#!/usr/bin/env python


#############################################################################
##
## Copyright (C) 2010 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."
## $QT_END_LICENSE$
##
#############################################################################


# This is only needed for Python v2 but is harmless for Python v3.
import sip
sip.setapi('QString', 2)

import math

from PyQt4 import QtCore, QtGui

import diagramscene_rc


class Arrow(QtGui.QGraphicsLineItem):
    def __init__(self, startItem, endItem, parent=None, scene=None):
        super(Arrow, self).__init__(parent, scene)

        self.arrowHead = QtGui.QPolygonF()

        self.myStartItem = startItem
        self.myEndItem = endItem
        self.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True)
        self.myColor = QtCore.Qt.black
        self.setPen(QtGui.QPen(self.myColor, 2, QtCore.Qt.SolidLine,
                QtCore.Qt.RoundCap, QtCore.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 QtCore.QRectF(p1, QtCore.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 = QtCore.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 = QtCore.QLineF(myStartItem.pos(), myEndItem.pos())
        endPolygon = myEndItem.polygon()
        p1 = endPolygon.first() + myEndItem.pos()

        intersectPoint = QtCore.QPointF()
        for i in endPolygon:
            p2 = i + myEndItem.pos()
            polyLine = QtCore.QLineF(p1, p2)
            intersectType = polyLine.intersect(centerLine, intersectPoint)
            if intersectType == QtCore.QLineF.BoundedIntersection:
                break
            p1 = p2

        self.setLine(QtCore.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() + QtCore.QPointF(math.sin(angle + math.pi / 3.0) * arrowSize,
                                        math.cos(angle + math.pi / 3) * arrowSize)
        arrowP2 = line.p1() + QtCore.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(QtGui.QPen(myColor, 1, QtCore.Qt.DashLine))
            myLine = QtCore.QLineF(line)
            myLine.translate(0, 4.0)
            painter.drawLine(myLine)
            myLine.translate(0,-8.0)
            painter.drawLine(myLine)


class DiagramTextItem(QtGui.QGraphicsTextItem):
    lostFocus = QtCore.pyqtSignal(QtGui.QGraphicsTextItem)

    selectedChange = QtCore.pyqtSignal(QtGui.QGraphicsItem)

    def __init__(self, parent=None, scene=None):
        super(DiagramTextItem, self).__init__(parent, scene)

        self.setFlag(QtGui.QGraphicsItem.ItemIsMovable)
        self.setFlag(QtGui.QGraphicsItem.ItemIsSelectable)

    def itemChange(self, change, value):
        if change == QtGui.QGraphicsItem.ItemSelectedChange:
            self.selectedChange.emit(self)
        return value

    def focusOutEvent(self, event):
        self.setTextInteractionFlags(QtCore.Qt.NoTextInteraction)
        self.lostFocus.emit(self)
        super(DiagramTextItem, self).focusOutEvent(event)

    def mouseDoubleClickEvent(self, event):
        if self.textInteractionFlags() == QtCore.Qt.NoTextInteraction:
            self.setTextInteractionFlags(QtCore.Qt.TextEditorInteraction)
        super(DiagramTextItem, self).mouseDoubleClickEvent(event)


class DiagramItem(QtGui.QGraphicsPolygonItem):
    Step, Conditional, StartEnd, Io = range(4)

    def __init__(self, diagramType, contextMenu, parent=None, scene=None):
        super(DiagramItem, self).__init__(parent, scene)

        self.arrows = []

        self.diagramType = diagramType
        self.contextMenu = contextMenu

        path = QtGui.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 = QtGui.QPolygonF([
                    QtCore.QPointF(-100, 0), QtCore.QPointF(0, 100),
                    QtCore.QPointF(100, 0), QtCore.QPointF(0, -100),
                    QtCore.QPointF(-100, 0)])
        elif self.diagramType == self.Step:
            self.myPolygon = QtGui.QPolygonF([
                    QtCore.QPointF(-100, -100), QtCore.QPointF(100, -100),
                    QtCore.QPointF(100, 100), QtCore.QPointF(-100, 100),
                    QtCore.QPointF(-100, -100)])
        else:
            self.myPolygon = QtGui.QPolygonF([
                    QtCore.QPointF(-120, -80), QtCore.QPointF(-70, 80),
                    QtCore.QPointF(120, 80), QtCore.QPointF(70, -80),
                    QtCore.QPointF(-120, -80)])

