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

Package	mx.managers
Class	public class DragManager
Inheritance	DragManager Object

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The DragManager class manages drag and drop operations, which let you move data from one place to another in a Flex application. For example, you can select an object, such as an item in a List control or a Flex control, such as an Image control, and then drag it over another component to add it to that component.

All methods and properties of the DragManager are static, so you do not need to create an instance of it.

All Flex components support drag and drop operations. Flex provides additional support for drag and drop to the List, Tree, and DataGrid controls.

When the user selects an item with the mouse, the selected component is called the drag initiator. The image displayed during the drag operation is called the drag proxy.

When the user moves the drag proxy over another component, the dragEnter event is sent to that component. If the component accepts the drag, it becomes the drop target and receives dragOver, dragExit, and dragDrop events.

When the drag is complete, a dragComplete event is sent to the drag initiator.

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
		isDragging : Boolean [static] [read-only] Read-only property that returns true if a drag is in progress.	DragManager
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object

Public Methods

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	Method		Defined By
		acceptDragDrop(target:IUIComponent):void [static] Call this method from your dragEnter event handler if you accept the drag/drop data.	DragManager
		doDrag(dragInitiator:IUIComponent, dragSource:DragSource, mouseEvent:MouseEvent, dragImage:IFlexDisplayObject = null, xOffset:Number = 0, yOffset:Number = 0, imageAlpha:Number = 0.5, allowMove:Boolean = true):void [static] Initiates a drag and drop operation.	DragManager
		getFeedback():String [static] Returns the current drag and drop feedback.	DragManager
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		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
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		showFeedback(feedback:String):void [static] Sets the feedback indicator for the drag and drop operation.	DragManager
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object

Styles

Styles are either common or associated with a specific theme. If the style is common, it can be used with any theme. If a style is associated with a specific theme, it can only be used if your application uses that theme.

Common Styles

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	Description	Defined By
copyCursor	Type: Class CSS Inheritance: no Cursor displayed during a copy operation. The default value is the "mx.skins.cursor.DragCopy" symbol in the Assets.swf file.	DragManager
defaultDragImageSkin	Type: Class CSS Inheritance: no Skin used to draw the default drag image, which is also called the drag proxy. The default value is `mx.skins.halo.DefaultDragImage`.	DragManager
linkCursor	Type: Class CSS Inheritance: no Cursor displayed during a link operation. The default value is the "mx.skins.cursor.DragLink" symbol in the Assets.swf file.	DragManager
moveCursor	Type: Class CSS Inheritance: no Cursor displayed during a move operation. The default value is the "mx.skins.cursor.DragMove" symbol in the Assets.swf file.	DragManager
rejectCursor	Type: Class CSS Inheritance: no Cursor displayed for a reject operation. The default value is the "mx.skins.cursor.DragReject" symbol in the Assets.swf file.	DragManager

Public Constants

	Constant		Defined By
		COPY : String = "copy" [static] Constant that specifies that the type of drag action is "copy".	DragManager
		LINK : String = "link" [static] Constant that specifies that the type of drag action is "link".	DragManager
		MOVE : String = "move" [static] Constant that specifies that the type of drag action is "move".	DragManager
		NONE : String = "none" [static] Constant that specifies that the type of drag action is "none".	DragManager

Property Detail

isDragging

property

isDragging:Boolean [read-only]

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Read-only property that returns true if a drag is in progress.

Implementation
public static function get isDragging():Boolean

Method Detail

acceptDragDrop

()

method

public static function acceptDragDrop(target:IUIComponent):void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Call this method from your dragEnter event handler if you accept the drag/drop data. Typically, you cast event.target to the data type of the drop target. In the following example, the drop target is an MX Canvas container:

DragManager.acceptDragDrop(Canvas(event.target));

Parameters

target:IUIComponent — The drop target accepting the drag.

doDrag

()

method

 public static function doDrag(dragInitiator:IUIComponent, dragSource:DragSource, mouseEvent:MouseEvent, dragImage:IFlexDisplayObject = null, xOffset:Number = 0, yOffset:Number = 0, imageAlpha:Number = 0.5, allowMove:Boolean = true):void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Initiates a drag and drop operation.

Parameters

	`dragInitiator:IUIComponent` — IUIComponent that specifies the component initiating the drag.

	`dragSource:DragSource` — DragSource object that contains the data being dragged.

	`mouseEvent:MouseEvent` — The MouseEvent that contains the mouse information for the start of the drag.

	`dragImage:IFlexDisplayObject` (default = `null`) — The image to drag. This argument is optional. If omitted, a standard drag rectangle is used during the drag and drop operation. If you specify an image, you must explicitly set a height and width of the image or else it will not appear.

	`xOffset:Number` (default = `0`) — Number that specifies the x offset, in pixels, for the `dragImage`. This argument is optional. If omitted, the drag proxy is shown at the upper-left corner of the drag initiator. The offset is expressed in pixels from the left edge of the drag proxy to the left edge of the drag initiator, and is usually a negative number.

	`yOffset:Number` (default = `0`) — Number that specifies the y offset, in pixels, for the `dragImage`. This argument is optional. If omitted, the drag proxy is shown at the upper-left corner of the drag initiator. The offset is expressed in pixels from the top edge of the drag proxy to the top edge of the drag initiator, and is usually a negative number.

	`imageAlpha:Number` (default = `0.5`) — Number that specifies the alpha value used for the drag image. This argument is optional. If omitted, the default alpha value is 0.5. A value of 0.0 indicates that the image is transparent; a value of 1.0 indicates it is fully opaque.

	`allowMove:Boolean` (default = `true`) — Indicates if a drop target is allowed to move the dragged data.

getFeedback

()

method

public static function getFeedback():String

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Returns the current drag and drop feedback.

Returns

String — Possible return values are DragManager.COPY, DragManager.MOVE, DragManager.LINK, or DragManager.NONE.

showFeedback

()

method

public static function showFeedback(feedback:String):void

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Sets the feedback indicator for the drag and drop operation. Possible values are DragManager.COPY, DragManager.MOVE, DragManager.LINK, or DragManager.NONE.

Parameters

feedback:String — The type of feedback indicator to display.

Constant Detail

COPY

Constant

public static const COPY:String = "copy"

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constant that specifies that the type of drag action is "copy".

LINK

Constant

public static const LINK:String = "link"

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constant that specifies that the type of drag action is "link".

MOVE

Constant

public static const MOVE:String = "move"

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constant that specifies that the type of drag action is "move".

NONE

Constant

public static const NONE:String = "none"

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constant that specifies that the type of drag action is "none".