mx.managers.FocusManager - Adobe® Flex® 4 Language Reference (Flex 4)

Package	mx.managers
Class	public class FocusManager
Inheritance	FocusManager EventDispatcher Object
Implements	IFocusManager

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The FocusManager class manages the focus on components in response to mouse activity or keyboard activity (Tab key). There can be several FocusManager instances in an application. Each FocusManager instance is responsible for a set of components that comprise a "tab loop". If you hit Tab enough times, focus traverses through a set of components and eventually get back to the first component that had focus. That is a "tab loop" and a FocusManager instance manages that loop. If there are popup windows with their own set of components in a "tab loop" those popup windows will have their own FocusManager instances. The main application always has a FocusManager instance.

The FocusManager manages focus from the "component level". In Flex, a UITextField in a component is the only way to allow keyboard entry of text. To the Flash Player or AIR, that UITextField has focus. However, from the FocusManager's perspective the component that parents the UITextField has focus. Thus there is a distinction between component-level focus and player-level focus. Application developers generally only have to deal with component-level focus while component developers must understand player-level focus.

All components that can be managed by the FocusManager must implement mx.managers.IFocusManagerComponent, whereas objects managed by player-level focus do not.

The FocusManager also managers the concept of a defaultButton, which is the Button on a form that dispatches a click event when the Enter key is pressed depending on where focus is at that time.

Public Properties

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	Property		Defined By
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		defaultButton : IButton A reference to the original default Button control.	FocusManager
		defaultButtonEnabled : Boolean A flag that indicates whether the FocusManager should check for the Enter key being pressed to activate the default button.	FocusManager
		focusPane : Sprite A single Sprite that is moved from container to container as the focus moves to those containers.	FocusManager
		nextTabIndex : int [read-only] The next unique tab index to use in this tab loop.	FocusManager
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object
		showFocusIndicator : Boolean A flag that indicates whether to display an indicator that a component has focus.	FocusManager

Public Methods

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	Method		Defined By
		FocusManager(container:IFocusManagerContainer, popup:Boolean = false) Constructor.	FocusManager
		activate():void The SystemManager activates and deactivates a FocusManager if more than one IFocusManagerContainer is visible at the same time.	FocusManager
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.	EventDispatcher
		deactivate():void The SystemManager activates and deactivates a FocusManager if more than one IFocusManagerContainer is visible at the same time.	FocusManager
		dispatchEvent(event:Event):Boolean Dispatches an event into the event flow.	EventDispatcher
		findFocusManagerComponent(o:InteractiveObject):IFocusManagerComponent Returns the IFocusManagerComponent that contains the given object, if any.	FocusManager
		getFocus():IFocusManagerComponent Gets the IFocusManagerComponent component that currently has the focus.	FocusManager
		getNextFocusManagerComponent(backward:Boolean = false):IFocusManagerComponent Returns the IFocusManagerComponent that would receive focus if the user pressed the Tab key to navigate to another component.	FocusManager
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	EventDispatcher
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		hideFocus():void Sets showFocusIndicator to false and removes the visual focus indicator from the focused object, if any.	FocusManager
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	EventDispatcher
		setFocus(o:IFocusManagerComponent):void Sets focus to an IFocusManagerComponent component.	FocusManager
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		showFocus():void Sets showFocusIndicator to true and draws the visual focus indicator on the focused object, if any.	FocusManager
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String [override] Returns a String representation of the component hosting the FocusManager object, with the String ".focusManager" appended to the end of the String.	FocusManager
		valueOf():Object Returns the primitive value of the specified object.	Object
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	EventDispatcher

Events

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	Event		Summary	Defined By
		activate	[broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active.	EventDispatcher
		deactivate	[broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive.	EventDispatcher

Property Detail

defaultButton

property

defaultButton:IButton

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

A reference to the original default Button control. Pressing the Enter key while the focus is on any control activates the Button control by dispatching a click event on the Button control, just as if it was clicked with the mouse. The actual default Button control changes if focus is given to another Button control, but switches back to the original if focus is not on a button.

This property is managed by Flex containers; do not set it directly to specify the default button.

The defaultButton must be of class mx.controls.Button even though this property is of type IUIComponent.

