QDialogButtonBox Class

The QDialogButtonBox class is a widget that presents buttons in a layout that is appropriate to the current widget style. More...

Header: #include <QDialogButtonBox>
qmake: QT += widgets
Since: Qt 4.2
Inherits: QWidget

This class was introduced in Qt 4.2.

Public Types

enum ButtonLayout { WinLayout, MacLayout, KdeLayout, GnomeLayout, AndroidLayout }
enum ButtonRole { InvalidRole, AcceptRole, RejectRole, DestructiveRole, ActionRole, …, ResetRole }
enum StandardButton { Ok, Open, Save, Cancel, Close, …, NoButton }

Properties

Public Functions

bool centerButtons() const
Qt::Orientation orientation() const
void setCenterButtons(bool center)
void setOrientation(Qt::Orientation orientation)
void setStandardButtons(QDialogButtonBox::StandardButtons buttons)
QDialogButtonBox::StandardButtons standardButtons() const

Detailed Description

Dialogs and message boxes typically present buttons in a layout that conforms to the interface guidelines for that platform. Invariably, different platforms have different layouts for their dialogs. QDialogButtonBox allows a developer to add buttons to it and will automatically use the appropriate layout for the user's desktop environment.

Most buttons for a dialog follow certain roles. Such roles include:

  • Accepting or rejecting the dialog.
  • Asking for help.
  • Performing actions on the dialog itself (such as resetting fields or applying changes).

There can also be alternate ways of dismissing the dialog which may cause destructive results.

Most dialogs have buttons that can almost be considered standard (e.g. OK and Cancel buttons). It is sometimes convenient to create these buttons in a standard way.

There are a couple ways of using QDialogButtonBox. One ways is to create the buttons (or button texts) yourself and add them to the button box, specifying their role.

     findButton = new QPushButton(tr("&Find"));
     findButton->setDefault(true);

     moreButton = new QPushButton(tr("&More"));
     moreButton->setCheckable(true);
     moreButton->setAutoDefault(false);

Alternatively, QDialogButtonBox provides several standard buttons (e.g. OK, Cancel, Save) that you can use. They exist as flags so you can OR them together in the constructor.

     buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok
                                      | QDialogButtonBox::Cancel);

     connect(buttonBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
     connect(buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);

You can mix and match normal buttons and standard buttons.

Currently the buttons are laid out in the following way if the button box is horizontal:

GnomeLayout HorizontalButton box laid out in horizontal GnomeLayout
KdeLayout HorizontalButton box laid out in horizontal KdeLayout
MacLayout HorizontalButton box laid out in horizontal MacLayout
WinLayout HorizontalButton box laid out in horizontal WinLayout

The buttons are laid out the following way if the button box is vertical:

Additionally, button boxes that contain only buttons with ActionRole or HelpRole can be considered modeless and have an alternate look on macOS:

modeless horizontal MacLayoutScreenshot of modeless horizontal MacLayout
modeless vertical MacLayoutScreenshot of modeless vertical MacLayout

When a button is clicked in the button box, the clicked() signal is emitted for the actual button is that is pressed. For convenience, if the button has an AcceptRole, RejectRole, or HelpRole, the accepted(), rejected(), or helpRequested() signals are emitted respectively.

If you want a specific button to be default you need to call QPushButton::setDefault() on it yourself. However, if there is no default button set and to preserve which button is the default button across platforms when using the QPushButton::autoDefault property, the first push button with the accept role is made the default button when the QDialogButtonBox is shown,

See also QMessageBox, QPushButton, and QDialog.

Member Type Documentation

enum QDialogButtonBox::ButtonLayout

This enum describes the layout policy to be used when arranging the buttons contained in the button box.

ConstantValueDescription
QDialogButtonBox::WinLayout0Use a policy appropriate for applications on Windows.
QDialogButtonBox::MacLayout1Use a policy appropriate for applications on macOS.
QDialogButtonBox::KdeLayout2Use a policy appropriate for applications on KDE.
QDialogButtonBox::GnomeLayout3Use a policy appropriate for applications on GNOME.
QDialogButtonBox::AndroidLayoutGnomeLayout + 2Use a policy appropriate for applications on Android. This enum value was added in Qt 5.10.

The button layout is specified by the current style. However, on the X11 platform, it may be influenced by the desktop environment.

enum QDialogButtonBox::ButtonRole

This enum describes the roles that can be used to describe buttons in the button box. Combinations of these roles are as flags used to describe different aspects of their behavior.

ConstantValueDescription
QDialogButtonBox::InvalidRole-1The button is invalid.
QDialogButtonBox::AcceptRole0Clicking the button causes the dialog to be accepted (e.g. OK).
QDialogButtonBox::RejectRole1Clicking the button causes the dialog to be rejected (e.g. Cancel).
QDialogButtonBox::DestructiveRole2Clicking the button causes a destructive change (e.g. for Discarding Changes) and closes the dialog.
QDialogButtonBox::ActionRole3Clicking the button causes changes to the elements within the dialog.
QDialogButtonBox::HelpRole4The button can be clicked to request help.
QDialogButtonBox::YesRole5The button is a "Yes"-like button.
QDialogButtonBox::NoRole6The button is a "No"-like button.
QDialogButtonBox::ApplyRole8The button applies current changes.
QDialogButtonBox::ResetRole7The button resets the dialog's fields to default values.

See also StandardButton.

enum QDialogButtonBox::StandardButton

These enums describe flags for standard buttons. Each button has a defined ButtonRole.

ConstantValueDescription
QDialogButtonBox::Ok0x00000400An "OK" button defined with the AcceptRole.
QDialogButtonBox::Open0x00002000An "Open" button defined with the AcceptRole.
QDialogButtonBox::Save0x00000800A "Save" button defined with the AcceptRole.
QDialogButtonBox::Cancel0x00400000A "Cancel" button defined with the RejectRole.
QDialogButtonBox::Close0x00200000A "Close" button defined with the RejectRole.
QDialogButtonBox::Discard0x00800000A "Discard" or "Don't Save" button, depending on the platform, defined with the DestructiveRole.
QDialogButtonBox::Apply0x02000000An "Apply" button defined with the ApplyRole.
QDialogButtonBox::Reset0x04000000A "Reset" button defined with the ResetRole.
QDialogButtonBox::RestoreDefaults0x08000000A "Restore Defaults" button defined with the ResetRole.
QDialogButtonBox::Help0x01000000A "Help" button defined with the HelpRole.
QDialogButtonBox::SaveAll0x00001000A "Save All" button defined with the AcceptRole.
QDialogButtonBox::Yes0x00004000A "Yes" button defined with the YesRole.
QDialogButtonBox::YesToAll0x00008000A "Yes to All" button defined with the YesRole.
QDialogButtonBox::No0x00010000A "No" button defined with the NoRole.
QDialogButtonBox::NoToAll0x00020000A "No to All" button defined with the NoRole.
QDialogButtonBox::Abort0x00040000An "Abort" button defined with the RejectRole.
QDialogButtonBox::Retry0x00080000A "Retry" button defined with the AcceptRole.
QDialogButtonBox::Ignore0x00100000An "Ignore" button defined with the AcceptRole.
QDialogButtonBox::NoButton0x00000000An invalid button.

See also ButtonRole and standardButtons.

Property Documentation

centerButtons : bool

This property holds whether the buttons in the button box are centered

By default, this property is false. This behavior is appropriate for most types of dialogs. A notable exception is message boxes on most platforms (e.g. Windows), where the button box is centered horizontally.

Access functions:

bool centerButtons() const
void setCenterButtons(bool center)

See also QMessageBox.

orientation : Qt::Orientation

This property holds the orientation of the button box

By default, the orientation is horizontal (i.e. the buttons are laid out side by side). The possible orientations are Qt::Horizontal and Qt::Vertical.

Access functions:

Qt::Orientation orientation() const
void setOrientation(Qt::Orientation orientation)

standardButtons : StandardButtons

collection of standard buttons in the button box

This property controls which standard buttons are used by the button box.

Access functions:

QDialogButtonBox::StandardButtons standardButtons() const
void setStandardButtons(QDialogButtonBox::StandardButtons buttons)

See also addButton().