qobject

If I run this code: #!/usr/local/bin/ python3 import sys from PyQt4.QtCore import * from PyQt4.QtGui import * class Window(QMainWindow): def __init__(self): super().__init__() self.button1 = QPushButton("1") self.button2 = QPushButton("2") self.setCentralWidget(self.button1) self.button1.clicked.connect(lambda: self.setCentralWidget(self.button2)) self.button2.clicked.connect(lambda: self.setCentralWidget(self.button1)) self.show() if __name__ == '__main__': import sys app = QApplication(sys.argv) window = Window() sys.exit(app.exec_()) ...I get this output: Traceback (most recent call last):

In my application, I have the following class hierarchy: class Word { ... } template <typename T> class Dictionary { ... }; class WordDictionary : public Dictionary<Word> { Q_OBJECT ... } The WordDictionary class parses a dictionary which takes a long time. I am running the parsing function from within a separate thread and I want it to be able to signal the GUI thread from time to time to provide progress updates based on the current line number being parsed. That's why I want it to be a Q_OBJECT. I tried to make the base class Dictionary a Q_OBJECT but got a message that Q_OBJECT templates

Is there a way to create a completely new window instance, as a child window of the main QML window in a QmlApplication? // ChildWindow.qml Rectangle { id: childWindow width: 100 height: 100 // stuff } // main.qml Rectangle { id: window width: 1000 height: 600 MouseArea { anchors.fill: parent onClicked: createAWindow(childWindow); } } I am trying to avoid writing a Q_OBJECT class just for instanciating the new window within a new QmlApplicationViewer . There is no way to create top-level windows using only built-in QML functionality. However there's a project on Qt Labs called Desktop

I inherited a class from QObject : class Parent: public QObject { Q_OBJECT QObject* cl; public: Parent(QObject *parent=0):QObject(parent) { cl = NULL; } QObject* getCl() const { return cl; } void setCl(QObject *obj) { cl = obj; } }; But when I write : Parent ev; I get the following error: main.obj:-1: error: LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall Parent::metaObject(void)const " (?metaObject@Parent@@UBEPBUQMetaObject@@XZ) main.obj:-1: error: LNK2001: unresolved external symbol "public: virtual void * __thiscall Parent::qt_metacast(char const *

I'm using Qt and have some real basic problems. I have created my own widget MyTest that have a variable obj . I need to set this variable obj from an object outside of the widget so that the variable is copied not just a pointer to another object. I get an error message and can't figure out how to do this basic stuff. This is the code I'm using: MyTest.h: class MyTest : public QWidget { Q_OBJECT public: void setObj(QObject &inobj); QObject obj; .... } MyTest.cpp: void MyTest::setObj(QObject &inobj) { obj = inobj; //HERE I get the error message: "illegal access from 'QObject' to protected