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Qt 4.8
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Qt 4.8
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The QAbstractMessageHandler class provides a callback interface for handling messages. More...
#include <qabstractmessagehandler.h>
Public Functions | |
| void | message (QtMsgType type, const QString &description, const QUrl &identifier=QUrl(), const QSourceLocation &sourceLocation=QSourceLocation()) |
| Sends a message to this message handler. More... | |
| QAbstractMessageHandler (QObject *parent=0) | |
| Constructs a QAbstractMessageHandler. More... | |
| virtual | ~QAbstractMessageHandler () |
| Destructs this QAbstractMessageHandler. More... | |
 Public Functions inherited from QObject | |
| bool | blockSignals (bool b) |
| If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More... | |
| const QObjectList & | children () const |
| Returns a list of child objects. More... | |
| bool | connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const |
| bool | disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0) |
| bool | disconnect (const QObject *receiver, const char *member=0) |
| void | dumpObjectInfo () |
| Dumps information about signal connections, etc. More... | |
| void | dumpObjectTree () |
| Dumps a tree of children to the debug output. More... | |
| QList< QByteArray > | dynamicPropertyNames () const |
| Returns the names of all properties that were dynamically added to the object using setProperty(). More... | |
| virtual bool | event (QEvent *) |
| This virtual function receives events to an object and should return true if the event e was recognized and processed. More... | |
| virtual bool | eventFilter (QObject *, QEvent *) |
| Filters events if this object has been installed as an event filter for the watched object. More... | |
| template<typename T > | |
| T | findChild (const QString &aName=QString()) const |
| Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More... | |
| template<typename T > | |
| QList< T > | findChildren (const QString &aName=QString()) const |
| Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More... | |
| template<typename T > | |
| QList< T > | findChildren (const QRegExp &re) const |
| bool | inherits (const char *classname) const |
| Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More... | |
| void | installEventFilter (QObject *) |
| Installs an event filter filterObj on this object. More... | |
| bool | isWidgetType () const |
| Returns true if the object is a widget; otherwise returns false. More... | |
| void | killTimer (int id) |
| Kills the timer with timer identifier, id. More... | |
| virtual const QMetaObject * | metaObject () const |
| Returns a pointer to the meta-object of this object. More... | |
| void | moveToThread (QThread *thread) |
| Changes the thread affinity for this object and its children. More... | |
| QString | objectName () const |
| QObject * | parent () const |
| Returns a pointer to the parent object. More... | |
| QVariant | property (const char *name) const |
| Returns the value of the object's name property. More... | |
| Q_INVOKABLE | QObject (QObject *parent=0) |
| Constructs an object with parent object parent. More... | |
| void | removeEventFilter (QObject *) |
| Removes an event filter object obj from this object. More... | |
| void | setObjectName (const QString &name) |
| void | setParent (QObject *) |
| Makes the object a child of parent. More... | |
| bool | setProperty (const char *name, const QVariant &value) |
| Sets the value of the object's name property to value. More... | |
| void | setUserData (uint id, QObjectUserData *data) |
| bool | signalsBlocked () const |
| Returns true if signals are blocked; otherwise returns false. More... | |
| int | startTimer (int interval) |
| Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More... | |
| QThread * | thread () const |
| Returns the thread in which the object lives. More... | |
| QObjectUserData * | userData (uint id) const |
| virtual | ~QObject () |
| Destroys the object, deleting all its child objects. More... | |
Protected Functions | |
| virtual void | handleMessage (QtMsgType type, const QString &description, const QUrl &identifier, const QSourceLocation &sourceLocation)=0 |
| This function must be implemented by the sub-class. More... | |
| Protected Functions inherited from QObject | |
| virtual void | childEvent (QChildEvent *) |
| This event handler can be reimplemented in a subclass to receive child events. More... | |
| virtual void | connectNotify (const char *signal) |
| This virtual function is called when something has been connected to signal in this object. More... | |
| virtual void | customEvent (QEvent *) |
| This event handler can be reimplemented in a subclass to receive custom events. More... | |
| virtual void | disconnectNotify (const char *signal) |
| This virtual function is called when something has been disconnected from signal in this object. More... | |
| QObject (QObjectPrivate &dd, QObject *parent=0) | |
| int | receivers (const char *signal) const |
| Returns the number of receivers connected to the signal. More... | |
| QObject * | sender () const |
| Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More... | |
| int | senderSignalIndex () const |
| virtual void | timerEvent (QTimerEvent *) |
| This event handler can be reimplemented in a subclass to receive timer events for the object. More... | |
