ComponentOne ASP.NET MVC Controls
DropDown Class
File
wijmo.input.js
Module
wijmo.input
Base Class
Control
Derived Classes
ComboBox, InputColor, InputDate

DropDown control (abstract).

Contains an input element and a button used to show or hide the drop-down.

Derived classes must override the _createDropDown method to create whatever editor they want to show in the drop down area (a list of items, a calendar, a color editor, etc).

Constructor

Properties

Methods

Events

Constructor

constructor

constructor(element: any, options?): DropDown

Initializes a new instance of the DropDown class.

Parameters
Optional

The JavaScript object containing initialization data for the control.

Returns
DropDown

Properties

autoExpandSelection

Gets or sets a value that indicates whether the control should automatically expand the selection to whole words/numbers when the control is clicked.

The default value for this property is true.

Type
boolean

 

Static controlTemplate

Gets or sets the template used to instantiate DropDown controls.

Type
any

hostElement

Gets the DOM element that is hosting the control.

Inherited From
Control
Type
HTMLElement

inputElement

Gets the HTML input element hosted by the control.

Use this property in situations where you want to customize the attributes of the input element.

Type
HTMLInputElement

inputType

Gets or sets the "type" attribute of the HTML input element hosted by the control.

The default value for this property is text.

Type
string

isAnimated

Gets or sets a value that indicates whether the control should use a fade-in animation when displaying the drop-down.

The default value for this property is false.

Type
boolean

isDisabled

Gets or sets a value that determines whether the control is disabled.

Disabled controls cannot get mouse or keyboard events.

Inherited From
Control
Type
boolean

isDroppedDown

Gets or sets a value that indicates whether the drop down is currently visible.

The default value for this property is false.

Type
boolean

isReadOnly

Gets or sets a value that indicates whether the user can modify the control value using the mouse and keyboard.

The default value for this property is false.

Type
boolean

isRequired

Gets or sets a value that determines whether the control value must be set to a non-null value or whether it can be set to null (by deleting the content of the control).

This property defaults to true for most controls, including ComboBox, InputDate, InputTime, InputDateTime, and InputColor. It defaults to false for the AutoComplete control.

Type
boolean

isTouching

Gets a value that indicates whether the control is currently handling a touch event.

Inherited From
Control
Type
boolean

isUpdating

Gets a value that indicates whether the control is currently being updated.

Inherited From
Control
Type
boolean

placeholder

Gets or sets the string shown as a hint when the control is empty.

Type
string

rightToLeft

Gets a value indicating whether the control is hosted in an element with right-to-left layout.

Inherited From
Control
Type
boolean

showDropDownButton

Gets or sets a value that indicates whether the control should display a drop-down button.

The default value for this property is true.

Type
boolean

text

Gets or sets the text shown on the control.

Type
string

Methods

addEventListener

addEventListener(target: EventTarget, type: string, fn: any, capture?: boolean, passive?: boolean): void

Adds an event listener to an element owned by this Control.

The control keeps a list of attached listeners and their handlers, making it easier to remove them when the control is disposed (see the dispose and removeEventListener methods).

Failing to remove event listeners may cause memory leaks.

The passive parameter is set to false by default, which means the event handler may call event.preventDefault(). If you are adding passive handlers to touch or wheel events, setting this parameter to true will improve application performance.

For details on passive event listeners, please see Improving scrolling performance with passive listeners.

Parameters
  • target: EventTarget

    Target element for the event.

  • type: string

    String that specifies the event.

  • fn: any

    Function to execute when the event occurs.

  • capture: boolean
Optional

Whether the listener should be handled by the control before it is handled by the target element.

Indicates that the handler will never call preventDefault().

Inherited From
Control
Returns
void

applyTemplate

applyTemplate(classNames: string, template: string, parts: Object, namePart?: string): HTMLElement

Applies the template to a new instance of a control, and returns the root element.

This method should be called by constructors of templated controls. It is responsible for binding the template parts to the corresponding control members.

For example, the code below applies a template to an instance of an InputNumber control. The template must contain elements with the 'wj-part' attribute set to 'input', 'btn-inc', and 'btn-dec'. The control members '_tbx', '_btnUp', and '_btnDn' will be assigned references to these elements.

this.applyTemplate('wj-control wj-inputnumber', template, {
  _tbx: 'input',
  _btnUp: 'btn-inc',
  _btnDn: 'btn-dec'
}, 'input');
Parameters
Inherited From
Control
Returns
HTMLElement

beginUpdate

beginUpdate(): void

Suspends notifications until the next call to endUpdate.

Inherited From
Control
Returns
void

containsFocus

containsFocus(): boolean

Checks whether this control contains the focused element.

Inherited From
Control
Returns
boolean

deferUpdate

deferUpdate(fn: Function): void

Executes a function within a beginUpdate/endUpdate block.

The control will not be updated until the function has been executed. This method ensures endUpdate is called even if the function throws an exception.

