Wt  3.3.9
Public Member Functions | List of all members
Wt::Ext::ComboBox Class Reference

A widget that provides a drop-down combo-box control. More...

#include <Wt/Ext/ComboBox>

Inheritance diagram for Wt::Ext::ComboBox:
Inheritance graph
[legend]

Public Member Functions

 ComboBox (WContainerWidget *parent=0)
 Create an empty combo-box with optional parent.
 
void addItem (const WString &text)
 Add an option item. More...
 
int count () const
 Get the number of items.
 
int currentIndex () const
 Get the currently selected item. More...
 
void insertItem (int index, const WString &text)
 Insert an option item at the specified position. More...
 
void removeItem (int index)
 Remove the option item at the specified position. More...
 
void setCurrentIndex (int index)
 Change the current selection. More...
 
void setItemText (int index, const WString &text)
 Change the text for a specified option. More...
 
const WString currentText () const
 Get the text of the currently selected item. More...
 
const WString itemText (int index) const
 Get the text of a particular item. More...
 
void setModel (WAbstractItemModel *model)
 Set the model to be used for the items. More...
 
void setModelColumn (int index)
 Set the column in the model to be used for the items. More...
 
void setEditable (bool how)
 Set if the combo-box is editable. More...
 
void setQueryDelay (int milliSeconds)
 Configure the delay to filter the list matching the current input. More...
 
void setMinQueryLength (int numChars)
 Configure the minimum number of characters to be entered before filtering the drop-down list. More...
 
void setPageSize (int pageSize)
 Configure a page size to show matching values one page at a time. More...
 
void setDataLocation (DataLocation dataLocation)
 Configure the location of the data for the combo-box. More...
 
virtual void refresh ()
 Refresh the widget. More...
 
void clear ()
 Clear all items.
 
JSignal< int > & activated ()
 Signal emitted when the selection changed.
 
- Public Member Functions inherited from Wt::Ext::LineEdit
 LineEdit (WContainerWidget *parent=0)
 Create a new line edit with empty content.
 
 LineEdit (const WString &content, WContainerWidget *parent=0)
 Construct a line edit with given content.
 
void setTextSize (int chars)
 Specify the width of the line edit in number of characters.
 
int textSize () const
 Return the current width of the line edit in number of characters. More...
 
void setText (const WString &value)
 Change the content of the line edit.
 
const WStringtext () const
 Return the current content.
 
void setMaxLength (int length)
 Specify the maximum length of text that can be entered. More...
 
int maxLength () const
 Returns the maximum length of text that can be entered. More...
 
void setEchoMode (EchoMode echoMode)
 Set the echo mode. More...
 
EchoMode echoMode () const
 Return the echo mode.
 
virtual WValidator::State validate ()
 Validate the field.
 
EventSignal< WKeyEvent > & keyWentDown ()
 Event signal emitted when a keyboard key is pushed down.
 
EventSignal< WKeyEvent > & keyPressed ()
 Event signal emitted when a keyboard key is pressed.
 
EventSignal< WKeyEvent > & keyWentUp ()
 Event signal emitted when a keyboard key is released.
 
EventSignalenterPressed ()
 Event signal emitted when enter was pressed. More...
 
- Public Member Functions inherited from Wt::Ext::FormField
void setErrorMessageLocation (MessageLocation location)
 Set the location of the validation error message.
 
void setValidator (WValidator *validator)
 Set a validator. More...
 
WValidatorvalidator () const
 Return the validator.
 
WLabellabel () const
 Return the label associate with this formfield. More...
 
void setFocus ()
 Give focus to this widget.
 
EventSignalchanged ()
 Signal emitted when the value was changed.
 
EventSignalblurred ()
 Signal emitted when the widget lost focus.
 
EventSignalfocussed ()
 Signal emitted when the widget recieved focus.
 
- Public Member Functions inherited from Wt::Ext::Component
void setEnabled (bool how)
 Enables or disables the widget. More...
 
void enable ()
 Enables the widget.
 
void disable ()
 Disables the widget.
 
- Public Member Functions inherited from Wt::Ext::Widget
 ~Widget ()
 Delete a widget.
 
virtual void setHidden (bool hidden, const WAnimation &animation=WAnimation())
 Hides or shows the widget. More...
 
