com.trolltech.qt.gui
Class QCheckBox

java.lang.Object
  extended by com.trolltech.qt.internal.QSignalEmitterInternal
      extended by com.trolltech.qt.QSignalEmitter
          extended by com.trolltech.qt.QtJambiObject
              extended by com.trolltech.qt.core.QObject
                  extended by com.trolltech.qt.gui.QWidget
                      extended by com.trolltech.qt.gui.QAbstractButton
                          extended by com.trolltech.qt.gui.QCheckBox
All Implemented Interfaces:
QPaintDeviceInterface, QtJambiInterface

public class QCheckBox
extends QAbstractButton

The QCheckBox widget provides a checkbox with a text label. A QCheckBox is an option button that can be switched on (checked) or off (unchecked). Checkboxes are typically used to represent features in an application that can be enabled or disabled without affecting others, but different types of behavior can be implemented.

A QButtonGroup can be used to group check buttons visually.

Whenever a checkbox is checked or cleared it emits the signal stateChanged() . Connect to this signal if you want to trigger an action each time the checkbox changes state. You can use isChecked() to query whether or not a checkbox is checked.

In addition to the usual checked and unchecked states, QCheckBox optionally provides a third state to indicate "no change". This is useful whenever you need to give the user the option of neither checking nor unchecking a checkbox. If you need this third state, enable it with setTristate(), and use checkState() to query the current toggle state.

Just like QPushButton, a checkbox displays text, and optionally a small icon. The icon is set with setIcon(). The text can be set in the constructor or with setText(). A shortcut key can be specified by preceding the preferred character with an ampersand. For example:

        QCheckBox checkbox = new QCheckBox("C&ase sensitive", this);
In this example the shortcut is Alt+A. See the QShortcut documentation for details (to display an actual ampersand, use '&&').

Important inherited functions: text(), setText(), text(), pixmap(), setPixmap(), accel(), setAccel(), isToggleButton(), setDown(), isDown(), isOn(), checkState(), autoRepeat(), isExclusiveToggle(), group(), setAutoRepeat(), toggle(), pressed() , released() , clicked() , toggled() , checkState(), and stateChanged() .



A checkbox shown in the Macintosh widget style.


A checkbox shown in the Windows XP widget style.


A checkbox shown in the Plastique widget style.

See also:
QAbstractButton, QRadioButton, and GUI Design Handbook: Check Box.


Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.gui.QWidget
QWidget.RenderFlag, QWidget.RenderFlags
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.PrivateSignal0, QSignalEmitter.PrivateSignal1, QSignalEmitter.PrivateSignal2, QSignalEmitter.PrivateSignal3, QSignalEmitter.PrivateSignal4, QSignalEmitter.PrivateSignal5, QSignalEmitter.PrivateSignal6, QSignalEmitter.PrivateSignal7, QSignalEmitter.PrivateSignal8, QSignalEmitter.PrivateSignal9, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9
 
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal
 
Field Summary
 QSignalEmitter.Signal1 stateChanged
          This signal takes 1 generic argument(s).
 
Fields inherited from class com.trolltech.qt.gui.QAbstractButton
clicked, pressed, released, toggled
 
Fields inherited from class com.trolltech.qt.gui.QWidget
customContextMenuRequested
 
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
currentSender
 
Constructor Summary
QCheckBox()
          Constructs a checkbox with the given parent, but with no text.
QCheckBox(QWidget parent)
          Constructs a checkbox with the given parent, but with no text.
QCheckBox(java.lang.String text)
          Constructs a checkbox with the given parent and text.
QCheckBox(java.lang.String text, QWidget parent)
          Constructs a checkbox with the given parent and text.
 
Method Summary
 Qt.CheckState checkState()
          Returns the check box's check state.
protected  void initStyleOption(QStyleOptionButton option)
          Initialize option with the values from this QCheckBox.
 boolean isTristate()
          This property holds whether the checkbox is a tri-state checkbox.
 void setCheckState(Qt.CheckState state)
          Sets the check box's check state to state.
 void setTristate()
          This property holds whether the checkbox is a tri-state checkbox.
 void setTristate(boolean y)
          This property holds whether the checkbox is a tri-state checkbox.
 
Methods inherited from class com.trolltech.qt.gui.QAbstractButton
animateClick, animateClick, autoExclusive, autoRepeat, autoRepeatDelay, autoRepeatInterval, checkStateSet, click, group, hitButton, icon, iconSize, isCheckable, isChecked, isDown, nextCheckState, setAutoExclusive, setAutoRepeat, setAutoRepeatDelay, setAutoRepeatInterval, setCheckable, setChecked, setDown, setIcon, setIconSize, setShortcut, setShortcut, setShortcut, setText, shortcut, text, toggle
 
