ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Drag and drop in AIR
Once a drag gesture has started, the Clipboard object can only be accessed from within an event handler for the
nativeDragEnter, nativeDragOver, and nativeDragDrop events. After the drag gesture has ended, the Clipboard
object cannot be read or reused.
An application object can be transferred as a reference and as a serialized object. References are only valid within the
originating application. Serialized object transfers are valid between AIR applications, but can only be used with
objects that remain valid when serialized and deserialized. Objects that are serialized are converted into the Action
Message Format for ActionScript 3 (AMF3), a string-based data-transfer format.
Working with the Flex framework
In most cases, it is better to use the Adobe® Flex drag-and-drop API when building Flex applications. The Flex
framework provides an equivalent feature set when a Flex application is run in AIR (it uses the AIR
NativeDragManager internally). Flex also maintains a more limited feature set when an application or component is
running within the more restrictive browser environment. AIR classes cannot be used in components or applications
that run outside the AIR run-time environment.
Supporting the drag-out gesture
Adobe AIR 1.0 and later
To support the drag-out gesture, you must create a Clipboard object in response to a mouseDown event and send it to
the NativeDragManager.doDrag() method. Your application can then listen for the nativeDragComplete event on
the initiating object to determine what action to take when the user completes or abandons the gesture.
Preparing data for transfer
Flash Player 9 and later, Adobe AIR 1.0 and later
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” on page 598.
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;
}
Last updated 6/6/2012
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