        self.setPolygon(self.myPolygon)
        self.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True)
        self.setFlag(QtGui.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 = QtGui.QPixmap(250, 250)
        pixmap.fill(QtCore.Qt.transparent)
        painter = QtGui.QPainter(pixmap)
        painter.setPen(QtGui.QPen(QtCore.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 == QtGui.QGraphicsItem.ItemPositionChange:
            for arrow in self.arrows:
                arrow.updatePosition()

        return value


class DiagramScene(QtGui.QGraphicsScene):
    InsertItem, InsertLine, InsertText, MoveItem  = range(4)

    itemInserted = QtCore.pyqtSignal(DiagramItem)

    textInserted = QtCore.pyqtSignal(QtGui.QGraphicsTextItem)

    itemSelected = QtCore.pyqtSignal(QtGui.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 = QtCore.Qt.white
        self.myTextColor = QtCore.Qt.black
        self.myLineColor = QtCore.Qt.black
        self.myFont = QtGui.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() != QtCore.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 = QtGui.QGraphicsLineItem(QtCore.QLineF(mouseEvent.scenePos(),
                                        mouseEvent.scenePos()))
            self.line.setPen(QtGui.QPen(self.myLineColor, 2))
            self.addItem(self.line)
        elif self.myMode == self.InsertText:
            textItem = DiagramTextItem()
            textItem.setFont(self.myFont)
            textItem.setTextInteractionFlags(QtCore.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 = QtCore.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(QtGui.QMainWindow):
    InsertTextButton = 10

    def __init__(self):
        super(MainWindow, self).__init__()

        self.createActions()
        self.createMenus()
        self.createToolBox()

        self.scene = DiagramScene(self.itemMenu)
        self.scene.setSceneRect(QtCore.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 = QtGui.QHBoxLayout()
        layout.addWidget(self.toolBox)
        self.view = QtGui.QGraphicsView(self.scene)
        layout.addWidget(self.view)

        self.widget = QtGui.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(QtGui.QBrush(QtGui.QPixmap(':/images/background1.png')))
        elif text == "White Grid":
            self.scene.setBackgroundBrush(QtGui.QBrush(QtGui.QPixmap(':/images/background2.png')))
        elif text == "Gray Grid":
            self.scene.setBackgroundBrush(QtGui.QBrush(QtGui.QPixmap(':/images/background3.png')))
        else:
            self.scene.setBackgroundBrush(QtGui.QBrush(QtGui.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 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 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',
                    QtGui.QColor(self.textAction.data())))
        self.textButtonTriggered()

    def itemColorChanged(self):
        self.fillAction = self.sender()
        self.fillColorToolButton.setIcon(self.createColorToolButtonIcon(
                    ':/images/floodfill.png',
                    QtGui.QColor(self.fillAction.data())))
        self.fillButtonTriggered()

    def lineColorChanged(self):
        self.lineAction = self.sender()
        self.lineColorToolButton.setIcon(self.createColorToolButtonIcon(
                    ':/images/linecolor.png',
                    QtGui.QColor(self.lineAction.data())))
        self.lineButtonTriggered()

    def textButtonTriggered(self):
        self.scene.setTextColor(QtGui.QColor(self.textAction.data()))

    def fillButtonTriggered(self):
        self.scene.setItemColor(QtGui.QColor(self.fillAction.data()))

    def lineButtonTriggered(self):
        self.scene.setLineColor(QtGui.QColor(self.lineAction.data()))

    def handleFontChange(self):
        font = self.fontCombo.currentFont()
        font.setPointSize(self.fontSizeCombo.currentText().toInt()[0])
        if self.boldAction.isChecked():
            font.setWeight(QtGui.QFont.Bold)
        else:
            font.setWeight(QtGui.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() == QtGui.QFont.Bold)
        self.italicAction.setChecked(font.italic())
        self.underlineAction.setChecked(font.underline())

    def about(self):
        QtGui.QMessageBox.about(self, "About Diagram Scene",
                "The <b>Diagram Scene</b> example shows use of the graphics framework.")

