class QWidget#

The QWidget class is the base class of all user interface objects. More

Inheritance diagram of PySide6.QtWidgets.QWidget

Inherited by: QWizardPage, QToolBar, QTabWidget, QTabBar, QStatusBar, QSplitterHandle, QSplashScreen, QSizeGrip, QRubberBand, QProgressBar, QMenuBar, QMenu, QMdiSubWindow, QMainWindow, QLineEdit, QKeySequenceEdit, QGroupBox, QFrame, QToolBox, QStackedWidget, QSplitter, QLabel, QLCDNumber, QAbstractScrollArea, QTextEdit, QTextBrowser, QScrollArea, QPlainTextEdit, QMdiArea, QGraphicsView, QAbstractItemView, QTreeView, QTreeWidget, QHelpContentWidget, QTableView, QTableWidget, QListView, QUndoView, QListWidget, QHelpIndexWidget, QHeaderView, QColumnView, QPdfView, QFocusFrame, QDockWidget, QDialogButtonBox, QDialog, QWizard, QProgressDialog, QMessageBox, QInputDialog, QFontDialog, QErrorMessage, QColorDialog, QPrintPreviewDialog, QPageSetupDialog, QAbstractPrintDialog, QPrintDialog, QComboBox, QFontComboBox, QCalendarWidget, QAbstractSpinBox, QSpinBox, QDoubleSpinBox, QDateTimeEdit, QTimeEdit, QDateEdit, QAbstractSlider, QSlider, QScrollBar, QDial, QAbstractButton, QToolButton, QRadioButton, QPushButton, QCommandLinkButton, QCheckBox, QSvgWidget, QQuickWidget, QAbstract3DGraph, Q3DSurface, Q3DScatter, Q3DBars, QPrintPreviewWidget, QPdfPageSelector, QOpenGLWidget, QVideoWidget, QHelpSearchResultWidget, QHelpSearchQueryWidget, QHelpFilterSettingsWidget, QDesignerWidgetBoxInterface, QDesignerPropertyEditorInterface, QDesignerObjectInspectorInterface, QDesignerFormWindowInterface, QDesignerActionEditorInterface, QFileDialog, QWebEngineView, QChartView

Synopsis#

Properties#

Methods#

Virtual methods#

Slots#

Signals#

Static functions#

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description#

The widget is the atom of the user interface: it receives mouse, keyboard and other events from the window system, and paints a representation of itself on the screen. Every widget is rectangular, and they are sorted in a Z-order. A widget is clipped by its parent and by the widgets in front of it.

A widget that is not embedded in a parent widget is called a window. Usually, windows have a frame and a title bar, although it is also possible to create windows without such decoration using suitable window flags. In Qt, QMainWindow and the various subclasses of QDialog are the most common window types.

Every widget’s constructor accepts one or two standard arguments:

  1. QWidget *parent = nullptr is the parent of the new widget. If it is None (the default), the new widget will be a window. If not, it will be a child of parent, and be constrained by parent's geometry (unless you specify Qt::Window as window flag).

  2. Qt::WindowFlags f = { } (where available) sets the window flags; the default is suitable for most widgets, but to get, for example, a window without a window system frame, you must use special flags.

QWidget has many member functions, but some of them have little direct functionality; for example, QWidget has a font property, but never uses this itself. There are many subclasses that provide real functionality, such as QLabel , QPushButton , QListWidget , and QTabWidget .

Top-Level and Child Widgets#

A widget without a parent widget is always an independent window (top-level widget). For these widgets, setWindowTitle() and setWindowIcon() set the title bar and icon, respectively.

Non-window widgets are child widgets, displayed within their parent widgets. Most widgets in Qt are mainly useful as child widgets. For example, it is possible to display a button as a top-level window, but most people prefer to put their buttons inside other widgets, such as QDialog .

../../_images/parent-child-widgets.png

The diagram above shows a QGroupBox widget being used to hold various child widgets in a layout provided by QGridLayout . The QLabel child widgets have been outlined to indicate their full sizes.

If you want to use a QWidget to hold child widgets, you will usually want to add a layout to the parent QWidget . See Layout Management for more information.

Composite Widgets#

When a widget is used as a container to group a number of child widgets, it is known as a composite widget. These can be created by constructing a widget with the required visual properties - a QFrame , for example - and adding child widgets to it, usually managed by a layout.

Composite widgets can also be created by subclassing a standard widget, such as QWidget or QFrame , and adding the necessary layout and child widgets in the constructor of the subclass. Many of the examples provided with Qt use this approach, and it is also covered in the Qt Widgets Tutorial .

Custom Widgets and Painting#

Since QWidget is a subclass of QPaintDevice, subclasses can be used to display custom content that is composed using a series of painting operations with an instance of the QPainter class. This approach contrasts with the canvas-style approach used by the Graphics View Framework where items are added to a scene by the application and are rendered by the framework itself.

Each widget performs all painting operations from within its paintEvent() function. This is called whenever the widget needs to be redrawn, either because of some external change or when requested by the application.

The Analog Clock example shows how a simple widget can handle paint events.

Size Hints and Size Policies#

When implementing a new widget, it is almost always useful to reimplement sizeHint() to provide a reasonable default size for the widget and to set the correct size policy with setSizePolicy() .

By default, composite widgets that do not provide a size hint will be sized according to the space requirements of their child widgets.

The size policy lets you supply good default behavior for the layout management system, so that other widgets can contain and manage yours easily. The default size policy indicates that the size hint represents the preferred size of the widget, and this is often good enough for many widgets.

Note

The size of top-level widgets are constrained to 2/3 of the desktop’s height and width. You can resize() the widget manually if these bounds are inadequate.

Events#

Widgets respond to events that are typically caused by user actions. Qt delivers events to widgets by calling specific event handler functions with instances of QEvent subclasses containing information about each event.

If your widget only contains child widgets, you probably don’t need to implement any event handlers. If you want to detect a mouse click in a child widget, call the child’s underMouse() function inside the widget’s mousePressEvent() .

The Scribble example implements a wider set of events to handle mouse movement, button presses, and window resizing.

You will need to supply the behavior and content for your own widgets, but here is a brief overview of the events that are relevant to QWidget , starting with the most common ones:

  • paintEvent() is called whenever the widget needs to be repainted. Every widget displaying custom content must implement it. Painting using a QPainter can only take place in a paintEvent() or a function called by a paintEvent() .

  • resizeEvent() is called when the widget has been resized.

  • mousePressEvent() is called when a mouse button is pressed while the mouse cursor is inside the widget, or when the widget has grabbed the mouse using grabMouse() . Pressing the mouse without releasing it is effectively the same as calling grabMouse() .

  • mouseReleaseEvent() is called when a mouse button is released. A widget receives mouse release events when it has received the corresponding mouse press event. This means that if the user presses the mouse inside your widget, then drags the mouse somewhere else before releasing the mouse button, your widget receives the release event. There is one exception: if a popup menu appears while the mouse button is held down, this popup immediately steals the mouse events.

  • mouseDoubleClickEvent() is called when the user double-clicks in the widget. If the user double-clicks, the widget receives a mouse press event, a mouse release event, (a mouse click event,) a second mouse press, this event and finally a second mouse release event. (Some mouse move events may also be received if the mouse is not held steady during this operation.) It is not possible to distinguish a click from a double-click until the second click arrives. (This is one reason why most GUI books recommend that double-clicks be an extension of single-clicks, rather than trigger a different action.)

Widgets that accept keyboard input need to reimplement a few more event handlers:

  • keyPressEvent() is called whenever a key is pressed, and again when a key has been held down long enough for it to auto-repeat. The Tab and Shift+Tab keys are only passed to the widget if they are not used by the focus-change mechanisms. To force those keys to be processed by your widget, you must reimplement event() .

  • focusInEvent() is called when the widget gains keyboard focus (assuming you have called setFocusPolicy() ). Well-behaved widgets indicate that they own the keyboard focus in a clear but discreet way.

  • focusOutEvent() is called when the widget loses keyboard focus.

You may be required to also reimplement some of the less common event handlers:

  • mouseMoveEvent() is called whenever the mouse moves while a mouse button is held down. This can be useful during drag and drop operations. If you call setMouseTracking (true), you get mouse move events even when no buttons are held down. (See also the Drag and Drop guide.)

  • keyReleaseEvent() is called whenever a key is released and while it is held down (if the key is auto-repeating). In that case, the widget will receive a pair of key release and key press event for every repeat. The Tab and Shift+Tab keys are only passed to the widget if they are not used by the focus-change mechanisms. To force those keys to be processed by your widget, you must reimplement event() .

  • wheelEvent() is called whenever the user turns the mouse wheel while the widget has the focus.

  • enterEvent() is called when the mouse enters the widget’s screen space. (This excludes screen space owned by any of the widget’s children.)

  • leaveEvent() is called when the mouse leaves the widget’s screen space. If the mouse enters a child widget, it will not cause a leaveEvent() .

  • moveEvent() is called when the widget has been moved relative to its parent.

  • closeEvent() is called when the user closes the widget (or when close() is called).

