The QDesignerPropertySheetExtension class allows you to manipulate a widget's properties which is displayed in Qt Designer's property editor. 更多...
头: | #include <QDesignerPropertySheetExtension> |
CMake: |
find_package(Qt6 COMPONENTS Designer REQUIRED)
target_link_libraries(mytarget PRIVATE Qt6::Designer) |
qmake: | QT += designer |
virtual | ~QDesignerPropertySheetExtension () |
virtual int | count () const = 0 |
virtual bool | hasReset (int index ) const = 0 |
virtual int | indexOf (const QString & name ) const = 0 |
virtual bool | isAttribute (int index ) const = 0 |
virtual bool | isChanged (int index ) const = 0 |
virtual bool | isEnabled (int index ) const = 0 |
virtual bool | isVisible (int index ) const = 0 |
virtual QVariant | property (int index ) const = 0 |
virtual QString | propertyGroup (int index ) const = 0 |
virtual QString | propertyName (int index ) const = 0 |
virtual bool | reset (int index ) = 0 |
virtual void | setAttribute (int index , bool attribute ) = 0 |
virtual void | setChanged (int index , bool changed ) = 0 |
virtual void | setProperty (int index , const QVariant & value ) = 0 |
virtual void | setPropertyGroup (int index , const QString & group ) = 0 |
virtual void | setVisible (int index , bool visible ) = 0 |
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:
QDesignerPropertySheetExtension *propertySheet = 0; QExtensionManager manager = formEditor->extensionManager(); propertySheet = qt_extension<QDesignerPropertySheetExtension*>(manager, widget); int index = propertySheet->indexOf(QLatin1String("margin")); propertySheet->setProperty(index, 10); propertySheet->setChanged(index, true); delete propertySheet;
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 setWidgetProperty() , instead.
When implementing a custom widget plugin, a pointer to
Qt Designer
's current
QDesignerFormEditorInterface
object (
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 Qt Designer '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 Qt Designer '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.
Keep the following limitations in mind:
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 () 宏:
class MyPropertySheetExtension : public QObject, public QDesignerPropertySheetExtension { Q_OBJECT Q_INTERFACES(QDesignerPropertySheetExtension) public: ... }
This enables Qt Designer 要使用 qobject_cast () to query for supported interfaces using nothing but a QObject 指针。
在 Qt Designer 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 Qt Designer 's extension manager .
When a property sheet extension is required, Qt Designer 's 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, Qt Designer will use the default property sheet.
There are four available types of extensions in Qt Designer : 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.
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 并重实现 QExtensionFactory::createExtension () 函数。例如:
QObject *ANewExtensionFactory::createExtension(QObject *object, const QString &iid, QObject *parent) const { if (iid != Q_TYPEID(QDesignerPropertySheetExtension)) return 0; if (MyCustomWidget *widget = qobject_cast<MyCustomWidget*> (object)) return new MyPropertySheetExtension(widget, parent); return 0; }
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:
QObject *AGeneralExtensionFactory::createExtension(QObject *object, const QString &iid, QObject *parent) const { MyCustomWidget *widget = qobject_cast<MyCustomWidget*>(object); if (widget && (iid == Q_TYPEID(QDesignerTaskMenuExtension))) { return new MyTaskMenuExtension(widget, parent); } else if (widget && (iid == Q_TYPEID(QDesignerPropertySheetExtension))) { return new MyPropertySheetExtension(widget, parent); } else { return 0; } }
For a complete example using an extension class, see the 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 Qt Designer 's task menu.
另请参阅 QDesignerDynamicPropertySheetExtension , QExtensionFactory , QExtensionManager ,和 创建自定义 Widget 扩展 .
[virtual]
QDesignerPropertySheetExtension::
~QDesignerPropertySheetExtension
()
Destroys the property sheet extension.
[pure virtual]
int
QDesignerPropertySheetExtension::
count
() const
Returns the selected widget's number of properties.
[pure virtual]
bool
QDesignerPropertySheetExtension::
hasReset
(
int
index
) const
Returns true if the property at the given index has a reset button in Qt Designer 's property editor, otherwise false.
[pure virtual]
int
QDesignerPropertySheetExtension::
indexOf
(const
QString
&
name
) const
Returns the index for a given property name .
另请参阅 propertyName ().
[pure virtual]
bool
QDesignerPropertySheetExtension::
isAttribute
(
int
index
) const
Returns true if the property at the given index is an attribute, which will be excluded from the UI file, otherwise false.
另请参阅 indexOf () 和 setAttribute ().
[pure virtual]
bool
QDesignerPropertySheetExtension::
isChanged
(
int
index
) const
Returns true if the value of the property at the given index differs from the property's default value, otherwise false.
另请参阅 indexOf (), setChanged (),和 reset ().
[pure virtual, since 5.0]
bool
QDesignerPropertySheetExtension::
isEnabled
(
int
index
) const
Returns true if the property at the given index is enabled in Qt Designer 's property editor, otherwise false.
该函数在 Qt 5.0 引入。
另请参阅 indexOf ().
[pure virtual]
bool
QDesignerPropertySheetExtension::
isVisible
(
int
index
) const
Returns true if the property at the given index is visible in Qt Designer 's property editor, otherwise false.
另请参阅 indexOf () 和 setVisible ().
[pure virtual]
QVariant
QDesignerPropertySheetExtension::
property
(
int
index
) const
Returns the value of the property at the given index .
另请参阅 indexOf (), setProperty (),和 propertyGroup ().
[pure virtual]
QString
QDesignerPropertySheetExtension::
propertyGroup
(
int
index
) const
Returns the property group for the property at the given index .
Qt Designer '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.
另请参阅 indexOf () 和 setPropertyGroup ().
[pure virtual]
QString
QDesignerPropertySheetExtension::
propertyName
(
int
index
) const
Returns the name of the property at the given index .
另请参阅 indexOf ().
[pure virtual]
bool
QDesignerPropertySheetExtension::
reset
(
int
index
)
Resets the value of the property at the given index , to the default value. Returns true if a default value could be found, otherwise false.
另请参阅 indexOf (), hasReset (),和 isChanged ().
[pure virtual]
void
QDesignerPropertySheetExtension::
setAttribute
(
int
index
,
bool
attribute
)
若 attribute is true, the property at the given index is made an attribute which will be excluded from the UI file; otherwise it will be included.
另请参阅 indexOf () 和 isAttribute ().
[pure virtual]
void
QDesignerPropertySheetExtension::
setChanged
(
int
index
,
bool
changed
)
Sets whether the property at the given index is different from its default value, or not, depending on the changed 参数。
另请参阅 indexOf () 和 isChanged ().
[pure virtual]
void
QDesignerPropertySheetExtension::
setProperty
(
int
index
, const
QVariant
&
value
)
设置 value of the property at the given index .
警告: 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 setWidgetProperty() , instead.
另请参阅 indexOf (), property (),和 propertyGroup ().
[pure virtual]
void
QDesignerPropertySheetExtension::
setPropertyGroup
(
int
index
, const
QString
&
group
)
Sets the property group for the property at the given index to 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.
另请参阅 indexOf (), property (),和 propertyGroup ().
[pure virtual]
void
QDesignerPropertySheetExtension::
setVisible
(
int
index
,
bool
visible
)
若 visible is true, the property at the given index is visible in Qt Designer 's property editor; otherwise the property is hidden.