+++ /dev/null
-/****************************************************************************
-**
-** Copyright (C) Qxt Foundation. Some rights reserved.
-**
-** This file is part of the QxtCore module of the Qt eXTension library
-**
-** This library is free software; you can redistribute it and/or modify it
-** under the terms of th Common Public License, version 1.0, as published by
-** IBM.
-**
-** This file is provided "AS IS", without WARRANTIES OR CONDITIONS OF ANY
-** KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT LIMITATION, ANY
-** WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY OR
-** FITNESS FOR A PARTICULAR PURPOSE.
-**
-** You should have received a copy of the CPL along with this file.
-** See the LICENSE file and the cpl1.0.txt file included with the source
-** distribution for more information. If you did not receive a copy of the
-** license, contact the Qxt Foundation.
-**
-** <http://libqxt.sourceforge.net> <foundation@libqxt.org>
-**
-****************************************************************************/
-
-#ifndef QXTBOUNDFUNCTION_H
-#define QXTBOUNDFUNCTION_H
-
-#include <QObject>
-#include <QMetaObject>
-#include <QGenericArgument>
-#include <qxtmetaobject.h>
-#include <qxtnull.h>
-#include <QThread>
-#include <QtDebug>
-
-/**
- * \class QxtBoundFunction
- * \ingroup QxtCore
- * \brief Binds parameters to a function call
- *
- * A bound function is very similar to what the C++ FAQ Lite refers to as "functionoids."
- * (http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.10)
- * It is similar in use to a function pointer, but allows any or all parameters to be
- * pre-filled with constant values. The remaining parameters are specified when the
- * function is invoked, for instance, by a Qt signal connection.
- *
- * By far, the most common expected use is to provide a parameter to a slot when the
- * signal doesn't have offer one. Many developers new to Qt try to write code like this:
- * \code
- * connect(button, SIGNAL(clicked()), lineEdit, SLOT(setText("Hello, world")));
- * \endcode
- * Experienced Qt developers will immediately spot the flaw here. The typical solution
- * is to create a short, one-line wrapper slot that invokes the desired function. Some
- * clever developers may even use QSignalMapper to handle slots that only need one
- * int or QString parameter.
- *
- * QxtBoundFunction enables the previous connect statement to be written like this:
- * \code
- * connect(button, SIGNAL(clicked()), QxtMetaObject::bind(lineEdit, SLOT(setText(QString)), Q_ARG(QString, "Hello, world!")));
- * \code
- * This accomplishes the same result without having to create a new slot, or worse,
- * an entire object, just to pass a constant value.
- *
- * Additionally, through the use of the QXT_BIND macro, parameters from the signal
- * can be rearranged, skipped, or passed alongside constant arguments provided
- * with the Q_ARG macro. This can be used to provide stateful callbacks to a
- * generic function, for example.
- *
- * Many kinds of functions can be bound. The most common binding applies to
- * Qt signals and slots, but standard C/C++ functions can be bound as well.
- * Future development may add the ability to bind to C++ member functions,
- * and developers can make custom QxtBoundFunction subclasses for even more
- * flexibility if necessary.
- */
-class QxtBoundFunction : public QObject
-{
- Q_OBJECT
-public:
- /**
- * Invokes the bound function and returns a value.
- *
- * The template parameter should be the return type of the invoked function. This overload accepts
- * QVariant parameters and will guess the data type of each parameter based on the type of the QVariant.
- */
- template <class T>
- inline QxtNullable<T> invoke(QXT_PROTO_10ARGS(QVariant))
- {
- if (!parent() || QThread::currentThread() == parent()->thread())
- return invoke<T>(Qt::DirectConnection, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
-#if QT_VERSION >= 0x040300
- return invoke<T>(Qt::BlockingQueuedConnection, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
-#else
- qWarning() << "QxtBoundFunction::invoke: Cannot return a value using a queued connection";
- return qxtNull;
-#endif
- }
-
- /**
- * Invokes the bound function and returns a value.
- *
- * The template parameter should be the return type of the invoked function. This overload accepts
- * QGenericArgument parameters, expressed using the Q_ARG() macro.
- */
- template <class T>
- QxtNullable<T> invoke(Qt::ConnectionType type, QVariant p1, QXT_PROTO_9ARGS(QVariant))
- {
- if (type == Qt::QueuedConnection)
- {
- qWarning() << "QxtBoundFunction::invoke: Cannot return a value using a queued connection";
- return qxtNull;
- }
- T retval;
- // I know this is a totally ugly function call
- if (invoke(type, QGenericReturnArgument(qVariantFromValue<T>(*reinterpret_cast<T*>(0)).typeName(), reinterpret_cast<void*>(&retval)),
- p1, p2, p3, p4, p5, p6, p7, p8, p9, p10))
- {
- return retval;
- }
- else
- {
- return qxtNull;
- }
- }
-
- /**
- * Invokes the bound function, discarding the return value.
- *
- * This overload accepts QVariant parameters and will guess the data type of each
- * parameter based on the type of the QVariant.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- inline bool invoke(QVariant p1, QXT_PROTO_9ARGS(QVariant))
- {
- return invoke(Qt::AutoConnection, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
- }
- /**
- * Invokes the bound function, discarding the return value.
- *
- * This overload accepts QVariant parameters and will guess the data type of each
- * parameter based on the type of the QVariant. It also allows you to specify the
- * connection type, allowing the bound function to be invoked across threads using
- * the Qt event loop.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- bool invoke(Qt::ConnectionType, QVariant p1, QXT_PROTO_9ARGS(QVariant));
-
- /**
- * Invokes the bound function, discarding the return value.
- *
- * This overload accepts QGenericArgument parameters, expressed using the Q_ARG()
- * macro.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- inline bool invoke(QXT_PROTO_10ARGS(QGenericArgument))
- {
- return invoke(Qt::AutoConnection, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
- }
- /**
- * Invokes the bound function, discarding the return value.
- *
- * This overload accepts QGenericArgument parameters, expressed using the Q_ARG()
- * macro. It also allows you to specify the connection type, allowing the bound
- * function to be invoked across threads using the Qt event loop.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- inline bool invoke(Qt::ConnectionType type, QXT_PROTO_10ARGS(QGenericArgument)) {
- return invoke(type, QGenericReturnArgument(), p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
- }
-
- /**
- * Invokes the bound function and assigns the return value to a parameter passed by reference.
- *
- * Use the Q_RETURN_ARG() macro to pass a reference to an assignable object of the function's
- * return type. When the function completes, its return value will be stored in that object.
- *
- * This overload accepts QVariant parameters and will guess the data type of each
- * parameter based on the type of the QVariant.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- inline bool invoke(QGenericReturnArgument returnValue, QVariant p1, QXT_PROTO_9ARGS(QVariant))
- {
- return invoke(Qt::AutoConnection, returnValue, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
- }
- /**
- * Invokes the bound function and assigns the return value to a parameter passed by reference.
- *
- * Use the Q_RETURN_ARG() macro to pass a reference to an assignable object of the function's
- * return type. When the function completes, its return value will be stored in that object.
- *
- * This overload accepts QVariant parameters and will guess the data type of each
- * parameter based on the type of the QVariant. It also allows you to specify the
- * connection type, allowing the bound function to be invoked across threads using
- * the Qt event loop.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- bool invoke(Qt::ConnectionType type, QGenericReturnArgument returnValue, QVariant p1, QXT_PROTO_9ARGS(QVariant));
-
- /**
- * Invokes the bound function and assigns the return value to a parameter passed by reference.
- *
- * Use the Q_RETURN_ARG() macro to pass a reference to an assignable object of the function's
- * return type. When the function completes, its return value will be stored in that object.
- *
- * This overload accepts QGenericArgument parameters, expressed using the Q_ARG()
- * macro.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- inline bool invoke(QGenericReturnArgument returnValue, QXT_PROTO_10ARGS(QGenericArgument))
- {
- return invoke(Qt::AutoConnection, returnValue, p1, p2, p3, p4, p5, p6, p7, p8, p9, p10);
- }
- /**
- * Invokes the bound function and assigns the return value to a parameter passed by reference.
- *
- * Use the Q_RETURN_ARG() macro to pass a reference to an assignable object of the function's
- * return type. When the function completes, its return value will be stored in that object.
- *
- * This overload accepts QGenericArgument parameters, expressed using the Q_ARG()
- * macro. It also allows you to specify the connection type, allowing the bound
- * function to be invoked across threads using the Qt event loop.
- *
- * This function returns true if the invocation was successful, otherwise it
- * returns false.
- */
- bool invoke(Qt::ConnectionType type, QGenericReturnArgument returnValue, QXT_PROTO_10ARGS(QGenericArgument));
-
-protected:
-#ifndef QXT_DOXYGEN_RUN
- QxtBoundFunction(QObject* parent = 0);
-#endif
-
- /**
- * Performs the work of invoking the bound function.
- *
- * This function is pure virtual. The various QxtMetaObject::bind() functions return opaque subclasses
- * of QxtBoundFunction. If you wish to create a new kind of bound function, reimplement this function to
- * perform the invocation and assign the function's return value, if any, to the returnValue parameter.
- *
- * This function should return true if the invocation is successful and false if an error occurs.
- */
- virtual bool invokeImpl(Qt::ConnectionType type, QGenericReturnArgument returnValue, QXT_PROTO_10ARGS(QGenericArgument)) = 0;
-};
-
-#endif
projects / quassel.git / blobdiff