There are also some rather obscure events described in the documentation for QEvent::Type. To handle these events, you need to reimplement event() directly.

The default implementation of event() handles Tab and Shift+Tab (to move the keyboard focus), and passes on most of the other events to one of the more specialized handlers above.

Events and the mechanism used to deliver them are covered in The Event System.

Groups of Functions and Properties#

Context

Functions and Properties

Window functions

show() , hide() , raise() , lower() , close() .

Top-level windows

windowModified , windowTitle , windowIcon , isActiveWindow , activateWindow() , minimized , showMinimized() , maximized , showMaximized() , fullScreen , showFullScreen() , showNormal() .

Window contents

update() , repaint() , scroll() .

Geometry

pos , x() , y() , rect , size , width() , height() , move() , resize() , sizePolicy , sizeHint() , minimumSizeHint() , updateGeometry() , layout() , frameGeometry , geometry , childrenRect , childrenRegion , adjustSize() , mapFromGlobal() , mapToGlobal() , mapFromParent() , mapToParent() , maximumSize , minimumSize , sizeIncrement , baseSize , setFixedSize()

Mode

visible , isVisibleTo() , enabled , isEnabledTo() , modal , isWindow() , mouseTracking , updatesEnabled , visibleRegion() .

Look and feel

style() , setStyle() , styleSheet , cursor , font , palette , backgroundRole() , setBackgroundRole() , fontInfo() , fontMetrics() .

Keyboard focus functions

focus , focusPolicy , setFocus() , clearFocus() , setTabOrder() , setFocusProxy() , focusNextChild() , focusPreviousChild() .

Mouse and keyboard grabbing

grabMouse() , releaseMouse() , grabKeyboard() , releaseKeyboard() , mouseGrabber() , keyboardGrabber() .

Event handlers

event() , mousePressEvent() , mouseReleaseEvent() , mouseDoubleClickEvent() , mouseMoveEvent() , keyPressEvent() , keyReleaseEvent() , focusInEvent() , focusOutEvent() , wheelEvent() , enterEvent() , leaveEvent() , paintEvent() , moveEvent() , resizeEvent() , closeEvent() , dragEnterEvent() , dragMoveEvent() , dragLeaveEvent() , dropEvent() , childEvent(), showEvent() , hideEvent() , customEvent(). changeEvent() ,

System functions

parentWidget() , window() , setParent() , winId() , find() , metric() .

Context menu

contextMenuPolicy , contextMenuEvent() , customContextMenuRequested() , actions()

Interactive help

setToolTip() , setWhatsThis()

Widget Style Sheets#

In addition to the standard widget styles for each platform, widgets can also be styled according to rules specified in a style sheet . This feature enables you to customize the appearance of specific widgets to provide visual cues to users about their purpose. For example, a button could be styled in a particular way to indicate that it performs a destructive action.

The use of widget style sheets is described in more detail in the Qt Style Sheets document.

Transparency and Double Buffering#

QWidget automatically double-buffers its painting, so there is no need to write double-buffering code in paintEvent() to avoid flicker.

The contents of parent widgets are propagated by default to each of their children as long as Qt::WA_PaintOnScreen is not set. Custom widgets can be written to take advantage of this feature by updating irregular regions (to create non-rectangular child widgets), or painting with colors that have less than full alpha component. The following diagram shows how attributes and properties of a custom widget can be fine-tuned to achieve different effects.

../../_images/propagation-custom.png

In the above diagram, a semi-transparent rectangular child widget with an area removed is constructed and added to a parent widget (a QLabel showing a pixmap). Then, different properties and widget attributes are set to achieve different effects:

  • The left widget has no additional properties or widget attributes set. This default state suits most custom widgets that have transparency, are irregularly-shaped, or do not paint over their entire area with an opaque brush.

  • The center widget has the autoFillBackground property set. This property is used with custom widgets that rely on the widget to supply a default background, and do not paint over their entire area with an opaque brush.

  • The right widget has the Qt::WA_OpaquePaintEvent widget attribute set. This indicates that the widget will paint over its entire area with opaque colors. The widget’s area will initially be uninitialized, represented in the diagram with a red diagonal grid pattern that shines through the overpainted area.

To rapidly update custom widgets with simple background colors, such as real-time plotting or graphing widgets, it is better to define a suitable background color (using setBackgroundRole() with the QPalette::Window role), set the autoFillBackground property, and only implement the necessary drawing functionality in the widget’s paintEvent() .

To rapidly update custom widgets that constantly paint over their entire areas with opaque content, for example, video streaming widgets, it is better to set the widget’s Qt::WA_OpaquePaintEvent, avoiding any unnecessary overhead associated with repainting the widget’s background.

If a widget has both the Qt::WA_OpaquePaintEvent widget attribute and the autoFillBackground property set, the Qt::WA_OpaquePaintEvent attribute takes precedence. Depending on your requirements, you should choose either one of them.

The contents of parent widgets are also propagated to standard Qt widgets. This can lead to some unexpected results if the parent widget is decorated in a non-standard way, as shown in the diagram below.

../../_images/propagation-standard.png

The scope for customizing the painting behavior of standard Qt widgets, without resorting to subclassing, is slightly less than that possible for custom widgets. Usually, the desired appearance of a standard widget can be achieved by setting its autoFillBackground property.

Creating Translucent Windows#

You can create windows with translucent regions on window systems that support compositing.

To enable this feature in a top-level widget, set its Qt::WA_TranslucentBackground attribute with setAttribute() and ensure that its background is painted with non-opaque colors in the regions you want to be partially transparent.

Platform notes:

  • X11: This feature relies on the use of an X server that supports ARGB visuals and a compositing window manager.

  • Windows: The widget needs to have the Qt::FramelessWindowHint window flag set for the translucency to work.

  • macOS: The widget needs to have the Qt::FramelessWindowHint window flag set for the translucency to work.

Native Widgets vs Alien Widgets#

Alien widgets are widgets unknown to the windowing system. They do not have a native window handle associated with them. This feature significantly speeds up widget painting, resizing, and removes flicker.

Should you require the old behavior with native windows, choose one of the following options:

  1. Use the QT_USE_NATIVE_WINDOWS=1 in your environment.

  2. Set the Qt::AA_NativeWindows attribute on your application. All widgets will be native widgets.

  3. Set the Qt::WA_NativeWindow attribute on widgets: The widget itself and all its ancestors will become native (unless Qt::WA_DontCreateNativeAncestors is set).

  4. Call winId to enforce a native window (this implies 3).

  5. Set the Qt::WA_PaintOnScreen attribute to enforce a native window (this implies 3).

class RenderFlag#

(inherits enum.Flag) This enum describes how to render the widget when calling render() .

Constant

Description

QWidget.DrawWindowBackground

If you enable this option, the widget’s background is rendered into the target even if autoFillBackground is not set. By default, this option is enabled.

QWidget.DrawChildren

If you enable this option, the widget’s children are rendered recursively into the target. By default, this option is enabled.

QWidget.IgnoreMask

If you enable this option, the widget’s mask() is ignored when rendering into the target. By default, this option is disabled.

Note

Properties can be used directly when from __feature__ import true_property is used or via accessor functions otherwise.

property acceptDropsᅟ: bool#

This property holds whether drop events are enabled for this widget.

Setting this property to true announces to the system that this widget may be able to accept drop events.

If the widget is the desktop ( windowType() == Qt::Desktop), this may fail if another application is using the desktop; you can call acceptDrops() to test if this occurs.

Warning

Do not modify this property in a drag and drop event handler.

By default, this property is false.

See also

Drag and Drop

Access functions:
property accessibleDescriptionᅟ: str#

This property holds the widget’s description as seen by assistive technologies.

The accessible description of a widget should convey what a widget does. While the accessibleName should be a short and concise string (e.g. Save), the description should give more context, such as Saves the current document.

This property has to be localized.

By default, this property contains an empty string and Qt falls back to using the tool tip to provide this information.

Access functions:
property accessibleNameᅟ: str#

This property holds the widget’s name as seen by assistive technologies.

This is the primary name by which assistive technology such as screen readers announce this widget. For most widgets setting this property is not required. For example for QPushButton the button’s text will be used.

It is important to set this property when the widget does not provide any text. For example a button that only contains an icon needs to set this property to work with screen readers. The name should be short and equivalent to the visual information conveyed by the widget.

This property has to be localized.

By default, this property contains an empty string.

Access functions:
property autoFillBackgroundᅟ: bool#

This property holds whether the widget background is filled automatically.

If enabled, this property will cause Qt to fill the background of the widget before invoking the paint event. The color used is defined by the QPalette::Window color role from the widget’s palette.

In addition, Windows are always filled with QPalette::Window, unless the WA_OpaquePaintEvent or WA_NoSystemBackground attributes are set.

This property cannot be turned off (i.e., set to false) if a widget’s parent has a static gradient for its background.

Warning

Use this property with caution in conjunction with Qt Style Sheets . When a widget has a style sheet with a valid background or a border-image, this property is automatically disabled.

By default, this property is false.

See also

Transparency and Double Buffering

Access functions:
property baseSizeᅟ: QSize#

This property holds the base size of the widget.