Parameters
Inherited From
Control
Returns
void

dispose

dispose(): void

Disposes of the control by removing its association with the host element.

The dispose method automatically removes any event listeners added with the addEventListener method.

Calling the dispose method is important in applications that create and remove controls dynamically. Failing to dispose of the controls may cause memory leaks.

Inherited From
Control
Returns
void

Static disposeAll

disposeAll(e?: HTMLElement): void

Disposes of all Wijmo controls contained in an HTML element.

Parameters
Inherited From
Control
Returns
void

endUpdate

endUpdate(): void

Resumes notifications suspended by calls to beginUpdate.

Inherited From
Control
Returns
void

focus

focus(): void

Sets the focus to this control.

Inherited From
Control
Returns
void

Static getControl

getControl(element: any): Control

Gets the control that is hosted in a given DOM element.

Parameters
Inherited From
Control
Returns
Control

getTemplate

getTemplate(): string

Gets the HTML template used to create instances of the control.

This method traverses up the class hierarchy to find the nearest ancestor that specifies a control template. For example, if you specify a prototype for the ComboBox control, which does not specify a template, it will override the template defined by the DropDown base class (the nearest ancestor that does specify a template).

Inherited From
Control
Returns
string

initialize

initialize(options: any): void

Initializes the control by copying the properties from a given object.

This method allows you to initialize controls using plain data objects instead of setting the value of each property in code.

For example:

grid.initialize({
  itemsSource: myList,
  autoGenerateColumns: false,
  columns: [
    { binding: 'id', header: 'Code', width: 130 },
    { binding: 'name', header: 'Name', width: 60 } 
  ]
});

// is equivalent to
grid.itemsSource = myList;
grid.autoGenerateColumns = false;

// etc.

The initialization data is type-checked as it is applied. If the initialization object contains unknown property names or invalid data types, this method will throw.

Parameters
Inherited From
Control
Returns
void

invalidate

invalidate(fullUpdate?: boolean): void

Invalidates the control causing an asynchronous refresh.

Parameters
Inherited From
Control
Returns
void

Static invalidateAll

invalidateAll(e?: HTMLElement): void

Invalidates all Wijmo controls contained in an HTML element.

Use this method when your application has dynamic panels that change the control's visibility or dimensions. For example, splitters, accordions, and tab controls usually change the visibility of its content elements. In this case, failing to notify the controls contained in the element may cause them to stop working properly.

If this happens, you must handle the appropriate event in the dynamic container and call the invalidateAll method so the contained Wijmo controls will update their layout information properly.

Parameters
Inherited From
Control
Returns
void

onGotFocus

onGotFocus(e?: EventArgs): void

Raises the gotFocus event.

Parameters
Inherited From
Control
Returns
void

onIsDroppedDownChanged

onIsDroppedDownChanged(e?: EventArgs): void

Raises the isDroppedDownChanged event.

Parameters
Returns
void

onIsDroppedDownChanging

onIsDroppedDownChanging(e: CancelEventArgs): boolean

Raises the isDroppedDownChanging event.

Parameters
Returns
boolean

onLostFocus

onLostFocus(e?: EventArgs): void

Raises the lostFocus event.

Parameters
Inherited From
Control
Returns
void

onRefreshed

onRefreshed(e?: EventArgs): void

Raises the refreshed event.

Parameters
Inherited From
Control
Returns
void

onRefreshing

onRefreshing(e?: EventArgs): void

Raises the refreshing event.

Parameters
Inherited From
Control
Returns
void

onTextChanged

onTextChanged(e?: EventArgs): void

Raises the textChanged event.

Parameters
Returns
void

refresh

refresh(fullUpdate?: boolean): void

Refreshes the control.

Parameters
Inherited From
Control
Returns
void

Static refreshAll

refreshAll(e?: HTMLElement): void

Refreshes all Wijmo controls contained in an HTML element.

This method is similar to invalidateAll, except the controls are updated immediately rather than after an interval.

Parameters
Inherited From
Control
Returns
void

removeEventListener

removeEventListener(target?: EventTarget, type?: string, fn?: any, capture?: boolean): number

Removes one or more event listeners attached to elements owned by this Control.

Parameters
Inherited From
Control
Returns
number

selectAll

selectAll(): void

Sets the focus to the control and selects all its content.

Returns
void

Events

gotFocus

Occurs when the control gets the focus.

Inherited From
Control
Arguments
EventArgs

isDroppedDownChanged

Occurs after the drop down is shown or hidden.

Arguments
EventArgs

isDroppedDownChanging

Occurs before the drop down is shown or hidden.

Arguments
CancelEventArgs

lostFocus

Occurs when the control loses the focus.

Inherited From
Control
Arguments
EventArgs

refreshed

Occurs after the control has refreshed its contents.

Inherited From
Control
Arguments
EventArgs

refreshing

Occurs when the control is about to refresh its contents.

Inherited From
Control
Arguments
EventArgs

textChanged

Occurs when the value of the text property changes.

Arguments
EventArgs