paint(self, painter, option, widget):
          painter.setPen(Qt.NoPen)
          painter.setBrush(QColor(0, 0, 0, 64))
          painter.drawRoundedRect(self.bounds.translated(2, 2), 25.0, 25.0)
  
          if self.fillRect:
              painter.setBrush(QApplication.palette().brush(QPalette.Window))
          else:
              painter.setBrush(self.gradient)
  
          painter.setPen(QPen(Qt.black, 1))
          painter.drawRoundedRect(self.bounds, 25.0, 25.0)
          if not self.pix.isNull():
              painter.scale(1.95, 1.95)
              painter.drawPixmap(-self.pix.width() / 2, -self.pix.height() / 2, self.pix)
  
      def boundingRect(self):
          return self.bounds.adjusted(0, 0, 2, 2)
  
      def pixmap(self):
          return QPixmap(self.pix)
  
      def setPixmap(self, pixmap):
          self.pix = QPixmap(pixmap)
          self.update()
  
  
  class FlippablePad(RoundRectItem):
      def __init__(self, size, parent=None):
          super(FlippablePad, self).__init__(self.boundsFromSize(size),
                  QColor(226, 255, 92, 64), parent)
  
          numIcons = size.width() * size.height()
          pixmaps = []
          it = QDirIterator(":/images", ["*.png"])
          while it.hasNext() and len(pixmaps) < numIcons:
              pixmaps.append(it.next())
  
          iconRect = QRectF(-54, -54, 108, 108)
          iconColor = QColor(214, 240, 110, 128)
          self.iconGrid = []
          n = 0
  
          for y in range(size.height()):
              row = []
  
              for x in range(size.width()):
                  rect = RoundRectItem(iconRect, iconColor, self)
                  rect.setZValue(1)
                  rect.setPos(self.posForLocation(x, y, size))
                  rect.setPixmap(pixmaps[n % len(pixmaps)])
                  n += 1
  
                  row.append(rect)
  
              self.iconGrid.append(row)
  
      def iconAt(self, column, row):
          return self.iconGrid[row][column]
  
      @staticmethod
      def boundsFromSize(size):
          return QRectF((-size.width() / 2.0) * 150,
                  (-size.height() / 2.0) * 150, size.width() * 150,
                  size.height() * 150)
  
      @staticmethod
      def posForLocation(column, row, size):
          return QPointF(column * 150, row * 150) - QPointF((size.width() - 1) * 75, (size.height() - 1) * 75)
  
  
  class SplashItem(QGraphicsObject):
      def __init__(self, parent=None):
          super(SplashItem, self).__init__(parent)
  
          self.text = "Welcome to the Pad Navigator Example. You can use the " \
                  "keyboard arrows to navigate the icons, and press enter to " \
                  "activate an item. Press any key to begin."
  
          self.setCacheMode(QGraphicsItem.DeviceCoordinateCache)
  
      def boundingRect(self):
          return QRectF(0, 0, 400, 175)
  
      def paint(self, painter, option, widget):
          painter.setPen(QPen(Qt.black, 2))
          painter.setBrush(QColor(245, 245, 255, 220))
          painter.setClipRect(self.boundingRect())
          painter.drawRoundedRect(3, -100 + 3, 400 - 6, 250 - 6, 25.0, 25.0)
  
          textRect = self.boundingRect().adjusted(10, 10, -10, -10)
          flags = int(Qt.AlignTop | Qt.AlignLeft) | Qt.TextWordWrap
  
          font = QFont()
          font.setPixelSize(18)
          painter.setPen(Qt.black)
          painter.setFont(font)
          painter.drawText(textRect, flags, self.text)
  
  
  if __name__ == '__main__':
  
      import sys
  
      app = QApplication(sys.argv)
  
      navigator = PadNavigator(QSize(3, 3))
      navigator.show()
  
      sys.exit(app.exec_())
  