The base size is used to calculate a proper widget size if the widget defines sizeIncrement() .

By default, for a newly-created widget, this property contains a size with zero width and height.

Access functions:
property childrenRectᅟ: QRect#

This property holds the bounding rectangle of the widget’s children.

Hidden children are excluded.

By default, for a widget with no children, this property contains a rectangle with zero width and height located at the origin.

Access functions:
property childrenRegionᅟ: QRegion#

This property holds the combined region occupied by the widget’s children.

Hidden children are excluded.

By default, for a widget with no children, this property contains an empty region.

Access functions:
property contextMenuPolicyᅟ: Qt.ContextMenuPolicy#

This property holds how the widget shows a context menu.

The default value of this property is Qt::DefaultContextMenu, which means the contextMenuEvent() handler is called. Other values are Qt::NoContextMenu, Qt::PreventContextMenu, Qt::ActionsContextMenu, and Qt::CustomContextMenu. With Qt::CustomContextMenu, the signal customContextMenuRequested() is emitted.

Access functions:
property cursorᅟ: QCursor#

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

This property holds the cursor shape for this widget.

The mouse cursor will assume this shape when it’s over this widget. See the list of predefined cursor objects for a range of useful shapes.

An editor widget might use an I-beam cursor:

setCursor(Qt.IBeamCursor)

If no cursor has been set, or after a call to unsetCursor(), the parent’s cursor is used.

By default, this property contains a cursor with the Qt::ArrowCursor shape.

Some underlying window implementations will reset the cursor if it leaves a widget even if the mouse is grabbed. If you want to have a cursor set for all widgets, even when outside the window, consider QGuiApplication::setOverrideCursor().

Access functions:
property enabledᅟ: bool#

This property holds whether the widget is enabled.

In general an enabled widget handles keyboard and mouse events; a disabled widget does not. An exception is made with QAbstractButton .

Some widgets display themselves differently when they are disabled. For example a button might draw its label grayed out. If your widget needs to know when it becomes enabled or disabled, you can use the changeEvent() with type QEvent::EnabledChange.

Disabling a widget implicitly disables all its children. Enabling respectively enables all child widgets unless they have been explicitly disabled. It it not possible to explicitly enable a child widget which is not a window while its parent widget remains disabled.

By default, this property is true.

Access functions:
property focusᅟ: bool#

This property holds whether this widget (or its focus proxy) has the keyboard input focus.

By default, this property is false.

Note

Obtaining the value of this property for a widget is effectively equivalent to checking whether focusWidget() refers to the widget.

Access functions:
property focusPolicyᅟ: Qt.FocusPolicy#

This property holds the way the widget accepts keyboard focus.

The policy is Qt::TabFocus if the widget accepts keyboard focus by tabbing, Qt::ClickFocus if the widget accepts focus by clicking, Qt::StrongFocus if it accepts both, and Qt::NoFocus (the default) if it does not accept focus at all.

You must enable keyboard focus for a widget if it processes keyboard events. This is normally done from the widget’s constructor. For instance, the QLineEdit constructor calls setFocusPolicy(Qt::StrongFocus).

If the widget has a focus proxy, then the focus policy will be propagated to it.

Access functions:
property fontᅟ: QFont#

This property holds the font currently set for the widget.

This property describes the widget’s requested font. The font is used by the widget’s style when rendering standard components, and is available as a means to ensure that custom widgets can maintain consistency with the native platform’s look and feel. It’s common that different platforms, or different styles, define different fonts for an application.

When you assign a new font to a widget, the properties from this font are combined with the widget’s default font to form the widget’s final font. You can call fontInfo() to get a copy of the widget’s final font. The final font is also used to initialize QPainter’s font.

The default depends on the system environment. QApplication maintains a system/theme font which serves as a default for all widgets. There may also be special font defaults for certain types of widgets. You can also define default fonts for widgets yourself by passing a custom font and the name of a widget to setFont() . Finally, the font is matched against Qt’s font database to find the best match.

QWidget propagates explicit font properties from parent to child. If you change a specific property on a font and assign that font to a widget, that property will propagate to all the widget’s children, overriding any system defaults for that property. Note that fonts by default don’t propagate to windows (see isWindow() ) unless the Qt::WA_WindowPropagation attribute is enabled.

QWidget ‘s font propagation is similar to its palette propagation.

The current style, which is used to render the content of all standard Qt widgets, is free to choose to use the widget font, or in some cases, to ignore it (partially, or completely). In particular, certain styles like GTK style, Mac style, and Windows Vista style, apply special modifications to the widget font to match the platform’s native look and feel. Because of this, assigning properties to a widget’s font is not guaranteed to change the appearance of the widget. Instead, you may choose to apply a styleSheet .

Note

If Qt Style Sheets are used on the same widget as setFont(), style sheets will take precedence if the settings conflict.

Access functions:
property frameGeometryᅟ: QRect#

This property holds geometry of the widget relative to its parent including any window frame.

See the Window Geometry documentation for an overview of geometry issues with windows.

By default, this property contains a value that depends on the user’s platform and screen geometry.

See also

geometry() x() y() pos()

Access functions:
property frameSizeᅟ: QSize#

This property holds the size of the widget including any window frame.

By default, this property contains a value that depends on the user’s platform and screen geometry.

Access functions:
property fullScreenᅟ: bool#

This property holds whether the widget is shown in full screen mode.

A widget in full screen mode occupies the whole screen area and does not display window decorations, such as a title bar.

By default, this property is false.

See also

windowState() minimized maximized

Access functions:
property geometryᅟ: QRect#

This property holds the geometry of the widget relative to its parent and excluding the window frame.

When changing the geometry, the widget, if visible, receives a move event ( moveEvent() ) and/or a resize event ( resizeEvent() ) immediately. If the widget is not currently visible, it is guaranteed to receive appropriate events before it is shown.

The size component is adjusted if it lies outside the range defined by minimumSize() and maximumSize() .

Warning

Calling setGeometry() inside resizeEvent() or moveEvent() can lead to infinite recursion.

See the Window Geometry documentation for an overview of geometry issues with windows.

By default, this property contains a value that depends on the user’s platform and screen geometry.

Access functions:
property heightᅟ: int#

This property holds the height of the widget excluding any window frame.

See the Window Geometry documentation for an overview of geometry issues with windows.

By default, this property contains a value that depends on the user’s platform and screen geometry.

See also

geometry width size

Access functions:

property inputMethodHintsᅟ: Combination of Qt.InputMethodHint#

This property holds What input method specific hints the widget has..

This is only relevant for input widgets. It is used by the input method to retrieve hints as to how the input method should operate. For example, if the Qt::ImhFormattedNumbersOnly flag is set, the input method may change its visual components to reflect that only numbers can be entered.

Warning

Some widgets require certain flags to work as intended. To set a flag, do w->setInputMethodHints(w->inputMethodHints()|f) instead of w->setInputMethodHints(f).

Note

The flags are only hints, so the particular input method implementation is free to ignore them. If you want to be sure that a certain type of characters are entered, you should also set a QValidator on the widget.

The default value is Qt::ImhNone.

Access functions:
property isActiveWindowᅟ: bool#

This property holds whether this widget’s window is the active window.

The active window is the window that contains the widget that has keyboard focus (The window may still have focus if it has no widgets or none of its widgets accepts keyboard focus).

When popup windows are visible, this property is true for both the active window and for the popup.

By default, this property is false.

Access functions:
property layoutDirectionᅟ: Qt.LayoutDirection#

This property holds the layout direction for this widget..

Note

This method no longer affects text layout direction since Qt 4.7.

By default, this property is set to Qt::LeftToRight.

When the layout direction is set on a widget, it will propagate to the widget’s children, but not to a child that is a window and not to a child for which setLayoutDirection() has been explicitly called. Also, child widgets added after setLayoutDirection() has been called for the parent do not inherit the parent’s layout direction.

See also

layoutDirection

Access functions:
property localeᅟ: QLocale#

This property holds the widget’s locale.

As long as no special locale has been set, this is either the parent’s locale or (if this widget is a top level widget), the default locale.

If the widget displays dates or numbers, these should be formatted using the widget’s locale.

See also

setDefault()

Access functions:
property maximizedᅟ: bool#

This property holds whether this widget is maximized.

This property is only relevant for windows.

Note

Due to limitations on some window systems, this does not always report the expected results (e.g., if the user on X11 maximizes the window via the window manager, Qt has no way of distinguishing this from any other resize). This is expected to improve as window manager protocols evolve.

By default, this property is false.

Access functions:
property maximumHeightᅟ: int#

This property holds the widget’s maximum height in pixels.

This property corresponds to the height held by the maximumSize property.

By default, this property contains a value of 16777215.

Note

The definition of the QWIDGETSIZE_MAX macro limits the maximum size of widgets.

Access functions:
property maximumSizeᅟ: QSize#

This property holds the widget’s maximum size in pixels.

The widget cannot be resized to a larger size than the maximum widget size.

By default, this property contains a size in which both width and height have values of 16777215.

Note

The definition of the QWIDGETSIZE_MAX macro limits the maximum size of widgets.

