Graphics/UMLGraphicsView.py

# -*- coding: utf-8 -*-

# Copyright (c) 2007 - 2013 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a subclass of E5GraphicsView for our diagrams.
"""

from PyQt4.QtCore import pyqtSignal, Qt, QSignalMapper, QFileInfo, QEvent, \
    QRectF
from PyQt4.QtGui import QGraphicsView, QAction, QToolBar, QDialog, QPrinter, \
    QPrintDialog

from E5Graphics.E5GraphicsView import E5GraphicsView

from E5Gui import E5MessageBox, E5FileDialog
from E5Gui.E5ZoomWidget import E5ZoomWidget

from .UMLItem import UMLItem

import UI.Config
import UI.PixmapCache

import Preferences


class UMLGraphicsView(E5GraphicsView):
    """
    Class implementing a specialized E5GraphicsView for our diagrams.
    
    @signal relayout() emitted to indicate a relayout of the diagram
        is requested
    """
    relayout = pyqtSignal()
    
    def __init__(self, scene, parent=None):
        """
        Constructor
        
        @param scene reference to the scene object (QGraphicsScene)
        @param parent parent widget of the view (QWidget)
        """
        E5GraphicsView.__init__(self, scene, parent)
        self.setObjectName("UMLGraphicsView")
        self.setViewportUpdateMode(QGraphicsView.FullViewportUpdate)
        
        self.diagramName = "Unnamed"
        self.__itemId = -1
        
        self.border = 10
        self.deltaSize = 100.0
        
        self.__zoomWidget = E5ZoomWidget(
            UI.PixmapCache.getPixmap("zoomOut.png"),
            UI.PixmapCache.getPixmap("zoomIn.png"),
            UI.PixmapCache.getPixmap("zoomReset.png"), self)
        parent.statusBar().addPermanentWidget(self.__zoomWidget)
        self.__zoomWidget.setMapping(
            E5GraphicsView.ZoomLevels, E5GraphicsView.ZoomLevelDefault)
        self.__zoomWidget.valueChanged.connect(self.setZoom)
        self.zoomValueChanged.connect(self.__zoomWidget.setValue)
        
        self.__initActions()
        
        scene.changed.connect(self.__sceneChanged)
        
        self.grabGesture(Qt.PinchGesture)
        
    def __initActions(self):
        """
        Private method to initialize the view actions.
        """
        self.alignMapper = QSignalMapper(self)
        self.alignMapper.mapped[int].connect(self.__alignShapes)
        
        self.deleteShapeAct = \
            QAction(UI.PixmapCache.getIcon("deleteShape.png"),
                    self.trUtf8("Delete shapes"), self)
        self.deleteShapeAct.triggered[()].connect(self.__deleteShape)
        
        self.incWidthAct = \
            QAction(UI.PixmapCache.getIcon("sceneWidthInc.png"),
                    self.trUtf8("Increase width by {0} points").format(
                        self.deltaSize),
                    self)
        self.incWidthAct.triggered[()].connect(self.__incWidth)
        
        self.incHeightAct = \
            QAction(UI.PixmapCache.getIcon("sceneHeightInc.png"),
                    self.trUtf8("Increase height by {0} points").format(
                        self.deltaSize),
                    self)
        self.incHeightAct.triggered[()].connect(self.__incHeight)
        
        self.decWidthAct = \
            QAction(UI.PixmapCache.getIcon("sceneWidthDec.png"),
                    self.trUtf8("Decrease width by {0} points").format(
                        self.deltaSize),
                    self)
        self.decWidthAct.triggered[()].connect(self.__decWidth)
        
        self.decHeightAct = \
            QAction(UI.PixmapCache.getIcon("sceneHeightDec.png"),
                    self.trUtf8("Decrease height by {0} points").format(
                        self.deltaSize),
                    self)
        self.decHeightAct.triggered[()].connect(self.__decHeight)
        
        self.setSizeAct = \
            QAction(UI.PixmapCache.getIcon("sceneSize.png"),
                    self.trUtf8("Set size"), self)
        self.setSizeAct.triggered[()].connect(self.__setSize)
        
        self.rescanAct = \
            QAction(UI.PixmapCache.getIcon("rescan.png"),
                    self.trUtf8("Re-Scan"), self)
        self.rescanAct.triggered[()].connect(self.__rescan)
        
        self.relayoutAct = \
            QAction(UI.PixmapCache.getIcon("relayout.png"),
                    self.trUtf8("Re-Layout"), self)
        self.relayoutAct.triggered[()].connect(self.__relayout)
        
        self.alignLeftAct = \
            QAction(UI.PixmapCache.getIcon("shapesAlignLeft.png"),
                    self.trUtf8("Align Left"), self)
        self.alignMapper.setMapping(self.alignLeftAct, Qt.AlignLeft)
        self.alignLeftAct.triggered[()].connect(self.alignMapper.map)
        
        self.alignHCenterAct = \
            QAction(UI.PixmapCache.getIcon("shapesAlignHCenter.png"),
                    self.trUtf8("Align Center Horizontal"), self)
        self.alignMapper.setMapping(self.alignHCenterAct, Qt.AlignHCenter)
        self.alignHCenterAct.triggered[()].connect(self.alignMapper.map)
        
        self.alignRightAct = \
            QAction(UI.PixmapCache.getIcon("shapesAlignRight.png"),
                    self.trUtf8("Align Right"), self)
        self.alignMapper.setMapping(self.alignRightAct, Qt.AlignRight)
        self.alignRightAct.triggered[()].connect(self.alignMapper.map)
        
        self.alignTopAct = \
            QAction(UI.PixmapCache.getIcon("shapesAlignTop.png"),
                    self.trUtf8("Align Top"), self)
        self.alignMapper.setMapping(self.alignTopAct, Qt.AlignTop)
        self.alignTopAct.triggered[()].connect(self.alignMapper.map)
        
        self.alignVCenterAct = \
            QAction(UI.PixmapCache.getIcon("shapesAlignVCenter.png"),
                    self.trUtf8("Align Center Vertical"), self)
        self.alignMapper.setMapping(self.alignVCenterAct, Qt.AlignVCenter)
        self.alignVCenterAct.triggered[()].connect(self.alignMapper.map)
        
        self.alignBottomAct = \
            QAction(UI.PixmapCache.getIcon("shapesAlignBottom.png"),
                    self.trUtf8("Align Bottom"), self)
        self.alignMapper.setMapping(self.alignBottomAct, Qt.AlignBottom)
        self.alignBottomAct.triggered[()].connect(self.alignMapper.map)
        
    def __checkSizeActions(self):
        """
        Private slot to set the enabled state of the size actions.
        """
        diagramSize = self._getDiagramSize(10)
        sceneRect = self.scene().sceneRect()
        if (sceneRect.width() - self.deltaSize) < diagramSize.width():
            self.decWidthAct.setEnabled(False)
        else:
            self.decWidthAct.setEnabled(True)
        if (sceneRect.height() - self.deltaSize) < diagramSize.height():
            self.decHeightAct.setEnabled(False)
        else:
            self.decHeightAct.setEnabled(True)
        
    def __sceneChanged(self, areas):
        """
        Private slot called when the scene changes.
        
        @param areas list of rectangles that contain changes (list of QRectF)
        """
        if len(self.scene().selectedItems()) > 0:
            self.deleteShapeAct.setEnabled(True)
        else:
            self.deleteShapeAct.setEnabled(False)
        
        sceneRect = self.scene().sceneRect()
        newWidth = width = sceneRect.width()
        newHeight = height = sceneRect.height()
        rect = self.scene().itemsBoundingRect()
        # calculate with 10 pixel border on each side
        if sceneRect.right() - 10 < rect.right():
            newWidth = rect.right() + 10
        if sceneRect.bottom() - 10 < rect.bottom():
            newHeight = rect.bottom() + 10
        
        if newHeight != height or newWidth != width:
            self.setSceneSize(newWidth, newHeight)
            self.__checkSizeActions()
        
    def initToolBar(self):
        """
        Public method to populate a toolbar with our actions.
        
