#!/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
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
## 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 (pyqtSignal, QLineF, QPointF, QRect, QRectF, QSize,
        QSizeF, Qt)
from PyQt5.QtGui import (QBrush, QColor, QFont, QIcon, QIntValidator, QPainter,
        QPainterPath, QPen, QPixmap, QPolygonF)
from PyQt5.QtWidgets import (QAction, QApplication, QButtonGroup, QComboBox,
        QFontComboBox, QGraphicsItem, QGraphicsLineItem, QGraphicsPolygonItem,
        QGraphicsScene, QGraphicsTextItem, QGraphicsView, QGridLayout,
        QHBoxLayout, QLabel, QMainWindow, QMenu, QMessageBox, QSizePolicy,
        QToolBox, QToolButton, QWidget)
 
import diagramscene_rc
 
 
class Arrow(QGraphicsLineItem):
    def __init__(self, startItem, endItem, parent=None, scene=None):
        super(Arrow, self).__init__(parent, scene)
 
        self.arrowHead = QPolygonF()
 
        self.myStartItem = startItem
        self.myEndItem = endItem
        self.setFlag(QGraphicsItem.ItemIsSelectable, True)
        self.myColor = Qt.black
        self.setPen(QPen(self.myColor, 2, Qt.SolidLine, Qt.RoundCap,
                Qt.RoundJoin))
 
    def setColor(self, color):
        self.myColor = color
 
    def startItem(self):
        return self.myStartItem
 
    def endItem(self):
        return self.myEndItem
 
    def boundingRect(self):
        extra = (self.pen().width() + 20) / 2.0
        p1 = self.line().p1()
        p2 = self.line().p2()
        return QRectF(p1, QSizeF(p2.x() - p1.x(), p2.y() - p1.y())).normalized().adjusted(-extra, -extra, extra, extra)
 
    def shape(self):
        path = super(Arrow, self).shape()
        path.addPolygon(self.arrowHead)
        return path
 
    def updatePosition(self):
        line = QLineF(self.mapFromItem(self.myStartItem, 0, 0), self.mapFromItem(self.myEndItem, 0, 0))
        self.setLine(line)
 
    def paint(self, painter, option, widget=None):
        if (self.myStartItem.collidesWithItem(self.myEndItem)):
            return
 
        myStartItem = self.myStartItem
        myEndItem = self.myEndItem
        myColor = self.myColor
        myPen = self.pen()
        myPen.setColor(self.myColor)
        arrowSize = 20.0
        painter.setPen(myPen)
        painter.setBrush(self.myColor)
 
        centerLine = QLineF(myStartItem.pos(), myEndItem.pos())
        endPolygon = myEndItem.polygon()
        p1 = endPolygon.first() + myEndItem.pos()
 
        intersectPoint = QPointF()
        for i in endPolygon:
            p2 = i + myEndItem.pos()
            polyLine = QLineF(p1, p2)
            intersectType = polyLine.intersect(centerLine, intersectPoint)
            if intersectType == QLineF.BoundedIntersection:
                break
            p1 = p2
 
        self.setLine(QLineF(intersectPoint, myStartItem.pos()))
        line = self.line()
 
        angle = math.acos(line.dx() / line.length())
        if line.dy() >= 0:
            angle = (math.pi * 2.0) - angle
 
        arrowP1 = line.p1() + QPointF(math.sin(angle + math.pi / 3.0) * arrowSize,
                                        math.cos(angle + math.pi / 3) * arrowSize)
        arrowP2 = line.p1() + QPointF(math.sin(angle + math.pi - math.pi / 3.0) * arrowSize,
                                        math.cos(angle + math.pi - math.pi / 3.0) * arrowSize)
 
        self.arrowHead.clear()
        for point in [line.p1(), arrowP1, arrowP2]:
            self.arrowHead.append(point)
 
        painter.drawLine(line)
        painter.drawPolygon(self.arrowHead)
        if self.isSelected():
            painter.setPen(QPen(myColor, 1, Qt.DashLine))
            myLine = QLineF(line)
            myLine.translate(0, 4.0)
            painter.drawLine(myLine)
            myLine.translate(0,-8.0)
            painter.drawLine(myLine)
 
 
class DiagramTextItem(QGraphicsTextItem):
    lostFocus = pyqtSignal(QGraphicsTextItem)
 
    selectedChange = pyqtSignal(QGraphicsItem)
 
