Qt slots with return values

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Reply to PyQt slot return value on Mon, 26 Jan 2015 01:55:18 GMT @pyqtSlot( result = str ) is only for the C++ declaration. you can not use the return value with an emit Event. PyQt slot return value | Qt Forum Qt Development Language Bindings PyQt slot return value PyQt slot return value. This topic has been deleted. Only users with topic management privileges can see it. thumperj. last edited by . Any help with this would be appreciated, including hints on how to debug further. The pyqtSlot decorator takes a result as one of the parameters. ... Qt.ConnectionType BlockingQueuedConnection public static final Qt.ConnectionType BlockingQueuedConnection Same as QueuedConnection , except that the current thread blocks until the slot has been delivered.This connection type should only be used for receivers in a different thread. Note that misuse of this type can lead to dead locks in your application.

I think that the return value for a slot is only available when the function is called directly (when it is a normal C++ function) or when using invokeMethod. I think this is really meant for internal Qt functions rather than for normal use in programs using Qt. Edit: For the sample case

Requests the specified Qt Quick scenegraph backend. Backends can either be built-in or be installed in form of dynamically loaded plugins. Scene Graph - OpenGL Under QML | Qt Quick 5.12.2 class Squircle : public QQuickItem { Q_Object Q_Property( qreal t READ t Write setT Notify tChanged) public: Squircle(); qreal t() const { return m_t; } void setT( qreal t); signals: void tChanged(); public slots: void sync(); void cleanup … How to Use a QSqlQueryModel in QML - Qt Wiki

Qt app development with C++ has advantages as well. For some scenarios you need features that are only available with Qt C++. Also, C++ is fast andIn contrast to the previous example, our new class also uses a return value for the increment slot. No further adjustments are required to receive the...

This is currently being used in some places inside Qt, f.i. the QNetworkAccessManager::authenticationRequired signal expects the connected slots to fill in the QAuthenticator object (and notice that it doesn't work with queued connections). Thus, I see no point in supporting return values across connections.

Qt signals and slots return value - Palmer Cross Country

Feb 13, 2012 ... Debugging Qt's signal-slot connections… What do ... If need be, ensure that connect succeeds by testing its return value (it should return true . Signals and Slots | Introduction to GUI Programming with Python and Qt Feb 8, 2008 ... In C++/Qt, slots are methods that must be declared with a special syntax; ... If the values are the same, we do nothing and return; otherwise, we ...

QAbstractItemModel Class | Qt Core 5.12.3

This page describes a few alternative approaches for connecting signals between QML and PySide. Simple illustrative examples about the signal connectivity are also provided in the pyside-examples repository. Browse the git tree directly or download a tarball of all examples and refer to the examples/declarative/signals directory. Can Qt signals return a value? - ExceptionsHub Boost.Signals allows various strategies of using the return values of slots to form the return value of the signal. E.g. adding them, forming a vector out of them, or returning the last one. The common wisdom (expressed in the Qt documentation [EDIT: as well as some answers to this question ]) is that no such thing is possible with Qt signals. Qt Remote Objects 5.9 - Qt Documentation Snapshots The idea is to extend existing Qt's functionalities to enable an easy exchange of information between processes or computers. One of the key features of Qt to enable this is the distinction between an objects API (defined by its Q_Property, Signals and Slots) and the implementation of that API. New Signal Slot Syntax - Qt Wiki Connecting in Qt 5. There are several ways to connect a signal in Qt 5. Old syntax. Qt 5 continues to support the old string-based syntax for connecting signals and slots defined in a QObject or any class that inherits from QObject (including QWidget)