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QRadioButton Class Reference

The QRadioButton widget provides a radio button with a text label. More...

#include <qradiobutton.h>

Inherits QButton.

List of all member functions.

Public Members

Public Slots

Important Inherited Members

Properties


Detailed Description

The QRadioButton widget provides a radio button with a text label.

QRadioButton and QCheckBox are both option buttons. That is, they can be switched on (checked) or off (unchecked). The classes differ in how the choices for the user are restricted. Check boxes define "many of many" choices, whereas radio buttons provide a "one of many" choice. In a group of radio buttons only one button at a time can be checked; if the user selects another button, the previously selected button is switched off.

Although it is technically possible to implement radio-behavior with check boxes and vice versa, it is strongly recommended to stick with the well-known semantics. Otherwise your users would be pretty confused.

The easiest way to implement a "one of many" choice is simply to stick the radio buttons into QButtonGroup.

Whenever a button is switched on or off it emits the signal toggled(). Connect to this signal if you want to trigger an action each time the button changes state. Otherwise, use isChecked() to query whether or not a particular button is selected.

See also QPushButton, QToolButton and GUI Design Handbook: Radio Button.


Member Function Documentation

QRadioButton::QRadioButton ( QWidget * parent, const char * name = 0 )

Constructs a radio button with no text.

The parent and name arguments are sent to the QWidget constructor.

QRadioButton::QRadioButton ( const QString & text, QWidget * parent, const char * name = 0 )

Constructs a radio button with the text text.

The parent and name arguments are sent to the QWidget constructor.

int QButton::accel () const

Returns the accelerator associated with the button. See the "accel" property for details.

bool QButton::autoRepeat () const

Returns TRUE if autoRepeat is enabled; otherwise returns FALSE. See the "autoRepeat" property for details.

void QButton::clicked () [signal]

This signal is emitted when the button is activated (i.e. first pressed down and then released when the mouse cursor is inside the button), when the accelerator key is typed or when animateClick() is called.

The QButtonGroup::clicked() signal does the same job, if you want to connect several buttons to the same slot.

See also pressed(), released() and toggled().

Examples: listbox/listbox.cpp, network/clientserver/client/client.cpp, network/ftpclient/ftpmainwindow.cpp, progressbar/progressbar.cpp, richtext/richtext.cpp, t2/main.cpp and t4/main.cpp.

QButtonGroup * QButton::group () const

Returns a pointer to the group of which this button is a member.

If the button is not a member of any QButtonGroup, this function returns 0.

See also setGroup() and QButtonGroup.

bool QRadioButton::isChecked () const

Returns TRUE if the radio button is checked; otherwise returns FALSE. See the "checked" property for details.

bool QButton::isDown () const

Returns TRUE if the button is down (i.e. pressed); otherwise returns FALSE. See the "down" property for details.

bool QButton::isExclusiveToggle () const

Returns TRUE if the button is an exclusive toggle; otherwise returns FALSE. See the "exclusiveToggle" property for details.

bool QButton::isOn () const

Returns TRUE if the button is toggled; otherwise returns FALSE. See the "on" property for details.

bool QButton::isToggleButton () const

Returns TRUE if the button is a toggle button; otherwise returns FALSE. See the "toggleButton" property for details.

const QPixmap * QButton::pixmap () const

Returns the pixmap shown on the button. See the "pixmap" property for details.

void QButton::pressed () [signal]

This signal is emitted when the button is pressed down.

See also released() and clicked().

Examples: network/httpd/httpd.cpp and popup/popup.cpp.

void QButton::released () [signal]

This signal is emitted when the button is released.

See also pressed(), clicked() and toggled().

void QButton::setAccel ( int ) [virtual]

Sets the accelerator associated with the button. See the "accel" property for details.

void QButton::setAutoRepeat ( bool ) [virtual]

Sets whether autoRepeat is enabled. See the "autoRepeat" property for details.

void QRadioButton::setChecked ( bool check ) [virtual slot]

Sets whether the radio button is checked to check. See the "checked" property for details.

void QButton::setDown ( bool ) [virtual]

Sets whether the button is down (i.e. pressed). See the "down" property for details.

void QButton::setPixmap ( const QPixmap & ) [virtual]

Sets the pixmap shown on the button. See the "pixmap" property for details.

void QButton::setText ( const QString & ) [virtual]

Sets the text shown on the button. See the "text" property for details.

ToggleState QButton::state () const

Returns TRUE if the button is toggled; otherwise returns FALSE. See the "toggleState" property for details.

void QButton::stateChanged ( int state ) [signal]

This signal is emitted whenever a toggle button changes status. state is 2 if the button is on, 1 if it is in the "no change" state or 0 if the button is off.

This may be the result of a user action, toggle() slot activation, setState(), or because setOn() was called.

See also clicked().

QString QButton::text () const

Returns the text shown on the button. See the "text" property for details.

void QButton::toggle () [slot]

Toggles the state of a toggle button.

See also on, setOn(), toggled() and toggleButton.

void QButton::toggled ( bool on ) [signal]

This signal is emitted whenever a toggle button changes status. on is TRUE if the button is on, or FALSE if the button is off.

This may be the result of a user action, toggle() slot activation, or because setOn() was called.

See also clicked().

Example: listbox/listbox.cpp.


Property Documentation

int accel

This property holds the accelerator associated with the button.

This property will return 0 if there is no accelerator set, if you set this property to 0 then any current accelerator is removed.

Set this property's value with setAccel() and get this property's value with accel().

bool autoRepeat

This property holds whether autoRepeat is enabled.

If autoRepeat is enabled then the clicked() signal is emitted at regular intervals if the button is down. This property has no effect on toggle buttons.

Set this property's value with setAutoRepeat() and get this property's value with autoRepeat().

bool checked

This property holds whether the radio button is checked.

This property will not effect any other radio buttons unless they have been placed in a QButtonGroup.

Set this property's value with setChecked() and get this property's value with isChecked().

QPixmap pixmap

This property holds the pixmap shown on the button.

This property will return 0 if the button has no pixmap.

If the pixmap is monochrome (i.e., it is a QBitmap or its depth is 1) and it does not have a mask, this property will set the pixmap to be its own mask. The purpose of this is to draw transparent bitmaps which are important for toggle buttons, for example.

Set this property's value with setPixmap() and get this property's value with pixmap().

QString text

This property holds the text shown on the button.

This property will return a null string if the button has no text. If the text has an ampersand '&' in it, then an accelerator is automatically created for it using the character after the ampersand as the accelerator key.

Set this property's value with setText() and get this property's value with text().


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