    def __init__(self, parent=None, scene=None):
        super(DiagramTextItem, self).__init__(parent, scene)
 
        self.setFlag(QGraphicsItem.ItemIsMovable)
        self.setFlag(QGraphicsItem.ItemIsSelectable)
 
    def itemChange(self, change, value):
        if change == QGraphicsItem.ItemSelectedChange:
            self.selectedChange.emit(self)
        return value
 
    def focusOutEvent(self, event):
        self.setTextInteractionFlags(Qt.NoTextInteraction)
        self.lostFocus.emit(self)
        super(DiagramTextItem, self).focusOutEvent(event)
 
    def mouseDoubleClickEvent(self, event):
        if self.textInteractionFlags() == Qt.NoTextInteraction:
            self.setTextInteractionFlags(Qt.TextEditorInteraction)
        super(DiagramTextItem, self).mouseDoubleClickEvent(event)
 
 
class DiagramItem(QGraphicsPolygonItem):
    Step, Conditional, StartEnd, Io = range(4)
 
    def __init__(self, diagramType, contextMenu, parent=None):
        super(DiagramItem, self).__init__(parent)
 
        self.arrows = []
 
        self.diagramType = diagramType
        self.contextMenu = contextMenu
 
        path = QPainterPath()
        if self.diagramType == self.StartEnd:
            path.moveTo(200, 50)
            path.arcTo(150, 0, 50, 50, 0, 90)
            path.arcTo(50, 0, 50, 50, 90, 90)
            path.arcTo(50, 50, 50, 50, 180, 90)
            path.arcTo(150, 50, 50, 50, 270, 90)
            path.lineTo(200, 25)
            self.myPolygon = path.toFillPolygon()
        elif self.diagramType == self.Conditional:
            self.myPolygon = QPolygonF([
                    QPointF(-100, 0), QPointF(0, 100),
                    QPointF(100, 0), QPointF(0, -100),
                    QPointF(-100, 0)])
        elif self.diagramType == self.Step:
            self.myPolygon = QPolygonF([
                    QPointF(-100, -100), QPointF(100, -100),
                    QPointF(100, 100), QPointF(-100, 100),
                    QPointF(-100, -100)])
        else:
            self.myPolygon = QPolygonF([
                    QPointF(-120, -80), QPointF(-70, 80),
                    QPointF(120, 80), QPointF(70, -80),
                    QPointF(-120, -80)])
 
        self.setPolygon(self.myPolygon)
        self.setFlag(QGraphicsItem.ItemIsMovable, True)
        self.setFlag(QGraphicsItem.ItemIsSelectable, True)
 
    def removeArrow(self, arrow):
        try:
            self.arrows.remove(arrow)
        except ValueError:
            pass
 
    def removeArrows(self):
        for arrow in self.arrows[:]:
            arrow.startItem().removeArrow(arrow)
            arrow.endItem().removeArrow(arrow)
            self.scene().removeItem(arrow)
 
    def addArrow(self, arrow):
        self.arrows.append(arrow)
 
    def image(self):
        pixmap = QPixmap(250, 250)
        pixmap.fill(Qt.transparent)
        painter = QPainter(pixmap)
        painter.setPen(QPen(Qt.black, 8))
        painter.translate(125, 125)
        painter.drawPolyline(self.myPolygon)
        return pixmap
 
    def contextMenuEvent(self, event):
        self.scene().clearSelection()
        self.setSelected(True)
        self.myContextMenu.exec_(event.screenPos())
 
    def itemChange(self, change, value):
        if change == QGraphicsItem.ItemPositionChange:
            for arrow in self.arrows:
                arrow.updatePosition()
 
        return value
 
 
class DiagramScene(QGraphicsScene):
    InsertItem, InsertLine, InsertText, MoveItem  = range(4)
 
    itemInserted = pyqtSignal(DiagramItem)
 
    textInserted = pyqtSignal(QGraphicsTextItem)
 
    itemSelected = pyqtSignal(QGraphicsItem)
 
    def __init__(self, itemMenu, parent=None):
        super(DiagramScene, self).__init__(parent)
 
        self.myItemMenu = itemMenu
        self.myMode = self.MoveItem
        self.myItemType = DiagramItem.Step
        self.line = None
        self.textItem = None
        self.myItemColor = Qt.white
        self.myTextColor = Qt.black
        self.myLineColor = Qt.black
        self.myFont = QFont()
 