Access functions:
property maximumWidthᅟ: int#

This property holds the widget’s maximum width in pixels.

This property corresponds to the width held by the maximumSize property.

By default, this property contains a value of 16777215.

Note

The definition of the QWIDGETSIZE_MAX macro limits the maximum size of widgets.

Access functions:
property minimizedᅟ: bool#

This property holds whether this widget is minimized (iconified).

This property is only relevant for windows.

By default, this property is false.

See also

showMinimized() visible show() hide() showNormal() maximized

Access functions:
property minimumHeightᅟ: int#

This property holds the widget’s minimum height in pixels.

This property corresponds to the height held by the minimumSize property.

By default, this property has a value of 0.

Access functions:
property minimumSizeᅟ: QSize#

This property holds the widget’s minimum size.

The widget cannot be resized to a smaller size than the minimum widget size. The widget’s size is forced to the minimum size if the current size is smaller.

The minimum size set by this function will override the minimum size defined by QLayout . To unset the minimum size, use a value of QSize(0, 0).

By default, this property contains a size with zero width and height.

Access functions:
property minimumSizeHintᅟ: QSize#

This property holds the recommended minimum size for the widget.

If the value of this property is an invalid size, no minimum size is recommended.

The default implementation of minimumSizeHint() returns an invalid size if there is no layout for this widget, and returns the layout’s minimum size otherwise. Most built-in widgets reimplement minimumSizeHint().

QLayout will never resize a widget to a size smaller than the minimum size hint unless minimumSize() is set or the size policy is set to QSizePolicy::Ignore. If minimumSize() is set, the minimum size hint will be ignored.

Access functions:
property minimumWidthᅟ: int#

This property holds the widget’s minimum width in pixels.

This property corresponds to the width held by the minimumSize property.

By default, this property has a value of 0.

Access functions:
property modalᅟ: bool#

This property holds whether the widget is a modal widget.

This property only makes sense for windows. A modal widget prevents widgets in all other windows from getting any input.

By default, this property is false.

Access functions:
property mouseTrackingᅟ: bool#

This property holds whether mouse tracking is enabled for the widget.

If mouse tracking is disabled (the default), the widget only receives mouse move events when at least one mouse button is pressed while the mouse is being moved.

If mouse tracking is enabled, the widget receives mouse move events even if no buttons are pressed.

See also

mouseMoveEvent()

Access functions:
property normalGeometryᅟ: QRect#

This property holds the geometry of the widget as it will appear when shown as a normal (not maximized or full screen) top-level widget.

If the widget is already in this state the normal geometry will reflect the widget’s current geometry() .

For child widgets this property always holds an empty rectangle.

By default, this property contains an empty rectangle.

Access functions:
property paletteᅟ: QPalette#

This property holds the widget’s palette.

This property describes the widget’s palette. The palette is used by the widget’s style when rendering standard components, and is available as a means to ensure that custom widgets can maintain consistency with the native platform’s look and feel. It’s common that different platforms, or different styles, have different palettes.

When you assign a new palette to a widget, the color roles from this palette are combined with the widget’s default palette to form the widget’s final palette. The palette entry for the widget’s background role is used to fill the widget’s background (see autoFillBackground ), and the foreground role initializes QPainter’s pen.

The default depends on the system environment. QApplication maintains a system/theme palette which serves as a default for all widgets. There may also be special palette defaults for certain types of widgets (e.g., on Windows Vista, all classes that derive from QMenuBar have a special default palette). You can also define default palettes for widgets yourself by passing a custom palette and the name of a widget to setPalette() . Finally, the style always has the option of polishing the palette as it’s assigned (see polish() ).

QWidget propagates explicit palette roles from parent to child. If you assign a brush or color to a specific role on a palette and assign that palette to a widget, that role will propagate to all the widget’s children, overriding any system defaults for that role. Note that palettes by default don’t propagate to windows (see isWindow() ) unless the Qt::WA_WindowPropagation attribute is enabled.

QWidget ‘s palette propagation is similar to its font propagation.

The current style, which is used to render the content of all standard Qt widgets, is free to choose colors and brushes from the widget palette, or, in some cases, to ignore the palette (partially, or completely). In particular, certain styles like GTK style, Mac style, and Windows Vista style, depend on third party APIs to render the content of widgets, and these styles typically do not follow the palette. Because of this, assigning roles to a widget’s palette is not guaranteed to change the appearance of the widget. Instead, you may choose to apply a styleSheet .

Warning

Do not use this function in conjunction with Qt Style Sheets . When using style sheets, the palette of a widget can be customized using the “color”, “background-color”, “selection-color”, “selection-background-color” and “alternate-background-color”.

Access functions:
property posᅟ: QPoint#

This property holds the position of the widget within its parent widget.

If the widget is a window, the position is that of the widget on the desktop, including its frame.

When changing the position, the widget, if visible, receives a move event ( moveEvent() ) immediately. If the widget is not currently visible, it is guaranteed to receive an event before it is shown.

By default, this property contains a position that refers to the origin.

Warning

Calling move() or setGeometry() inside moveEvent() can lead to infinite recursion.

See the Window Geometry documentation for an overview of geometry issues with windows.

Note

Not all windowing systems support setting or querying top level window positions. On such a system, programmatically moving windows may not have any effect, and artificial values may be returned for the current positions, such as QPoint(0, 0).

Access functions:
property rectᅟ: QRect#

This property holds the internal geometry of the widget excluding any window frame.

The rect property equals QRect(0, 0, width() , height() ).

See the Window Geometry documentation for an overview of geometry issues with windows.

By default, this property contains a value that depends on the user’s platform and screen geometry.

See also

size

Access functions:
property sizeᅟ: QSize#

This property holds the size of the widget excluding any window frame.

If the widget is visible when it is being resized, it receives a resize event ( resizeEvent() ) immediately. If the widget is not currently visible, it is guaranteed to receive an event before it is shown.

The size is adjusted if it lies outside the range defined by minimumSize() and maximumSize() .

By default, this property contains a value that depends on the user’s platform and screen geometry.

Warning

Calling resize() or setGeometry() inside resizeEvent() can lead to infinite recursion.

Note

Setting the size to QSize(0, 0) will cause the widget to not appear on screen. This also applies to windows.

Access functions:
property sizeHintᅟ: QSize#

This property holds the recommended size for the widget.

If the value of this property is an invalid size, no size is recommended.

The default implementation of sizeHint() returns an invalid size if there is no layout for this widget, and returns the layout’s preferred size otherwise.

Access functions:
property sizeIncrementᅟ: QSize#

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

This property holds the size increment of the widget.

When the user resizes the window, the size will move in steps of sizeIncrement(). width() pixels horizontally and sizeIncrement. height() pixels vertically, with baseSize() as the basis. Preferred widget sizes are for non-negative integers i and j:

width = baseSize().width() + i * sizeIncrement().width()
height = baseSize().height() + j * sizeIncrement().height()

Note that while you can set the size increment for all widgets, it only affects windows.

By default, this property contains a size with zero width and height.

Warning

The size increment has no effect under Windows, and may be disregarded by the window manager on X11.

Access functions:
property sizePolicyᅟ: QSizePolicy#

This property holds the default layout behavior of the widget.

If there is a QLayout that manages this widget’s children, the size policy specified by that layout is used. If there is no such QLayout , the result of this function is used.

The default policy is Preferred/Preferred, which means that the widget can be freely resized, but prefers to be the size sizeHint() returns. Button-like widgets set the size policy to specify that they may stretch horizontally, but are fixed vertically. The same applies to lineedit controls (such as QLineEdit , QSpinBox or an editable QComboBox ) and other horizontally orientated widgets (such as QProgressBar ). QToolButton ‘s are normally square, so they allow growth in both directions. Widgets that support different directions (such as QSlider , QScrollBar or QHeader) specify stretching in the respective direction only. Widgets that can provide scroll bars (usually subclasses of QScrollArea ) tend to specify that they can use additional space, and that they can make do with less than sizeHint() .

Access functions:
property statusTipᅟ: str#

This property holds the widget’s status tip.

By default, this property contains an empty string.

See also

toolTip whatsThis

Access functions:
property styleSheetᅟ: str#

This property holds the widget’s style sheet.

The style sheet contains a textual description of customizations to the widget’s style, as described in the Qt Style Sheets document.

Since Qt 4.5, Qt style sheets fully supports macOS.

Warning

Qt style sheets are currently not supported for custom QStyle subclasses. We plan to address this in some future release.

Access functions:
property tabletTrackingᅟ: bool#

This property holds whether tablet tracking is enabled for the widget.

If tablet tracking is disabled (the default), the widget only receives tablet move events when the stylus is in contact with the tablet, or at least one stylus button is pressed, while the stylus is being moved.

If tablet tracking is enabled, the widget receives tablet move events even while hovering in proximity. This is useful for monitoring position as well as the auxiliary properties such as rotation and tilt, and providing feedback in the UI.

See also

tabletEvent()

Access functions:
property toolTipᅟ: str#

This property holds the widget’s tooltip.