Implementation
public function get defaultButton():IButton
public function set defaultButton(value:IButton):void

defaultButtonEnabled

property

defaultButtonEnabled:Boolean

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

A flag that indicates whether the FocusManager should check for the Enter key being pressed to activate the default button. TextArea and other components that want to recognize the Enter key set this property to false to disable the Enter key from dispatching a click event on the default button, if it exists.

Implementation
public function get defaultButtonEnabled():Boolean
public function set defaultButtonEnabled(value:Boolean):void

focusPane

property

focusPane:Sprite

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

A single Sprite that is moved from container to container as the focus moves to those containers. The Sprite is used as the parent of the visual indicator that a component has focus.

Implementation
public function get focusPane():Sprite
public function set focusPane(value:Sprite):void

nextTabIndex

property

nextTabIndex:int [read-only]

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The next unique tab index to use in this tab loop.

Implementation
public function get nextTabIndex():int

showFocusIndicator

property

showFocusIndicator:Boolean

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

A flag that indicates whether to display an indicator that a component has focus. If true a component receiving focus draws a visible indicator that it has focus.

By default, this is false until the user uses the Tab key, then it is set to true.

In general it is better to use the showFocus() and hideFocus() methods to change this property as those methods also update the visual indicator that a component has focus.

Implementation
public function get showFocusIndicator():Boolean
public function set showFocusIndicator(value:Boolean):void

Constructor Detail

FocusManager

()

Constructor

public function FocusManager(container:IFocusManagerContainer, popup:Boolean = false)

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constructor.

A FocusManager manages the focus within the children of an IFocusManagerContainer. It installs itself in the IFocusManagerContainer during execution of the constructor.

Parameters

	`container:IFocusManagerContainer` — An IFocusManagerContainer that hosts the FocusManager.

	`popup:Boolean` (default = `false`) — If `true`, indicates that the container is a popup component and not the main application.

Method Detail

activate

()

method

public function activate():void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The SystemManager activates and deactivates a FocusManager if more than one IFocusManagerContainer is visible at the same time. If the mouse is clicked in an IFocusManagerContainer with a deactivated FocusManager, the SystemManager will call the activate() method on that FocusManager. The FocusManager that was activated will have its deactivate() method called prior to the activation of another FocusManager.

The FocusManager adds event handlers that allow it to monitor focus related keyboard and mouse activity.

deactivate

()

method

public function deactivate():void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The FocusManager removes event handlers that allow it to monitor focus related keyboard and mouse activity.

findFocusManagerComponent

()

method

public function findFocusManagerComponent(o:InteractiveObject):IFocusManagerComponent

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns the IFocusManagerComponent that contains the given object, if any. Because the player can set focus to a subcomponent of a Flex component this method determines which IFocusManagerComponent has focus from the component perspective.

Parameters

o:InteractiveObject — An object that can have player-level focus.

Returns

IFocusManagerComponent — The IFOcusManagerComponent containing o or null

getFocus

()

method

public function getFocus():IFocusManagerComponent

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Gets the IFocusManagerComponent component that currently has the focus. Calling this method is recommended instead of using the Stage object because it indicates which component has focus. The Stage might return a subcomponent in that component.

Returns

IFocusManagerComponent — IFocusManagerComponent object that has focus.

getNextFocusManagerComponent

()

method

public function getNextFocusManagerComponent(backward:Boolean = false):IFocusManagerComponent

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns the IFocusManagerComponent that would receive focus if the user pressed the Tab key to navigate to another component. It will return the same component as the current focused component if there are no other valid components in the application.

Parameters

backward:Boolean (default = false) — If true, return the object as if the Shift-Tab keys were pressed.

Returns

IFocusManagerComponent — The component that would receive focus.

hideFocus

()

method

public function hideFocus():void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Sets showFocusIndicator to false and removes the visual focus indicator from the focused object, if any.

setFocus

()

method

public function setFocus(o:IFocusManagerComponent):void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Sets focus to an IFocusManagerComponent component. Does not check for the components visibility, enabled state, or any other conditions.

Parameters

o:IFocusManagerComponent — A component that can receive focus.

showFocus

()

method

public function showFocus():void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Sets showFocusIndicator to true and draws the visual focus indicator on the focused object, if any.

toString

()

method

override public function toString():String

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns a String representation of the component hosting the FocusManager object, with the String ".focusManager" appended to the end of the String.

Returns

String — Returns a String representation of the component hosting the FocusManager object, with the String ".focusManager" appended to the end of the String.