        @return the populated toolBar (QToolBar)
        """
        toolBar = QToolBar(self.trUtf8("Graphics"), self)
        toolBar.setIconSize(UI.Config.ToolBarIconSize)
        toolBar.addAction(self.deleteShapeAct)
        toolBar.addSeparator()
        toolBar.addAction(self.alignLeftAct)
        toolBar.addAction(self.alignHCenterAct)
        toolBar.addAction(self.alignRightAct)
        toolBar.addAction(self.alignTopAct)
        toolBar.addAction(self.alignVCenterAct)
        toolBar.addAction(self.alignBottomAct)
        toolBar.addSeparator()
        toolBar.addAction(self.incWidthAct)
        toolBar.addAction(self.incHeightAct)
        toolBar.addAction(self.decWidthAct)
        toolBar.addAction(self.decHeightAct)
        toolBar.addAction(self.setSizeAct)
        toolBar.addSeparator()
        toolBar.addAction(self.rescanAct)
        toolBar.addAction(self.relayoutAct)
        
        return toolBar
        
    def filteredItems(self, items, itemType=UMLItem):
        """
        Public method to filter a list of items.
        
        @param items list of items as returned by the scene object
            (QGraphicsItem)
        @param itemType type to be filtered (class)
        @return list of interesting collision items (QGraphicsItem)
        """
        return [itm for itm in items if isinstance(itm, itemType)]
        
    def selectItems(self, items):
        """
        Public method to select the given items.
        
        @param items list of items to be selected (list of QGraphicsItemItem)
        """
        # step 1: deselect all items
        self.unselectItems()
        
        # step 2: select all given items
        for itm in items:
            if isinstance(itm, UMLItem):
                itm.setSelected(True)
        
    def selectItem(self, item):
        """
        Public method to select an item.
        
        @param item item to be selected (QGraphicsItemItem)
        """
        if isinstance(item, UMLItem):
            item.setSelected(not item.isSelected())
        
    def __deleteShape(self):
        """
        Private method to delete the selected shapes from the display.
        """
        for item in self.scene().selectedItems():
            item.removeAssociations()
            item.setSelected(False)
            self.scene().removeItem(item)
            del item
        
    def __incWidth(self):
        """
        Private method to handle the increase width context menu entry.
        """
        self.resizeScene(self.deltaSize, True)
        self.__checkSizeActions()
        
    def __incHeight(self):
        """
        Private method to handle the increase height context menu entry.
        """
        self.resizeScene(self.deltaSize, False)
        self.__checkSizeActions()
        
    def __decWidth(self):
        """
        Private method to handle the decrease width context menu entry.
        """
        self.resizeScene(-self.deltaSize, True)
        self.__checkSizeActions()
        
    def __decHeight(self):
        """
        Private method to handle the decrease height context menu entry.
        """
        self.resizeScene(-self.deltaSize, False)
        self.__checkSizeActions()
        
    def __setSize(self):
        """
        Private method to handle the set size context menu entry.
        """
        from .UMLSceneSizeDialog import UMLSceneSizeDialog
        rect = self._getDiagramRect(10)
        sceneRect = self.scene().sceneRect()
        dlg = UMLSceneSizeDialog(sceneRect.width(), sceneRect.height(),
                                  rect.width(), rect.height(), self)
        if dlg.exec_() == QDialog.Accepted:
            width, height = dlg.getData()
            self.setSceneSize(width, height)
        self.__checkSizeActions()
        
    def autoAdjustSceneSize(self, limit=False):
        """
        Public method to adjust the scene size to the diagram size.
        
        @param limit flag indicating to limit the scene to the
            initial size (boolean)
        """
        super().autoAdjustSceneSize(limit=limit)
        self.__checkSizeActions()
        
    def saveImage(self):
        """
        Public method to handle the save context menu entry.
        """
        fname, selectedFilter = E5FileDialog.getSaveFileNameAndFilter(
            self,
            self.trUtf8("Save Diagram"),
            "",
            self.trUtf8("Portable Network Graphics (*.png);;"
                        "Scalable Vector Graphics (*.svg)"),
            "",
            E5FileDialog.Options(E5FileDialog.DontConfirmOverwrite))
        if fname:
            ext = QFileInfo(fname).suffix()
            if not ext:
                ex = selectedFilter.split("(*")[1].split(")")[0]
                if ex:
                    fname += ex
            if QFileInfo(fname).exists():
                res = E5MessageBox.yesNo(
                    self,
                    self.trUtf8("Save Diagram"),
                    self.trUtf8("<p>The file <b>{0}</b> already exists."
                                " Overwrite it?</p>").format(fname),
                    icon=E5MessageBox.Warning)
                if not res:
                    return
            