Note that by default tooltips are only shown for widgets that are children of the active window. You can change this behavior by setting the attribute Qt::WA_AlwaysShowToolTips on the window, not on the widget with the tooltip.

If you want to control a tooltip’s behavior, you can intercept the event() function and catch the QEvent::ToolTip event (e.g., if you want to customize the area for which the tooltip should be shown).

By default, this property contains an empty string.

Access functions:
property toolTipDurationᅟ: int#

This property holds the widget’s tooltip duration.

Specifies how long time the tooltip will be displayed, in milliseconds. If the value is -1 (default) the duration is calculated depending on the length of the tooltip.

See also

toolTip

Access functions:
property updatesEnabledᅟ: bool#

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

This property holds whether updates are enabled.

An updates enabled widget receives paint events and has a system background; a disabled widget does not. This also implies that calling update() and repaint() has no effect if updates are disabled.

By default, this property is true.

setUpdatesEnabled() is normally used to disable updates for a short period of time, for instance to avoid screen flicker during large changes. In Qt, widgets normally do not generate screen flicker, but on X11 the server might erase regions on the screen when widgets get hidden before they can be replaced by other widgets. Disabling updates solves this.

Example:

setUpdatesEnabled(False)
bigVisualChanges()
setUpdatesEnabled(True)

Disabling a widget implicitly disables all its children. Enabling a widget enables all child widgets except top-level widgets or those that have been explicitly disabled. Re-enabling updates implicitly calls update() on the widget.

See also

paintEvent()

Access functions:
property visibleᅟ: bool#

This property holds whether the widget is visible.

Calling setVisible(true) or show() sets the widget to visible status if all its parent widgets up to the window are visible. If an ancestor is not visible, the widget won’t become visible until all its ancestors are shown. If its size or position has changed, Qt guarantees that a widget gets move and resize events just before it is shown. If the widget has not been resized yet, Qt will adjust the widget’s size to a useful default using adjustSize() .

Calling setVisible(false) or hide() hides a widget explicitly. An explicitly hidden widget will never become visible, even if all its ancestors become visible, unless you show it.

A widget receives show and hide events when its visibility status changes. Between a hide and a show event, there is no need to waste CPU cycles preparing or displaying information to the user. A video application, for example, might simply stop generating new frames.

A widget that happens to be obscured by other windows on the screen is considered to be visible. The same applies to iconified windows and windows that exist on another virtual desktop (on platforms that support this concept). A widget receives spontaneous show and hide events when its mapping status is changed by the window system, e.g. a spontaneous hide event when the user minimizes the window, and a spontaneous show event when the window is restored again.

You seldom have to reimplement the setVisible() function. If you need to change some settings before a widget is shown, use showEvent() instead. If you need to do some delayed initialization use the Polish event delivered to the event() function.

Access functions:
property whatsThisᅟ: str#

This property holds the widget’s What’s This help text..

By default, this property contains an empty string.

Access functions:
property widthᅟ: int#

This property holds the width of the widget excluding any window frame.

See the Window Geometry documentation for an overview of geometry issues with windows.

Note

Do not use this function to find the width of a screen on a multi-screen desktop. See QScreen for details.

By default, this property contains a value that depends on the user’s platform and screen geometry.

See also

geometry height size

Access functions:

property windowFilePathᅟ: str#

This property holds the file path associated with a widget.

This property only makes sense for windows. It associates a file path with a window. If you set the file path, but have not set the window title, Qt sets the window title to the file name of the specified path, obtained using QFileInfo::fileName().

If the window title is set at any point, then the window title takes precedence and will be shown instead of the file path string.

Additionally, on macOS, this has an added benefit that it sets the proxy icon for the window, assuming that the file path exists.

If no file path is set, this property contains an empty string.

By default, this property contains an empty string.

Access functions:
property windowIconᅟ: QIcon#

This property holds the widget’s icon.

This property only makes sense for windows. If no icon has been set, windowIcon() returns the application icon (QApplication::windowIcon()).

Note

On macOS, window icons represent the active document, and will not be displayed unless a file path has also been set using setWindowFilePath .

Access functions:
property windowIconTextᅟ: str#

This property holds the text to be displayed on the icon of a minimized window.

This property only makes sense for windows. If no icon text has been set, this accessor returns an empty string. It is only implemented on the X11 platform, and only certain window managers use this window property.

This property is deprecated.

Access functions:
property windowModalityᅟ: Qt.WindowModality#

This property holds which windows are blocked by the modal widget.

This property only makes sense for windows. A modal widget prevents widgets in other windows from getting input. The value of this property controls which windows are blocked when the widget is visible. Changing this property while the window is visible has no effect; you must hide() the widget first, then show() it again.

By default, this property is Qt::NonModal.

See also

isWindow() modal QDialog

Access functions:
property windowModifiedᅟ: bool#

This property holds whether the document shown in the window has unsaved changes.

A modified window is a window whose content has changed but has not been saved to disk. This flag will have different effects varied by the platform. On macOS the close button will have a modified look; on other platforms, the window title will have an ‘*’ (asterisk).

The window title must contain a “[*]” placeholder, which indicates where the ‘*’ should appear. Normally, it should appear right after the file name (e.g., “document1.txt[*] - Text Editor”). If the window isn’t modified, the placeholder is simply removed.

Note that if a widget is set as modified, all its ancestors will also be set as modified. However, if you call setWindowModified(false) on a widget, this will not propagate to its parent because other children of the parent might have been modified.

See also

windowTitle

Access functions:
property windowOpacityᅟ: float#

This property holds The level of opacity for the window..

The valid range of opacity is from 1.0 (completely opaque) to 0.0 (completely transparent).

By default the value of this property is 1.0.

This feature is available on Embedded Linux, macOS, Windows, and X11 platforms that support the Composite extension.

Note

On X11 you need to have a composite manager running, and the X11 specific _NET_WM_WINDOW_OPACITY atom needs to be supported by the window manager you are using.

Warning

Changing this property from opaque to transparent might issue a paint event that needs to be processed before the window is displayed correctly. This affects mainly the use of QScreen::grabWindow(). Also note that semi-transparent windows update and resize significantly slower than opaque windows.

See also

setMask()

Access functions:
property windowTitleᅟ: str#

This property holds the window title (caption).

This property only makes sense for top-level widgets, such as windows and dialogs. If no caption has been set, the title is based of the windowFilePath . If neither of these is set, then the title is an empty string.

If you use the windowModified mechanism, the window title must contain a “[*]” placeholder, which indicates where the ‘*’ should appear. Normally, it should appear right after the file name (e.g., “document1.txt[*] - Text Editor”). If the windowModified property is false (the default), the placeholder is simply removed.

On some desktop platforms (including Windows and Unix), the application name (from QGuiApplication::applicationDisplayName) is added at the end of the window title, if set. This is done by the QPA plugin, so it is shown to the user, but isn’t part of the windowTitle string.

See also

windowIcon windowModified windowFilePath

Access functions:
property xᅟ: int#

This property holds the x coordinate of the widget relative to its parent including any window frame.

See the Window Geometry documentation for an overview of geometry issues with windows.

By default, this property has a value of 0.

See also

frameGeometry y pos

Access functions:
property yᅟ: int#

This property holds the y coordinate of the widget relative to its parent and including any window frame.

See the Window Geometry documentation for an overview of geometry issues with windows.

By default, this property has a value of 0.

See also

frameGeometry x pos

Access functions:
__init__([parent=None[, f=Qt.WindowFlags()]])#
Parameters:

Constructs a widget which is a child of parent, with widget flags set to f.

If parent is None, the new widget becomes a window. If parent is another widget, this widget becomes a child window inside parent. The new widget is deleted when its parent is deleted.

The widget flags argument, f, is normally 0, but it can be set to customize the frame of a window (i.e. parent must be None). To customize the frame, use a value composed from the bitwise OR of any of the window flags.

If you add a child widget to an already visible widget you must explicitly show the child to make it visible.

Note that the X11 version of Qt may not be able to deliver all combinations of style flags on all systems. This is because on X11, Qt can only ask the window manager, and the window manager can override the application’s settings. On Windows, Qt can set whatever flags you want.

See also

windowFlags

acceptDrops()#
Return type:

bool

See also

setAcceptDrops()

Getter of property acceptDropsᅟ .

accessibleDescription()#
Return type:

str

Getter of property accessibleDescriptionᅟ .

accessibleName()#
Return type:

str

Getter of property accessibleNameᅟ .

actionEvent(event)#
Parameters:

eventQActionEvent

This event handler is called with the given event whenever the widget’s actions are changed.

actions()#
Return type:

.list of QAction

Returns the (possibly empty) list of this widget’s actions.

activateWindow()#

Sets the top-level widget containing this widget to be the active window.

An active window is a visible top-level window that has the keyboard input focus.

This function performs the same operation as clicking the mouse on the title bar of a top-level window. On X11, the result depends on the Window Manager. If you want to ensure that the window is stacked on top as well you should also call raise() . Note that the window must be visible, otherwise activateWindow() has no effect.

