|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QObject
com.trolltech.qt.gui.QWidget
com.trolltech.qt.gui.QAbstractSlider
com.trolltech.qt.gui.QDial
public class QDial
The QDial
class provides a rounded range control (like a speedometer or potentiometer). QDial
is used when the user needs to control a value within a program-definable range, and the range either wraps around (for example, with angles measured from 0 to 359 degrees) or the dialog layout needs a square widget.
Since QDial
inherits from QAbstractSlider
, the dial behaves in a similar way to a slider
. When wrapping()
is false (the default setting) there is no real difference between a slider and a dial. They both share the same signals, slots and member functions. Which one you use depends on the expectations of your users and on the type of application.
The dial initially emits valueChanged()
signals continuously while the slider is being moved; you can make it emit the signal less often by disabling the tracking
property. The sliderMoved()
signal is emitted continuously even when tracking is disabled.
The dial also emits sliderPressed()
and sliderReleased()
signals when the mouse button is pressed and released. Note that the dial's value can change without these signals being emitted since the keyboard and wheel can also be used to change the value.
Unlike the slider, QDial
attempts to draw a "nice" number of notches rather than one per line step. If possible, the number of notches drawn is one per line step, but if there aren't enough pixels to draw every one, QDial
will skip notches to try and draw a uniform set (e.g. by drawing every second or third notch).
Like the slider, the dial makes the QAbstractSlider
functions setValue(), addLine(), subtractLine(), addPage() and subtractPage() available as slots.
The dial's keyboard interface is fairly simple: The left/up and right/down arrow keys adjust the dial's value
by the defined singleStep
, Page Up and Page Down by the defined pageStep
, and the Home and End keys set the value to the defined minimum
and maximum
values.
If you are using the mouse wheel to adjust the dial, the increment value is determined by the lesser value of wheelScrollLines
multipled by singleStep
, and pageStep
.
![]() | ![]() | ![]() |
Dials shown in various widget styles (from left to right): Plastique, Windows XP, Macintosh. |
QScrollBar
, QSpinBox
, QSlider
, GUI Design Handbook: Slider, and Sliders Example.
Nested Class Summary |
---|
Nested classes/interfaces inherited from class com.trolltech.qt.gui.QAbstractSlider |
---|
QAbstractSlider.SliderAction, QAbstractSlider.SliderChange |
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.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9 |
Field Summary |
---|
Fields inherited from class com.trolltech.qt.gui.QAbstractSlider |
---|
actionTriggered, rangeChanged, sliderMoved, sliderPressed, sliderReleased, valueChanged |
Fields inherited from class com.trolltech.qt.gui.QWidget |
---|
customContextMenuRequested |
Constructor Summary | |
---|---|
QDial()
Constructs a dial. |
|
QDial(QWidget parent)
Constructs a dial. |
Method Summary | |
---|---|
static QDial |
fromNativePointer(QNativePointer nativePointer)
|
protected void |
initStyleOption(QStyleOptionSlider option)
Initialize option with the values from this QDial. |
boolean |
notchesVisible()
This property holds whether the notches are shown. |
int |
notchSize()
This property holds the current notch size. |
double |
notchTarget()
This property holds the target number of pixels between notches. |
void |
setNotchesVisible(boolean visible)
This property holds whether the notches are shown. |
void |
setNotchTarget(double target)
This property holds the target number of pixels between notches. |
void |
setWrapping(boolean on)
This property holds whether wrapping is enabled. |
boolean |
wrapping()
This property holds whether wrapping is enabled. |
Methods inherited from class com.trolltech.qt.gui.QAbstractSlider |
---|
hasTracking, invertedAppearance, invertedControls, isSliderDown, maximum, minimum, orientation, pageStep, repeatAction, setInvertedAppearance, setInvertedControls, setMaximum, setMinimum, setOrientation, setPageStep, setRange, setRepeatAction, setRepeatAction, setRepeatAction, setSingleStep, setSliderDown, setSliderPosition, setTracking, setValue, singleStep, sliderChange, sliderPosition, triggerAction, value |
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 java.lang.Object |
---|
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
---|
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
---|
public QDial()
The parent argument is sent to the QAbstractSlider
constructor.
public QDial(QWidget parent)
The parent argument is sent to the QAbstractSlider
constructor.
Method Detail |
---|
public final int notchSize()
notchTarget()
. notchTarget()
, and singleStep().
public final double notchTarget()
QDial
attempts to put between each notch. The actual size may differ from the target size.
The default notch target is 3.7 pixels.
public final boolean notchesVisible()
By default, this property is disabled.
public final void setNotchTarget(double target)
QDial
attempts to put between each notch. The actual size may differ from the target size.
The default notch target is 3.7 pixels.
public final void setNotchesVisible(boolean visible)
By default, this property is disabled.
public final void setWrapping(boolean on)
If enabled, the arrow can be oriented at any angle on the dial. If disabled, the arrow will be restricted to the upper part of the dial; if it is rotated into the space at the bottom of the dial, it will be clamped to the closest end of the valid range of values.
By default this property is false.
public final boolean wrapping()
If enabled, the arrow can be oriented at any angle on the dial. If disabled, the arrow will be restricted to the upper part of the dial; if it is rotated into the space at the bottom of the dial, it will be clamped to the closest end of the valid range of values.
By default this property is false.
public static QDial fromNativePointer(QNativePointer nativePointer)
protected final void initStyleOption(QStyleOptionSlider option)
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |