Class WComboBox
- Direct Known Subclasses:
WSelectionBox
public class WComboBox extends WFormWidget
A combo box provides the user with a set of options, from which one option may be selected.
WComboBox is an MVC view class, using a simple string list model by default. The model may be
populated using addItem()
or insertItem()
and the contents can be cleared
through clear()
. These methods manipulate the underlying getModel()
.
To use the combo box with a custom model instead of the default WStringListModel
, use
setModel()
.
To react to selection events, connect to the WFormWidget.changed()
, activated()
or sactivated()
signals.
At all times, the current selection index is available through getCurrentIndex()
and the current selection text using getCurrentText()
.
WComboBox
does not have support for auto-completion, this behaviour can be found in
the WSuggestionPopup
.
WComboBox is an inline
widget.
CSS
The widget corresponds to the HTML <select>
tag and does not provide
styling. It can be styled using inline or external CSS as appropriate.
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Nested Class Summary
Nested classes/interfaces inherited from class eu.webtoolkit.jwt.WObject
WObject.FormData
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Field Summary
Fields inherited from class eu.webtoolkit.jwt.WInteractWidget
dragTouchEndSlot_, dragTouchSlot_
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Constructor Summary
Constructors Constructor Description WComboBox()
Creates an empty combo-box with optional parent.WComboBox(WContainerWidget parent)
Creates an empty combo-box with optional parent. -
Method Summary
Modifier and Type Method Description Signal1<java.lang.Integer>
activated()
Signal emitted when the selection changed.void
addItem(java.lang.CharSequence text)
Adds an option item.void
clear()
Clears all items.int
findText(java.lang.CharSequence text, MatchOptions flags)
Returns the index of the first item that matches a text.int
getCount()
Returns the number of items.int
getCurrentIndex()
Returns the currently selected item.WString
getCurrentText()
Returns the text of the currently selected item.WString
getItemText(int index)
Returns the text of a particular item.WAbstractItemModel
getModel()
Returns the data model.SelectionMode
getSelectionMode()
Returns the selection mode.java.lang.String
getValueText()
Returns the current value.void
insertItem(int index, java.lang.CharSequence text)
Inserts an item at the specified position.boolean
isNoSelectionEnabled()
Returns whether 'no selection' is a valid state.void
refresh()
Refresh the widget.void
removeItem(int index)
Removes the item at the specified position.Signal1<WString>
sactivated()
Signal emitted when the selection changed.void
setCurrentIndex(int index)
Changes the current selection.protected void
setFormData(WObject.FormData formData)
void
setItemText(int index, java.lang.CharSequence text)
Changes the text for a specified option.void
setModel(WAbstractItemModel model)
Sets the model to be used for the items.void
setModelColumn(int index)
Sets the column in the model to be used for the items.void
setNoSelectionEnabled(boolean enabled)
Enables the ability to have 'no currently selected' item.void
setValueText(java.lang.String value)
Sets the current value.Methods inherited from class eu.webtoolkit.jwt.WFormWidget
changed, enableAjax, getEmptyText, getLabel, getPlaceholderText, getTabIndex, getValidator, isCanReceiveFocus, isReadOnly, propagateSetEnabled, remove, render, selected, setEmptyText, setEnabled, setHidden, setPlaceholderText, setReadOnly, setToolTip, setValidator, validate, validated
Methods inherited from class eu.webtoolkit.jwt.WInteractWidget
clicked, doubleClicked, enterPressed, escapePressed, gestureChanged, gestureEnded, gestureStarted, getMouseOverDelay, isEnabled, keyPressed, keyWentDown, keyWentUp, load, mouseDragged, mouseMoved, mouseWentDown, mouseWentOut, mouseWentOver, mouseWentUp, mouseWheel, setDraggable, setDraggable, setDraggable, setDraggable, setMouseOverDelay, setPopup, touchEnded, touchMoved, touchStarted, unsetDraggable
Methods inherited from class eu.webtoolkit.jwt.WWebWidget
addStyleClass, blurred, callJavaScriptMember, childrenChanged, createDomElement, doJavaScript, escapeText, escapeText, escapeText, escapeText, find, findById, focussed, getAttributeValue, getBaseZIndex, getChildren, getClearSides, getDecorationStyle, getDomChanges, getFloatSide, getHeight, getHtmlTagName, getId, getJavaScriptMember, getLineHeight, getMargin, getMaximumHeight, getMaximumWidth, getMinimumHeight, getMinimumWidth, getOffset, getPositionScheme, getScrollVisibilityMargin, getStyleClass, getToolTip, getVerticalAlignment, getVerticalAlignmentLength, getWidth, hasFocus, hasStyleClass, isDisabled, isHidden, isHiddenKeepsGeometry, isInline, isLoaded, isPopup, isRendered, isScrollVisibilityEnabled, isScrollVisible, isSetFirstFocus, isThemeStyleEnabled, isVisible, jsStringLiteral, jsStringLiteral, parentResized, parentResized, propagateSetVisible, removeScript, removeStyleClass, resize, scrollVisibilityChanged, setAttributeValue, setBaseZIndex, setCanReceiveFocus, setClearSides, setDecorationStyle, setDeferredToolTip, setDisabled, setFloatSide, setFocus, setHiddenKeepsGeometry, setHtmlTagName, setId, setInline, setJavaScriptMember, setLineHeight, setLoadLaterWhenInvisible, setMargin, setMaximumSize, setMinimumSize, setOffsets, setPositionScheme, setScrollVisibilityEnabled, setScrollVisibilityMargin, setSelectable, setStyleClass, setTabIndex, setThemeStyleEnabled, setVerticalAlignment, updateSignalConnection, voidEventSignal
Methods inherited from class eu.webtoolkit.jwt.WWidget
acceptDrops, acceptDrops, addCssRule, addCssRule, addJSignal, addStyleClass, animateHide, animateShow, boxBorder, boxPadding, createJavaScript, disable, dropEvent, enable, getDropTouch, getJsRef, getParent, hide, htmlText, isExposed, isLayoutSizeAware, layoutSizeChanged, needsRerender, positionAt, positionAt, removeChild, removeStyleClass, render, resize, scheduleRender, scheduleRender, scheduleRender, setClearSides, setDeferredToolTip, setFocus, setHeight, setHidden, setLayoutSizeAware, setMargin, setMargin, setMargin, setMargin, setMargin, setObjectName, setOffsets, setOffsets, setOffsets, setOffsets, setOffsets, setToolTip, setVerticalAlignment, setWidth, show, stopAcceptDrops, toggleStyleClass, toggleStyleClass, tr
Methods inherited from class eu.webtoolkit.jwt.WObject
addChild, getObjectName
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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WComboBox
Creates an empty combo-box with optional parent. -
WComboBox
public WComboBox()Creates an empty combo-box with optional parent.
