Package org.eclipse.swt.dnd

Class Clipboard

java.lang.Object
org.eclipse.swt.dnd.Clipboard
public class Clipboard extends Object
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.

See Also:
Restriction:
This class is not intended to be subclassed by clients.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Clipboard(Display display)
    Constructs a new instance of this class.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected void
    checkSubclass()
    Checks that this class can be subclassed.
    protected void
    checkWidget()
    Throws an SWTException if the receiver can not be accessed by the caller.
    void
    clearContents()
    If this clipboard is currently the owner of the data on the system clipboard, clear the contents.
    void
    clearContents(int clipboards)
    If this clipboard is currently the owner of the data on the specified clipboard, clear the contents.
    void
    dispose()
    Disposes of the operating system resources associated with the clipboard.
    String[]
    getAvailableTypeNames()
    Returns a platform specific list of the data types currently available on the system clipboard.
    TransferData[]
    getAvailableTypes()
    Returns an array of the data types currently available on the system clipboard.
    TransferData[]
    getAvailableTypes(int clipboards)
    Returns an array of the data types currently available on the specified clipboard.
    Object
    getContents(Transfer transfer)
    Retrieve the data of the specified type currently available on the system clipboard.
    Object
    getContents(Transfer transfer, int clipboards)
    Retrieve the data of the specified type currently available on the specified clipboard.
    boolean
    isDisposed()
    Returns true if the clipboard has been disposed, and false otherwise.
    void
    setContents(Object[] data, Transfer[] dataTypes)
    Place data of the specified type on the system clipboard.
    void
    setContents(Object[] data, Transfer[] dataTypes, int clipboards)
    Place data of the specified type on the specified clipboard.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Clipboard

      public Clipboard(Display display)
      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
      Throws:
      SWTException -
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
      • ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
      See Also:

  • Method Details

    • 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.

      Throws:
      SWTException -
      • ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass

    • checkWidget

      protected void checkWidget()
      Throws an SWTException if the receiver can not be accessed by the caller. This may include both checks on the state of the receiver and more generally on the entire execution context. This method should be called by widget implementors to enforce the standard SWT invariants.

      Currently, it is an error to invoke any method (other than isDisposed()) on a widget that has had its dispose() method called. It is also an error to call widget methods from any thread that is different from the thread that created the widget.

      In future releases of SWT, there may be more or fewer error checks and exceptions may be thrown for different reasons.

      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • clearContents

      public void clearContents()
      If this clipboard is currently the owner of the data on the system clipboard, clear the contents. If this clipboard is not the owner, then nothing is done. Note that there are clipboard assistant applications that take ownership of data or make copies of data when it is placed on the clipboard. In these cases, it may not be possible to clear the clipboard.
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      3.1

    • clearContents

      public void clearContents(int clipboards)
      If this clipboard is currently the owner of the data on the specified clipboard, clear the contents. If this clipboard is not the owner, then nothing is done.

      Note that there are clipboard assistant applications that take ownership of data or make copies of data when it is placed on the clipboard. In these cases, it may not be possible to clear the clipboard.

      The clipboards value is either one of the clipboard constants defined in class DND, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those DND clipboard constants.

      Parameters:
      clipboards - to be cleared
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      3.1
      See Also:

    • dispose

      public void dispose()
      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.

      Throws:
      SWTException -
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent

    • getContents

      public Object getContents(Transfer transfer)
      Retrieve the data of the specified type currently available on the system clipboard. Refer to the specific subclass of Transfer 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
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if transfer is null
      See Also:

    • getContents

      public Object getContents(Transfer transfer, int clipboards)
      Retrieve the data of the specified type currently available on the specified clipboard. Refer to the specific subclass of Transfer 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, DND.CLIPBOARD);
    if (rtfData != null) System.out.println("RTF Text is "+rtfData);
    clipboard.dispose();

      The clipboards value is either one of the clipboard constants defined in class DND, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those DND clipboard constants.

      Parameters:
      transfer - the transfer agent for the type of data being requested
      clipboards - on which to look for data
      Returns:
      the data obtained from the clipboard or null if no data of this type is available
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if transfer is null
      Since:
      3.1
      See Also:

    • isDisposed

      public boolean isDisposed()
      Returns true if the clipboard has been disposed, and false otherwise.

      This method gets the dispose state for the clipboard. When a clipboard has been disposed, it is an error to invoke any other method using the clipboard.

      Returns:
      true when the widget is disposed and false otherwise
      Since:
      3.0

    • setContents

      public void setContents(Object[] data, Transfer[] dataTypes)
      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 from the system clipboard, regardless of type.

      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 modifies 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 copy/paste 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();
        Transfer[] transfers = new Transfer[]{textTransfer, rtfTransfer};
        Object[] data = new Object[]{textData, rtfData};
        clipboard.setContents(data, transfers);
        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
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if data is null or datatypes is null or the length of data is not the same as the length of dataTypes
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      SWTError -
      • ERROR_CANNOT_SET_CLIPBOARD - if the clipboard is locked or otherwise unavailable

      NOTE: ERROR_CANNOT_SET_CLIPBOARD should be an SWTException, since it is a recoverable error, but can not be changed due to backward compatibility.

    • setContents

      public void setContents(Object[] data, Transfer[] dataTypes, int clipboards)
      Place data of the specified type on the specified clipboard. More than one type of data can be placed on the specified clipboard at the same time. Setting the data clears any previous data from the specified clipboard, regardless of type.

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

      The clipboards value is either one of the clipboard constants defined in class DND, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those DND clipboard constants.

      The following snippet shows text and RTF text being set on the copy/paste 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();
        Transfer[] transfers = new Transfer[]{textTransfer, rtfTransfer};
        Object[] data = new Object[]{textData, rtfData};
        clipboard.setContents(data, transfers, DND.CLIPBOARD);
        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
      clipboards - on which to set the data
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if data is null or datatypes is null or the length of data is not the same as the length of dataTypes
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      SWTError -
      • ERROR_CANNOT_SET_CLIPBOARD - if the clipboard is locked or otherwise unavailable

      NOTE: ERROR_CANNOT_SET_CLIPBOARD should be an SWTException, since it is a recoverable error, but can not be changed due to backward compatibility.

      Since:
      3.1
      See Also:

    • getAvailableTypes

      public TransferData[] getAvailableTypes()
      Returns an array of the data types currently available on the system clipboard. Use with Transfer.isSupportedType.
      Returns:
      array of data types currently available on the system clipboard
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      3.0
      See Also:

    • getAvailableTypes

      public TransferData[] getAvailableTypes(int clipboards)
      Returns an array of the data types currently available on the specified clipboard. Use with Transfer.isSupportedType.

      The clipboards value is either one of the clipboard constants defined in class DND, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those DND clipboard constants.

      Parameters:
      clipboards - from which to get the data types
      Returns:
      array of data types currently available on the specified clipboard
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      3.1
      See Also:

    • getAvailableTypeNames

      public String[] getAvailableTypeNames()
      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
      Throws:
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver