def __init__(self,
viewport,
viewportMngr,
vpType,
prototypeMngr,
parent=None):
""" Initialization of the CompositionView class
Parameters:
viewportMngr - the manager of the viewports where the composition
view can reside in
prototypeMngr - the manager of the prototypes is used to obtain
the results of the solver
"""
QtWidgets.QDialog.__init__(self, parent)
self.prototypeManager = prototypeMngr
self.viewport = viewport
self.viewportManager = viewportMngr
self.settings = Settings()
self.setWindowFlags(QtCore.Qt.Window)
self.timer = QtCore.QObject()
# QtCore.qsrand(QtCore.QTime(0,0,0).secsTo(QtCore.QTime.currentTime()))
self.tree = Tree(None)
self.infoOverlay = CVInfoOverlay(self)
self.connections = []
self.ui = Ui_compositionView()
self.ui.setupUi(self)
self.ui.graphicsView.setupViewport(
QtOpenGL.QGLWidget(
QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers
| QtOpenGL.QGL.DoubleBuffer)))
# self.ui.graphicsView.setViewport(QtGui.QWidget())
self.ui.graphicsView.setRenderHints(
QtGui.QPainter.Antialiasing | QtGui.QPainter.SmoothPixmapTransform)
self.collapsed = False
self.currentTool = None
self.viewportType = vpType
self.first = False
self.nodeId = 0
self.overConstrainedColor = QtGui.QColor(0, 0, 255)
self.underConstrainedColor = QtGui.QColor(255, 0, 0)
self.wellConstrainedColor = QtGui.QColor(0, 255, 0)
self.unsolvedColor = QtGui.QColor(125, 124, 255)
self.setScene()
self.createTriggers()
def __init__(self, viewport, viewportMngr, vpType, prototypeMngr, parent=None):
""" Initialization of the CompositionView class
Parameters:
viewportMngr - the manager of the viewports where the composition view can reside in
prototypeMngr - the manager of the prototypes is used to obtain the results of the solver
"""
QtGui.QDialog.__init__(self, parent)
self.prototypeManager = prototypeMngr
self.viewport = viewport
self.viewportManager = viewportMngr
self.settings = Settings()
self.setWindowFlags(QtCore.Qt.Window)
self.timer = QtCore.QObject()
#QtCore.qsrand(QtCore.QTime(0,0,0).secsTo(QtCore.QTime.currentTime()))
self.tree = Tree(None)
self.infoOverlay = CVInfoOverlay(self)
self.connections = []
self.ui = Ui_compositionView()
self.ui.setupUi(self)
self.ui.graphicsView.setupViewport(QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers|QtOpenGL.QGL.DoubleBuffer)))
#self.ui.graphicsView.setViewport(QtGui.QWidget())
self.ui.graphicsView.setRenderHints(QtGui.QPainter.Antialiasing | QtGui.QPainter.SmoothPixmapTransform)
self.collapsed = False
self.currentTool = None
self.viewportType = vpType
self.first = False
self.nodeId = 0
self.overConstrainedColor = QtGui.QColor(0,0,255)
self.underConstrainedColor = QtGui.QColor(255,0,0)
self.wellConstrainedColor = QtGui.QColor(0,255,0)
self.unsolvedColor = QtGui.QColor(125,124,255)
self.setScene()
self.createTriggers()
class CompositionView(QtGui.QDialog):
""" A view where the decomposition of the system of constraints is visualised as a tree """
def __init__(self, viewport, viewportMngr, vpType, prototypeMngr, parent=None):
""" Initialization of the CompositionView class
Parameters:
viewportMngr - the manager of the viewports where the composition view can reside in
prototypeMngr - the manager of the prototypes is used to obtain the results of the solver
"""
QtGui.QDialog.__init__(self, parent)
self.prototypeManager = prototypeMngr
self.viewport = viewport
self.viewportManager = viewportMngr
self.settings = Settings()
self.setWindowFlags(QtCore.Qt.Window)
self.timer = QtCore.QObject()
#QtCore.qsrand(QtCore.QTime(0,0,0).secsTo(QtCore.QTime.currentTime()))
self.tree = Tree(None)
self.infoOverlay = CVInfoOverlay(self)
self.connections = []
self.ui = Ui_compositionView()
self.ui.setupUi(self)
self.ui.graphicsView.setupViewport(QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers|QtOpenGL.QGL.DoubleBuffer)))
#self.ui.graphicsView.setViewport(QtGui.QWidget())
self.ui.graphicsView.setRenderHints(QtGui.QPainter.Antialiasing | QtGui.QPainter.SmoothPixmapTransform)
self.collapsed = False
self.currentTool = None
self.viewportType = vpType
self.first = False
self.nodeId = 0