            success = super().saveImage(
                fname, QFileInfo(fname).suffix().upper())
            if not success:
                E5MessageBox.critical(
                    self,
                    self.trUtf8("Save Diagram"),
                    self.trUtf8(
                        """<p>The file <b>{0}</b> could not be saved.</p>""")
                        .format(fname))
        
    def __relayout(self):
        """
        Private slot to handle the re-layout context menu entry.
        """
        self.__itemId = -1
        self.scene().clear()
        self.relayout.emit()
        
    def __rescan(self):
        """
        Private slot to handle the re-scan context menu entry.
        """
        # 1. save positions of all items and names of selected items
        itemPositions = {}
        selectedItems = []
        for item in self.filteredItems(self.scene().items(), UMLItem):
            name = item.getName()
            if name:
                itemPositions[name] = (item.x(), item.y())
                if item.isSelected():
                    selectedItems.append(name)
        
        # 2. save
        
        # 2. re-layout the diagram
        self.__relayout()
        
        # 3. move known items to the saved positions
        for item in self.filteredItems(self.scene().items(), UMLItem):
            name = item.getName()
            if name in itemPositions:
                item.setPos(*itemPositions[name])
            if name in selectedItems:
                item.setSelected(True)
        
    def printDiagram(self):
        """
        Public slot called to print the diagram.
        """
        printer = QPrinter(mode=QPrinter.ScreenResolution)
        printer.setFullPage(True)
        if Preferences.getPrinter("ColorMode"):
            printer.setColorMode(QPrinter.Color)
        else:
            printer.setColorMode(QPrinter.GrayScale)
        if Preferences.getPrinter("FirstPageFirst"):
            printer.setPageOrder(QPrinter.FirstPageFirst)
        else:
            printer.setPageOrder(QPrinter.LastPageFirst)
        printer.setPageMargins(
            Preferences.getPrinter("LeftMargin") * 10,
            Preferences.getPrinter("TopMargin") * 10,
            Preferences.getPrinter("RightMargin") * 10,
            Preferences.getPrinter("BottomMargin") * 10,
            QPrinter.Millimeter
        )
        printer.setPrinterName(Preferences.getPrinter("PrinterName"))
        
        printDialog = QPrintDialog(printer, self)
        if printDialog.exec_():
            super().printDiagram(printer, self.diagramName)
        
    def printPreviewDiagram(self):
        """
        Public slot called to show a print preview of the diagram.
        """
        from PyQt4.QtGui import QPrintPreviewDialog
        
        printer = QPrinter(mode=QPrinter.ScreenResolution)
        printer.setFullPage(True)
        if Preferences.getPrinter("ColorMode"):
            printer.setColorMode(QPrinter.Color)
        else:
            printer.setColorMode(QPrinter.GrayScale)
        if Preferences.getPrinter("FirstPageFirst"):
            printer.setPageOrder(QPrinter.FirstPageFirst)
        else:
            printer.setPageOrder(QPrinter.LastPageFirst)
        printer.setPageMargins(
            Preferences.getPrinter("LeftMargin") * 10,
            Preferences.getPrinter("TopMargin") * 10,
            Preferences.getPrinter("RightMargin") * 10,
            Preferences.getPrinter("BottomMargin") * 10,
            QPrinter.Millimeter
        )
        printer.setPrinterName(Preferences.getPrinter("PrinterName"))
        
        preview = QPrintPreviewDialog(printer, self)
        preview.paintRequested[QPrinter].connect(self.__printPreviewPrint)
        preview.exec_()
        
    def __printPreviewPrint(self, printer):
        """
        Private slot to generate a print preview.
        
        @param printer reference to the printer object (QPrinter)
        """
        super().printDiagram(printer, self.diagramName)
        
    def setDiagramName(self, name):
        """
        Public slot to set the diagram name.
        
        @param name diagram name (string)
        """
        self.diagramName = name
        
    def __alignShapes(self, alignment):
        """
        Private slot to align the selected shapes.
        