On Windows, if you are calling this when the application is not currently the active one then it will not make it the active window. It will change the color of the taskbar entry to indicate that the window has changed in some way. This is because Microsoft does not allow an application to interrupt what the user is currently doing in another application.

addAction(icon, text, receiver, member[, type=Qt.AutoConnection])#
Parameters:
Return type:

QAction

addAction(text, receiver, member[, type=Qt.AutoConnection])
Parameters:
Return type:

QAction

addAction(text, shortcut, receiver, member[, type=Qt.AutoConnection])
Parameters:
Return type:

QAction

addAction(text, shortcut)
Parameters:
Return type:

QAction

addAction(text)
Parameters:

text – str

Return type:

QAction

addAction(icon, text, shortcut, receiver, member[, type=Qt.AutoConnection])
Parameters:
Return type:

QAction

addAction(icon, text, shortcut)
Parameters:
Return type:

QAction

addAction(icon, text)
Parameters:
  • iconQIcon

  • text – str

Return type:

QAction

addAction(text, shortcut, callable)
Parameters:
  • text – str

  • shortcutQKeySequence

  • callable – object

Return type:

QAction

addAction(text, callable)
Parameters:
  • text – str

  • callable – object

Return type:

QAction

addAction(icon, text, shortcut, callable)
Parameters:
Return type:

QAction

addAction(icon, text, callable)
Parameters:
  • iconQIcon

  • text – str

  • callable – object

Return type:

QAction

addAction(action)
Parameters:

actionQAction

Appends the action action to this widget’s list of actions.

All QWidgets have a list of QActions. However, they can be represented graphically in many different ways. The default use of the QAction list (as returned by actions() ) is to create a context QMenu .

A QWidget should only have one of each action and adding an action it already has will not cause the same action to be in the widget twice.

The ownership of action is not transferred to this QWidget .

addActions(actions)#
Parameters:

actions – .list of QAction

Appends the actions actions to this widget’s list of actions.

adjustSize()#

Adjusts the size of the widget to fit its contents.

This function uses sizeHint() if it is valid, i.e., the size hint’s width and height are >= 0. Otherwise, it sets the size to the children rectangle that covers all child widgets (the union of all child widget rectangles).

For windows, the screen size is also taken into account. If the sizeHint() is less than (200, 100) and the size policy is expanding , the window will be at least (200, 100). The maximum size of a window is 2/3 of the screen’s width and height.

autoFillBackground()#
Return type:

bool

Getter of property autoFillBackgroundᅟ .

backgroundRole()#
Return type:

ColorRole

Returns the background role of the widget.

The background role defines the brush from the widget’s palette that is used to render the background.

If no explicit background role is set, the widget inherts its parent widget’s background role.

backingStore()#
Return type:

QBackingStore

Returns the QBackingStore this widget will be drawn into.

baseSize()#
Return type:

QSize

See also

setBaseSize()

Getter of property baseSizeᅟ .

changeEvent(event)#
Parameters:

eventQEvent

This event handler can be reimplemented to handle state changes.

The state being changed in this event can be retrieved through the event supplied.

Change events include: QEvent::ToolBarChange, QEvent::ActivationChange, QEvent::EnabledChange, QEvent::FontChange, QEvent::StyleChange, QEvent::PaletteChange, QEvent::WindowTitleChange, QEvent::IconTextChange, QEvent::ModifiedChange, QEvent::MouseTrackingChange, QEvent::ParentChange, QEvent::WindowStateChange, QEvent::LanguageChange, QEvent::LocaleChange, QEvent::LayoutDirectionChange, QEvent::ReadOnlyChange.

childAt(p)#
Parameters:

pQPoint

Return type:

QWidget

This is an overloaded function.

Returns the visible child widget at point p in the widget’s own coordinate system.

childAt(x, y)
Parameters:
  • x – int

  • y – int

Return type:

QWidget

Returns the visible child widget at the position (x, y) in the widget’s coordinate system. If there is no visible child widget at the specified position, the function returns None.

childrenRect()#
Return type:

QRect

Getter of property childrenRectᅟ .

childrenRegion()#
Return type:

QRegion

Getter of property childrenRegionᅟ .

clearFocus()#

Takes keyboard input focus from the widget.

If the widget has active focus, a focus out event is sent to this widget to tell it that it has lost the focus.

This widget must enable focus setting to get the keyboard input focus; that is, it must call setFocusPolicy() .

clearMask()#

Removes any mask set by setMask() .

See also

setMask()

close()#
Return type:

bool

Closes this widget. Returns true if the widget was closed; otherwise returns false.

First it sends the widget a QCloseEvent. The widget is hidden if it accepts the close event. If it ignores the event, nothing happens. The default implementation of closeEvent() accepts the close event.

If the widget has the Qt::WA_DeleteOnClose flag, the widget is also deleted. A close events is delivered to the widget no matter if the widget is visible or not.

The QGuiApplication::lastWindowClosed() signal is emitted when the last visible primary window (i.e. window with no parent) with the Qt::WA_QuitOnClose attribute set is closed. By default this attribute is set for all widgets except transient windows such as splash screens, tool windows, and popup menus.

closeEvent(event)#
Parameters:

eventQCloseEvent

This event handler is called with the given event when Qt receives a window close request for a top-level widget from the window system.

By default, the event is accepted and the widget is closed. You can reimplement this function to change the way the widget responds to window close requests. For example, you can prevent the window from closing by calling ignore() on all events.

Main window applications typically use reimplementations of this function to check whether the user’s work has been saved and ask for permission before closing.

See also

event() hide() close() QCloseEvent

contentsMargins()#
Return type:

QMargins

The contentsMargins function returns the widget’s contents margins.

contentsRect()#
Return type:

QRect

Returns the area inside the widget’s margins.

contextMenuEvent(event)#
Parameters:

eventQContextMenuEvent

This event handler, for event event, can be reimplemented in a subclass to receive widget context menu events.

The handler is called when the widget’s contextMenuPolicy is Qt::DefaultContextMenu.

The default implementation ignores the context event. See the QContextMenuEvent documentation for more details.

See also

event() customContextMenuRequested()

contextMenuPolicy()#
Return type:

ContextMenuPolicy

Getter of property contextMenuPolicyᅟ .

create([arg__1=0[, initializeWindow=true[, destroyOldWindow=true]]])#
Parameters:
  • arg__1WId

  • initializeWindow – bool

  • destroyOldWindow – bool

Creates a new widget window.

The parameters window, initializeWindow, and destroyOldWindow are ignored in Qt 5. Please use QWindow::fromWinId() to create a QWindow wrapping a foreign window and pass it to createWindowContainer() instead.

createWinId()#
static createWindowContainer(window[, parent=None[, flags=Qt.WindowFlags()]])#
Parameters:
Return type:

QWidget

Creates a QWidget that makes it possible to embed window into a QWidget -based application.

The window container is created as a child of parent and with window flags flags.

Once the window has been embedded into the container, the container will control the window’s geometry and visibility. Explicit calls to QWindow::setGeometry(), QWindow::show() or QWindow::hide() on an embedded window is not recommended.

The container takes over ownership of window. The window can be removed from the window container with a call to QWindow::setParent().

The window container is attached as a native child window to the toplevel window it is a child of. When a window container is used as a child of a QAbstractScrollArea or QMdiArea , it will create a native window for every widget in its parent chain to allow for proper stacking and clipping in this use case. Creating a native window for the window container also allows for proper stacking and clipping. This must be done before showing the window container. Applications with many native child windows may suffer from performance issues.

The window container has a number of known limitations:

  • Stacking order; The embedded window will stack on top of the widget hierarchy as an opaque box. The stacking order of multiple overlapping window container instances is undefined.

  • Rendering Integration; The window container does not interoperate with QGraphicsProxyWidget , render() or similar functionality.

  • Focus Handling; It is possible to let the window container instance have any focus policy and it will delegate focus to the window via a call to QWindow::requestActivate(). However, returning to the normal focus chain from the QWindow instance will be up to the QWindow instance implementation itself. For instance, when entering a Qt Quick based window with tab focus, it is quite likely that further tab presses will only cycle inside the QML application. Also, whether QWindow::requestActivate() actually gives the window focus, is platform dependent.

  • Using many window container instances in a QWidget -based application can greatly hurt the overall performance of the application.

cursor()#
Return type:

QCursor

See also

setCursor()

Getter of property cursorᅟ .

customContextMenuRequested(pos)#
Parameters:

posQPoint

This signal is emitted when the widget’s contextMenuPolicy is Qt::CustomContextMenu, and the user has requested a context menu on the widget. The position pos is the position of the context menu event that the widget receives. Normally this is in widget coordinates. The exception to this rule is QAbstractScrollArea and its subclasses that map the context menu event to coordinates of the viewport() .

destroy([destroyWindow=true[, destroySubWindows=true]])#
Parameters:
  • destroyWindow – bool

  • destroySubWindows – bool

Frees up window system resources. Destroys the widget window if destroyWindow is true.

destroy() calls itself recursively for all the child widgets, passing destroySubWindows for the destroyWindow parameter. To have more control over destruction of subwidgets, destroy subwidgets selectively first.

