org.eclipse.swt.dnd
Class Clipboard

java.lang.Object
  |
  +--org.eclipse.swt.dnd.Clipboard

public class Clipboard

extends Object

Untamed: The Clipboard provides a mechanism for transferring data from one application to another or within an application.

IMPORTANT: This class is not intended to be subclassed.

Field Summary

private int	CFSTR_PREFERREDDROPEFFECT
private Object[]	data
private Display	display
private org.eclipse.swt.internal.ole.win32.COMObject	iDataObject
private int	MAX_RETRIES
private int	refCount
private Transfer[]	transferAgents

Constructor Summary

Clipboard(Display display)
Enabled: Constructs a new instance of this class.

Method Summary

private int	AddRef()
protected void	checkSubclass() Checks that this class can be subclassed.
private void	createCOMInterfaces()
void	dispose() Enabled: Disposes of the operating system resources associated with the clipboard.
private void	disposeCOMInterfaces()
private int	EnumFormatEtc(int dwDirection, int ppenumFormatetc)
String[]	getAvailableTypeNames() Enabled: Returns a platform specific list of the data types currently available on the system clipboard.
Object	getContents(Transfer transfer) Enabled: Retrieve the data of the specified type currently available on the system clipboard.
private int	GetData(int pFormatetc, int pmedium)
private int	QueryGetData(int pFormatetc)
private int	QueryInterface(int riid, int ppvObject)
private int	Release()
void	setContents(Object[] data, Transfer[] dataTypes) Enabled: Place data of the specified type on the system clipboard.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

display

private Display display

iDataObject

private org.eclipse.swt.internal.ole.win32.COMObject iDataObject

refCount

private int refCount

MAX_RETRIES

private final int MAX_RETRIES

transferAgents

private Transfer[] transferAgents

data

private Object[] data

CFSTR_PREFERREDDROPEFFECT

private int CFSTR_PREFERREDDROPEFFECT

Constructor Detail

Clipboard

public Clipboard(Display display)

Enabled: Constructs a new instance of this class. Creating an instance of a Clipboard may cause system resources to be allocated depending on the platform. It is therefore mandatory that the Clipboard instance be disposed when no longer required.

Parameters:

display - the display on which to allocate the clipboard

See Also:

dispose(), checkSubclass()

Method Detail

checkSubclass

protected void checkSubclass()

Checks that this class can be subclassed.

The SWT class library is intended to be subclassed only at specific, controlled points. This method enforces this rule unless it is overridden.

IMPORTANT: By providing an implementation of this method that allows a subclass of a class which does not normally allow subclassing to be created, the implementer agrees to be fully responsible for the fact that any such subclass will likely fail between SWT releases and will be strongly platform specific. No support is provided for user-written classes which are implemented in this fashion.

The ability to subclass outside of the allowed SWT classes is intended purely to enable those not on the SWT development team to implement patches in order to get around specific limitations in advance of when those limitations can be addressed by the team. Subclassing should not be attempted without an intimate and detailed understanding of the hierarchy.

dispose

public void dispose()

Enabled: Disposes of the operating system resources associated with the clipboard. The data will still be available on the system clipboard after the dispose method is called.

NOTE: On some platforms the data will not be available once the application has exited or the display has been disposed.

getContents

public Object getContents(Transfer transfer)

Enabled: Retrieve the data of the specified type currently available on the system clipboard. Refer to the specific subclass of Tramsfer to determine the type of object returned.

The following snippet shows text and RTF text being retrieved from the clipboard:

    Clipboard clipboard = new Clipboard(display);
    TextTransfer textTransfer = TextTransfer.getInstance();
    String textData = (String)clipboard.getContents(textTransfer);
    if (textData != null) System.out.println("Text is "+textData);
    RTFTransfer rtfTransfer = RTFTransfer.getInstance();
    String rtfData = (String)clipboard.getContents(rtfTransfer);
    if (rtfData != null) System.out.println("RTF Text is "+rtfData);
    clipboard.dispose();
    

Parameters:

transfer - the transfer agent for the type of data being requested

Returns:

the data obtained from the clipboard or null if no data of this type is available

See Also:

Transfer

setContents

public void setContents(Object[] data,
                        Transfer[] dataTypes)

Enabled: Place data of the specified type on the system clipboard. More than one type of data can be placed on the system clipboard at the same time. Setting the data clears any previous data of the same type from the system clipboard and also clears data of any other type currently on the system clipboard.

NOTE: On some platforms, the data is immediately copied to the system clipboard but on other platforms it is provided upon request. As a result, if the application modifes the data object it has set on the clipboard, that modification may or may not be available when the data is subsequently requested.

The following snippet shows text and RTF text being set on the clipboard:

 	Clipboard clipboard = new Clipboard(display);
		String textData = "Hello World";
		String rtfData = "{\\rtf1\\b\\i Hello World}";
		TextTransfer textTransfer = TextTransfer.getInstance();
		RTFTransfer rtfTransfer = RTFTransfer.getInstance();
		clipboard.setContents(new Object[]{textData, rtfData}, new Transfer[]{textTransfer, rtfTransfer});
		clipboard.dispose();
 

Parameters:

data - the data to be set in the clipboard

dataTypes - the transfer agents that will convert the data to its platform specific format; each entry in the data array must have a corresponding dataType

AddRef

private int AddRef()

createCOMInterfaces

private void createCOMInterfaces()

disposeCOMInterfaces

private void disposeCOMInterfaces()

EnumFormatEtc

private int EnumFormatEtc(int dwDirection,
                          int ppenumFormatetc)

GetData

private int GetData(int pFormatetc,
                    int pmedium)

QueryGetData

private int QueryGetData(int pFormatetc)

QueryInterface

private int QueryInterface(int riid,
                           int ppvObject)

Release

private int Release()

getAvailableTypeNames

public String[] getAvailableTypeNames()

Enabled: Returns a platform specific list of the data types currently available on the system clipboard.

Note: getAvailableTypeNames is a utility for writing a Transfer sub-class. It should NOT be used within an application because it provides platform specific information.

Returns:

a platform specific list of the data types currently available on the system clipboard