    def setLineColor(self, color):
        self.myLineColor = color
        if self.isItemChange(Arrow):
            item = self.selectedItems()[0]
            item.setColor(self.myLineColor)
            self.update()
 
    def setTextColor(self, color):
        self.myTextColor = color
        if self.isItemChange(DiagramTextItem):
            item = self.selectedItems()[0]
            item.setDefaultTextColor(self.myTextColor)
 
    def setItemColor(self, color):
        self.myItemColor = color
        if self.isItemChange(DiagramItem):
            item = self.selectedItems()[0]
            item.setBrush(self.myItemColor)
 
    def setFont(self, font):
        self.myFont = font
        if self.isItemChange(DiagramTextItem):
            item = self.selectedItems()[0]
            item.setFont(self.myFont)
 
    def setMode(self, mode):
        self.myMode = mode
 
    def setItemType(self, type):
        self.myItemType = type
 
    def editorLostFocus(self, item):
        cursor = item.textCursor()
        cursor.clearSelection()
        item.setTextCursor(cursor)
 
        if item.toPlainText():
            self.removeItem(item)
            item.deleteLater()
 
    def mousePressEvent(self, mouseEvent):
        if (mouseEvent.button() != Qt.LeftButton):
            return
 
        if self.myMode == self.InsertItem:
            item = DiagramItem(self.myItemType, self.myItemMenu)
            item.setBrush(self.myItemColor)
            self.addItem(item)
            item.setPos(mouseEvent.scenePos())
            self.itemInserted.emit(item)
        elif self.myMode == self.InsertLine:
            self.line = QGraphicsLineItem(QLineF(mouseEvent.scenePos(),
                    mouseEvent.scenePos()))
            self.line.setPen(QPen(self.myLineColor, 2))
            self.addItem(self.line)
        elif self.myMode == self.InsertText:
            textItem = DiagramTextItem()
            textItem.setFont(self.myFont)
            textItem.setTextInteractionFlags(Qt.TextEditorInteraction)
            textItem.setZValue(1000.0)
            textItem.lostFocus.connect(self.editorLostFocus)
            textItem.selectedChange.connect(self.itemSelected)
            self.addItem(textItem)
            textItem.setDefaultTextColor(self.myTextColor)
            textItem.setPos(mouseEvent.scenePos())
            self.textInserted.emit(textItem)
 
        super(DiagramScene, self).mousePressEvent(mouseEvent)
 
    def mouseMoveEvent(self, mouseEvent):
        if self.myMode == self.InsertLine and self.line:
            newLine = QLineF(self.line.line().p1(), mouseEvent.scenePos())
            self.line.setLine(newLine)
        elif self.myMode == self.MoveItem:
            super(DiagramScene, self).mouseMoveEvent(mouseEvent)
 
    def mouseReleaseEvent(self, mouseEvent):
        if self.line and self.myMode == self.InsertLine:
            startItems = self.items(self.line.line().p1())
            if len(startItems) and startItems[0] == self.line:
                startItems.pop(0)
            endItems = self.items(self.line.line().p2())
            if len(endItems) and endItems[0] == self.line:
                endItems.pop(0)
 
            self.removeItem(self.line)
            self.line = None
 
            if len(startItems) and len(endItems) and \
                    isinstance(startItems[0], DiagramItem) and \
                    isinstance(endItems[0], DiagramItem) and \
                    startItems[0] != endItems[0]:
                startItem = startItems[0]
                endItem = endItems[0]
                arrow = Arrow(startItem, endItem)
                arrow.setColor(self.myLineColor)
                startItem.addArrow(arrow)
                endItem.addArrow(arrow)
                arrow.setZValue(-1000.0)
                self.addItem(arrow)
                arrow.updatePosition()
 
        self.line = None
        super(DiagramScene, self).mouseReleaseEvent(mouseEvent)
 
    def isItemChange(self, type):
        for item in self.selectedItems():
            if isinstance(item, type):
                return True
        return False
 
 
class MainWindow(QMainWindow):
    InsertTextButton = 10
 
    def __init__(self):
        super(MainWindow, self).__init__()
 
        self.createActions()
        self.createMenus()
        self.createToolBox()
 