- Public Member Functions inherited from Wt::WWebWidget
 WWebWidget (WContainerWidget *parent=0)
 Construct a WebWidget with a given parent. More...
 
virtual void setPositionScheme (PositionScheme scheme)
 Sets the CSS position scheme. More...
 
virtual PositionScheme positionScheme () const
 Returns the CSS position scheme. More...
 
virtual void setOffsets (const WLength &offset, WFlags< Side > sides=All)
 Sets CSS offsets for a non-statically positioned widget. More...
 
virtual WLength offset (Side s) const
 Returns a CSS offset. More...
 
virtual void resize (const WLength &width, const WLength &height)
 Resizes the widget. More...
 
virtual WLength width () const
 Returns the width. More...
 
virtual WLength height () const
 Returns the height. More...
 
virtual void setMinimumSize (const WLength &width, const WLength &height)
 Sets a minimum size. More...
 
virtual WLength minimumWidth () const
 Returns the minimum width. More...
 
virtual WLength minimumHeight () const
 Returns the minimum height. More...
 
virtual void setMaximumSize (const WLength &width, const WLength &height)
 Sets a maximum size. More...
 
virtual WLength maximumWidth () const
 Returns the maximum width. More...
 
virtual WLength maximumHeight () const
 Returns the maximum height. More...
 
virtual void setLineHeight (const WLength &height)
 Sets the CSS line height for contained text.
 
virtual WLength lineHeight () const
 Returns the CSS line height for contained text. More...
 
virtual void setFloatSide (Side s)
 Specifies a CSS float side. More...
 
virtual Side floatSide () const
 Returns the CSS float side. More...
 
virtual void setClearSides (WFlags< Side > sides)
 Sets the sides that should be cleared of floats. More...
 
virtual WFlags< SideclearSides () const
 Returns the sides that should remain empty. More...
 
virtual void setMargin (const WLength &margin, WFlags< Side > sides=All)
 Sets CSS margins around the widget. More...
 
virtual WLength margin (Side side) const
 Returns a CSS margin set. More...
 
virtual void setHiddenKeepsGeometry (bool enabled)
 Sets whether the widget keeps its geometry when hidden. More...
 
virtual bool hiddenKeepsGeometry () const
 Returns whether the widget keeps its geometry when hidden. More...
 
virtual bool isHidden () const
 Returns whether the widget is set hidden. More...
 
virtual bool isVisible () const
 Returns whether the widget is visible. More...
 
virtual void setDisabled (bool disabled)
 Sets whether the widget is disabled. More...
 
virtual bool isDisabled () const
 Returns whether the widget is set disabled. More...
 
virtual bool isEnabled () const
 Returns whether the widget is enabled. More...
 
virtual void setPopup (bool popup)
 Lets the widget overlay over other sibling widgets. More...
 
virtual bool isPopup () const
 Returns whether the widget is overlayed. More...
 
virtual void setInline (bool isInline)
 Sets whether the widget is displayed inline or as a block. More...
 
virtual bool isInline () const
 Returns whether the widget is displayed inline or as block. More...
 
virtual void setDecorationStyle (const WCssDecorationStyle &style)
 Sets a CSS decoration style. More...
 
virtual WCssDecorationStyledecorationStyle ()
 Returns the decoration style of this widget. More...
 
virtual void setStyleClass (const WString &styleClass)
 Sets (one or more) CSS style classes. More...
 
virtual WString styleClass () const
 Returns the CSS style class. More...
 
virtual void addStyleClass (const WString &styleClass, bool force=false)
 Adds a CSS style class. More...
 
virtual void removeStyleClass (const WString &styleClass, bool force=false)
 Removes a CSS style class. More...
 
virtual bool hasStyleClass (const WString &styleClass) const
 Returns whether the widget has a style class.
 
virtual void setVerticalAlignment (AlignmentFlag alignment, const WLength &length=WLength())
 Sets the vertical alignment. More...
 
virtual AlignmentFlag verticalAlignment () const
 Returns the vertical alignment. More...
 
virtual WLength verticalAlignmentLength () const
 Returns the fixed vertical alignment that was set. More...
 
virtual void setToolTip (const WString &text, TextFormat textFormat=PlainText)
 Sets a tooltip. More...
 
virtual void setDeferredToolTip (bool enable, TextFormat textFormat=PlainText)
 Enable deferred tooltip. More...
 
virtual WString toolTip () const
 Returns the tooltip.
 
virtual void setAttributeValue (const std::string &name, const WString &value)
 Sets an attribute value. More...
 