self.overConstrainedColor = QtGui.QColor(0,0,255)
self.underConstrainedColor = QtGui.QColor(255,0,0)
self.wellConstrainedColor = QtGui.QColor(0,255,0)
self.unsolvedColor = QtGui.QColor(125,124,255)
self.setScene()
self.createTriggers()
def createTriggers(self):
""" Create the triggers for the components in the graphical window """
QtCore.QObject.connect(self.ui.zoomInButton,QtCore.SIGNAL("clicked()"),self.zoomIn)
QtCore.QObject.connect(self.ui.zoomOutButton,QtCore.SIGNAL("clicked()"),self.zoomOut)
QtCore.QObject.connect(self.ui.fitButton, QtCore.SIGNAL("clicked()"), self.fit)
QtCore.QObject.connect(self.ui.collapseButton, QtCore.SIGNAL("clicked()"), self.collapse)
QtCore.QObject.connect(self.ui.graphicsScene, QtCore.SIGNAL("changed(const QList<QRectF> & )"), self.updateSceneRect)
QtCore.QObject.connect(self.ui.verticalSlider,QtCore.SIGNAL("valueChanged(int)"),self.setupMatrix)
QtCore.QObject.connect(self.settings.dvData,QtCore.SIGNAL("treeOrientationChanged()"), self.updateTreeOrientation)
def setScene(self):
""" The scene where the tree is visualised in, will be created and set """
self.initView()
def getViewportType(self):
return self.viewportType
def updateGL(self):
self.update()
def createDecomposition(self):
""" Create a new decomposition. If an older one exists it will be removed. """
if self.ui.graphicsScene != None:
for item in self.ui.graphicsView.items():
item.hide()
if item.parentItem() == None:
self.ui.graphicsScene.removeItem(item)
if self.tree.root != None:
self.tree.clear(self.tree.root)
del self.connections[:]
del self.settings.dvData.fixedClusterIds[:]
self.initView()
def initView(self):
""" Updating the view with new data and nodes for the visualisation of the tree """
if self.prototypeManager.result != None:
self.nodeId = 0
self.tree.root = self.populateTree(self.prototypeManager.result.subs, None, self.prototypeManager.result)
self.drawTree(self.ui.graphicsScene, self.tree.root, self.tree.root.children)
self.drawConnections(self.ui.graphicsScene)
self.determineCollapse(self.tree.root)
self.showConnections()
self.tree.root.showChildren()
self.updateTree()
self.addInfoOverlay()
self.initFixStates()
def updateViewports(self):
self.viewportManager.updateViewports()
def updateTree(self):
""" Update the tree, where the node positions and connections between the nodes are updated """
self.tree.clear(self.tree.root)
self.tree.updateTree()
self.updateNodePositions(self.tree.root)
self.showConnections()
def populateTree(self, nodes, rootNode, currentNode, id=0):
""" Recursive function to populate a tree, from the results of the solver to finally display it in the Decomposition View.
The population is depth first.
Parameters:
nodes - the childnodes
rootNode - root node of the (partial) tree
currentNode - the current node of the result obtained from the constraints solver
"""
if len(currentNode.variables) == 1:
self.createLeafPoint(rootNode, currentNode.variables[0], self.nodeId)
else:
newNode = CVCluster(self, rootNode, self.nodeId)
newNode.flag = currentNode.flag
newNode.variables = currentNode.variables
needCollapse = False
""" Add children to the rootNode to create the full tree """
if rootNode != None:
#self.setCollapse(newNode)
rootNode.children += [newNode]
""" Create a connection between the nodes if the current node has a rootnode"""
newConnection = CVConnection(self, rootNode, newNode)
self.connections += [newConnection]
""" get the leaf nodes """
if len(nodes) == 0:
for variable in newNode.variables:
self.createLeafPoint(newNode, variable, self.nodeId)
# Rick 20091116 - skip this for debug
# for node in nodes:
# self.nodeId += 1
# self.populateTree(node.subs, newNode, node, self.nodeId)
""" To return the whole tree, a check will be performed for the rootnode """
if rootNode == None:
return newNode
def initFixStates(self):
""" Initialize the fix states from another view if available """
for fixedId in self.settings.dvData.fixedClusterIds:
self.updateState(fixedId, True, self.tree.root)
def stateChange(self, id, fixed):
""" Change the state of the cluster which might be fixed and report it
to the other decomposition views.
