Supporting the drag-out gesture

To prepare data or an object for dragging, create a Clipboard object and add the information to be transferred in one or more formats. You can use the standard data formats to pass data that can be translated automatically to native clipboard formats, and application-defined formats to pass objects.

If it is computationally expensive to convert the information to be transferred into a particular format, you can supply the name of a handler function to perform the conversion. The function is called if and only if the receiving component or application reads the associated format.

For more information on clipboard formats, see Clipboard data formats .

The following example illustrates how to create a Clipboard object containing a bitmap in several formats: a Bitmap object, a native bitmap format, and a file list format containing the file from which the bitmap was originally loaded:

import flash.desktop.Clipboard; 
import flash.display.Bitmap; 
import flash.filesystem.File; 
public function createClipboard(image:Bitmap, sourceFile:File):Clipboard{ 
    var transfer:Clipboard = new Clipboard(); 
    transfer.setData("CUSTOM_BITMAP", image, true); //Flash object by value and by reference 
    transfer.setData(ClipboardFormats.BITMAP_FORMAT, image.bitmapData, false); 
    transfer.setData(ClipboardFormats.FILE_LIST_FORMAT, new Array(sourceFile), false); 
    return transfer; 
}

To start a drag operation, call the NativeDragManager.doDrag() method in response to a mouse down event. The doDrag() method is a static method that takes the following parameters:

The following example illustrates how to start a drag operation for a bitmap object loaded from a file. The example loads an image and, on a mouseDown event, starts the drag operation.

package 
{ 
import flash.desktop.NativeDragManager; 
import mx.core.UIComponent; 
import flash.display.Sprite; 
import flash.display.Loader; 
import flash.system.LoaderContext; 
import flash.net.URLRequest; 
import flash.geom.Point; 
import flash.desktop.Clipboard; 
import flash.display.Bitmap; 
import flash.filesystem.File; 
import flash.events.Event; 
import flash.events.MouseEvent; 
 
public class DragOutExample extends UIComponent Sprite { 
    protected var fileURL:String = "app:/image.jpg"; 
    protected var display:Bitmap; 
 
    private function init():void { 
        loadImage(); 
    } 
    private function onMouseDown(event:MouseEvent):void { 
        var bitmapFile:File = new File(fileURL); 
        var transferObject:Clipboard = createClipboard(display, bitmapFile); 
        NativeDragManager.doDrag(this,  
                            transferObject, 
                            display.bitmapData, 
                            new Point(-mouseX,-mouseY)); 
    } 
    public function createClipboard(image:Bitmap, sourceFile:File):Clipboard { 
        var transfer:Clipboard = new Clipboard(); 
        transfer.setData("bitmap",  
                            image,  
                            true);  
                            // ActionScript 3 Bitmap object by value and by reference 
        transfer.setData(ClipboardFormats.BITMAP_FORMAT,  
                            image.bitmapData,  
                            false);  
                            // Standard BitmapData format 
        transfer.setData(ClipboardFormats.FILE_LIST_FORMAT,  
                            new Array(sourceFile),  
                            false);  
                            // Standard file list format 
        return transfer;  
    } 
    private function loadImage():void { 
        var url:URLRequest = new URLRequest(fileURL); 
        var loader:Loader = new Loader(); 
        loader.load(url,new LoaderContext()); 
        loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoadComplete);       
    } 
    private function onLoadComplete(event:Event):void { 
        display = event.target.loader.content; 
        var flexWrapper:UIComponent = new UIComponent(); 
        flexWrapper.addChild(event.target.loader.content); 
        addChild(flexWrapper); 
        flexWrapper.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown); 
    } 
} 
}

When a user drops the dragged item by releasing the mouse, the initiator object dispatches a nativeDragComplete event. You can check the dropAction property of the event object and then take the appropriate action. For example, if the action is NativeDragAction.MOVE, you could remove the source item from its original location. The user can abandon a drag gesture by releasing the mouse button while the cursor is outside an eligible drop target. The drag manager sets the dropAction property for an abandoned gesture to NativeDragAction.NONE .