virtual WString attributeValue (const std::string &name) const
 Returns an attribute value. More...
 
virtual void setJavaScriptMember (const std::string &name, const std::string &value)
 Sets a JavaScript member. More...
 
virtual std::string javaScriptMember (const std::string &name) const
 Returns the value of a JavaScript member. More...
 
virtual void callJavaScriptMember (const std::string &name, const std::string &args)
 Calls a JavaScript member. More...
 
virtual void load ()
 Loads content just before the widget is used. More...
 
virtual bool loaded () const
 Returns whether this widget has been loaded. More...
 
virtual void setId (const std::string &id)
 Sets the CSS Id. More...
 
virtual WWidgetfind (const std::string &name)
 Finds a descendent widget by name. More...
 
virtual WWidgetfindById (const std::string &id)
 Finds a descendent widget by id.
 
virtual void setSelectable (bool selectable)
 Sets as selectable. More...
 
virtual void doJavaScript (const std::string &javascript)
 Executes the given JavaScript statements when the widget is rendered or updated. More...
 
virtual const std::string id () const
 Returns the (unique) identifier for this object. More...
 
void setLoadLaterWhenInvisible (bool)
 Change the way the widget is loaded when invisible. More...
 
std::string htmlTagName () const
 returns the current html tag name More...
 
void setHtmlTagName (const std::string &tag)
 set the custom HTML tag name More...
 
const std::vector< WWidget * > & children () const
 Returns contained widgets. More...
 
SignalchildrenChanged ()
 Signal emitted when children have been added or removed. More...
 
virtual void setCanReceiveFocus (bool enabled)
 Sets whether the widget can receive focus. More...
 
virtual bool canReceiveFocus () const
 Returns whether the widget can receive focus. More...
 
virtual bool setFirstFocus ()
 Set focus on the widget's first descendant. More...
 
virtual void setFocus (bool focus)
 Sets focus. More...
 
virtual bool hasFocus () const
 Returns whether the widget currently has the focus.
 
virtual void setTabIndex (int index)
 Sets the tab index. More...
 
virtual int tabIndex () const
 Returns the tab index. More...
 
EventSignalblurred ()
 Signal emitted when the widget lost focus. More...
 
EventSignalfocussed ()
 Signal emitted when the widget recieved focus. More...
 
virtual bool scrollVisibilityEnabled () const WT_CXX11ONLY(finaloverride)
 Returns whether scroll visibility detection is enabled for this widget. More...
 
virtual void setScrollVisibilityEnabled (bool enabled) WT_CXX11ONLY(finaloverride)
 Sets whether scroll visibility detection is enabled for this widget. More...
 
virtual int scrollVisibilityMargin () const WT_CXX11ONLY(finaloverride)
 Returns the margin around the viewport within which the widget is considered visible. More...
 
virtual void setScrollVisibilityMargin (int margin) WT_CXX11ONLY(finaloverride)
 Sets the margin around the viewport within which the widget is considered visible. More...
 
virtual Signal< bool > & scrollVisibilityChanged () WT_CXX11ONLY(finaloverride)
 Signal triggered when the scroll visibility of this widget changes. More...
 
virtual bool isScrollVisible () const WT_CXX11ONLY(finaloverride)
 Returns whether this widget is currently considered scroll visible. More...
 
virtual void setThemeStyleEnabled (bool enabled)
 Sets whether theme styling for a widget is enabled or disabled. More...
 
virtual bool isThemeStyleEnabled () const
 Returns whether this widget is currently styled by the chosen theme. More...
 
- Public Member Functions inherited from Wt::WWidget
virtual ~WWidget ()
 Destructor. More...
 
WWidgetparent () const
 Returns the parent widget. More...
 
virtual void removeChild (WObject *child)
 Removes a child object. More...
 
void setWidth (const WLength &width)
 Sets the width. More...
 
void setHeight (const WLength &height)
 Sets the height. More...
 
virtual void positionAt (const WWidget *widget, Orientation orientation=Vertical)
 Positions a widget next to another widget. More...
 
virtual void toggleStyleClass (const WString &styleClass, bool add, bool force=false)
 Toggles a CSS style class.
 
std::string jsRef () const
 Returns a JavaScript expression to the corresponding DOM node. More...
 
void setFocus ()
 Sets focus. More...
 
virtual void acceptDrops (const std::string &mimeType, const WString &hoverStyleClass=WString())
 Sets a mime type to be accepted for dropping. More...
 