Paramaters:
id - unique id of the cluster
fixed - should the clusters be fixed or not
"""
self.viewportManager.updateDecompositionFixed(id, fixed)
if fixed:
self.settings.dvData.fixedClusterIds += [id]
elif not fixed:
self.settings.dvData.fixedClusterIds = filter(lambda x:x!=id, self.settings.dvData.fixedClusterIds)
def updateState(self, id, fixed, rootNode):
""" Update the fixed cluster, with the visuals.
Parameters:
id - unique id of the cluster
fixed - should the cluster be fixed or not
rootNode - recursive funcion to walk the tree
"""
if rootNode.identifier == id:
if fixed and rootNode.isVisible():
rootNode.fixGraphic.show()
rootNode.clusterActive = True
elif fixed and not rootNode.isVisible():
rootNode.fixGraphic.hide()
rootNode.clusterActive = True
else:
rootNode.fixGraphic.hide()
rootNode.clusterActive = False
self.prototypeManager.removeClusterObjects([rootNode.permCluster], True, True)
rootNode.permCluster = None
return True
for node in rootNode.children:
found = self.updateState(id, fixed, node)
if found:
break
return False
def createLeafPoint(self, node, variable, id):
cvPoint = CVPoint(self, node, id)
cvPoint.setWidthAndHeight(20, 20)
cvPoint.prtRef = self.prototypeManager.getObjectByKey(variable)
cvPoint.isCollapsed = False
cvPoint.canCollapse = False
#cvPoint.setInfoOverlay()
node.children += [cvPoint]
newConnection = CVConnection(self, node, cvPoint)
self.connections += [newConnection]
def setCollapse(self, node):
node.isCollapsed = False
if not isinstance(node, CVPoint):
if not node.collapseFromResult():
node.updateCluster()
def determineCollapse(self, node):
self.setCollapse(node)
for child in node.children:
self.determineCollapse(child)
def addInfoOverlay(self):
self.ui.graphicsScene.addItem(self.infoOverlay)
self.infoOverlay.hide()
def drawTree(self, scene, root, childNodes):
""" The different nodes are added to the scene and will automatically be drawn
Parameters:
scene - the scene where the rootnode has to be drawn in
root - the rootnode of the (sub-) tree
childNode - the children of this root node
"""
root.setPos(root.position)
scene.addItem(root)
#print "#nodes: ", len(childNodes), " position: ",root.position.x(), " " , root.position.y()
for node in childNodes:
self.drawTree(scene, node, node.children)
def drawConnections(self, scene):
""" The connections between the nodes are added to the scene and will automatically be drawn
Parameters:
scene - the scene where the connections has to be drawn in
"""
for connection in self.connections:
#connection.setPos()
scene.addItem(connection)
def showConnections(self):
""" Show/hide the connections between the nodes, this depends if the node is collapsed """
for connection in self.connections:
connection.setPos(connection.nodeTo.position)
if connection.nodeFrom.isCollapsed or (connection.nodeTo.isVisible() == False):
connection.hide()
else:
connection.show()
def updateConnections(self):
for connection in self.connections:
connection.update()
def nrVisibleConnections(self):
number = 0
#for connection in self.connections:
#print "x, y: " , connection.x(), connection.y()
#print "nr of visible connections: " , number
def updateNodePositions(self, node):
""" Map the position of the nodes in the tree on the graphical view
Parameters:
node - a node in the tree for which the position is set
"""
node.setPos(node.position)
for childNode in node.children:
self.updateNodePositions(childNode)
def updateSceneRect(self, rectList=None):
self.ui.graphicsScene.setSceneRect(self.ui.graphicsScene.itemsBoundingRect())
def updateTreeOrientation(self):
self.tree.orientation = self.settings.dvData.treeAlignment
def zoomIn(self):
""" Zoom in the graphics view, by updating the vertical slider """
self.ui.verticalSlider.setValue(self.ui.verticalSlider.value() + 1)
def zoomOut(self):
""" Zoom out the graphics view, by updating the vertical slider """
self.ui.verticalSlider.setValue(self.ui.verticalSlider.value() - 1)
def fit(self):
""" Fits the tree exactly in the graphics view """
self.ui.graphicsView.fitInView(0.0, 0.0, self.ui.graphicsScene.width(), self.ui.graphicsScene.height(), QtCore.Qt.KeepAspectRatio)
""" Update the slider """
value = (math.log(self.ui.graphicsView.matrix().m11(),2)*50) + 250.0
self.ui.verticalSlider.setValue(value)
def collapseAll(self, node):
if node.canCollapse:
node.collapse()
for childNode in node.children:
self.collapseAll(childNode)
def expandAll(self, node):
node.expand()
for childNode in node.children:
self.expandAll(childNode)
def collapse(self):
if self.collapsed:
self.collapsed = False
self.collapseAll(self.tree.root)
else:
self.collapsed = True
self.expandAll(self.tree.root)
self.updateTree()
self.update()
def setupMatrix(self, value):
""" Zoom in/out the graphics view, depending on the value of the slider
Parameters
value - value of the updated slider
"""
scale = math.pow(2.0, (self.ui.verticalSlider.value()-250.0)/50.0)
matrix = QtGui.QMatrix()
matrix.scale(scale,scale)
self.ui.graphicsView.setMatrix(matrix)
class CompositionView(QtGui.QDialog):
""" A view where the decomposition of the system of constraints is visualised as a tree """
def __init__(self,
viewport,
viewportMngr,
vpType,
prototypeMngr,
parent=None):
""" Initialization of the CompositionView class
Parameters:
viewportMngr - the manager of the viewports where the composition view can reside in
prototypeMngr - the manager of the prototypes is used to obtain the results of the solver
"""
QtGui.QDialog.__init__(self, parent)
self.prototypeManager = prototypeMngr
self.viewport = viewport
self.viewportManager = viewportMngr
self.settings = Settings()
self.setWindowFlags(QtCore.Qt.Window)
self.timer = QtCore.QObject()
#QtCore.qsrand(QtCore.QTime(0,0,0).secsTo(QtCore.QTime.currentTime()))
self.tree = Tree(None)
self.infoOverlay = CVInfoOverlay(self)
self.connections = []
self.ui = Ui_compositionView()
self.ui.setupUi(self)
self.ui.graphicsView.setupViewport(
QtOpenGL.QGLWidget(
QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers
| QtOpenGL.QGL.DoubleBuffer)))
#self.ui.graphicsView.setViewport(QtGui.QWidget())
self.ui.graphicsView.setRenderHints(
QtGui.QPainter.Antialiasing | QtGui.QPainter.SmoothPixmapTransform)
self.collapsed = False
self.currentTool = None
self.viewportType = vpType
self.first = False
self.nodeId = 0
self.overConstrainedColor = QtGui.QColor(0, 0, 255)
self.underConstrainedColor = QtGui.QColor(255, 0, 0)
self.wellConstrainedColor = QtGui.QColor(0, 255, 0)
self.unsolvedColor = QtGui.QColor(125, 124, 255)
self.setScene()
self.createTriggers()
def createTriggers(self):
""" Create the triggers for the components in the graphical window """
QtCore.QObject.connect(self.ui.zoomInButton,
QtCore.SIGNAL("clicked()"), self.zoomIn)
QtCore.QObject.connect(self.ui.zoomOutButton,
QtCore.SIGNAL("clicked()"), self.zoomOut)
QtCore.QObject.connect(self.ui.fitButton, QtCore.SIGNAL("clicked()"),
self.fit)
QtCore.QObject.connect(self.ui.collapseButton,
QtCore.SIGNAL("clicked()"), self.collapse)
QtCore.QObject.connect(
self.ui.graphicsScene,
QtCore.SIGNAL("changed(const QList<QRectF> & )"),
self.updateSceneRect)
QtCore.QObject.connect(self.ui.verticalSlider,
QtCore.SIGNAL("valueChanged(int)"),
self.setupMatrix)
QtCore.QObject.connect(self.settings.dvData,
