PyQt節點接口 - Parrent對ItemIsMovable對象

Question

因此，我正在建設一個基於節點的接口使用PyQt爲我正在進行的項目，我有一些問題獲取屬於基地的對象不遵循它在太空中。我想當用戶拖動基節點時，子對象（輸入和輸出框）跟隨它。我有一個可以拖拽的節點，但是子對象沒有正確地執行。有任何想法嗎？

#!/usr/bin/python 
# -*- coding: utf-8 -*- 

""" 
This is the base py file for the GUI 
""" 

import sys 
from PyQt4 import QtGui, QtCore 
from array import * 


""" 
Base class for a node. Contains all the initialization, drawing, and containing inputs and outputs 
""" 

class node(): 

    width = 100 
    height = 100 
    color = 1 
    x = 90 
    y = 60 
    inputs=[] 
    outputs=[] 


    def __init__(self, nWidth, nHeight): 
     self.width = nWidth 
     self.height = nHeight 
     self.iniNodeData() 

    """ 
    This is where inputs and outputs will be created 
    """ 
    def iniNodeData(self): 
     for j in range(5): 
      this = self 
      x = input(this,90, 0+(j*10)) 
      self.inputs.append(x) 



    """Draw the node then the input and output objects""" 
    def draw(self, drawObj): 
     item = drawObj.addRect(self.x, self.y, self.width, self.height) 
     item.setFlag(QtGui.QGraphicsItem.ItemIsMovable) 
     for curInput in self.inputs: 
      curInput.draw(drawObj) 
     print("(", self.x, ",", self.y, ")") 



""" 
Nodes will evaluate from the last node to the first node, therefore inputs are evaluted 
""" 
class input(): 
    currentConnectedNode = None 
    currentConnectedOutput = None 
    parentNode = None 
    width = 10 
    height = 10 
    x = 1 
    y = 1 
    color = 1 

    def __init__(self, pnode, posX, posY): 

     self.parentNode = pnode 
     self.x = posX 
     self.y = posY 
     self.color = 1 


    def draw(self, drawObj): 
     item = drawObj.addRect(self.x+self.parentNode.x, self.y+self.parentNode.y, self.width, self.height) 


class output(): 
    parentNode = None 


class MainWindow(QtGui.QGraphicsView): 

    nodes = [] 

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

     self.initUI() 

    def initUI(self): 

     for j in range(1): 
      x = node(100,100) 
      self.nodes.append(x) 

     self.setScene(QtGui.QGraphicsScene())  
     self.setWindowTitle('RIS RIB Generator') 
     self.setGeometry(800, 600, 800, 850) 

     self.initNodes() 

     self.show() 


    def initNodes(self): 

     for curNode in self.nodes: 
      curNode.draw(self.scene()) 



def main(): 

    app = QtGui.QApplication(sys.argv) 
    mainwindow = MainWindow() 
    mainwindow.show() 
    app.exec_() 


if __name__ == '__main__': 
    main() 

Answer 1

好了，所以一個星期後，我想通了。你需要做一些事情。

保證標誌是正確的：

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

一旦這些設置，你可以使用內置的事件handelers但這些在乘坐原有的。所以從你的用戶定義的內部，你需要從基類調用事件handeler。例如：

def mousePressEvent(self, e): 
    print("Square got mouse press event") 
    print("Event came to us accepted: %s"%(e.isAccepted(),)) 
    QtGui.QGraphicsRectItem.mousePressEvent(self, e) 

這是我的工作示例。

#!/usr/bin/python 
# -*- coding: utf-8 -*- 

""" 
This is the base py file for the GUI 

Todo list 
----------------- 
- Pop up menu for adding new Nodes 
- node connectivity 
- create data structure for storing 

""" 

import sys 
from PyQt4 import QtGui, QtCore 
from array import * 

""" 
Base class for a node. Contains all the inilization, drawing, and containing inputs and outputs 
""" 
class node(QtGui.QGraphicsRectItem): 

    width = 100 
    height = 100 
    color = 1 
    x = 90 
    y = 60 
    inputs=[] 
    outputs=[] 
    viewObj = None 

    def __init__(self, n_x, n_y, n_width,n_height): 
     QtGui.QGraphicsRectItem.__init__(self, n_x, n_y, n_width, n_height) 
     self.width = n_width 
     self.height = n_height 
     self.x = n_x 
     self.y = n_y 
     self.setFlag(QtGui.QGraphicsItem.ItemIsMovable, True) 
     self.setFlag(QtGui.QGraphicsItem.ItemIsSelectable, True) 
     self.iniNodeData() 

    def mousePressEvent(self, e): 
     print("Square got mouse press event") 
     print("Event came to us accepted: %s"%(e.isAccepted(),)) 
     QtGui.QGraphicsRectItem.mousePressEvent(self, e) 

    def mouseReleaseEvent(self, e): 
     print("Square got mouse release event") 
     print("Event came to us accepted: %s"%(e.isAccepted(),)) 
     QtGui.QGraphicsRectItem.mouseReleaseEvent(self, e) 