virtual void stopAcceptDrops (const std::string &mimeType)
 Indicates that a mime type is no longer accepted for dropping. More...
 
virtual void setObjectName (const std::string &name)
 Sets an object name. More...
 
virtual void htmlText (std::ostream &out)
 Streams the (X)HTML representation. More...
 
bool isRendered () const
 Returns whether the widget is rendered. More...
 
void hide ()
 Hides the widget. More...
 
void animateHide (const WAnimation &animation)
 Hides the widget using an animation. More...
 
void show ()
 Shows the widget. More...
 
void animateShow (const WAnimation &animation)
 Shows the widget using an animation. More...
 
void enable ()
 Enables the widget. More...
 
void disable ()
 Disable thes widget. More...
 
bool layoutSizeAware () const
 Returns whether the widget is layout size aware. More...
 
- Public Member Functions inherited from Wt::WObject
 WObject (WObject *parent=0)
 Create a WObject with a given parent object. More...
 
virtual ~WObject ()
 Destructor. More...
 
virtual std::string objectName () const
 Returns the object name. More...
 
void resetLearnedSlots ()
 Resets learned stateless slot implementations. More...
 
template<class T >
void resetLearnedSlot (void(T::*method)())
 Resets a learned stateless slot implementation. More...
 
template<class T >
WStatelessSlot * implementStateless (void(T::*method)())
 Declares a slot to be stateless and learn client-side behaviour on first invocation. More...
 
template<class T >
WStatelessSlot * implementStateless (void(T::*method)(), void(T::*undoMethod)())
 Declares a slot to be stateless and learn client-side behaviour in advance. More...
 
void isNotStateless ()
 Marks the current function as not stateless. More...
 
template<class T >
WStatelessSlot * implementJavaScript (void(T::*method)(), const std::string &jsCode)
 Provides a JavaScript implementation for a method. More...
 
void addChild (WObject *child)
 Adds a child object. More...
 
const std::vector< WObject * > & children () const
 Returns the children.
 
WObjectparent () const
 Returns the parent object.
 

Additional Inherited Members

- Public Types inherited from Wt::Ext::LineEdit
- Public Types inherited from Wt::Ext::FormField
- Public Types inherited from Wt::WObject
typedef void(WObject::* Method) ()
 Typedef for a WObject method without arguments.
 
- Static Public Member Functions inherited from Wt::WWebWidget
static WString escapeText (const WString &text, bool newlinesToo=false)
 Escape HTML control characters in the text, to display literally (deprecated). More...
 
static std::string & escapeText (std::string &text, bool newlinestoo=false)
 Escape HTML control characters in the text, to display literally (deprecated). More...
 
static bool removeScript (WString &text)
 Remove tags/attributes from text that are not passive (deprecated). More...
 
static std::string jsStringLiteral (const std::string &v, char delimiter= '\'')
 Turn a UTF8 encoded string into a JavaScript string literal. More...
 
- Static Public Member Functions inherited from Wt::WWidget
static WString tr (const char *key)
 Short hand for WString::tr() More...
 
- Protected Member Functions inherited from Wt::Ext::FormField
 FormField (WContainerWidget *parent=0)
 Create a form field.
 
virtual void render (WFlags< RenderFlag > flags)
 Renders the widget. More...
 
- Protected Member Functions inherited from Wt::Ext::Component
virtual void propagateSetEnabled (bool enabled)
 Propagates that a widget was enabled or disabled through children. More...
 
- Protected Member Functions inherited from Wt::WWebWidget
virtual void enableAjax ()
 Progresses to an Ajax-enabled widget. More...
 
virtual WStatelessSlot * getStateless (Method method)
 On-demand stateless slot implementation. More...
 
- Protected Member Functions inherited from Wt::WWidget
void setLayoutSizeAware (bool sizeAware)
 Sets the widget to be aware of its size set by a layout manager. More...
 
virtual void layoutSizeChanged (int width, int height)
 Virtual method that indicates a size change. More...
 
 WWidget (WContainerWidget *parent=0)
 Creates a widget. More...
 
virtual void dropEvent (WDropEvent dropEvent)
 Handles a drop event. More...
 
virtual int boxPadding (Orientation orientation) const
 Returns the widget's built-in padding. More...
 
virtual int boxBorder (Orientation orientation) const
 Returns the widget's built-in border width. More...
 
void scheduleRender (WFlags< RepaintFlag > flags=0)
 Schedules rerendering of the widget. More...
 
