org.apache.poi.hpsf
Class Thumbnail

java.lang.Object
  org.apache.poi.hpsf.Thumbnail

public final class Thumbnail
extends java.lang.Object

Class to manipulate data in the Clipboard Variant (VT_CF) format.

Author:

Drew Varner (Drew.Varner inOrAround sc.edu)

See Also:

SummaryInformation.getThumbnail()

Field Summary

static int	CF_BITMAP Clipboard Format - Bitmap
static int	CF_DIB Clipboard Format - Device Independent Bitmap
static int	CF_ENHMETAFILE Clipboard Format - Enhanced Windows metafile format
static int	CF_METAFILEPICT Clipboard Format - Windows metafile format.
static int	CFTAG_FMTID Clipboard Format Tag - Format ID
static int	CFTAG_MACINTOSH Clipboard Format Tag - Macintosh clipboard format
static int	CFTAG_NODATA Clipboard Format Tag - No Data
static int	CFTAG_WINDOWS Clipboard Format Tag - Windows clipboard format
static int	OFFSET_CF Offset in bytes where the Clipboard Format starts in the byte[] returned by SummaryInformation.getThumbnail()
static int	OFFSET_CFTAG Offset in bytes where the Clipboard Format Tag starts in the byte[] returned by SummaryInformation.getThumbnail()
static int	OFFSET_WMFDATA Offset in bytes where the Windows Metafile (WMF) image data starts in the byte[] returned by SummaryInformation.getThumbnail()

Constructor Summary

Thumbnail()
Default Constructor.

Thumbnail(byte[] thumbnailData)
Creates a Thumbnail instance and initializes with the specified image bytes.

Method Summary

long	getClipboardFormat() Returns an int representing the Clipboard Format
long	getClipboardFormatTag() Returns an int representing the Clipboard Format Tag
byte[]	getThumbnail() Returns the thumbnail as a byte[] in VT_CF format.
byte[]	getThumbnailAsWMF() Returns the Thumbnail as a byte[] of WMF data if the Thumbnail's Clipboard Format Tag is CFTAG_WINDOWS and its Clipboard Format is CF_METAFILEPICT
void	setThumbnail(byte[] thumbnail) Sets the Thumbnail's underlying byte[] in VT_CF format.

Methods inherited from class java.lang.Object

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

Field Detail

OFFSET_CFTAG

public static int OFFSET_CFTAG

Offset in bytes where the Clipboard Format Tag starts in the byte[] returned by SummaryInformation.getThumbnail()

OFFSET_CF

public static int OFFSET_CF

Offset in bytes where the Clipboard Format starts in the byte[] returned by SummaryInformation.getThumbnail()

This is only valid if the Clipboard Format Tag is CFTAG_WINDOWS

OFFSET_WMFDATA

public static int OFFSET_WMFDATA

Offset in bytes where the Windows Metafile (WMF) image data starts in the byte[] returned by SummaryInformation.getThumbnail()

There is only WMF data at this point in the byte[] if the Clipboard Format Tag is CFTAG_WINDOWS and the Clipboard Format is CF_METAFILEPICT.

Note: The byte[] that starts at OFFSET_WMFDATA and ends at getThumbnail().length - 1 forms a complete WMF image. It can be saved to disk with a .wmf file type and read using a WMF-capable image viewer.

CFTAG_WINDOWS

public static int CFTAG_WINDOWS

Clipboard Format Tag - Windows clipboard format

A DWORD indicating a built-in Windows clipboard format value

CFTAG_MACINTOSH

public static int CFTAG_MACINTOSH

Clipboard Format Tag - Macintosh clipboard format

A DWORD indicating a Macintosh clipboard format value

CFTAG_FMTID

public static int CFTAG_FMTID

Clipboard Format Tag - Format ID

A GUID containing a format identifier (FMTID). This is rarely used.

CFTAG_NODATA

public static int CFTAG_NODATA

Clipboard Format Tag - No Data

A DWORD indicating No data. This is rarely used.

CF_METAFILEPICT

public static int CF_METAFILEPICT

Clipboard Format - Windows metafile format. This is the recommended way to store thumbnails in Property Streams.

Note: This is not the same format used in regular WMF images. The clipboard version of this format has an extra clipboard-specific header.

CF_DIB

public static int CF_DIB

Clipboard Format - Device Independent Bitmap

CF_ENHMETAFILE

public static int CF_ENHMETAFILE

Clipboard Format - Enhanced Windows metafile format

CF_BITMAP

public static int CF_BITMAP

Clipboard Format - Bitmap

Obsolete, see msdn.microsoft.com/library/en-us/dnw98bk/html/clipboardoperations.asp.

Constructor Detail

Thumbnail

public Thumbnail()

Default Constructor. If you use it then one you'll have to add the thumbnail byte[] from SummaryInformation.getThumbnail() to do any useful manipulations, otherwise you'll get a NullPointerException.

Thumbnail

public Thumbnail(byte[] thumbnailData)

Creates a Thumbnail instance and initializes with the specified image bytes.

Parameters:

thumbnailData - The thumbnail data

Method Detail

getThumbnail

public byte[] getThumbnail()

Returns the thumbnail as a byte[] in VT_CF format.

Returns:

The thumbnail value

See Also:

SummaryInformation.getThumbnail()

setThumbnail

public void setThumbnail(byte[] thumbnail)

Sets the Thumbnail's underlying byte[] in VT_CF format.

Parameters:

thumbnail - The new thumbnail value

See Also:

SummaryInformation.getThumbnail()

getClipboardFormatTag

public long getClipboardFormatTag()

Returns an int representing the Clipboard Format Tag

Possible return values are:

• CFTAG_WINDOWS
• CFTAG_MACINTOSH
• CFTAG_FMTID
• CFTAG_NODATA

Returns:

A flag indicating the Clipboard Format Tag

getClipboardFormat

public long getClipboardFormat()
                        throws HPSFException

Returns an int representing the Clipboard Format

Will throw an exception if the Thumbnail's Clipboard Format Tag is not CFTAG_WINDOWS.

Possible return values are:

• CF_METAFILEPICT
• CF_DIB
• CF_ENHMETAFILE
• CF_BITMAP

Returns:

a flag indicating the Clipboard Format

Throws:

HPSFException - if the Thumbnail isn't CFTAG_WINDOWS

getThumbnailAsWMF

public byte[] getThumbnailAsWMF()
                         throws HPSFException

Returns the Thumbnail as a byte[] of WMF data if the Thumbnail's Clipboard Format Tag is CFTAG_WINDOWS and its Clipboard Format is CF_METAFILEPICT

This byte[] is in the traditional WMF file, not the clipboard-specific version with special headers.

See http://www.wvware.com/caolan/ora-wmf.html for more information on the WMF image format.

Returns:

A WMF image of the Thumbnail

Throws:

HPSFException - if the Thumbnail isn't CFTAG_WINDOWS and CF_METAFILEPICT