QtCore.SIGNAL("treeOrientationChanged()"),
self.updateTreeOrientation)
def setScene(self):
""" The scene where the tree is visualised in, will be created and set """
self.initView()
def getViewportType(self):
return self.viewportType
def updateGL(self):
self.update()
def createDecomposition(self):
""" Create a new decomposition. If an older one exists it will be removed. """
if self.ui.graphicsScene != None:
for item in self.ui.graphicsView.items():
item.hide()
if item.parentItem() == None:
self.ui.graphicsScene.removeItem(item)
if self.tree.root != None:
self.tree.clear(self.tree.root)
del self.connections[:]
del self.settings.dvData.fixedClusterIds[:]
self.initView()
def initView(self):
""" Updating the view with new data and nodes for the visualisation of the tree """
if self.prototypeManager.result != None:
self.nodeId = 0
self.tree.root = self.populateTree(
self.prototypeManager.result.subs, None,
self.prototypeManager.result)
# return # Rick 20090522 debug
self.drawTree(self.ui.graphicsScene, self.tree.root,
self.tree.root.children)
self.drawConnections(self.ui.graphicsScene)
self.determineCollapse(self.tree.root)
self.showConnections()
self.tree.root.showChildren()
self.updateTree()
self.addInfoOverlay()
self.initFixStates()
def updateViewports(self):
self.viewportManager.updateViewports()
def updateTree(self):
""" Update the tree, where the node positions and connections between the nodes are updated """
self.tree.clear(self.tree.root)
self.tree.updateTree()
self.updateNodePositions(self.tree.root)
self.showConnections()
def populateTree(self, nodes, rootNode, currentNode, id=0):
""" Recursive function to populate a tree, from the results of the solver to finally display it in the Decomposition View.
The population is depth first.
Parameters:
nodes - the childnodes
rootNode - root node of the (partial) tree
currentNode - the current node of the result obtained from the constraints solver
"""
if len(currentNode.variables) == 1:
self.createLeafPoint(rootNode, currentNode.variables[0],
self.nodeId)
else:
newNode = CVCluster(self, rootNode, self.nodeId)
newNode.flag = currentNode.flag
newNode.variables = currentNode.variables
needCollapse = False
""" Add children to the rootNode to create the full tree """
if rootNode != None:
#self.setCollapse(newNode)
rootNode.children += [newNode]
""" Create a connection between the nodes if the current node has a rootnode"""
newConnection = CVConnection(self, rootNode, newNode)
self.connections += [newConnection]
""" get the leaf nodes """
if len(nodes) == 0:
for variable in newNode.variables:
self.createLeafPoint(newNode, variable, self.nodeId)
for node in nodes:
self.nodeId += 1
self.populateTree(node.subs, newNode, node, self.nodeId)
""" To return the whole tree, a check will be performed for the rootnode """
if rootNode == None:
return newNode
def initFixStates(self):
""" Initialize the fix states from another view if available """
for fixedId in self.settings.dvData.fixedClusterIds:
self.updateState(fixedId, True, self.tree.root)
def stateChange(self, id, fixed):
""" Change the state of the cluster which might be fixed and report it
to the other decomposition views.
Paramaters:
id - unique id of the cluster
fixed - should the clusters be fixed or not
"""
self.viewportManager.updateDecompositionFixed(id, fixed)
if fixed:
self.settings.dvData.fixedClusterIds += [id]
elif not fixed:
self.settings.dvData.fixedClusterIds = filter(
lambda x: x != id, self.settings.dvData.fixedClusterIds)
def updateState(self, id, fixed, rootNode):
""" Update the fixed cluster, with the visuals.