        self.scene = DiagramScene(self.itemMenu)
        self.scene.setSceneRect(QRectF(0, 0, 5000, 5000))
        self.scene.itemInserted.connect(self.itemInserted)
        self.scene.textInserted.connect(self.textInserted)
        self.scene.itemSelected.connect(self.itemSelected)
 
        self.createToolbars()
 
        layout = QHBoxLayout()
        layout.addWidget(self.toolBox)
        self.view = QGraphicsView(self.scene)
        layout.addWidget(self.view)
 
        self.widget = QWidget()
        self.widget.setLayout(layout)
 
        self.setCentralWidget(self.widget)
        self.setWindowTitle("Diagramscene")
 
    def backgroundButtonGroupClicked(self, button):
        buttons = self.backgroundButtonGroup.buttons()
        for myButton in buttons:
            if myButton != button:
                button.setChecked(False)
 
        text = button.text()
        if text == "Blue Grid":
            self.scene.setBackgroundBrush(QBrush(QPixmap(':/images/background1.png')))
        elif text == "White Grid":
            self.scene.setBackgroundBrush(QBrush(QPixmap(':/images/background2.png')))
        elif text == "Gray Grid":
            self.scene.setBackgroundBrush(QBrush(QPixmap(':/images/background3.png')))
        else:
            self.scene.setBackgroundBrush(QBrush(QPixmap(':/images/background4.png')))
 
        self.scene.update()
        self.view.update()
 
    def buttonGroupClicked(self, id):
        buttons = self.buttonGroup.buttons()
        for button in buttons:
            if self.buttonGroup.button(id) != button:
                button.setChecked(False)
 
        if id == self.InsertTextButton:
            self.scene.setMode(DiagramScene.InsertText)
        else:
            self.scene.setItemType(id)
            self.scene.setMode(DiagramScene.InsertItem)
 
    def deleteItem(self):
        for item in self.scene.selectedItems():
            if isinstance(item, DiagramItem):
                item.removeArrows()
            self.scene.removeItem(item)
 
    def pointerGroupClicked(self, i):
        self.scene.setMode(self.pointerTypeGroup.checkedId())
 
    def bringToFront(self):
        if not self.scene.selectedItems():
            return
 
        selectedItem = self.scene.selectedItems()[0]
        overlapItems = selectedItem.collidingItems()
 
        zValue = 0
        for item in overlapItems:
            if (item.zValue() >= zValue and isinstance(item, DiagramItem)):
                zValue = item.zValue() + 0.1
        selectedItem.setZValue(zValue)
 
    def sendToBack(self):
        if not self.scene.selectedItems():
            return
 
        selectedItem = self.scene.selectedItems()[0]
        overlapItems = selectedItem.collidingItems()
 
        zValue = 0
        for item in overlapItems:
            if (item.zValue() <= zValue and isinstance(item, DiagramItem)):
                zValue = item.zValue() - 0.1
        selectedItem.setZValue(zValue)
 
    def itemInserted(self, item):
        self.pointerTypeGroup.button(DiagramScene.MoveItem).setChecked(True)
        self.scene.setMode(self.pointerTypeGroup.checkedId())
        self.buttonGroup.button(item.diagramType).setChecked(False)
 
    def textInserted(self, item):
        self.buttonGroup.button(self.InsertTextButton).setChecked(False)
        self.scene.setMode(self.pointerTypeGroup.checkedId())
 
    def currentFontChanged(self, font):
        self.handleFontChange()
 
    def fontSizeChanged(self, font):
        self.handleFontChange()
 
    def sceneScaleChanged(self, scale):
        newScale = scale.left(scale.indexOf("%")).toDouble()[0] / 100.0
        oldMatrix = self.view.matrix()
        self.view.resetMatrix()
        self.view.translate(oldMatrix.dx(), oldMatrix.dy())
        self.view.scale(newScale, newScale)
 
    def textColorChanged(self):
        self.textAction = self.sender()
        self.fontColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/textpointer.png',
                        QColor(self.textAction.data())))
        self.textButtonTriggered()
 
    def itemColorChanged(self):
        self.fillAction = self.sender()
        self.fillColorToolButton.setIcon(
                self.createColorToolButtonIcon( ':/images/floodfill.png',
                        QColor(self.fillAction.data())))
        self.fillButtonTriggered()
 
    def lineColorChanged(self):
        self.lineAction = self.sender()
        self.lineColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/linecolor.png',
                        QColor(self.lineAction.data())))
        self.lineButtonTriggered()
 