    def createToolBox(self):
        self.buttonGroup = QtGui.QButtonGroup()
        self.buttonGroup.setExclusive(False)
        self.buttonGroup.buttonClicked[int].connect(self.buttonGroupClicked)

        layout = QtGui.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 = QtGui.QToolButton()
        textButton.setCheckable(True)
        self.buttonGroup.addButton(textButton, self.InsertTextButton)
        textButton.setIcon(QtGui.QIcon(QtGui.QPixmap(':/images/textpointer.png')
                            .scaled(30, 30)))
        textButton.setIconSize(QtCore.QSize(50, 50))

        textLayout = QtGui.QGridLayout()
        textLayout.addWidget(textButton, 0, 0, QtCore.Qt.AlignHCenter)
        textLayout.addWidget(QtGui.QLabel("Text"), 1, 0,
                QtCore.Qt.AlignCenter)
        textWidget = QtGui.QWidget()
        textWidget.setLayout(textLayout)
        layout.addWidget(textWidget, 1, 1)

        layout.setRowStretch(3, 10)
        layout.setColumnStretch(2, 10)

        itemWidget = QtGui.QWidget()
        itemWidget.setLayout(layout)

        self.backgroundButtonGroup = QtGui.QButtonGroup()
        self.backgroundButtonGroup.buttonClicked.connect(self.backgroundButtonGroupClicked)

        backgroundLayout = QtGui.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 = QtGui.QWidget()
        backgroundWidget.setLayout(backgroundLayout)

        self.toolBox = QtGui.QToolBox()
        self.toolBox.setSizePolicy(QtGui.QSizePolicy(QtGui.QSizePolicy.Maximum, QtGui.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 = QtGui.QAction(
                QtGui.QIcon(':/images/bringtofront.png'), "Bring to &Front",
                self, shortcut="Ctrl+F", statusTip="Bring item to front",
                triggered=self.bringToFront)

        self.sendBackAction = QtGui.QAction(
                QtGui.QIcon(':/images/sendtoback.png'), "Send to &Back", self,
                shortcut="Ctrl+B", statusTip="Send item to back",
                triggered=self.sendToBack)

        self.deleteAction = QtGui.QAction(QtGui.QIcon(':/images/delete.png'),
                "&Delete", self, shortcut="Delete",
                statusTip="Delete item from diagram",
                triggered=self.deleteItem)

        self.exitAction = QtGui.QAction("E&xit", self, shortcut="Ctrl+X",
                statusTip="Quit Scenediagram example", triggered=self.close)

        self.boldAction = QtGui.QAction(QtGui.QIcon(':/images/bold.png'),
                "Bold", self, checkable=True, shortcut="Ctrl+B",
                triggered=self.handleFontChange)

        self.italicAction = QtGui.QAction(QtGui.QIcon(':/images/italic.png'),
                "Italic", self, checkable=True, shortcut="Ctrl+I",
                triggered=self.handleFontChange)

        self.underlineAction = QtGui.QAction(
                QtGui.QIcon(':/images/underline.png'), "Underline", self,
                checkable=True, shortcut="Ctrl+U",
                triggered=self.handleFontChange)

        self.aboutAction = QtGui.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 = QtGui.QFontComboBox()
        self.fontCombo.currentFontChanged.connect(self.currentFontChanged)

        self.fontSizeCombo = QtGui.QComboBox()
        self.fontSizeCombo.setEditable(True)
        for i in range(8, 30, 2):
            self.fontSizeCombo.addItem(str(i))
        validator = QtGui.QIntValidator(2, 64, self)
        self.fontSizeCombo.setValidator(validator)
        self.fontSizeCombo.currentIndexChanged.connect(self.fontSizeChanged)

        self.fontColorToolButton = QtGui.QToolButton()
        self.fontColorToolButton.setPopupMode(QtGui.QToolButton.MenuButtonPopup)
        self.fontColorToolButton.setMenu(
                self.createColorMenu(self.textColorChanged, QtCore.Qt.black))
        self.textAction = self.fontColorToolButton.menu().defaultAction()
        self.fontColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/textpointer.png',
                        QtCore.Qt.black))
        self.fontColorToolButton.setAutoFillBackground(True)
        self.fontColorToolButton.clicked.connect(self.textButtonTriggered)

        self.fillColorToolButton = QtGui.QToolButton()
        self.fillColorToolButton.setPopupMode(QtGui.QToolButton.MenuButtonPopup)
        self.fillColorToolButton.setMenu(
                self.createColorMenu(self.itemColorChanged, QtCore.Qt.white))
        self.fillAction = self.fillColorToolButton.menu().defaultAction()
        self.fillColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/floodfill.png',
                        QtCore.Qt.white))
        self.fillColorToolButton.clicked.connect(self.fillButtonTriggered)

