Class BitmapEncoder

java.lang.Object

org.knowm.xchart.BitmapEncoder

public final class BitmapEncoder
extends Object

A helper class with static methods for saving Charts as bitmaps

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	BitmapEncoder.BitmapFormat

Constructor Summary

Constructors

Modifier	Constructor	Description
private	BitmapEncoder()	Constructor - Private constructor to prevent instantiation

Method Summary

Modifier and Type	Method	Description
static String	addFileExtension(String fileName, BitmapEncoder.BitmapFormat bitmapFormat)	Only adds the extension of the BitmapFormat to the filename if the filename doesn't already have it.
static <T extends Chart<?,?>> byte[]	getBitmapBytes(T chart, BitmapEncoder.BitmapFormat bitmapFormat)	Generates a byte[] for a given chart
static <T extends Chart<?,?>> BufferedImage	getBufferedImage(T chart)
private static BufferedImage	mergeImages(List<BufferedImage> images, Integer rows, Integer cols)
static <T extends Chart<?,?>> void	saveBitmap(List<T> charts, Integer rows, Integer cols, OutputStream targetStream, BitmapEncoder.BitmapFormat bitmapFormat)	Save list of Charts into a given stream.
static <T extends Chart<?,?>> void	saveBitmap(List<T> charts, Integer rows, Integer cols, String fileName, BitmapEncoder.BitmapFormat bitmapFormat)	Save list of Charts as an image file.
static <T extends Chart<?,?>> void	saveBitmap(T chart, OutputStream targetStream, BitmapEncoder.BitmapFormat bitmapFormat)	Write a Chart into a given stream.
static <T extends Chart<?,?>> void	saveBitmap(T chart, String fileName, BitmapEncoder.BitmapFormat bitmapFormat)	Save a Chart as an image file
static <T extends Chart<?,?>> void	saveBitmapWithDPI(T chart, String fileName, BitmapEncoder.BitmapFormat bitmapFormat, int DPI)	Save a chart as a PNG with a custom DPI.
static <T extends Chart<?,?>> void	saveJPGWithQuality(T chart, String fileName, float quality)	Save a Chart as a JPEG file
private static void	setDPI(IIOMetadata metadata, int DPI)	Sets the metadata correctly

Methods inherited from class Object

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

Constructor Details

BitmapEncoder

private BitmapEncoder()

Constructor - Private constructor to prevent instantiation

Method Details

addFileExtension

public static String addFileExtension(String fileName,
 BitmapEncoder.BitmapFormat bitmapFormat)

Only adds the extension of the BitmapFormat to the filename if the filename doesn't already have it.

Parameters:

fileName -

bitmapFormat -

Returns:

filename (if extension already exists), otherwise;: filename + "." + extension

saveBitmap

public static <T extends Chart<?,?>> void saveBitmap(T chart,
 String fileName,
 BitmapEncoder.BitmapFormat bitmapFormat)
                                              throws IOException

Save a Chart as an image file

Parameters:

chart -

fileName -

bitmapFormat -

Throws:

IOException

saveBitmap

public static <T extends Chart<?,?>> void saveBitmap(T chart,
 OutputStream targetStream,
 BitmapEncoder.BitmapFormat bitmapFormat)
                                              throws IOException

Write a Chart into a given stream. Does not close the target stream automatically at the end of the operation

Parameters:

chart -

targetStream -

bitmapFormat -

Throws:

IOException

saveBitmap

public static <T extends Chart<?,?>> void saveBitmap(List<T> charts,
 Integer rows,
 Integer cols,
 String fileName,
 BitmapEncoder.BitmapFormat bitmapFormat)
                                              throws IOException

Save list of Charts as an image file. Function assumes that all charts are the same size (width, height). Number of charts should equal rows multiplied by cols.

Parameters:

charts -

rows - number of rows

cols - number of columns

fileName -

bitmapFormat -

Throws:

IOException

saveBitmap

public static <T extends Chart<?,?>> void saveBitmap(List<T> charts,
 Integer rows,
 Integer cols,
 OutputStream targetStream,
 BitmapEncoder.BitmapFormat bitmapFormat)
                                              throws IOException

Save list of Charts into a given stream. Does not close the target stream automatically at the end of the operation. Function assumes that all charts are the same size (width, height). Number of charts should equal rows multiplied by cols.

Parameters:

charts -

rows - number of rows

cols - number of columns

targetStream -

bitmapFormat -

Throws:

IOException

saveBitmapWithDPI

public static <T extends Chart<?,?>> void saveBitmapWithDPI(T chart,
 String fileName,
 BitmapEncoder.BitmapFormat bitmapFormat,
 int DPI)
                                                     throws IOException

Save a chart as a PNG with a custom DPI. The default DPI is 72, which is fine for displaying charts on a computer monitor, but for printing charts, a DPI of around 300 is much better.

Parameters:

chart -

fileName -

DPI -

Throws:

IOException

setDPI

private static void setDPI(IIOMetadata metadata,
 int DPI)
                    throws IIOInvalidTreeException

Sets the metadata correctly

Parameters:

metadata -

DPI -

Throws:

IIOInvalidTreeException

saveJPGWithQuality

public static <T extends Chart<?,?>> void saveJPGWithQuality(T chart,
 String fileName,
 float quality)
                                                      throws IOException

Save a Chart as a JPEG file

Parameters:

chart -

fileName -

quality - - a float between 0 and 1 (1 = maximum quality)

Throws:

IOException

getBitmapBytes

public static <T extends Chart<?,?>> byte[] getBitmapBytes(T chart,
 BitmapEncoder.BitmapFormat bitmapFormat)
                                                    throws IOException

Generates a byte[] for a given chart

Parameters:

chart -

Returns:

a byte[] for a given chart

Throws:

IOException

getBufferedImage

public static <T extends Chart<?,?>> BufferedImage getBufferedImage(T chart)

mergeImages

private static BufferedImage mergeImages(List<BufferedImage> images,
 Integer rows,
 Integer cols)