    def textButtonTriggered(self):
        self.scene.setTextColor(QColor(self.textAction.data()))
 
    def fillButtonTriggered(self):
        self.scene.setItemColor(QColor(self.fillAction.data()))
 
    def lineButtonTriggered(self):
        self.scene.setLineColor(QColor(self.lineAction.data()))
 
    def handleFontChange(self):
        font = self.fontCombo.currentFont()
        font.setPointSize(self.fontSizeCombo.currentText().toInt()[0])
        if self.boldAction.isChecked():
            font.setWeight(QFont.Bold)
        else:
            font.setWeight(QFont.Normal)
        font.setItalic(self.italicAction.isChecked())
        font.setUnderline(self.underlineAction.isChecked())
 
        self.scene.setFont(font)
 
    def itemSelected(self, item):
        font = item.font()
        color = item.defaultTextColor()
        self.fontCombo.setCurrentFont(font)
        self.fontSizeCombo.setEditText(str(font.pointSize()))
        self.boldAction.setChecked(font.weight() == QFont.Bold)
        self.italicAction.setChecked(font.italic())
        self.underlineAction.setChecked(font.underline())
 
    def about(self):
        QMessageBox.about(self, "About Diagram Scene",
                "The <b>Diagram Scene</b> example shows use of the graphics framework.")
 
    def createToolBox(self):
        self.buttonGroup = QButtonGroup()
        self.buttonGroup.setExclusive(False)
        self.buttonGroup.buttonClicked[int].connect(self.buttonGroupClicked)
 
        layout = QGridLayout()
        layout.addWidget(self.createCellWidget("Conditional", DiagramItem.Conditional),
                0, 0)
        layout.addWidget(self.createCellWidget("Process", DiagramItem.Step), 0,
                1)
        layout.addWidget(self.createCellWidget("Input/Output", DiagramItem.Io),
                1, 0)
 
        textButton = QToolButton()
        textButton.setCheckable(True)
        self.buttonGroup.addButton(textButton, self.InsertTextButton)
        textButton.setIcon(QIcon(QPixmap(':/images/textpointer.png').scaled(30, 30)))
        textButton.setIconSize(QSize(50, 50))
 
        textLayout = QGridLayout()
        textLayout.addWidget(textButton, 0, 0, Qt.AlignHCenter)
        textLayout.addWidget(QLabel("Text"), 1, 0, Qt.AlignCenter)
        textWidget = QWidget()
        textWidget.setLayout(textLayout)
        layout.addWidget(textWidget, 1, 1)
 
        layout.setRowStretch(3, 10)
        layout.setColumnStretch(2, 10)
 
        itemWidget = QWidget()
        itemWidget.setLayout(layout)
 
        self.backgroundButtonGroup = QButtonGroup()
        self.backgroundButtonGroup.buttonClicked.connect(self.backgroundButtonGroupClicked)
 
        backgroundLayout = QGridLayout()
        backgroundLayout.addWidget(self.createBackgroundCellWidget("Blue Grid",
                ':/images/background1.png'), 0, 0)
        backgroundLayout.addWidget(self.createBackgroundCellWidget("White Grid",
                ':/images/background2.png'), 0, 1)
        backgroundLayout.addWidget(self.createBackgroundCellWidget("Gray Grid",
                ':/images/background3.png'), 1, 0)
        backgroundLayout.addWidget(self.createBackgroundCellWidget("No Grid",
                ':/images/background4.png'), 1, 1)
 
        backgroundLayout.setRowStretch(2, 10)
        backgroundLayout.setColumnStretch(2, 10)
 
        backgroundWidget = QWidget()
        backgroundWidget.setLayout(backgroundLayout)
 
        self.toolBox = QToolBox()
        self.toolBox.setSizePolicy(QSizePolicy(QSizePolicy.Maximum, QSizePolicy.Ignored))
        self.toolBox.setMinimumWidth(itemWidget.sizeHint().width())
        self.toolBox.addItem(itemWidget, "Basic Flowchart Shapes")
        self.toolBox.addItem(backgroundWidget, "Backgrounds")
 
    def createActions(self):
        self.toFrontAction = QAction(
                QIcon(':/images/bringtofront.png'), "Bring to &Front",
                self, shortcut="Ctrl+F", statusTip="Bring item to front",
                triggered=self.bringToFront)
 
        self.sendBackAction = QAction(
                QIcon(':/images/sendtoback.png'), "Send to &Back", self,
                shortcut="Ctrl+B", statusTip="Send item to back",
                triggered=self.sendToBack)
 
        self.deleteAction = QAction(QIcon(':/images/delete.png'),
                "&Delete", self, shortcut="Delete",
                statusTip="Delete item from diagram",
                triggered=self.deleteItem)
 
        self.exitAction = QAction("E&xit", self, shortcut="Ctrl+X",
                statusTip="Quit Scenediagram example", triggered=self.close)
 
        self.boldAction = QAction(QIcon(':/images/bold.png'),
                "Bold", self, checkable=True, shortcut="Ctrl+B",
                triggered=self.handleFontChange)
 
        self.italicAction = QAction(QIcon(':/images/italic.png'),
                "Italic", self, checkable=True, shortcut="Ctrl+I",
                triggered=self.handleFontChange)
 
        self.underlineAction = QAction(
                QIcon(':/images/underline.png'), "Underline", self,
                checkable=True, shortcut="Ctrl+U",
                triggered=self.handleFontChange)
 
        self.aboutAction = QAction("A&bout", self, shortcut="Ctrl+B",
                triggered=self.about)
 
    def createMenus(self):
        self.fileMenu = self.menuBar().addMenu("&File")
        self.fileMenu.addAction(self.exitAction)
 
        self.itemMenu = self.menuBar().addMenu("&Item")
        self.itemMenu.addAction(self.deleteAction)
        self.itemMenu.addSeparator()
        self.itemMenu.addAction(self.toFrontAction)
        self.itemMenu.addAction(self.sendBackAction)
 
        self.aboutMenu = self.menuBar().addMenu("&Help")
        self.aboutMenu.addAction(self.aboutAction)
 
    def createToolbars(self):
        self.editToolBar = self.addToolBar("Edit")
        self.editToolBar.addAction(self.deleteAction)
        self.editToolBar.addAction(self.toFrontAction)
        self.editToolBar.addAction(self.sendBackAction)
 
        self.fontCombo = QFontComboBox()
        self.fontCombo.currentFontChanged.connect(self.currentFontChanged)
 
        self.fontSizeCombo = QComboBox()
        self.fontSizeCombo.setEditable(True)
        for i in range(8, 30, 2):
            self.fontSizeCombo.addItem(str(i))
        validator = QIntValidator(2, 64, self)
        self.fontSizeCombo.setValidator(validator)
        self.fontSizeCombo.currentIndexChanged.connect(self.fontSizeChanged)
 
        self.fontColorToolButton = QToolButton()
        self.fontColorToolButton.setPopupMode(QToolButton.MenuButtonPopup)
        self.fontColorToolButton.setMenu(
                self.createColorMenu(self.textColorChanged, Qt.black))
        self.textAction = self.fontColorToolButton.menu().defaultAction()
        self.fontColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/textpointer.png',
                        Qt.black))
        self.fontColorToolButton.setAutoFillBackground(True)
        self.fontColorToolButton.clicked.connect(self.textButtonTriggered)
 
        self.fillColorToolButton = QToolButton()
        self.fillColorToolButton.setPopupMode(QToolButton.MenuButtonPopup)
        self.fillColorToolButton.setMenu(
                self.createColorMenu(self.itemColorChanged, Qt.white))
        self.fillAction = self.fillColorToolButton.menu().defaultAction()
        self.fillColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/floodfill.png',
                        Qt.white))
        self.fillColorToolButton.clicked.connect(self.fillButtonTriggered)
 
        self.lineColorToolButton = QToolButton()
        self.lineColorToolButton.setPopupMode(QToolButton.MenuButtonPopup)
        self.lineColorToolButton.setMenu(
                self.createColorMenu(self.lineColorChanged, Qt.black))
        self.lineAction = self.lineColorToolButton.menu().defaultAction()
        self.lineColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/linecolor.png',
                        Qt.black))
        self.lineColorToolButton.clicked.connect(self.lineButtonTriggered)
 
        self.textToolBar = self.addToolBar("Font")
        self.textToolBar.addWidget(self.fontCombo)
        self.textToolBar.addWidget(self.fontSizeCombo)
        self.textToolBar.addAction(self.boldAction)
        self.textToolBar.addAction(self.italicAction)
        self.textToolBar.addAction(self.underlineAction)
 