        self.lineColorToolButton = QtGui.QToolButton()
        self.lineColorToolButton.setPopupMode(QtGui.QToolButton.MenuButtonPopup)
        self.lineColorToolButton.setMenu(
                self.createColorMenu(self.lineColorChanged, QtCore.Qt.black))
        self.lineAction = self.lineColorToolButton.menu().defaultAction()
        self.lineColorToolButton.setIcon(
                self.createColorToolButtonIcon(':/images/linecolor.png',
                        QtCore.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 = QtGui.QToolButton()
        pointerButton.setCheckable(True)
        pointerButton.setChecked(True)
        pointerButton.setIcon(QtGui.QIcon(':/images/pointer.png'))
        linePointerButton = QtGui.QToolButton()
        linePointerButton.setCheckable(True)
        linePointerButton.setIcon(QtGui.QIcon(':/images/linepointer.png'))

        self.pointerTypeGroup = QtGui.QButtonGroup()
        self.pointerTypeGroup.addButton(pointerButton, DiagramScene.MoveItem)
        self.pointerTypeGroup.addButton(linePointerButton,
                DiagramScene.InsertLine)
        self.pointerTypeGroup.buttonClicked[int].connect(self.pointerGroupClicked)

        self.sceneScaleCombo = QtGui.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 = QtGui.QToolButton()
        button.setText(text)
        button.setIcon(QtGui.QIcon(image))
        button.setIconSize(QtCore.QSize(50, 50))
        button.setCheckable(True)
        self.backgroundButtonGroup.addButton(button)

        layout = QtGui.QGridLayout()
        layout.addWidget(button, 0, 0, QtCore.Qt.AlignHCenter)
        layout.addWidget(QtGui.QLabel(text), 1, 0, QtCore.Qt.AlignCenter)

        widget = QtGui.QWidget()
        widget.setLayout(layout)

        return widget

    def createCellWidget(self, text, diagramType):
        item = DiagramItem(diagramType, self.itemMenu)
        icon = QtGui.QIcon(item.image())

        button = QtGui.QToolButton()
        button.setIcon(icon)
        button.setIconSize(QtCore.QSize(50, 50))
        button.setCheckable(True)
        self.buttonGroup.addButton(button, diagramType)

        layout = QtGui.QGridLayout()
        layout.addWidget(button, 0, 0, QtCore.Qt.AlignHCenter)
        layout.addWidget(QtGui.QLabel(text), 1, 0, QtCore.Qt.AlignCenter)

        widget = QtGui.QWidget()
        widget.setLayout(layout)

        return widget

    def createColorMenu(self, slot, defaultColor):
        colors = [QtCore.Qt.black, QtCore.Qt.white, QtCore.Qt.red, QtCore.Qt.blue, QtCore.Qt.yellow]
        names = ["black", "white", "red", "blue", "yellow"]

        colorMenu = QtGui.QMenu(self)
        for color, name in zip(colors, names):
            action = QtGui.QAction(self.createColorIcon(color), name, self,
                    triggered=slot)
            action.setData(QtGui.QColor(color)) 
            colorMenu.addAction(action)
            if color == defaultColor:
                colorMenu.setDefaultAction(action)
        return colorMenu

    def createColorToolButtonIcon(self, imageFile, color):
        pixmap = QtGui.QPixmap(50, 80)
        pixmap.fill(QtCore.Qt.transparent)
        painter = QtGui.QPainter(pixmap)
        image = QtGui.QPixmap(imageFile)
        target = QtCore.QRect(0, 0, 50, 60)
        source = QtCore.QRect(0, 0, 42, 42)
        painter.fillRect(QtCore.QRect(0, 60, 50, 80), color)
        painter.drawPixmap(target, image, source)
        painter.end()

        return QtGui.QIcon(pixmap)

    def createColorIcon(self, color):
        pixmap = QtGui.QPixmap(20, 20)
        painter = QtGui.QPainter(pixmap)
        painter.setPen(QtCore.Qt.NoPen)
        painter.fillRect(QtCore.QRect(0, 0, 20, 20), color)
        painter.end()

        return QtGui.QIcon(pixmap)


if __name__ == '__main__':

    import sys

    app = QtGui.QApplication(sys.argv)

    mainWindow = MainWindow()
    mainWindow.setGeometry(100, 100, 800, 500)
    mainWindow.show()

    sys.exit(app.exec_())
