QAxBase(3qt)QAxBase(3qt)NAMEQAxBase - Abstract class that provides an API to initalize and access a
COM object
SYNOPSIS
This class is part of the Qt ActiveQt Extension.
#include <qaxbase.h>
Inherited by QAxObject and QAxWidget.
Public Members
QAxBase ( IUnknown * iface = 0 )
virtual ~QAxBase ()
QString control () const
long queryInterface ( const QUuid & uuid, void ** iface ) const
QVariant dynamicCall ( const QCString & function, const QVariant & var1
= QVariant ( ), const QVariant & var2 = QVariant ( ), const
QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant (
), const QVariant & var5 = QVariant ( ), const QVariant & var6 =
QVariant ( ), const QVariant & var7 = QVariant ( ), const QVariant
& var8 = QVariant ( ) )
QVariant dynamicCall ( const QCString & function, QValueList<QVariant>
& vars )
QAxObject * querySubObject ( const QCString & name, const QVariant &
var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const
QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant (
), const QVariant & var5 = QVariant ( ), const QVariant & var6 =
QVariant ( ), const QVariant & var7 = QVariant ( ), const QVariant
& var8 = QVariant ( ) )
PropertyBag propertyBag () const
void setPropertyBag ( const PropertyBag & bag )
QString generateDocumentation ()
virtual bool propertyWritable ( const char * prop ) const
virtual void setPropertyWritable ( const char * prop, bool ok )
bool isNull () const
QVariant asVariant () const
enum PropertyBag { }
virtual void clear ()
bool setControl ( const QString & )
void disableMetaObject ()
void disableClassInfo ()
void disableEventSink ()
Signals
void signal ( const QString & name, int argc, void * argv )
void propertyChanged ( const QString & name )
void exception ( int code, const QString & source, const QString &
desc, const QString & help )
Properties
QString control - the name of the COM object wrapped by this QAxBase
object
Protected Members
virtual bool initialize ( IUnknown ** ptr )
bool initializeRemote ( IUnknown ** ptr )
bool initializeLicensed ( IUnknown ** ptr )
bool initializeActive ( IUnknown ** ptr )
DESCRIPTION
This class is defined in the Qt ActiveQt Extension, which can be found
in the qt/extensions directory. It is not included in the main Qt API.
The QAxBase class is an abstract class that provides an API to
initalize and access a COM object.
QAxBase is an abstract class that cannot be used directly, and is
instantiated through the subclasses QAxObject and QAxWidget. This class
provides the API to access the COM object directly through its IUnknown
implementation. If the COM object implements the IDispatch interface,
the properties and methods of that object become available as Qt
properties and slots.
connect( buttonBack, SIGNAL(clicked()), webBrowser, SLOT(GoBack()) );
Properties exposed by the object's IDispatch implementation can be read
and written through the property system provided by the Qt Object Model
(both subclasses are QObjects, so you can use setProperty() and
property() as with QObject). Properties with multiple parameters are
not supported.
activeX->setProperty( "text", "some text" );
int value = activeX->property( "value" );
Write-functions for properties and other methods exposed by the
object's IDispatch implementation can be called directly using
dynamicCall(), or indirectly as slots connected to a signal.
webBrowser->dynamicCall( "GoHome()" );
Outgoing events supported by the COM object are emitted as standard Qt
signals.
connect( webBrowser, SIGNAL(TitleChanged(const QString&)),
this, SLOT(setCaption(const QString&)) );
QAxBase transparently converts between COM data types and the
equivalent Qt data types. Some COM types have no equivalent Qt data
structure.
Supported COM datatypes are listed in the first column of following
table. The second column is the Qt type that can be used with the
QObject property functions. The third column is the Qt type that is
used in the prototype of generated signals and slots for in-parameters,
and the last column is the Qt type that is used in the prototype of
signals and slots for out-parameters. <center>.nf
</center>
Supported are also enumerations, and typedefs to supported types.
To call the methods of a COM interface described by the following IDL
dispinterface IControl
{
properties:
[id(1)] BSTR text;
[id(2)] IFontDisp *font;
methods:
[id(6)] void showColumn( [in] int i );
[id(3)] bool addColumn( [in] BSTR t );
[id(4)] int fillList( [in, out] SAFEARRAY(VARIANT) *list );
[id(5)] IDispatch *item( [in] int i );
};
use the QAxBase API like this:
QAxObject object( "<CLSID>" );
QString text = object.property( "text" ).toString();
object.setProperty( "font", QFont( "Times New Roman", 12 ) );
connect( this, SIGNAL(clicked(int)), &object, SLOT(showColumn(int)) );
bool ok = object.dynamicCall( "addColumn(const QString&)", "Column 1" ).toBool();
QValueList<QVariant> varlist;
QValueList<QVariant> parameters;
parameters << QVariant( varlist );
int n = object.dynamicCall( "fillList(QValueList<QVariant>&)", parameters ).toInt();
QAxObject *item = object.querySubItem( "item(int)", 5 );
Note that the QValueList the object should fill has to be provided as
an element in the parameter list of QVariants.
If you need to access properties or pass parameters of unsupported
datatypes you must access the COM object directly through its IDispatch
implementation or other interfaces. Those interfaces can be retrieved
through queryInterface().
IUnknown *iface = 0;
activeX->queryInterface( IID_IUnknown, (void**)&iface );
if ( iface ) {
// use the interface
iface->Release();
}
To get the definition of the COM interfaces you will have to use the
header files provided with the component you want to use. Some
compilers can also import type libraries using the #import compiler
directive. See the component documentation to find out which type
libraries you have to import, and how to use them.
If you need to react to events that pass parameters of unsupported
datatypes you can use the generic signal that delivers the event data
as provided by the COM event.
Member Type Documentation
QAxBase::PropertyBag
A QMap<QString,QVariant> that can store properties as name:value pairs.
MEMBER FUNCTION DOCUMENTATIONQAxBase::QAxBase ( IUnknown * iface = 0 )
Creates a QAxBase object that wraps the COM object iface. If iface is 0
(the default), use setControl() to instantiate a COM object.
QAxBase::~QAxBase () [virtual]
Shuts down the COM object and destroys the QAxBase object.
See also clear().
QVariant QAxBase::asVariant () const
Returns a QVariant that wraps the COM object. The variant can then be
used as a parameter in e.g. dynamicCall().
void QAxBase::clear () [virtual]
Disconnects and destroys the COM object.
If you reimplement this function you must also reimplement the
destructor to call clear(), and call this implementation at the end of
your clear() function.
QString QAxBase::control () const
Returns the name of the COM object wrapped by this QAxBase object. See
the "control" property for details.
void QAxBase::disableClassInfo ()
Disables the class info generation for this ActiveX container. If you
don't require any class information about the ActiveX control use this
function to speed up the meta object generation.
Note that this function must be called immediately after construction
of the object (without passing an object identifier), and before
calling QAxWidget->setControl().
void QAxBase::disableEventSink ()
Disables the event sink implementation for this ActiveX container. If
you don't intend to listen to the ActiveX control's events use this
function to speed up the meta object generation.
Some ActiveX controls might be unstable when connected to an event
sink. To get OLE events you must use standard COM methods to register
your own event sink. Use queryInterface() to get access to the raw COM
object.
Note that this function should be called immediately after construction
of the object (without passing an object identifier), and before
calling QAxWidget->setControl().
void QAxBase::disableMetaObject ()
Disables the meta object generation for this ActiveX container. This
also disables the event sink and class info generation. If you don't
intend to use the Qt meta object implementation call this function to
speed up the meta object generation.
Some ActiveX controls might be unstable when used with OLE automation.
Use standard COM methods to use those controls through the COM
interfaces provided by queryInterface().
Note that this function must be called immediately after construction
of the object (without passing an object identifier), and before
calling QAxWidget->setControl().
QVariant QAxBase::dynamicCall ( const QCString & function, const QVariant &
var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const
QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant ( ),
const QVariant & var5 = QVariant ( ), const QVariant & var6 = QVariant
( ), const QVariant & var7 = QVariant ( ), const QVariant & var8 =
QVariant ( ) )
Calls the COM object's method function, passing the parameters var1,
var1, var2, var3, var4, var5, var6, var7 and var8, and returns the
value returned by the method, or an invalid QVariant if the method does
not return a value or when the function call failed.
If function is a method of the object the string must be provided as
the full prototype, for example as it would be written in a
QObject::connect() call.
activeX->dynamicCall( "Navigate(const QString&)", "www.trolltech.com" );
Alternatively a function can be called passing the parameters embedded
in the string, e.g. above function can also be invoked using
activeX->dynamicCall("Navigate(\"www.trolltech.com\");
All parameters are passed as strings; it depends on the control whether
they are interpreted correctly, and is slower than using the prototype
with correctly typed parameters.
If function is a property the string has to be the name of the
property. The property setter is called when var1 is a valid QVariant,
otherwise the getter is called.
activeX->dynamicCall( "Value", 5 );
QString text = activeX->dynamicCall( "Text" ).toString();
Note that it is faster to get and set properties using
QObject::property() and QObject::setProperty().
It is only possible to call functions through dynamicCall() that have
parameters or return values of datatypes supported by QVariant. See the
QAxBase class documentation for a list of supported and unsupported
datatypes. If you want to call functions that have unsupported
datatypes in the parameter list, use queryInterface() to retrieve the
appropriate COM interface, and use the function directly.
IWebBrowser2 *webBrowser = 0;
activeX->queryInterface( IID_IWebBrowser2, (void**)&webBrowser );
if ( webBrowser ) {
webBrowser->Navigate2( pvarURL );
webBrowser->Release();
}
This is also more efficient.
Example: qutlook/centralwidget.cpp.
QVariant QAxBase::dynamicCall ( const QCString & function,
QValueList<QVariant> & vars )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Calls the COM object's method function, passing the parameters in vars,
and returns the value returned by the method. If the method does not
return a value or when the function call failed this function returns
an invalid QVariant object.
The QVariant objects in vars are updated when the method has out-
parameters.
void QAxBase::exception ( int code, const QString & source, const QString &
desc, const QString & help ) [signal]
This signal is emitted when the COM object throws an exception while
called using the OLE automation interface IDispatch. code, source, desc
and help provide information about the exception as provided by the COM
server and can be used to provide useful feedback to the end user. help
includes the help file, and the help context ID in brackets, e.g.
"filename [id]".
QString QAxBase::generateDocumentation ()
Returns a rich text string with documentation for the wrapped COM
object. Dump the string to an HTML-file, or use it in e.g. a
QTextBrowser widget.
bool QAxBase::initialize ( IUnknown ** ptr ) [virtual protected]
This virtual function is called by setControl() and creates the
requested COM object. ptr is set to the object's IUnknown
implementation. The function returns TRUE if the object initialization
succeeded; otherwise the function returns FALSE.
The default implementation interprets the string returned by control(),
and calls initializeRemote(), initializeLicensed() or
initializeActive() if the string matches the respective patterns. If no
pattern is matched, or if remote or licensed initialization fails,
CoCreateInstance is used directly to create the object.
See the control property documentation for details about supported
patterns.
The interface returned in ptr must be referenced exactly once when this
function returns. The interface provided by e.g. CoCreateInstance is
already referenced, and there is no need to reference it again.
bool QAxBase::initializeActive ( IUnknown ** ptr ) [protected]
Returns an active instance running on the current machine, and returns
the IUnknown interface to the running object in ptr. This function
returns TRUE if successful, otherwise returns FALSE.
This function is called by initialize() if the control string contains
the substring "}&".
See also initialize().
bool QAxBase::initializeLicensed ( IUnknown ** ptr ) [protected]
Creates an instance of a licensed control, and returns the IUnknown
interface to the object in ptr. This functions returns TRUE if
successful, otherwise returns FALSE.
This function is called by initialize() if the control string contains
the substring "}:". The license key needs to follow this substring.
See also initialize().
bool QAxBase::initializeRemote ( IUnknown ** ptr ) [protected]
Creates the instance on a remote server, and returns the IUnknown
interface to the object in ptr. This function returns TRUE if
successful, otherwise returns FALSE.
This function is called by initialize() if the control string contains
the substring "/{". The information about the remote machine needs to
be provided in front of the substring.
See also initialize().
bool QAxBase::isNull () const
Returns TRUE if there is no COM object loaded by this wrapper;
otherwise return FALSE.
See also control.
PropertyBag QAxBase::propertyBag () const
Returns a name:value map of all the properties exposed by the COM
object.
This is more efficient than getting multiple properties individually if
the COM object supports property bags.
Warning: It is not guaranteed that the property bag implementation of
the COM object returns all properties, or that the properties returned
are the same as those available through the IDispatch interface.
void QAxBase::propertyChanged ( const QString & name ) [signal]
If the COM object supports property notification, this signal gets
emitted when the property called name is changed.
bool QAxBase::propertyWritable ( const char * prop ) const [virtual]
Returns TRUE if the property prop is writable; otherwise returns FALSE.
By default, all properties are writable.
Warning: Depending on the control implementation this setting might be
ignored for some properties.
See also setPropertyWritable() and propertyChanged().
long QAxBase::queryInterface ( const QUuid & uuid, void ** iface ) const
Requests the interface uuid from the COM object and sets the value of
iface to the provided interface, or to 0 if the requested interface
could not be provided.
Returns the result of the QueryInterface implementation of the COM
object.
See also control.
QAxObject * QAxBase::querySubObject ( const QCString & name, const QVariant &
var1 = QVariant ( ), const QVariant & var2 = QVariant ( ), const
QVariant & var3 = QVariant ( ), const QVariant & var4 = QVariant ( ),
const QVariant & var5 = QVariant ( ), const QVariant & var6 = QVariant
( ), const QVariant & var7 = QVariant ( ), const QVariant & var8 =
QVariant ( ) )
Returns a pointer to a QAxObject wrapping the COM object provided by
the method or property name, passing passing the parameters var1, var1,
var2, var3, var4, var5, var6, var7 and var8.
If name is provided by a method the string must include the full
function prototype.
If name is a property the string must be the name of the property, and
var1, ... var8 are ignored.
The returned QAxObject is a child of this object (which is either of
type QAxObject or QAxWidget), and is deleted when this object is
deleted. It is however safe to delete the returned object yourself, and
you should do so when you iterate over lists of subobjects.
COM enabled applications usually have an object model publishing
certain elements of the application as dispatch interfaces. Use this
method to navigate the hierarchy of the object model, e.g.
QAxWidget outlook( "Outlook.Application" );
QAxObject *session = outlook.querySubObject( "Session" );
if ( session ) {
QAxObject *defFolder = session->querySubObject(
"GetDefaultFolder(OlDefaultFolders)",
"olFolderContacts" );
//...
}
Example: qutlook/centralwidget.cpp.
bool QAxBase::setControl ( const QString & )
Sets the name of the COM object wrapped by this QAxBase object. See the
"control" property for details.
void QAxBase::setPropertyBag ( const PropertyBag & bag )
Sets the properties of the COM object to the corresponding values in
bag.
Warning: You should only set property bags that have been returned by
the propertyBag function, as it cannot be guaranteed that the property
bag implementation of the COM object supports the same properties that
are available through the IDispatch interface.
See also propertyBag().
void QAxBase::setPropertyWritable ( const char * prop, bool ok ) [virtual]
Sets the property prop to writable if ok is TRUE, otherwise sets prop
to be read-only. By default, all properties are writable.
Warning: Depending on the control implementation this setting might be
ignored for some properties.
See also propertyWritable() and propertyChanged().
void QAxBase::signal ( const QString & name, int argc, void * argv ) [signal]
This generic signal gets emitted when the COM object issues the event
name. argc is the number of parameters provided by the event
(DISPPARAMS.cArgs), and argv is the pointer to the parameter values
(DISPPARAMS.rgvarg). Note that the order of parameter values is turned
around, ie. the last element of the array is the first parameter in the
function.
void Receiver::slot( const QString &name, int argc, void *argv )
{
VARIANTARG *params = (VARIANTARG*)argv;
if ( name.startsWith( "BeforeNavigate2(" ) ) {
IDispatch *pDisp = params[argc-1].pdispVal;
VARIANTARG URL = *params[argc-2].pvarVal;
VARIANTARG Flags = *params[argc-3].pvarVal;
VARIANTARG TargetFrameName = *params[argc-4].pvarVal;
VARIANTARG PostData = *params[argc-5].pvarVal;
VARIANTARG Headers = *params[argc-6].pvarVal;
bool *Cancel = params[argc-7].pboolVal;
}
}
Use this signal if the event has parameters of unsupported data types.
Otherwise, connect directly to the signal name.
Property Documentation
QString control
This property holds the name of the COM object wrapped by this QAxBase
object.
Setting this property initilializes the COM object. Any COM object
previously set is shut down.
The most efficient way to set this property is by using the registered
component's UUID, e.g.
ctrl->setControl( "{8E27C92B-1264-101C-8A2F-040224009C02}" );
The second fastest way is to use the registered control's class name
(with or without version number), e.g.
ctrl->setControl( "MSCal.Calendar" );
The slowest, but easiest way to use is to use the control's full name,
e.g.
ctrl->setControl( "Calendar Control 9.0" );
If the component's UUID is used the following patterns can be used to
initialize the control on a remote machine, to initialize a licensed
control or to connect to a running object:
To initialize the control on a different machine use the following
pattern:
<domain/username>:<password>@server/{8E27C92B-1264-101C-8A2F-040224009C02}
To initialize a licensed control use the following pattern:
{8E27C92B-1264-101C-8A2F-040224009C02}:<LicenseKey>
To connect to an already running object use the following pattern:
{8E27C92B-1264-101C-8A2F-040224009C02}&
The first two patterns can be combined, e.g. to initialize a
licensed control on a remote machine:
ctrl->setControl("DOMAIN/user:password@server/{8E27C92B-1264-101C-8A2F-040224009C02}:LicenseKey");
The control's read function always returns the control's UUID, if
provided including the license key, and the name of the server, but not
including the username, the domain or the password.
Set this property's value with setControl() and get this property's
value with control().
SEE ALSO
http://doc.trolltech.com/qaxbase.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with a
web browser. This man page is provided as a convenience for those users
who prefer man pages, although this format is not officially supported
by Trolltech.
If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qaxbase.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QAxBase(3qt)