        self.colorToolBar = self.addToolBar("Color")
        self.colorToolBar.addWidget(self.fontColorToolButton)
        self.colorToolBar.addWidget(self.fillColorToolButton)
        self.colorToolBar.addWidget(self.lineColorToolButton)
 
        pointerButton = QToolButton()
        pointerButton.setCheckable(True)
        pointerButton.setChecked(True)
        pointerButton.setIcon(QIcon(':/images/pointer.png'))
        linePointerButton = QToolButton()
        linePointerButton.setCheckable(True)
        linePointerButton.setIcon(QIcon(':/images/linepointer.png'))
 
        self.pointerTypeGroup = QButtonGroup()
        self.pointerTypeGroup.addButton(pointerButton, DiagramScene.MoveItem)
        self.pointerTypeGroup.addButton(linePointerButton,
                DiagramScene.InsertLine)
        self.pointerTypeGroup.buttonClicked[int].connect(self.pointerGroupClicked)
 
        self.sceneScaleCombo = QComboBox()
        self.sceneScaleCombo.addItems(["50%", "75%", "100%", "125%", "150%"])
        self.sceneScaleCombo.setCurrentIndex(2)
        self.sceneScaleCombo.currentIndexChanged[str].connect(self.sceneScaleChanged)
 
        self.pointerToolbar = self.addToolBar("Pointer type")
        self.pointerToolbar.addWidget(pointerButton)
        self.pointerToolbar.addWidget(linePointerButton)
        self.pointerToolbar.addWidget(self.sceneScaleCombo)
 
    def createBackgroundCellWidget(self, text, image):
        button = QToolButton()
        button.setText(text)
        button.setIcon(QIcon(image))
        button.setIconSize(QSize(50, 50))
        button.setCheckable(True)
        self.backgroundButtonGroup.addButton(button)
 
        layout = QGridLayout()
        layout.addWidget(button, 0, 0, Qt.AlignHCenter)
        layout.addWidget(QLabel(text), 1, 0, Qt.AlignCenter)
 
        widget = QWidget()
        widget.setLayout(layout)
 
        return widget
 
    def createCellWidget(self, text, diagramType):
        item = DiagramItem(diagramType, self.itemMenu)
        icon = QIcon(item.image())
 
        button = QToolButton()
        button.setIcon(icon)
        button.setIconSize(QSize(50, 50))
        button.setCheckable(True)
        self.buttonGroup.addButton(button, diagramType)
 
        layout = QGridLayout()
        layout.addWidget(button, 0, 0, Qt.AlignHCenter)
        layout.addWidget(QLabel(text), 1, 0, Qt.AlignCenter)
 
        widget = QWidget()
        widget.setLayout(layout)
 
        return widget
 
    def createColorMenu(self, slot, defaultColor):
        colors = [Qt.black, Qt.white, Qt.red, Qt.blue, Qt.yellow]
        names = ["black", "white", "red", "blue", "yellow"]
 
        colorMenu = QMenu(self)
        for color, name in zip(colors, names):
            action = QAction(self.createColorIcon(color), name, self,
                    triggered=slot)
            action.setData(QColor(color)) 
            colorMenu.addAction(action)
            if color == defaultColor:
                colorMenu.setDefaultAction(action)
        return colorMenu
 
    def createColorToolButtonIcon(self, imageFile, color):
        pixmap = QPixmap(50, 80)
        pixmap.fill(Qt.transparent)
        painter = QPainter(pixmap)
        image = QPixmap(imageFile)
        target = QRect(0, 0, 50, 60)
        source = QRect(0, 0, 42, 42)
        painter.fillRect(QRect(0, 60, 50, 80), color)
        painter.drawPixmap(target, image, source)
        painter.end()
 
        return QIcon(pixmap)
 
    def createColorIcon(self, color):
        pixmap = QPixmap(20, 20)
        painter = QPainter(pixmap)
        painter.setPen(Qt.NoPen)
        painter.fillRect(QRect(0, 0, 20, 20), color)
        painter.end()
 
        return QIcon(pixmap)
 
 
if __name__ == '__main__':
 
    import sys
 
    app = QApplication(sys.argv)
 
    mainWindow = MainWindow()
    mainWindow.setGeometry(100, 100, 800, 500)
    mainWindow.show()
 
    sys.exit(app.exec_())