qt_demoe/designer/lib/sdk/propertysheet.qdoc

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/*!
\class QDesignerPropertySheetExtension
\brief The QDesignerPropertySheetExtension class allows you to
manipulate a widget's properties which is displayed in Qt
Designer's property editor.
\sa QDesignerDynamicPropertySheetExtension
\inmodule QtDesigner
QDesignerPropertySheetExtension provides a collection of functions that
are typically used to query a widget's properties, and to
manipulate the properties' appearance in the property editor. For
example:
\snippet doc/src/snippets/code/doc_src_qtdesigner.qdoc 15
Note that if you change the value of a property using the
QDesignerPropertySheetExtension::setProperty() function, the undo
stack is not updated. To ensure that a property's value can be
reverted using the undo stack, you must use the
QDesignerFormWindowCursorInterface::setProperty() function, or its
buddy \l
{QDesignerFormWindowCursorInterface::setWidgetProperty()}{setWidgetProperty()},
instead.
When implementing a custom widget plugin, a pointer to \QD's
current QDesignerFormEditorInterface object (\c formEditor in the
example above) is provided by the
QDesignerCustomWidgetInterface::initialize() function's parameter.
The property sheet, or any other extension, can be retrieved by
querying \QD's extension manager using the qt_extension()
function. When you want to release the extension, you only need to
delete the pointer.
All widgets have a default property sheet which populates \QD's
property editor with the widget's properties (i.e the ones defined
with the Q_PROPERTY() macro). But QDesignerPropertySheetExtension
also provides an interface for creating custom property sheet
extensions.
\warning \QD uses the QDesignerPropertySheetExtension to feed its
property editor. Whenever a widget is selected in its workspace,
\QD will query for the widget's property sheet extension. If the
selected widget has an implemented property sheet extension, this
extension will override the default property sheet.
To create a property sheet extension, your extension class must
inherit from both QObject and
QDesignerPropertySheetExtension. Then, since we are implementing
an interface, we must ensure that it's made known to the meta
object system using the Q_INTERFACES() macro:
\snippet doc/src/snippets/code/doc_src_qtdesigner.qdoc 16
This enables \QD to use qobject_cast() to query for supported
interfaces using nothing but a QObject pointer.
In \QD the extensions are not created until they are
required. For that reason, when implementing a property sheet
extension, you must also create a QExtensionFactory, i.e a class
that is able to make an instance of your extension, and register
it using \QD's \l {QExtensionManager}{extension manager}.
When a property sheet extension is required, \QD's \l
{QExtensionManager}{extension manager} will run through all its
registered factories calling QExtensionFactory::createExtension()
for each until the first one that is able to create a property
sheet extension for the selected widget, is found. This factory
will then make an instance of the extension. If no such factory
can be found, \QD will use the default property sheet.
There are four available types of extensions in \QD:
QDesignerContainerExtension, QDesignerMemberSheetExtension,
QDesignerPropertySheetExtension and QDesignerTaskMenuExtension. Qt
Designer's behavior is the same whether the requested extension is
associated with a multi page container, a member sheet, a property
sheet or a task menu.
The QExtensionFactory class provides a standard extension factory,
and can also be used as an interface for custom extension
factories. You can either create a new QExtensionFactory and
reimplement the QExtensionFactory::createExtension() function. For
example:
\snippet doc/src/snippets/code/doc_src_qtdesigner.qdoc 17
Or you can use an existing factory, expanding the
QExtensionFactory::createExtension() function to make the factory
able to create a property sheet extension extension as well. For
example:
\snippet doc/src/snippets/code/doc_src_qtdesigner.qdoc 18
For a complete example using an extension class, see the \l
{designer/taskmenuextension}{Task Menu Extension example}. The
example shows how to create a custom widget plugin for Qt
Designer, and how to to use the QDesignerTaskMenuExtension class
to add custom items to \QD's task menu.
\sa QExtensionFactory, QExtensionManager, {Creating Custom Widget
Extensions}
*/
/*!
\fn QDesignerPropertySheetExtension::~QDesignerPropertySheetExtension()
Destroys the property sheet extension.
*/
/*!
\fn int QDesignerPropertySheetExtension::count() const
Returns the selected widget's number of properties.
*/
/*!
\fn int QDesignerPropertySheetExtension::indexOf(const QString &name) const
Returns the index for a given property \a name.
\sa propertyName()
*/
/*!
\fn QString QDesignerPropertySheetExtension::propertyName(int index) const
Returns the name of the property at the given \a index.
\sa indexOf()
*/
/*!
\fn QString QDesignerPropertySheetExtension::propertyGroup(int index) const
Returns the property group for the property at the given \a index.
\QD's property editor supports property groups, i.e. sections of
related properties. A property can be related to a group using the
setPropertyGroup() function. The default group of any property is
the name of the class that defines it. For example, the
QObject::objectName property appears within the QObject property
group.
\sa indexOf(), setPropertyGroup()
*/
/*!
\fn void QDesignerPropertySheetExtension::setPropertyGroup(int index, const QString &group)
Sets the property group for the property at the given \a index to
\a group.
Relating a property to a group makes it appear within that group's
section in the property editor. The default property group of any
property is the name of the class that defines it. For example,
the QObject::objectName property appears within the QObject
property group.
\sa indexOf(), property(), propertyGroup()
*/
/*!
\fn bool QDesignerPropertySheetExtension::hasReset(int index) const
Returns true if the property at the given \a index has a reset
button in \QD's property editor, otherwise false.
\sa indexOf(), reset()
*/
/*!
\fn bool QDesignerPropertySheetExtension::reset(int index)
Resets the value of the property at the given \a index, to the
default value. Returns true if a default value could be found, otherwise false.
\sa indexOf(), hasReset(), isChanged()
*/
/*!
\fn bool QDesignerPropertySheetExtension::isVisible(int index) const
Returns true if the property at the given \a index is visible in
\QD's property editor, otherwise false.
\sa indexOf(), setVisible()
*/
/*!
\fn void QDesignerPropertySheetExtension::setVisible(int index, bool visible)
If \a visible is true, the property at the given \a index is
visible in \QD's property editor; otherwise the property is
hidden.
\sa indexOf(), isVisible()
*/
/*!
\fn bool QDesignerPropertySheetExtension::isAttribute(int index) const
Returns true if the property at the given \a index is an attribute,
which will be \e excluded from the UI file, otherwise false.
\sa indexOf(), setAttribute()
*/
/*!
\fn void QDesignerPropertySheetExtension::setAttribute(int index, bool attribute)
If \a attribute is true, the property at the given \a index is
made an attribute which will be \e excluded from the UI file;
otherwise it will be included.
\sa indexOf(), isAttribute()
*/
/*!
\fn QVariant QDesignerPropertySheetExtension::property(int index) const
Returns the value of the property at the given \a index.
\sa indexOf(), setProperty(), propertyGroup()
*/
/*!
\fn void QDesignerPropertySheetExtension::setProperty(int index, const QVariant &value)
Sets the \a value of the property at the given \a index.
\warning If you change the value of a property using this
function, the undo stack is not updated. To ensure that a
property's value can be reverted using the undo stack, you must
use the QDesignerFormWindowCursorInterface::setProperty()
function, or its buddy \l
{QDesignerFormWindowCursorInterface::setWidgetProperty()}{setWidgetProperty()},
instead.
\sa indexOf(), property(), propertyGroup()
*/
/*!
\fn bool QDesignerPropertySheetExtension::isChanged(int index) const
Returns true if the value of the property at the given \a index
differs from the property's default value, otherwise false.
\sa indexOf(), setChanged(), reset()
*/
/*!
\fn void QDesignerPropertySheetExtension::setChanged(int index, bool changed)
Sets whether the property at the given \a index is different from
its default value, or not, depending on the \a changed parameter.
\sa indexOf(), isChanged()
*/