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Method Details
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addItem
public void addItem(java.lang.CharSequence text)Adds an option item.Equivalent to
insertItem()
(getCount()
,text
). -
getCount
public int getCount()Returns the number of items. -
getCurrentIndex
public int getCurrentIndex()Returns the currently selected item.If no item is currently selected, the method returns -1.
By default, for a combo box, the first item is selected, and thus
getCurrentIndex()
= 0, while for a selection box no item is selected. -
insertItem
public void insertItem(int index, java.lang.CharSequence text)Inserts an item at the specified position.The item is inserted in the underlying model at position
index
. This requires that thegetModel()
is editable.- See Also:
addItem(CharSequence text)
,removeItem(int index)
-
removeItem
public void removeItem(int index)Removes the item at the specified position.The item is removed from the underlying model. This requires that the
getModel()
is editable.- See Also:
insertItem(int index, CharSequence text)
,clear()
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setCurrentIndex
public void setCurrentIndex(int index)Changes the current selection.Specify a value of -1 for
index
to clear the selection.Note: Setting a value of -1 works only if JavaScript is available.
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setItemText
public void setItemText(int index, java.lang.CharSequence text)Changes the text for a specified option.The text for the item at position
index
is changed. This requires that thegetModel()
is editable. -
getCurrentText
Returns the text of the currently selected item.- See Also:
getCurrentIndex()
,getItemText(int index)
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getItemText
Returns the text of a particular item. -
setModel
Sets the model to be used for the items.The
model
may not be 0, and ownership of the model is not transferred.The default value is a
WStringListModel
that is owned by the combo box. Items in the model can be grouped by setting theItemDataRole.LevelRole
. The contents is interpreted by Wt::asString, and subsequent items of the same group are rendered as children of a HTML<optgroup>
element.- See Also:
setModelColumn(int index)
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setModelColumn
public void setModelColumn(int index)Sets the column in the model to be used for the items.The column
index
in the model will be used to retrieve data.The default value is 0.
- See Also:
setModel(WAbstractItemModel model)
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getModel
Returns the data model.- See Also:
setModel(WAbstractItemModel model)
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findText
Returns the index of the first item that matches a text. -
getSelectionMode
Returns the selection mode.Always returns SingleSelection for a combo box, but may return ExtendedSelection for a selection box
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getValueText
public java.lang.String getValueText()Returns the current value.Returns
getCurrentText()
as a String.- Specified by:
getValueText
in classWFormWidget
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setValueText
public void setValueText(java.lang.String value)Sets the current value.Sets the current index to the item corresponding to
value
.- Specified by:
setValueText
in classWFormWidget
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refresh
public void refresh()Description copied from class:WWidget
Refresh the widget.The refresh method is invoked when the locale is changed using
WApplication#setLocale()
or when the user hit the refresh button.The widget must actualize its contents in response.
Note: This does *not* rerender the widget! Calling
refresh()
usually does not have any effect (unless you've reimplementedrefresh()
to attach to it an effect).- Overrides:
refresh
in classWFormWidget
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clear
public void clear()Clears all items.Removes all items from the underlying model. This requires that the
getModel()
is editable. -
activated
Signal emitted when the selection changed.The newly selected item is passed as an argument.
- See Also:
sactivated()
,getCurrentIndex()
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sactivated
Signal emitted when the selection changed.The newly selected text is passed as an argument.
- See Also:
activated()
,getCurrentText()
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setNoSelectionEnabled
public void setNoSelectionEnabled(boolean enabled)Enables the ability to have 'no currently selected' item.The setting may only be changed for a combo box (and not for a selection box). When enabled, the
getCurrentIndex()
may be '-1' also when the combo box contains values. The user can however not select this option, it is thus only useful as a default value.By default, no selection is
false
for a combo-box andtrue
for a selection box. -
isNoSelectionEnabled
public boolean isNoSelectionEnabled()Returns whether 'no selection' is a valid state.- See Also:
setNoSelectionEnabled(boolean enabled)
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setFormData
- Overrides:
setFormData
in classWObject
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