The QPushButton class provides a command button widget. It is one of the most commonly used widgets in any graphical user interface. The idea is to push or use a mouse to click a button to command the computer to perform some action or answer a question. Typical buttons are OK, Apply, Cancel, Close, Yes, No, and Help.

The button is rectangular and typically displays a text label describing its action. A shortcut key can be specified by preceding the preferred character with an ampersand in the text.

Push buttons display a textual label and optionally a small icon. These can be set using the constructors and changed later using setText() and setIcon(). If the button is disabled the appearance of the text and icon will be manipulated with respect to the GUI style to make the button look "disabled".

Shortcut

In the following example the shortcut is Alt+D.

Details

A push button emits the signal clicked() when it is activated by the mouse, the Spacebar or by a keyboard shortcut. Connect to this signal to perform the button's action. Push buttons also provide less commonly used signals, for example, pressed() and released().

Command buttons in dialogs are by default "auto default buttons", where they become the default push button automatically when they receive the keyboard input focus. A default button is a push button that is activated when the user presses the Enter or Return key in a dialog. You can change this with setAutoDefault(). Note that auto default buttons reserve a little extra space which is necessary to draw a default-button indicator. If you do not want this space around your buttons, call setAutoDefault(false).

The button widget has grown to accommodate a great many variations in the past decade. The Microsoft style guide now shows about ten different states of Windows push buttons and the text implies that there are dozens more when all the combinations of features are taken into consideration.

The most important modes or states are listed below.

• Available or not (grayed out, disabled)
• Standard push button, toggling push button or menu button
• On or off (only for toggling push buttons)
• Default or normal. The default button in a dialog can generally be "clicked" using the Enter or Return key
• Auto-repeat or not
• Pressed down or not

As a general rule, use a push button when the application or dialog window performs an action when the user clicks on it (such as Apply, Cancel, Close and Help) and when the widget is supposed to have a wide, rectangular shape with a text label. Small, typically square buttons that change the state of the window rather than performing an action (such as the buttons in the top-right corner of the QFileDialog) are not command buttons, but tool buttons. CopperSpice provides a special class (QToolButton) for these buttons.

If you need toggle behavior (see setCheckable()) or a button that auto-repeats the activation signal when being pushed down like the arrows in a scroll bar (see setAutoRepeat()), a command button is probably not what you want. When in doubt, use a tool button.

A variation of a command button is a menu button. These provide not just one command, but several, since when they are clicked they pop up a menu of options. Use the method setMenu() to associate a popup menu with a push button.

Other classes of buttons are option buttons link QRadioButton and check boxes QCheckBox.

	A push button shown in the Windows XP widget style.
	A push button shown in the Mac OS X widget style. Note that when a button's width becomes smaller than 50 or its height becomes smaller than 30, the button's corners are changed from round to square. Use the setMinimumSize() method to prevent this behavior.
	A push button shown in the Fusion widget style.

The QAbstractButton base class provides most of the modes and other API, and QPushButton provides GUI logic. Refer to QAbstractButton for more information about the API.

See also

QCheckBox, QRadioButton, QToolButton