- Static Protected Member Functions inherited from Wt::WObject
static WObjectsender ()
 Returns the sender of the current slot call. More...
 

Detailed Description

A widget that provides a drop-down combo-box control.

A combo-box provides the user with a choice of options to chose from. Use addItem(const WString&) or insertItem(int, const WString&) to populate the combo-box. All the content can be cleared through clear().

To act on a new selection, either connect a slot to the activated() signal.

At all times, the current selection index is available through currentIndex() or the text using currentText().

By default the ComboBox uses a WStringListModel to store the items. This may be changed by specifying a custom model with setModel().

When the combobox is configured to be editable, the user may enter a value which is not available in the list of values. In that case, currentText() will hold this value, while currentIndex() == -1 indicates that the value was not in the list.

By default, all the data is downloaded to the client. This may be changed using setDataLocation(DataLocation) to keep the data at hte server, and download data on-demand. This is useful if you have a very large list of options.

The API is a superset of the WComboBox API.

ExtComboBox-1.png
ComboBox with expanded drop-down list.

Member Function Documentation

void Wt::Ext::ComboBox::addItem ( const WString text)

Add an option item.

Equivalent to insertItem (count(), text).

int Wt::Ext::ComboBox::currentIndex ( ) const

Get the currently selected item.

If no item is currently selected, the method returns -1.
If the combo-box is editable and the entered text does not match an existing item, then this method also returns -1. Otherwise the index is returned of the first item that matches the value of currentText().

const WString Wt::Ext::ComboBox::currentText ( ) const

Get the text of the currently selected item.

This retrieves the current text entered by the user. When the combo-box is editable, this may be text that does not correspond to any of the items.

void Wt::Ext::ComboBox::insertItem ( int  index,
const WString text 
)

Insert an option item at the specified position.

The option item is inserted at position index.

const WString Wt::Ext::ComboBox::itemText ( int  index) const

Get the text of a particular item.

Use this method to get the text for the item at position index.

void Wt::Ext::ComboBox::refresh ( )
virtual

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 reimplemented refresh() to attach to it an effect).

Reimplemented from Wt::Ext::FormField.

void Wt::Ext::ComboBox::removeItem ( int  index)

Remove the option item at the specified position.

The option item at position index will be removed.

void Wt::Ext::ComboBox::setCurrentIndex ( int  index)

Change the current selection.

Specify a value of -1 for index to clear the selection.

void Wt::Ext::ComboBox::setDataLocation ( DataLocation  dataLocation)

Configure the location of the data for the combo-box.

When a ClientSide data location is specified, all data for the combo-box is downloaded when the combo-box is created. Using a ServerSide data location, data is downloaded to the client only when needed.

The defualt value is ClientSide.

void Wt::Ext::ComboBox::setEditable ( bool  how)

Set if the combo-box is editable.

An editable combo-box allows the user to specify a value that is not part of the list of values.

The default is false.

See also
currentText()
void Wt::Ext::ComboBox::setItemText ( int  index,
const WString text 
)

Change the text for a specified option.

Use this method to change the text for the item at position index.

void Wt::Ext::ComboBox::setMinQueryLength ( int  numChars)

Configure the minimum number of characters to be entered before filtering the drop-down list.

Values in the drop-down list will only be filtered when the entered text contains more that numChars characters.

The default value is 4.

See also
setQueryDelay(int)
void Wt::Ext::ComboBox::setModel ( WAbstractItemModel model)

Set the model to be used for the items.

The model may not be 0, and ownership of the model is not transferred.

See also
setModelColumn(int)
void Wt::Ext::ComboBox::setModelColumn ( int  index)

Set the column in the model to be used for the items.

The column index in the model will be used to retrieve data.

See also
setModel()
void Wt::Ext::ComboBox::setPageSize ( int  pageSize)

Configure a page size to show matching values one page at a time.

At most pageSize matches will be shown at the same time in the combo-box.

The default value is 0 (no paging).

void Wt::Ext::ComboBox::setQueryDelay ( int  milliSeconds)

Configure the delay to filter the list matching the current input.

After the a delay of milliSeconds milli seconds, the list items are filtered to match the currently entered text and the drop-down list is updated. It is recommended to specify a non-zero delay when using a Remote data location.

The default is 0.

See also
setMinQueryLength(int)

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