import sys
from PySide.QtCore import *
from PySide.QtGui import *

class TestFrame( QFrame ):
    def __init__( self, area, parent=None ):
        super( TestFrame, self ).__init__( parent )
        self.setFrameStyle( QFrame.StyledPanel )
        self.area = area
        self.frame_height = self.height()

    def setHeight(self, height):
        self.frame_height = height

    def resetGeometry(self, size):
        height = self.frame_height

        x = 0
        width = size.width()

        if self.area == Qt.TopDockWidgetArea:
            y = 0

        elif self.area == Qt.BottomDockWidgetArea:
            y = size.height() - height

        super(TestFrame, self).setGeometry(x, y, width, height)

class CentralFrame(QFrame):

    resized = Signal(QSize)

    def resizeEvent(self, event):
        assert isinstance(event, QResizeEvent)

        self.resized.emit(event.size())

class SliderWidget(QMainWindow):
    def __init__( self ):
        super( SliderWidget, self ).__init__()
        self.buildUI()

    def buildUI( self ):
        self.setLayout( QGridLayout() )

        # ANIMATION GROUP FOR TOP AND BOTTOM FRAMES
        self.animGroup = QParallelAnimationGroup()

        # CREATE WIDGETS
        self.frameCentre = CentralFrame( self )
        self.frameTop = TestFrame( Qt.TopDockWidgetArea, self.frameCentre )
        self.frameBottom = TestFrame( Qt.BottomDockWidgetArea, self.frameCentre )
        self.frameCentre.resized.connect(self.frameTop.resetGeometry)
        self.frameCentre.resized.connect(self.frameBottom.resetGeometry)
        self.btn = QPushButton( 'GO' )

        self.frameTop.setHeight(200)
        self.frameBottom.setHeight(200)
        self.frameCentre.setMinimumHeight(500)

        # TOOLTIPS
        self.frameTop.setToolTip( 'frame top' )
        self.frameCentre.setToolTip( 'frame centre' )
        self.frameBottom.setToolTip( 'frame bottom' )

        # SLIDE IN TOP AND BOTTOM FRAMES
        self.btn.clicked.connect( self.moveWidgets )

        # HIDE TOP AND BOTTOM AT FIRST - DEACTIVATE FOR DEBUGGING
        self.frameTop.hide()
        self.frameBottom.hide()

        # ADD CENTRETO LAYOUT
        self.setCentralWidget(self.frameCentre)
        layout = QVBoxLayout(self.frameCentre)
        layout.addWidget(self.btn)
        self.frameCentre.setLayout(layout)


    def moveWidgets( self ):
        '''trigger animations'''
        self.animGroup.clear()
        self.slideInWidget( self.frameTop, 'topDown' )
        self.slideInWidget( self.frameBottom, 'bottomUp')
        self.animGroup.start()

    def slideInWidget( self, widget, direction ):
        '''assign animation to frames'''
        assert direction in ( 'topDown', 'bottomUp' )
        # DEFINE START AND END POSITION - THIS IS WHERE I HAVE TROUBLE SETTING THE RIGHT POSITION
        if direction == 'topDown':
            start = widget.height() * -1
            end = 0
        elif direction == 'bottomUp':
            start = self.centralWidget().height()
            end = self.centralWidget().height() - widget.height()

        # START ANIMATION
        widget.show()
        slideInAnim = self.slideAnimation( widget, start, end )
        self.animGroup.addAnimation( slideInAnim )

    def slideAnimation( self, widget, start, end ):
        '''Define sliding animation'''
        slideAnimation = QPropertyAnimation( widget, 'pos' )
        slideAnimation.setDuration( 1000 )
        slideAnimation.setStartValue( QPoint( widget.pos().x(), start ) )
        slideAnimation.setEndValue( QPoint( widget.pos().x(), end ) )
        slideAnimation.setEasingCurve( QEasingCurve.OutCubic )
        return slideAnimation

if __name__ == "__main__":

    app = QApplication(sys.argv)
    sw = SliderWidget()

    sw.resize( 800, 750 )
    sw.show()

    sys.exit(app.exec_())