- Qt 6.5
- Qt Designer Manual
- C++ Classes
- QDesignerWidgetBoxInterface
- Qt 6.5.3 Reference Documentation

# QDesignerWidgetBoxInterface Class

The QDesignerWidgetBoxInterface class allows you to control the contents of Qt Designer's widget box. More...

Header: | #include <QDesignerWidgetBoxInterface>
CMake: | find_package(Qt6 REQUIRED COMPONENTS Designer) target_link_libraries(mytarget PRIVATE Qt6::Designer)
qmake: | QT += designer
Inherits: | QWidget

- List of all members, including inherited members

## Public Functions

| QDesignerWidgetBoxInterface(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags())
virtual | ~QDesignerWidgetBoxInterface()
virtual QString | fileName() const = 0
virtual bool | load() = 0
virtual bool | save() = 0
virtual void | setFileName(const QString &fileName) = 0

## Detailed Description

QDesignerWidgetBoxInterface contains a collection of functions that is typically used to manipulate the contents of Qt Designer's widget box.

Qt Designer uses an XML file to populate its widget box. The name of that file is one of the widget box's properties, and you can retrieve it using the fileName() function.

QDesignerWidgetBoxInterface also provides the save() function that saves the contents of the widget box in the file specified by the widget box's file name property. If you have made changes to the widget box, for example by dropping a widget into the widget box, without calling the save() function, the original content can be restored by a simple invocation of the load() function:

             auto *widgetBox = formEditor->widgetBox();

             widgetBox->load();

The QDesignerWidgetBoxInterface class is not intended to be instantiated directly. You can retrieve an interface to Qt Designer's widget box using the QDesignerFormEditorInterface::widgetBox() function. A pointer to Qt Designer's current QDesignerFormEditorInterface object (`formEditor` in the example above) is provided by the QDesignerCustomWidgetInterface::initialize() function's parameter. When implementing a custom widget plugin, you must subclass the QDesignerCustomWidgetInterface to expose your plugin to Qt Designer.

If you want to save your changes, and at the same time preserve the original contents, you can use the save() function combined with the setFileName() function to save your changes into another file. Remember to store the name of the original file first:

             QString originalFile = widgetBox->fileName();

             widgetBox->setFileName("myWidgetBox.xml");
             widgetBox->save();

Then you can restore the original contents of the widget box by resetting the file name to the original file and calling load():

             widgetBox->setFileName(originalFile);
             widgetBox->load();

In a similar way, you can later use your customized XML file:

             if (widgetBox->filename() != "myWidgetBox.xml") {
                 widgetBox->setFileName("myWidgetBox.xml");
                 widgetBox->load();
             }

See also QDesignerFormEditorInterface.

## Member Function Documentation

### `[explicit]` QDesignerWidgetBoxInterface::QDesignerWidgetBoxInterface(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags())

Constructs a widget box interface with the given parent and the specified window flags.

### `[virtual]` QDesignerWidgetBoxInterface::~QDesignerWidgetBoxInterface()

Destroys the widget box interface.

### `[pure virtual]` QString QDesignerWidgetBoxInterface::fileName() const

Returns the name of the XML file Qt Designer is currently using to populate its widget box.

See also setFileName().

### `[pure virtual]` bool QDesignerWidgetBoxInterface::load()

Populates Qt Designer's widget box by loading (or reloading) the currently specified XML file. Returns true if the file is successfully loaded; otherwise false.

See also setFileName().

### `[pure virtual]` bool QDesignerWidgetBoxInterface::save()

Saves the contents of Qt Designer's widget box in the file specified by the fileName() function. Returns true if the content is successfully saved; otherwise false.

See also fileName() and setFileName().

### `[pure virtual]` void QDesignerWidgetBoxInterface::setFileName(const QString &fileName)

Sets the XML file that Qt Designer will use to populate its widget box, to fileName. You must call load() to update the widget box with the new XML file.

See also fileName() and load().