wjhk.jupload2.filedata.helper

Class ImageHelper

java.lang.Object

wjhk.jupload2.filedata.helper.ImageHelper

All Implemented Interfaces:

ImageObserver

public class ImageHelper
extends Object
implements ImageObserver

Class that contains various utilities about picture, mainly about picture transformation.

Author:

etienne_sf

Field Summary

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

Constructors

Constructor and Description
ImageHelper(PictureUploadPolicy uploadPolicy, PictureFileData pictureFileData, int targetMaxWidth, int targetMaxHeight, int quarterRotation) Standard constructor.

Method Summary

Modifier and Type	Method and Description
BufferedImage	getBufferedImage(boolean highquality, BufferedImage sourceBufferedImage) This function resizes the picture, if necessary, according to the maxWidth and maxHeight, given to the ImageHelper constructor.
boolean	hasToTransformPicture() This function indicate if the picture has to be modified.
boolean	imageUpdate(Image img, int infoflags, int x, int y, int width, int height) Implementation of the ImageObserver interface.

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageHelper

public ImageHelper(PictureUploadPolicy uploadPolicy,
                   PictureFileData pictureFileData,
                   int targetMaxWidth,
                   int targetMaxHeight,
                   int quarterRotation)
            throws JUploadIOException

Standard constructor.

Parameters:

uploadPolicy - The current upload policy

pictureFileData - The picture file data to help

targetMaxWidth -

targetMaxHeight -

quarterRotation - Current quarter rotation (from 0 to 3)

Throws:

JUploadIOException

Method Detail

hasToTransformPicture

public boolean hasToTransformPicture()
                              throws JUploadException

This function indicate if the picture has to be modified. For instance : a maximum width, height, a target format...

Returns:

true if the picture must be transformed. false if the file can be directly transmitted.

Throws:

JUploadException - Contains any exception that could be thrown in this method

getBufferedImage

public BufferedImage getBufferedImage(boolean highquality,
                                      BufferedImage sourceBufferedImage)
                               throws JUploadException

This function resizes the picture, if necessary, according to the maxWidth and maxHeight, given to the ImageHelper constructor.
This function should only be called if isPicture is true. Otherwise, an exception is raised.
Note (Update given by David Gnedt): the highquality will condition the call of getScaledInstance, instead of a basic scale Transformation. The generated picture is of better quality, but this is longer, especially on 'small' CPU. Time samples, with one picture from my canon EOS20D, on a PII 500M:
~3s for the full screen preview with highquality to false, and a quarter rotation. 12s to 20s with highquality to true.
~5s for the first (small) preview of the picture, with both highquality to false or true.

Parameters:

highquality - (added by David Gnedt): if set to true, the BufferedImage.getScaledInstance() is called. This generates better image, but consumes more CPU.

sourceBufferedImage - The image to resize or rotate or both or no tranformation...

Returns:

A BufferedImage which contains the picture according to current parameters (resizing, rotation...), or null if this is not a picture.

Throws:

JUploadException - Contains any exception thrown from within this method.

imageUpdate

public boolean imageUpdate(Image img,
                           int infoflags,
                           int x,
                           int y,
                           int width,
                           int height)

Implementation of the ImageObserver interface. Used to follow the drawImage progression, and update the applet progress bar.

Specified by:

imageUpdate in interface ImageObserver

Parameters:

img -

infoflags -

x -

y -

width -

height -

Returns:

Whether or not the work must go on.