This function is usually called from the QWidget destructor.

dragEnterEvent(event)#
Parameters:

eventQDragEnterEvent

This event handler is called when a drag is in progress and the mouse enters this widget. The event is passed in the event parameter.

If the event is ignored, the widget won’t receive any drag move events .

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also

QDragQDragEnterEvent

dragLeaveEvent(event)#
Parameters:

eventQDragLeaveEvent

This event handler is called when a drag is in progress and the mouse leaves this widget. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also

QDragQDragLeaveEvent

dragMoveEvent(event)#
Parameters:

eventQDragMoveEvent

This event handler is called if a drag is in progress, and when any of the following conditions occur: the cursor enters this widget, the cursor moves within this widget, or a modifier key is pressed on the keyboard while this widget has the focus. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also

QDragQDragMoveEvent

dropEvent(event)#
Parameters:

eventQDropEvent

This event handler is called when the drag is dropped on this widget. The event is passed in the event parameter.

See the Drag-and-drop documentation for an overview of how to provide drag-and-drop in your application.

See also

QDragQDropEvent

effectiveWinId()#
Return type:

WId

Returns the effective window system identifier of the widget, i.e. the native parent’s window system identifier.

If the widget is native, this function returns the native widget ID. Otherwise, the window ID of the first native parent widget, i.e., the top-level widget that contains this widget, is returned.

Note

We recommend that you do not store this value as it is likely to change at run-time.

ensurePolished()#

Ensures that the widget and its children have been polished by QStyle (i.e., have a proper font and palette).

QWidget calls this function after it has been fully constructed but before it is shown the very first time. You can call this function if you want to ensure that the widget is polished before doing an operation, e.g., the correct font size might be needed in the widget’s sizeHint() reimplementation. Note that this function is called from the default implementation of sizeHint() .

Polishing is useful for final initialization that must happen after all constructors (from base classes as well as from subclasses) have been called.

If you need to change some settings when a widget is polished, reimplement event() and handle the QEvent::Polish event type.

Note

The function is declared const so that it can be called from other const functions (e.g., sizeHint() ).

See also

event()

enterEvent(event)#
Parameters:

eventQEnterEvent

This event handler can be reimplemented in a subclass to receive widget enter events which are passed in the event parameter.

An event is sent to the widget when the mouse cursor enters the widget.

See also

leaveEvent() mouseMoveEvent() event()

static find(arg__1)#
Parameters:

arg__1WId

Return type:

QWidget

Returns a pointer to the widget with window identifier/handle id.

The window identifier type depends on the underlying window system, see qwindowdefs.h for the actual definition. If there is no widget with this identifier, None is returned.

focusInEvent(event)#
Parameters:

eventQFocusEvent

This event handler can be reimplemented in a subclass to receive keyboard focus events (focus received) for the widget. The event is passed in the event parameter

A widget normally must setFocusPolicy() to something other than Qt::NoFocus to receive focus events. (Note that the application programmer can call setFocus() on any widget, even those that do not normally accept focus.)

The default implementation updates the widget (except for windows that do not specify a focusPolicy() ).

focusNextChild()#
Return type:

bool

Finds a new widget to give the keyboard focus to, as appropriate for Tab, and returns true if it can find a new widget, or false if it can’t.

focusNextPrevChild(next)#
Parameters:

next – bool

Return type:

bool

Finds a new widget to give the keyboard focus to, as appropriate for Tab and Shift+Tab, and returns true if it can find a new widget, or false if it can’t.

If next is true, this function searches forward, if next is false, it searches backward.

Sometimes, you will want to reimplement this function. For example, a web browser might reimplement it to move its “current active link” forward or backward, and call focusNextPrevChild() only when it reaches the last or first link on the “page”.

Child widgets call focusNextPrevChild() on their parent widgets, but only the window that contains the child widgets decides where to redirect focus. By reimplementing this function for an object, you thus gain control of focus traversal for all child widgets.

focusOutEvent(event)#
Parameters:

eventQFocusEvent

This event handler can be reimplemented in a subclass to receive keyboard focus events (focus lost) for the widget. The events is passed in the event parameter.

A widget normally must setFocusPolicy() to something other than Qt::NoFocus to receive focus events. (Note that the application programmer can call setFocus() on any widget, even those that do not normally accept focus.)

The default implementation updates the widget (except for windows that do not specify a focusPolicy() ).

focusPolicy()#
Return type:

FocusPolicy

See also

setFocusPolicy()

Getter of property focusPolicyᅟ .

focusPreviousChild()#
Return type:

bool

Finds a new widget to give the keyboard focus to, as appropriate for Shift+Tab, and returns true if it can find a new widget, or false if it can’t.

See also

focusNextChild()

focusProxy()#
Return type:

QWidget

Returns the focus proxy, or None if there is no focus proxy.

See also

setFocusProxy()

focusWidget()#
Return type:

QWidget

Returns the last child of this widget that setFocus had been called on. For top level widgets this is the widget that will get focus in case this window gets activated

This is not the same as focusWidget() , which returns the focus widget in the currently active window.

font()#
Return type:

QFont

See also

setFont()

Getter of property fontᅟ .

fontInfo()#
Return type:

QFontInfo

Returns the font info for the widget’s current font. Equivalent to QFontInfo(widget->font()).

fontMetrics()#
Return type:

QFontMetrics

Returns the font metrics for the widget’s current font. Equivalent to QFontMetrics(widget->font()).

foregroundRole()#
Return type:

ColorRole

Returns the foreground role.

The foreground role defines the color from the widget’s palette that is used to draw the foreground.

If no explicit foreground role is set, the function returns a role that contrasts with the background role.

frameGeometry()#
Return type:

QRect

Getter of property frameGeometryᅟ .

frameSize()#
Return type:

QSize

Getter of property frameSizeᅟ .

geometry()#
Return type:

QRect

See also

setGeometry()

Getter of property geometryᅟ .

grab([rectangle=QRect(QPoint(0, 0), QSize(-1, -1))])#
Parameters:

rectangleQRect

Return type:

QPixmap

Renders the widget into a pixmap restricted by the given rectangle. If the widget has any children, then they are also painted in the appropriate positions.

If a rectangle with an invalid size is specified (the default), the entire widget is painted.

See also

render() QPixmap

grabGesture(type[, flags=Qt.GestureFlags()])#
Parameters:

Subscribes the widget to a given gesture with specific flags.

grabKeyboard()#

Grabs the keyboard input.

This widget receives all keyboard events until releaseKeyboard() is called; other widgets get no keyboard events at all. Mouse events are not affected. Use grabMouse() if you want to grab that.

The focus widget is not affected, except that it doesn’t receive any keyboard events. setFocus() moves the focus as usual, but the new focus widget receives keyboard events only after releaseKeyboard() is called.

If a different widget is currently grabbing keyboard input, that widget’s grab is released first.

grabMouse()#

Grabs the mouse input.

This widget receives all mouse events until releaseMouse() is called; other widgets get no mouse events at all. Keyboard events are not affected. Use grabKeyboard() if you want to grab that.

Warning

Bugs in mouse-grabbing applications very often lock the terminal. Use this function with extreme caution, and consider using the -nograb command line option while debugging.

It is seldom necessary to grab the mouse when using Qt, as Qt grabs and releases it sensibly. In particular, Qt grabs the mouse when a mouse button is pressed and keeps it until the last button is released.

Note

Only visible widgets can grab mouse input. If isVisible() returns false for a widget, that widget cannot call grabMouse().

Note

On Windows, grabMouse() only works when the mouse is inside a window owned by the process. On macOS, grabMouse() only works when the mouse is inside the frame of that widget.

grabMouse(arg__1)
Parameters:

arg__1QCursor

This function overloads grabMouse() .

Grabs the mouse input and changes the cursor shape.

The cursor will assume shape cursor (for as long as the mouse focus is grabbed) and this widget will be the only one to receive mouse events until releaseMouse() is called().

Warning

Grabbing the mouse might lock the terminal.

grabShortcut(key[, context=Qt.WindowShortcut])#
Parameters:
Return type:

int

Adds a shortcut to Qt’s shortcut system that watches for the given key sequence in the given context. If the context is Qt::ApplicationShortcut, the shortcut applies to the application as a whole. Otherwise, it is either local to this widget, Qt::WidgetShortcut, or to the window itself, Qt::WindowShortcut.

If the same key sequence has been grabbed by several widgets, when the key sequence occurs a QEvent::Shortcut event is sent to all the widgets to which it applies in a non-deterministic order, but with the ``ambiguous’’ flag set to true.

Warning

You should not normally need to use this function; instead create QActions with the shortcut key sequences you require (if you also want equivalent menu options and toolbar buttons), or create QShortcuts if you just need key sequences. Both QAction and QShortcut handle all the event filtering for you, and provide signals which are triggered when the user triggers the key sequence, so are much easier to use than this low-level function.

graphicsEffect()#
Return type:

QGraphicsEffect

The graphicsEffect function returns a pointer to the widget’s graphics effect.

If the widget has no graphics effect, None is returned.

graphicsProxyWidget()#
Return type:

QGraphicsProxyWidget

Returns the proxy widget for the corresponding embedded widget in a graphics view; otherwise returns None.

hasFocus()#
Return type:

bool

Getter of property focusᅟ .

hasHeightForWidth()#
Return type:

bool

Returns true if the widget’s preferred height depends on its width; otherwise returns false.

hasMouseTracking()#
Return type:

bool

Getter of property mouseTrackingᅟ .

hasTabletTracking()#
Return type:

bool

Getter of property tabletTrackingᅟ .

heightForWidth(arg__1)#
Parameters:

arg__1 – int

Return type:

int

Returns the preferred height for this widget, given the width w.

If this widget has a layout, the default implementation returns the layout’s preferred height. if there is no layout, the default implementation returns -1 indicating that the preferred height does not depend on the width.

hide()#

Hides the widget. This function is equivalent to setVisible (false).

Note

If you are working with QDialog or its subclasses and you invoke the show() function after this function, the dialog will be displayed in its original position.

hideEvent(event)#
Parameters:

eventQHideEvent

This event handler can be reimplemented in a subclass to receive widget hide events. The event is passed in the event parameter.

Hide events are sent to widgets immediately after they have been hidden.

Note: A widget receives spontaneous show and hide events when its mapping status is changed by the window system, e.g. a spontaneous hide event when the user minimizes the window, and a spontaneous show event when the window is restored again. After receiving a spontaneous hide event, a widget is still considered visible in the sense of isVisible() .

See also

visible event() QHideEvent

inputMethodEvent(event)#
Parameters:

eventQInputMethodEvent

This event handler, for event event, can be reimplemented in a subclass to receive Input Method composition events. This handler is called when the state of the input method changes.

Note that when creating custom text editing widgets, the Qt::WA_InputMethodEnabled window attribute must be set explicitly (using the setAttribute() function) in order to receive input method events.

The default implementation calls event->ignore(), which rejects the Input Method event. See the QInputMethodEvent documentation for more details.

See also

event() QInputMethodEvent

inputMethodHints()#
Return type:

Combination of InputMethodHint

Getter of property inputMethodHintsᅟ .

inputMethodQuery(arg__1)#
Parameters:

arg__1InputMethodQuery

Return type:

object

This method is only relevant for input widgets. It is used by the input method to query a set of properties of the widget to be able to support complex input method operations as support for surrounding text and reconversions.

query specifies which property is queried.

insertAction(before, action)#
Parameters:

Inserts the action action to this widget’s list of actions, before the action before. It appends the action if before is None or before is not a valid action for this widget.

A QWidget should only have one of each action.

insertActions(before, actions)#
Parameters:
  • beforeQAction

  • actions – .list of QAction

Inserts the actions actions to this widget’s list of actions, before the action before. It appends the action if before is None or before is not a valid action for this widget.

A QWidget can have at most one of each action.

internalWinId()#
Return type:

WId

isActiveWindow()#
Return type:

bool

Getter of property isActiveWindowᅟ .

isAncestorOf(child)#
Parameters:

childQWidget

Return type:

bool

Returns true if this widget is a parent, (or grandparent and so on to any level), of the given child, and both widgets are within the same window; otherwise returns false.

isEnabled()#
Return type:

bool

Getter of property enabledᅟ .

isEnabledTo(arg__1)#
Parameters:

arg__1QWidget

Return type:

bool

Returns true if this widget would become enabled if ancestor is enabled; otherwise returns false.

This is the case if neither the widget itself nor every parent up to but excluding ancestor has been explicitly disabled.

isEnabledTo(0) returns false if this widget or any if its ancestors was explicitly disabled.

The word ancestor here means a parent widget within the same window.

Therefore isEnabledTo(0) stops at this widget’s window, unlike isEnabled() which also takes parent windows into considerations.

See also

setEnabled() enabled

isFullScreen()#
Return type:

bool

Getter of property fullScreenᅟ .

isHidden()#
Return type:

bool

Returns true if the widget is hidden, otherwise returns false.

A hidden widget will only become visible when show() is called on it. It will not be automatically shown when the parent is shown.

To check visibility, use ! isVisible() instead (notice the exclamation mark).

isHidden() implies ! isVisible() , but a widget can be not visible and not hidden at the same time. This is the case for widgets that are children of widgets that are not visible.

Widgets are hidden if:

  • they were created as independent windows,

  • they were created as children of visible widgets,

  • hide() or setVisible (false) was called.

isLeftToRight()#
Return type:

bool

isMaximized()#
Return type:

bool

Getter of property maximizedᅟ .

isMinimized()#
Return type:

bool

Getter of property minimizedᅟ .

isModal()#
Return type:

bool

Getter of property modalᅟ .

isRightToLeft()#
Return type:

bool

isTopLevel()#
Return type:

bool

Note

This function is deprecated.

Use isWindow() instead.

isVisible()#
Return type:

bool

Getter of property visibleᅟ .

isVisibleTo(arg__1)#
Parameters:

arg__1QWidget

Return type:

bool

Returns true if this widget would become visible if ancestor is shown; otherwise returns false.

The true case occurs if neither the widget itself nor any parent up to but excluding ancestor has been explicitly hidden.

This function will still return true if the widget is obscured by other windows on the screen, but could be physically visible if it or they were to be moved.

isVisibleTo(0) is identical to isVisible() .

isWindow()#
Return type:

bool

Returns true if the widget is an independent window, otherwise returns false.

A window is a widget that isn’t visually the child of any other widget and that usually has a frame and a window title .

A window can have a parent widget . It will then be grouped with its parent and deleted when the parent is deleted, minimized when the parent is minimized etc. If supported by the window manager, it will also have a common taskbar entry with its parent.

QDialog and QMainWindow widgets are by default windows, even if a parent widget is specified in the constructor. This behavior is specified by the Qt::Window flag.

isWindowModified()#
Return type:

bool

Getter of property windowModifiedᅟ .

keyPressEvent(event)#
Parameters:

eventQKeyEvent

This event handler, for event event, can be reimplemented in a subclass to receive key press events for the widget.

A widget must call setFocusPolicy() to accept focus initially and have focus in order to receive a key press event.

If you reimplement this handler, it is very important that you call the base class implementation if you do not act upon the key.

The default implementation closes popup widgets if the user presses the key sequence for QKeySequence::Cancel (typically the Escape key). Otherwise the event is ignored, so that the widget’s parent can interpret it.

Note that QKeyEvent starts with isAccepted() == true, so you do not need to call QKeyEvent::accept() - just do not call the base class implementation if you act upon the key.

keyReleaseEvent(event)#
Parameters:

eventQKeyEvent

This event handler, for event event, can be reimplemented in a subclass to receive key release events for the widget.

A widget must accept focus initially and have focus in order to receive a key release event.

If you reimplement this handler, it is very important that you call the base class implementation if you do not act upon the key.

The default implementation ignores the event, so that the widget’s parent can interpret it.

Note that QKeyEvent starts with isAccepted() == true, so you do not need to call QKeyEvent::accept() - just do not call the base class implementation if you act upon the key.

static keyboardGrabber()#
Return type:

QWidget

Returns the widget that is currently grabbing the keyboard input.

If no widget in this application is currently grabbing the keyboard, None is returned.

layout()#
Return type:

QLayout

Returns the layout manager that is installed on this widget, or None if no layout manager is installed.

The layout manager sets the geometry of the widget’s children that have been added to the layout.

layoutDirection()#
Return type:

LayoutDirection

Getter of property layoutDirectionᅟ .

leaveEvent(event)#
Parameters:

eventQEvent

This event handler can be reimplemented in a subclass to receive widget leave events which are passed in the event parameter.

A leave event is sent to the widget when the mouse cursor leaves the widget.

See also

enterEvent() mouseMoveEvent() event()

locale()#
Return type:

QLocale

See also

setLocale()

Getter of property localeᅟ .

lower()#

Lowers the widget to the bottom of the parent widget’s stack.

After this call the widget will be visually behind (and therefore obscured by) any overlapping sibling widgets.

See also

raise() stackUnder()

mapFrom(arg__1, arg__2)#
Parameters:
Return type:

QPoint

This is an overloaded function.

mapFrom(arg__1, arg__2)
Parameters:
Return type:

QPointF

Translates the widget coordinate pos from the coordinate system of parent to this widget’s coordinate system. The parent must not be None and must be a parent of the calling widget.

mapFromGlobal(arg__1)#
Parameters:

arg__1QPoint

Return type:

QPoint

This is an overloaded function.

mapFromGlobal(arg__1)
Parameters:

arg__1QPointF

Return type:

QPointF

Translates the global screen coordinate pos to widget coordinates.

mapFromParent(arg__1)#
Parameters:

arg__1QPoint

Return type:

QPoint

This is an overloaded function.

mapFromParent(arg__1)
Parameters:

arg__1QPointF

Return type:

QPointF

Translates the parent widget coordinate pos to widget coordinates.

Same as mapFromGlobal() if the widget has no parent.

mapTo(arg__1, arg__2)#
Parameters:
Return type:

QPoint

This is an overloaded function.

mapTo(arg__1, arg__2