Additional Inherited Members | |
| Public Slots inherited from QObject | |
| void | deleteLater () |
| Schedules this object for deletion. More... | |
| Signals inherited from QObject | |
| void | destroyed (QObject *=0) |
| This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More... | |
| Static Public Functions inherited from QObject | |
| static bool | connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection) |
| Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More... | |
| static bool | connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection) |
| static bool | disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member) |
| Disconnects signal in object sender from method in object receiver. More... | |
| static bool | disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member) |
| static uint | registerUserData () |
| static QString | tr (const char *sourceText, const char *comment=0, int n=-1) |
| static QString | trUtf8 (const char *sourceText, const char *comment=0, int n=-1) |
| Static Public Variables inherited from QObject | |
| static const QMetaObject | staticMetaObject |
| This variable stores the meta-object for the class. More... | |
| Protected Variables inherited from QObject | |
| QScopedPointer< QObjectData > | d_ptr |
| Static Protected Variables inherited from QObject | |
| static const QMetaObject | staticQtMetaObject |
| Related Functions inherited from QObject | |
| T | qFindChildqFindChildren (const QObject *obj, const QString &name)() |
| QList< T > | qFindChildrenqFindChildren (const QObject *obj, const QString &name)() |
| QList< T > | qFindChildrenqFindChildren (const QObject *obj, const QRegExp ®Exp)() |
| T * | qobject_cast (QObject *object) |
| QObjectList | |
| void * | qt_find_obj_child (QObject *parent, const char *type, const QString &name) |
| Returns a pointer to the object named name that inherits type and with a given parent. More... | |
The QAbstractMessageHandler class provides a callback interface for handling messages.
QAbstractMessageHandler is an abstract base class that provides a callback interface for handling messages. For example, class QXmlQuery parses and runs an XQuery. When it detects a compile or runtime error, it generates an appropriate error message, but rather than output the message itself, it passes the message to the message() function of its QAbstractMessageHandler. See QXmlQuery::setMessageHandler().
You create a message handler by subclassing QAbstractMessageHandler and implementing handleMessage(). You then pass a pointer to an instance of your subclass to any classes that must generate messages. The messages are sent to the message handler via the message() function, which forwards them to your handleMessge(). The effect is to serialize the handling of all messages, which means your QAbstractMessageHandler subclass is thread safe.
A single instance of QAbstractMessageHandler can be called on to handle messages from multiple sources. Hence, the content of a message, which is the description parameter passed to message() and handleMessage(), must be interpreted in light of the context that required the message to be sent. That context is specified by the identifier and sourceLocation parameters to message() handleMessage().
Definition at line 55 of file qabstractmessagehandler.h.
| QAbstractMessageHandler::QAbstractMessageHandler | ( | QObject * | parent = 0 | ) |
Constructs a QAbstractMessageHandler.
The parent is passed to the QObject base class constructor.
Definition at line 95 of file qabstractmessagehandler.cpp.
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virtual |
Destructs this QAbstractMessageHandler.
Definition at line 102 of file qabstractmessagehandler.cpp.
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protectedpure virtual |
This function must be implemented by the sub-class.
message() will call this function, passing in its parameters, type, description, identifier and sourceLocation unmodified.
Implemented in QPatternist::ColoringMessageHandler.
Referenced by message().
| void QAbstractMessageHandler::message | ( | QtMsgType | type, |
| const QString & | description, | ||
| const QUrl & | identifier = QUrl(), |
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| const QSourceLocation & | sourceLocation = QSourceLocation() |
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| ) |
Sends a message to this message handler.
type is the kind of message being sent. description is the message content. The identifier is a URI that identifies the message and is the key to interpreting the other arguments.
Typically, this class is used for reporting errors, as is the case for QXmlQuery, which uses a QAbstractMessageHandler to report compile and runtime XQuery errors. Hence, using a QUrl as the message identifier is was inspired by the explanation of error handling in the XQuery language. Because the identifier is composed of a namespace URI and a local part, identifiers with the same local part are unique. The caller is responsible for ensuring that identifier is either a valid QUrl or a default constructed QUrl.
sourceLocation identifies a location in a resource (i.e., file or document) where the need for reporting a message was detected.
This function unconditionally calls handleMessage(), passing all its parameters unmodified.
Definition at line 130 of file qabstractmessagehandler.cpp.
Referenced by QPatternist::ReportContext::createError(), and QPatternist::ReportContext::warning().