Parameters:
id - unique id of the cluster
fixed - should the cluster be fixed or not
rootNode - recursive funcion to walk the tree
"""
if rootNode.identifier == id:
if fixed and rootNode.isVisible():
rootNode.fixGraphic.show()
rootNode.clusterActive = True
elif fixed and not rootNode.isVisible():
rootNode.fixGraphic.hide()
rootNode.clusterActive = True
else:
rootNode.fixGraphic.hide()
rootNode.clusterActive = False
self.prototypeManager.removeClusterObjects(
[rootNode.permCluster], True, True)
rootNode.permCluster = None
return True
for node in rootNode.children:
found = self.updateState(id, fixed, node)
if found:
break
return False
def createLeafPoint(self, node, variable, id):
cvPoint = CVPoint(self, node, id)
cvPoint.setWidthAndHeight(20, 20)
cvPoint.prtRef = self.prototypeManager.getObjectByKey(variable)
cvPoint.isCollapsed = False
cvPoint.canCollapse = False
#cvPoint.setInfoOverlay()
node.children += [cvPoint]
newConnection = CVConnection(self, node, cvPoint)
self.connections += [newConnection]
def setCollapse(self, node):
node.isCollapsed = False
if not isinstance(node, CVPoint):
if not node.collapseFromResult():
node.updateCluster()
def determineCollapse(self, node):
self.setCollapse(node)
for child in node.children:
self.determineCollapse(child)
def addInfoOverlay(self):
self.ui.graphicsScene.addItem(self.infoOverlay)
self.infoOverlay.hide()
def drawTree(self, scene, root, childNodes):
""" The different nodes are added to the scene and will automatically be drawn
Parameters:
scene - the scene where the rootnode has to be drawn in
root - the rootnode of the (sub-) tree
childNode - the children of this root node
"""
root.setPos(root.position)
scene.addItem(root)
#print "#nodes: ", len(childNodes), " position: ",root.position.x(), " " , root.position.y()
for node in childNodes:
self.drawTree(scene, node, node.children)
def drawConnections(self, scene):
""" The connections between the nodes are added to the scene and will automatically be drawn
Parameters:
scene - the scene where the connections has to be drawn in
"""
for connection in self.connections:
#connection.setPos()
scene.addItem(connection)
def showConnections(self):
""" Show/hide the connections between the nodes, this depends if the node is collapsed """
for connection in self.connections:
connection.setPos(connection.nodeTo.position)
if connection.nodeFrom.isCollapsed or (
connection.nodeTo.isVisible() == False):
connection.hide()
else:
connection.show()
def updateConnections(self):
for connection in self.connections:
connection.update()
def nrVisibleConnections(self):
number = 0
#for connection in self.connections:
#print "x, y: " , connection.x(), connection.y()
#print "nr of visible connections: " , number
def updateNodePositions(self, node):
""" Map the position of the nodes in the tree on the graphical view
Parameters:
node - a node in the tree for which the position is set
"""
node.setPos(node.position)
for childNode in node.children:
self.updateNodePositions(childNode)
def updateSceneRect(self, rectList=None):
self.ui.graphicsScene.setSceneRect(
self.ui.graphicsScene.itemsBoundingRect())
def updateTreeOrientation(self):
self.tree.orientation = self.settings.dvData.treeAlignment
def zoomIn(self):
""" Zoom in the graphics view, by updating the vertical slider """
self.ui.verticalSlider.setValue(self.ui.verticalSlider.value() + 1)
def zoomOut(self):
""" Zoom out the graphics view, by updating the vertical slider """
self.ui.verticalSlider.setValue(self.ui.verticalSlider.value() - 1)
def fit(self):
""" Fits the tree exactly in the graphics view """
self.ui.graphicsView.fitInView(0.0, 0.0, self.ui.graphicsScene.width(),
self.ui.graphicsScene.height(),
QtCore.Qt.KeepAspectRatio)
""" Update the slider """
value = (math.log(self.ui.graphicsView.matrix().m11(), 2) * 50) + 250.0
self.ui.verticalSlider.setValue(value)
def collapseAll(self, node):
if node.canCollapse:
node.collapse()
for childNode in node.children:
self.collapseAll(childNode)
def expandAll(self, node):
node.expand()
for childNode in node.children:
self.expandAll(childNode)
def collapse(self):
if self.collapsed:
self.collapsed = False
self.collapseAll(self.tree.root)
else:
self.collapsed = True
self.expandAll(self.tree.root)
self.updateTree()
self.update()
def setupMatrix(self, value):
""" Zoom in/out the graphics view, depending on the value of the slider
Parameters
value - value of the updated slider
"""
scale = math.pow(2.0, (self.ui.verticalSlider.value() - 250.0) / 50.0)
matrix = QtGui.QMatrix()
matrix.scale(scale, scale)
self.ui.graphicsView.setMatrix(matrix)
