PYQT how to draw line between two buttons

Question

from PyQt4 import QtGui, QtCore

class Window(QtGui.QWidget):
    def __init__(self):
        QtGui.QWidget.__init__(self)
        self.view = View(self)
        self.button = QtGui.QPushButton('Clear View', self)
        self.button.clicked.connect(self.handleClearView)
        layout = QtGui.QVBoxLayout(self)
        layout.addWidget(self.view)
        layout.addWidget(self.button)


    def handleClearView(self):
        self.view.scene().clear()

class DragButton(QtGui.QPushButton):

    def mousePressEvent(self, event):
        self.__mousePressPos = None
        self.__mouseMovePos = None
        if event.button() == QtCore.Qt.LeftButton:
            self.__mousePressPos = event.globalPos()
            self.__mouseMovePos = event.globalPos()

        #super(DragButton, self).mousePressEvent(event)

    def mouseMoveEvent(self, event):
        if event.buttons() == QtCore.Qt.LeftButton:
            # adjust offset from clicked point to origin of widget
            currPos = self.mapToGlobal(self.pos())
            globalPos = event.globalPos()
            diff = globalPos - self.__mouseMovePos
            newPos = self.mapFromGlobal(currPos + diff)
            self.move(newPos)
            self.__mouseMovePos = globalPos

        #super(DragButton, self).mouseMoveEvent(event)

    def mouseReleaseEvent(self, event):
        if self.__mousePressPos is not None:
            moved = event.globalPos() - self.__mousePressPos 
            if moved.manhattanLength() > 3:
                event.ignore()
                return

        #super(DragButton, self).mouseReleaseEvent(event)

class View(QtGui.QGraphicsView):
    def __init__(self, parent):
        QtGui.QGraphicsView.__init__(self, parent)
        self.setScene(QtGui.QGraphicsScene(self))
        self.setSceneRect(QtCore.QRectF(self.viewport().rect()))
        btn1=DragButton('Test1', self)
        btn2=DragButton('Test2', self)

    def mousePressEvent(self, event):
        self._start = event.pos()

    def mouseReleaseEvent(self, event):
        start = QtCore.QPointF(self.mapToScene(self._start))
        end = QtCore.QPointF(self.mapToScene(event.pos()))
        self.scene().addItem(
            QtGui.QGraphicsLineItem(QtCore.QLineF(start, end)))
        for point in (start, end):
            text = self.scene().addSimpleText(
                '(%d, %d)' % (point.x(), point.y()))
            text.setBrush(QtCore.Qt.red)
            text.setPos(point)

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    window = Window()
    window.resize(640, 480)
    window.show()
    sys.exit(app.exec_())

Here is my code. There are two movable buttons on the QGraphicsView and I can draw line on the QGraphicsView with mouse dragging. But what I want to do is to draw line between two buttons. For detail, If I right click the btn1(Test1) and then right click the btn2(Test2) , the line would be created between two buttons. I'm struggling this problem for a month. Plz Help!

Answer 1

I am assuming that the line you need to draw between the buttons must also be movable. If not it is just simple you can just use :

lines = QtGui.QPainter()
lines.setPen(self)
lines.drawLine(x1,y1,x2,y2)

So, if the line needs to be movable along with the buttons then first you create a mini widget consisting of Two Buttons and the Line, so you can move the whole widget. This might help!, in that case.