问在Python中创建拖放建模工具

EN

from PyQt4 import QtCore, QtGui
import sys

class GraphicsScene(QtGui.QGraphicsScene):

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

    def dragEnterEvent(self, event):
        event.accept()

    def dragMoveEvent(self, event):
        event.accept()

    def dragLeaveEvent(self, event):
        event.accept()

    def dropEvent(self, event):
        text = QtGui.QGraphicsTextItem(event.mimeData().text())
        text.setPos(event.scenePos())
        self.addItem(text)
        event.accept()

class ListView(QtGui.QListView):

    def __init__(self, parent = None):
        super(ListView, self).__init__(parent)
        self.setDragEnabled(True)

    def dragEnterEvent(self, event):
        event.setDropAction(QtCore.Qt.MoveAction)
        event.accept()

    def startDrag(self, event):
        index = self.indexAt(event.pos())
        if not index.isValid():
            return

        selected = self.model().data(index, QtCore.Qt.DisplayRole)

        mimeData = QtCore.QMimeData()
        mimeData.setText(selected.toString())

        drag = QtGui.QDrag(self)
        drag.setMimeData(mimeData)

        result = drag.start(QtCore.Qt.MoveAction)
        if result: # == QtCore.Qt.MoveAction:
            pass

    def mouseMoveEvent(self, event):
        self.startDrag(event)

class MainWindow(QtGui.QMainWindow):

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

        self.setGeometry(100, 100, 400, 400)

        self.widget = QtGui.QWidget()
        self.setCentralWidget(self.widget)
        layout = QtGui.QGridLayout(self.widget)

        self.ListView = ListView()

        data = QtCore.QStringList()
        data << "one" << "two" << "three"
        self.model = QtGui.QStringListModel(data)
        

        self.ListView.setModel(self.model)

        self.GraphicsView = QtGui.QGraphicsView()
        self.scene = GraphicsScene()
        self.GraphicsView.setScene(self.scene)
        #self.GraphicsView.setSceneRect(0, 0, self.GraphicsView.width(), self.GraphicsView.height())
        
        layout.addWidget(self.ListView, 0, 0, 5, 5)
        layout.addWidget(self.GraphicsView, 0, 1, 5, 5)

        self.show()
        self.GraphicsView.setSceneRect(0, 0, self.GraphicsView.width(), self.GraphicsView.height())

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    window = MainWindow()
    sys.exit(app.exec_())

from PyQt4 import QtGui, QtCore

class DragButton(QtGui.QPushButton):

    def __init__(self, parent):
         super(DragButton,  self).__init__(parent)
         self.allowDrag = True
    
    def setAllowDrag(self, allowDrag):
        if type(allowDrag) == bool:
           self.allowDrag = allowDrag
        else:
            raise TypeError("You have to set a boolean type")
    
    def mouseMoveEvent(self, e):
        if e.buttons() != QtCore.Qt.RightButton:
            return
    
        if self.allowDrag == True:
            # write the relative cursor position to mime data
            mimeData = QtCore.QMimeData()
            # simple string with 'x,y'
            mimeData.setText('%d,%d' % (e.x(), e.y()))
            print mimeData.text()
    
            # let's make it fancy. we'll show a "ghost" of the button as we drag
            # grab the button to a pixmap
            pixmap = QtGui.QPixmap.grabWidget(self)
    
            # below makes the pixmap half transparent
            painter = QtGui.QPainter(pixmap)
            painter.setCompositionMode(painter.CompositionMode_DestinationIn)
            painter.fillRect(pixmap.rect(), QtGui.QColor(0, 0, 0, 127))
            painter.end()
    
            # make a QDrag
            drag = QtGui.QDrag(self)
            # put our MimeData
            drag.setMimeData(mimeData)
            # set its Pixmap
            drag.setPixmap(pixmap)
            # shift the Pixmap so that it coincides with the cursor position
            drag.setHotSpot(e.pos())
    
            # start the drag operation
            # exec_ will return the accepted action from dropEvent
            if drag.exec_(QtCore.Qt.LinkAction | QtCore.Qt.MoveAction) == QtCore.Qt.LinkAction:
                print 'linked'
            else:
                print 'moved'
    
    def mousePressEvent(self, e):
        QtGui.QPushButton.mousePressEvent(self, e)
        if e.button() == QtCore.Qt.LeftButton:
            print 'press'
            #AQUI DEBO IMPLEMENTAR EL MENU CONTEXTUAL
    
    def dragEnterEvent(self, e):
        e.accept()
    
    def dropEvent(self, e):
        # get the relative position from the mime data
        mime = e.mimeData().text()
        x, y = map(int, mime.split(','))
    
            # move
            # so move the dragged button (i.e. event.source())
        print e.pos()
            #e.source().move(e.pos()-QtCore.QPoint(x, y))
            # set the drop action as LinkAction
        e.setDropAction(QtCore.Qt.LinkAction)
        # tell the QDrag we accepted it
        e.accept()