v5.20192.631
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DropDown Class

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).

Hierarchy

Constructors

constructor

  • new DropDown(element: any, options?: any): DropDown
  • Initializes a new instance of the DropDown class.

    Parameters

    • element: any

      The DOM element that hosts the control, or a selector for the host element (e.g. '#theCtrl').

    • Optional options: any

      The JavaScript object containing initialization data for the control.

    Returns DropDown

Properties

autoExpandSelection

autoExpandSelection: boolean

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.

dropDown

dropDown: HTMLElement

Gets the drop down element shown when the isDroppedDown property is set to true.

dropDownCssClass

dropDownCssClass: string

Gets or sets a CSS class name to add to the control's drop-down element.

This property is useful when styling the drop-down element, because it is shown as a child of the document body rather than as a child of the control itself, which prevents using CSS selectors based on the parent control.

hostElement

hostElement: HTMLElement

Gets the DOM element that is hosting the control.

inputElement

inputElement: HTMLInputElement

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.

inputType

inputType: string

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

The default value for this property is text.

isAnimated

isAnimated: boolean

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.

isDisabled

isDisabled: boolean

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

Disabled controls cannot get mouse or keyboard events.

isDroppedDown

isDroppedDown: boolean

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

The default value for this property is false.

isReadOnly

isReadOnly: boolean

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.

isRequired

isRequired: boolean

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.

isTouching

isTouching: boolean

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

isUpdating

isUpdating: boolean

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

placeholder

placeholder: string

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

rightToLeft

rightToLeft: boolean

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

showDropDownButton

showDropDownButton: boolean

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

The default value for this property is true.

text

text: string

Gets or sets the text shown on the control.

Static controlTemplate

controlTemplate: string

Gets or sets the template used to instantiate DropDown controls.

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.

    • Optional capture: boolean

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

    • Optional passive: boolean

      Indicates that the handler will never call preventDefault().

    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

    • classNames: string

      Names of classes to add to the control's host element.

    • template: string

      An HTML string that defines the control template.

    • parts: Object

      A dictionary of part variables and their names.

    • Optional namePart: string

      Name of the part to be named after the host element. This determines how the control submits data when used in forms.

    Returns HTMLElement

beginUpdate

  • beginUpdate(): void

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

    • fn: Function

      Function to be executed.

    Returns void

endUpdate

  • endUpdate(): void

focus

  • focus(): void
  • Sets the focus to this control.

    Returns void

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).

    Returns string

hasOwnProperty

  • hasOwnProperty(v: PropertyKey): boolean
  • Determines whether an object has a property with the specified name.

    Parameters

    • v: PropertyKey

      A property name.

    Returns boolean

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

    • options: any

      Object that contains the initialization data.

    Returns void

invalidate

  • invalidate(fullUpdate?: boolean): void
  • Invalidates the control causing an asynchronous refresh.

    Parameters

    • Optional fullUpdate: boolean

      Whether to update the control layout as well as the content.

    Returns void

isPrototypeOf

  • isPrototypeOf(v: Object): boolean
  • Determines whether an object exists in another object's prototype chain.

    Parameters

    • v: Object

      Another object whose prototype chain is to be checked.

    Returns boolean

onIsDroppedDownChanged

  • onIsDroppedDownChanged(e?: EventArgs): void

onIsDroppedDownChanging

onRefreshed

onRefreshing

onTextChanged

propertyIsEnumerable

  • propertyIsEnumerable(v: PropertyKey): boolean
  • Determines whether a specified property is enumerable.

    Parameters

    • v: PropertyKey

      A property name.

    Returns boolean

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

    • Optional target: EventTarget

      Target element for the event. If null, removes listeners attached to all targets.

    • Optional type: string

      String that specifies the event. If null, removes listeners attached to all events.

    • Optional fn: any

      Handler to remove. If null, removes all handlers.

    • Optional capture: boolean

      Whether the listener is capturing. If null, removes capturing and non-capturing listeners.

    Returns number

    The number of listeners removed.

selectAll

  • selectAll(): void
  • Sets the focus to the control and selects all its content.

    Returns void

toLocaleString

  • toLocaleString(): string
  • Returns a date converted to a string using the current locale.

    Returns string

toString

  • toString(): string
  • Returns a string representation of an object.

    Returns string

valueOf

  • valueOf(): Object
  • Returns the primitive value of the specified object.

    Returns Object

Static disposeAll

  • disposeAll(e?: HTMLElement): void
  • Disposes of all Wijmo controls contained in an HTML element.

    Parameters

    • Optional e: HTMLElement

      Container element.

    Returns void

Static getControl

  • getControl(element: any): Control
  • Gets the control that is hosted in a given DOM element.

    Parameters

    • element: any

      The DOM element that hosts the control, or a CSS selector for the host element (e.g. '#theCtrl').

    Returns Control

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 Control.invalidateAll method so the contained Wijmo controls will update their layout information properly.

    Parameters

    • Optional e: HTMLElement

      Container element. If set to null, all Wijmo controls on the page will be invalidated.

    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

    • Optional e: HTMLElement

      Container element. If set to null, all Wijmo controls on the page will be invalidated.

    Returns void

Events

gotFocus

gotFocus: Event

Occurs when the control gets the focus.

isDroppedDownChanged

isDroppedDownChanged: Event

Occurs after the drop down is shown or hidden.

isDroppedDownChanging

isDroppedDownChanging: Event

Occurs before the drop down is shown or hidden.

lostFocus

lostFocus: Event

Occurs when the control loses the focus.

refreshed

refreshed: Event

Occurs after the control has refreshed its contents.

refreshing

refreshing: Event

Occurs when the control is about to refresh its contents.

textChanged

textChanged: Event

Occurs when the value of the text property changes.