        @param alignment alignment type (Qt.AlignmentFlag)
        """
        # step 1: get all selected items
        items = self.scene().selectedItems()
        if len(items) <= 1:
            return
        
        # step 2: find the index of the item to align in relation to
        amount = None
        for i, item in enumerate(items):
            rect = item.sceneBoundingRect()
            if alignment == Qt.AlignLeft:
                if amount is None or rect.x() < amount:
                    amount = rect.x()
                    index = i
            elif alignment == Qt.AlignRight:
                if amount is None or rect.x() + rect.width() > amount:
                    amount = rect.x() + rect.width()
                    index = i
            elif alignment == Qt.AlignHCenter:
                if amount is None or rect.width() > amount:
                    amount = rect.width()
                    index = i
            elif alignment == Qt.AlignTop:
                if amount is None or rect.y() < amount:
                    amount = rect.y()
                    index = i
            elif alignment == Qt.AlignBottom:
                if amount is None or rect.y() + rect.height() > amount:
                    amount = rect.y() + rect.height()
                    index = i
            elif alignment == Qt.AlignVCenter:
                if amount is None or rect.height() > amount:
                    amount = rect.height()
                    index = i
        rect = items[index].sceneBoundingRect()
        
        # step 3: move the other items
        for i, item in enumerate(items):
            if i == index:
                continue
            itemrect = item.sceneBoundingRect()
            xOffset = yOffset = 0
            if alignment == Qt.AlignLeft:
                xOffset = rect.x() - itemrect.x()
            elif alignment == Qt.AlignRight:
                xOffset = (rect.x() + rect.width()) - \
                          (itemrect.x() + itemrect.width())
            elif alignment == Qt.AlignHCenter:
                xOffset = (rect.x() + rect.width() // 2) - \
                          (itemrect.x() + itemrect.width() // 2)
            elif alignment == Qt.AlignTop:
                yOffset = rect.y() - itemrect.y()
            elif alignment == Qt.AlignBottom:
                yOffset = (rect.y() + rect.height()) - \
                          (itemrect.y() + itemrect.height())
            elif alignment == Qt.AlignVCenter:
                yOffset = (rect.y() + rect.height() // 2) - \
                          (itemrect.y() + itemrect.height() // 2)
            item.moveBy(xOffset, yOffset)
        
        self.scene().update()
    
    def __itemsBoundingRect(self, items):
        """
        Private method to calculate the bounding rectangle of the given items.
        
        @param items list of items to operate on (list of UMLItem)
        @return bounding rectangle (QRectF)
        """
        rect = self.scene().sceneRect()
        right = rect.left()
        bottom = rect.top()
        left = rect.right()
        top = rect.bottom()
        for item in items:
            rect = item.sceneBoundingRect()
            left = min(rect.left(), left)
            right = max(rect.right(), right)
            top = min(rect.top(), top)
            bottom = max(rect.bottom(), bottom)
        return QRectF(left, top, right - left, bottom - top)
    
    def keyPressEvent(self, evt):
        """
        Protected method handling key press events.
        
        @param evt reference to the key event (QKeyEvent)
        """
        key = evt.key()
        if key in [Qt.Key_Up, Qt.Key_Down, Qt.Key_Left, Qt.Key_Right]:
            items = self.filteredItems(self.scene().selectedItems())
            if items:
                if evt.modifiers() & Qt.ControlModifier:
                    stepSize = 50
                else:
                    stepSize = 5
                if key == Qt.Key_Up:
                    dx = 0
                    dy = -stepSize
                elif key == Qt.Key_Down:
                    dx = 0
                    dy = stepSize
                elif key == Qt.Key_Left:
                    dx = -stepSize
                    dy = 0
                else:
                    dx = stepSize
                    dy = 0
                for item in items:
                    item.moveBy(dx, dy)
                evt.accept()
                return
        
        super().keyPressEvent(evt)
    
    def wheelEvent(self, evt):
        """
        Protected method to handle wheel events.
        
        @param evt reference to the wheel event (QWheelEvent)
        """
        if evt.modifiers() & Qt.ControlModifier:
            if evt.delta() < 0:
                self.zoomOut()
            else:
                self.zoomIn()
            evt.accept()
            return
        
        super().wheelEvent(evt)
    
    def event(self, evt):
        """
        Protected method handling events.
        