Methods inherited from class com.trolltech.qt.gui.QWidget
acceptDrops, accessibleDescription, accessibleName, actionEvent, actions, activateWindow, addAction, addActions, adjustSize, autoFillBackground, backgroundRole, baseSize, changeEvent, childAt, childAt, childrenRect, childrenRegion, clearFocus, clearMask, close, closeEvent, contentsRect, contextMenuEvent, contextMenuPolicy, cursor, depth, destroy, destroy, destroy, dragEnterEvent, dragLeaveEvent, dragMoveEvent, dropEvent, effectiveWinId, ensurePolished, enterEvent, focusInEvent, focusNextChild, focusNextPrevChild, focusOutEvent, focusPolicy, focusPreviousChild, focusProxy, focusWidget, font, fontInfo, fontMetrics, foregroundRole, frameGeometry, frameSize, geometry, getContentsMargins, grabKeyboard, grabMouse, grabMouse, grabShortcut, grabShortcut, graphicsProxyWidget, hasFocus, hasMouseTracking, height, heightForWidth, heightMM, hide, hideEvent, inputContext, inputMethodEvent, inputMethodQuery, insertAction, insertActions, isActiveWindow, isAncestorOf, isEnabled, isEnabledTo, isFullScreen, isHidden, isMaximized, isMinimized, isModal, isVisible, isVisibleTo, isWindow, isWindowModified, keyboardGrabber, keyPressEvent, keyReleaseEvent, languageChange, layout, layoutDirection, leaveEvent, locale, logicalDpiX, logicalDpiY, lower, mapFrom, mapFromGlobal, mapFromParent, mapTo, mapToGlobal, mapToParent, mask, maximumHeight, maximumSize, maximumWidth, metric, minimumHeight, minimumSize, minimumSizeHint, minimumWidth, mouseDoubleClickEvent, mouseGrabber, mouseMoveEvent, mousePressEvent, mouseReleaseEvent, move, move, moveEvent, nativeParentWidget, nextInFocusChain, normalGeometry, numColors, overrideWindowFlags, overrideWindowFlags, overrideWindowState, paintEngine, paintEvent, paintingActive, palette, parentWidget, physicalDpiX, physicalDpiY, pos, raise, rect, releaseKeyboard, releaseMouse, releaseShortcut, removeAction, render, render, render, render, render, render, render, render, render, repaint, repaint, repaint, repaint, resetInputContext, resize, resize, resizeEvent, restoreGeometry, saveGeometry, scroll, scroll, setAcceptDrops, setAccessibleDescription, setAccessibleName, setAttribute, setAttribute, setAutoFillBackground, setBackgroundRole, setBaseSize, setBaseSize, setContentsMargins, setContentsMargins, setContextMenuPolicy, setCursor, setDisabled, setEnabled, setFixedHeight, setFixedSize, setFixedSize, setFixedWidth, setFocus, setFocus, setFocusPolicy, setFocusProxy, setFont, setForegroundRole, setGeometry, setGeometry, setHidden, setInputContext, setLayout, setLayoutDirection, setLocale, setMask, setMask, setMaximumHeight, setMaximumSize, setMaximumSize, setMaximumWidth, setMinimumHeight, setMinimumSize, setMinimumSize, setMinimumWidth, setMouseTracking, setPalette, setParent, setParent, setParent, setShortcutAutoRepeat, setShortcutAutoRepeat, setShortcutEnabled, setShortcutEnabled, setSizeIncrement, setSizeIncrement, setSizePolicy, setSizePolicy, setStatusTip, setStyle, setStyleSheet, setTabOrder, setToolTip, setUpdatesEnabled, setVisible, setWhatsThis, setWindowFilePath, setWindowFlags, setWindowFlags, setWindowIcon, setWindowIconText, setWindowModality, setWindowModified, setWindowOpacity, setWindowRole, setWindowState, setWindowState, setWindowTitle, show, showEvent, showFullScreen, showMaximized, showMinimized, showNormal, size, sizeHint, sizeIncrement, sizePolicy, stackUnder, statusTip, style, styleSheet, tabletEvent, testAttribute, toolTip, underMouse, unsetCursor, unsetLayoutDirection, unsetLocale, update, update, update, update, updateGeometry, updateMicroFocus, updatesEnabled, visibleRegion, whatsThis, wheelEvent, width, widthMM, window, windowFilePath, windowFlags, windowIcon, windowIconText, windowModality, windowOpacity, windowRole, windowState, windowTitle, windowType, winId, x, y
 
Methods inherited from class com.trolltech.qt.core.QObject
childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, startTimer, timerEvent, toString, userProperty
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
__qt_signalInitialization
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Field Detail

stateChanged

public final QSignalEmitter.Signal1 stateChanged

This signal takes 1 generic argument(s). We list their type and the name they go by in the description of this signal. <java.lang.Integer(named: state)>:

This signal is emitted whenever the check box's state changes, i. . whenever the user checks or unchecks it.

state contains the check box's new Qt::CheckState .

Constructor Detail

QCheckBox

public QCheckBox()
Constructs a checkbox with the given parent, but with no text.

The parent argument is passed on to the QAbstractButton constructor.


QCheckBox

public QCheckBox(QWidget parent)
Constructs a checkbox with the given parent, but with no text.

The parent argument is passed on to the QAbstractButton constructor.


QCheckBox

public QCheckBox(java.lang.String text)
Constructs a checkbox with the given parent and text.

The parent argument is passed on to the QAbstractButton constructor.


QCheckBox

public QCheckBox(java.lang.String text,
                 QWidget parent)
Constructs a checkbox with the given parent and text.

The parent argument is passed on to the QAbstractButton constructor.

Method Detail

checkState

public final Qt.CheckState checkState()
Returns the check box's check state. If you do not need tristate support, you can also use QAbstractButton::isChecked() which returns a boolean.

See also:
setCheckState(), and Qt::CheckState .


isTristate

public final boolean isTristate()
This property holds whether the checkbox is a tri-state checkbox. The default is false; i.e. the checkbox has only two states.


setCheckState

public final void setCheckState(Qt.CheckState state)
Sets the check box's check state to state. If you do not need tristate support, you can also use QAbstractButton::setChecked() which takes a boolean.

See also:
checkState(), and Qt::CheckState .


setTristate

public final void setTristate()
This property holds whether the checkbox is a tri-state checkbox. The default is false; i.e. the checkbox has only two states.


setTristate

public final void setTristate(boolean y)
This property holds whether the checkbox is a tri-state checkbox. The default is false; i.e. the checkbox has only two states.


initStyleOption

protected final void initStyleOption(QStyleOptionButton option)
Initialize option with the values from this QCheckBox. This method is useful for subclasses when they need a QStyleOptionButton, but don't want to fill in all the information themselves.