    """ 
    This is where inputs and outputs will be created based on node type 
    """ 
    def iniNodeData(self): 
     print('making node data') 
     for j in range(5): 
      this = self 
      x = input(this,0, 0+(j*10)) 
      self.inputs.append(x) 

     for k in range(5): 
      this = self 
      x = output(this,self.x+self.width, self.y+(k*10)) 
      self.outputs.append(x) 


    def mouseMoveEvent(self, event): 
     print('Dragging@') 
     QtGui.QGraphicsRectItem.mouseMoveEvent(self, event) 


    def mousePressEvent(self, event): 

     print('moving!') 

""" 
Nodes will evaluate from the last node to the first node, therefore inputs are evaluted 
""" 
class input(QtGui.QGraphicsRectItem): 
    currentConnectedNode = None 
    currentConnectedOutput = None 
    parentNode = None 
    width = 10 
    height = 10 
    x = 1 
    y = 1 
    color = 1 
    drawItem = None 

    def __init__(self, pnode, posX, posY): 
     self.parentNode = pnode 
     self.x = posX 
     self.y = posY 
     self.color = 1 
     QtGui.QGraphicsRectItem.__init__(self, self.x+self.parentNode.x, self.y+self.parentNode.y, self.width, self.height, self.parentNode) 



''' 
Output value from a node 
''' 
class output(node): 
    parentNode = None 
    width = 10 
    height = 10 
    x = 1 
    y = 1 

    def __init__(self, pnode, posX, posY): 
     self.parentNode = pnode 
     self.x = posX 
     self.y = posY 
     self.color = 1 
     QtGui.QGraphicsRectItem.__init__(self, self.x-self.width, self.y, self.width, self.height, self.parentNode) 


''' 
Check Click events on the scene Object 
''' 
class Scene(QtGui.QGraphicsScene): 


    nodes = [] 

    def mousePressEvent(self, e): 
     print("Scene got mouse press event") 
     print("Event came to us accepted: %s"%(e.isAccepted(),)) 
     QtGui.QGraphicsScene.mousePressEvent(self, e) 

    def mouseReleaseEvent(self, e): 
     print("Scene got mouse release event") 
     print("Event came to us accepted: %s"%(e.isAccepted(),)) 
     QtGui.QGraphicsScene.mouseReleaseEvent(self, e) 

    def dragMoveEvent(self, e): 
     print('Scene got drag move event') 

    def addNode(self): 
     newNode = self.addItem(node(250,250,100,150)) 
     self.nodes.append(newNode) 


''' 
Main Window Object 
''' 

class MainWindowUi(QtGui.QMainWindow): 
    def __init__(self): 
     QtGui.QMainWindow.__init__(self) 
     self.setWindowTitle('RIS RIB Generator') 
     self.scene = Scene(0, 0, 800, 850, self) 
     self.view = QtGui.QGraphicsView() 
     self.setCentralWidget(self.view) 
     self.view.setScene(self.scene) 


     exitAction = QtGui.QAction(QtGui.QIcon('exit24.png'), 'Exit', self) 
     exitAction.setShortcut('Ctrl+Q') 
     exitAction.setStatusTip('Exit application') 
     exitAction.triggered.connect(self.close) 

     newNodeAction = QtGui.QAction(QtGui.QIcon('exit24.png'), 'New Node', self) 
     newNodeAction.setStatusTip('Add a blank node') 
     newNodeAction.triggered.connect(self.scene.addNode) 


     self.statusBar() 
     menubar = self.menuBar() 
     fileMenu = menubar.addMenu('&File') 
     fileMenu.addAction(newNodeAction) 
     fileMenu.addAction(exitAction) 


''' 
Start Point 
''' 

if __name__ == '__main__': 
    app = QtGui.QApplication(sys.argv) 
    win = MainWindowUi() 
    win.show() 
    sys.exit(app.exec_())