        @param evt reference to the event (QEvent)
        @return flag indicating, if the event was handled (boolean)
        """
        if evt.type() == QEvent.Gesture:
            self.gestureEvent(evt)
            return True
        
        return super().event(evt)
    
    def gestureEvent(self, evt):
        """
        Protected method handling gesture events.
        
        @param evt reference to the gesture event (QGestureEvent
        """
        pinch = evt.gesture(Qt.PinchGesture)
        if pinch:
            if pinch.state() == Qt.GestureStarted:
                pinch.setScaleFactor(self.zoom() / 100.0)
            else:
                self.setZoom(int(pinch.scaleFactor() * 100))
            evt.accept()
    
    def getItemId(self):
        """
        Public method to get the ID to be assigned to an item.
        
        @return item ID (integer)
        """
        self.__itemId += 1
        return self.__itemId

    def findItem(self, id):
        """
        Public method to find an UML item based on the ID.
        
        @param id of the item to search for (integer)
        @return item found (UMLItem) or None
        """
        for item in self.scene().items():
            try:
                if item.getId() == id:
                    return item
            except AttributeError:
                continue
        
        return None
    
    def findItemByName(self, name):
        """
        Public method to find an UML item based on its name.
        
        @param name name to look for (string)
        @return item found (UMLItem) or None
        """
        for item in self.scene().items():
            try:
                if item.getName() == name:
                    return item
            except AttributeError:
                continue
        
        return None
    
    def getPersistenceData(self):
        """
        Public method to get a list of data to be persisted.
        
        @return list of data to be persisted (list of strings)
        """
        lines = [
            "diagram_name: {0}".format(self.diagramName),
        ]
        
        for item in self.filteredItems(self.scene().items(), UMLItem):
            lines.append("item: id={0}, x={1}, y={2}, item_type={3}{4}".format(
                item.getId(), item.x(), item.y(), item.getItemType(),
                item.buildItemDataString()))
        
        from .AssociationItem import AssociationItem
        for item in self.filteredItems(self.scene().items(), AssociationItem):
            lines.append("association: {0}".format(
                item.buildAssociationItemDataString()))
        
        return lines
    
    def parsePersistenceData(self, version, data):
        """
        Public method to parse persisted data.
        
        @param version version of the data (string)
        @param data persisted data to be parsed (list of string)
        @return tuple of flag indicating success (boolean) and faulty line
            number (integer)
        """
        umlItems = {}
        
        if not data[0].startswith("diagram_name:"):
            return False, 0
        self.diagramName = data[0].split(": ", 1)[1].strip()
        
        from .ClassItem import ClassItem
        from .ModuleItem import ModuleItem
        from .PackageItem import PackageItem
        from .AssociationItem import AssociationItem
        
        linenum = 0
        for line in data[1:]:
            linenum += 1
            if not line.startswith(("item:", "association:")):
                return False, linenum
            
            key, value = line.split(": ", 1)
            if key == "item":
                id, x, y, itemType, itemData = value.split(", ", 4)
                try:
                    id = int(id.split("=", 1)[1].strip())
                    x = float(x.split("=", 1)[1].strip())
                    y = float(y.split("=", 1)[1].strip())
                    itemType = itemType.split("=", 1)[1].strip()
                    if itemType == ClassItem.ItemType:
                        itm = ClassItem(x=x, y=y, scene=self.scene())
                    elif itemType == ModuleItem.ItemType:
                        itm = ModuleItem(x=x, y=y, scene=self.scene())
                    elif itemType == PackageItem.ItemType:
                        itm = PackageItem(x=x, y=y, scene=self.scene())
                    itm.setId(id)
                    umlItems[id] = itm
                    if not itm.parseItemDataString(version, itemData):
                        return False, linenum
                except ValueError:
                    return False, linenum
            elif key == "association":
                srcId, dstId, assocType, topToBottom = \
                    AssociationItem.parseAssociationItemDataString(
                        value.strip())
                assoc = AssociationItem(umlItems[srcId], umlItems[dstId],
                    assocType, topToBottom)
                self.scene().addItem(assoc)
        
        return True, -1