com.codename1.components

Class StorageImageAsync

java.lang.Object

com.codename1.ui.Image

com.codename1.ui.EncodedImage

com.codename1.components.StorageImageAsync

All Implemented Interfaces:

ActionSource

public class StorageImageAsync
extends EncodedImage

Asynchronous storage image that loads in the background and not during the paint cycle effectively not blocking the EDT drawing speed.

Method Summary

Modifier and Type	Method and Description
boolean	animate()
static StorageImageAsync	create(String fileName, Image placeholder) Creates an encoded image that maps to a storage file thus allowing to seamlessly cache images as needed.
byte[]	getImageData() Returns the byte array data backing the image allowing the image to be stored and discarded completely from RAM.
protected Image	getInternal() Returns the actual image represented by the encoded image, this image will be cached in a weak/soft reference internally.
boolean	isAnimation() Returns true if this is an animated image
protected void	resetCache() A subclass might choose to load asynchroniously and reset the cache when the image is ready.

Methods inherited from class com.codename1.ui.EncodedImage

asyncLock, create, create, create, create, create, createFromImage, createFromRGB, createMulti, drawImage, drawImage, getGraphics, getHeight, getImage, getWidth, isLocked, isOpaque, lock, modifyAlpha, modifyAlpha, rotate, scale, scaled, scaledEncoded, scaledHeight, scaledSmallerRatio, scaledWidth, subImage, toRGB, unlock

Methods inherited from class com.codename1.ui.Image

addActionListener, applyMask, applyMask, applyMaskAutoScale, createImage, createImage, createImage, createImage, createImage, createImage, createImage, createIndexed, createMask, createSVG, dispose, exifRotation, exifRotation, exifRotation, fill, fireChangedEvent, flipHorizontally, flipVertically, getExifOrientationTag, getExifOrientationTag, getImageName, getRGB, getRGB, getRGBCached, getSVGDocument, isAlphaMutableImageSupported, isJPEG, isPNG, isSVG, isSVGSupported, mirror, modifyAlphaWithTranslucency, removeActionListener, requiresDrawImage, rotate180Degrees, rotate270Degrees, rotate90Degrees, scaledLargerRatio, setImageName

Methods inherited from class java.lang.Object

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

Method Detail

resetCache

protected void resetCache()

A subclass might choose to load asynchroniously and reset the cache when the image is ready.

Overrides:

resetCache in class EncodedImage

getInternal

protected Image getInternal()

Returns the actual image represented by the encoded image, this image will be cached in a weak/soft reference internally. This method is useful to detect when the system actually created an image instance. You shouldn't invoke this method manually!

Overrides:

getInternal in class EncodedImage

Returns:

drawable image instance

getImageData

public byte[] getImageData()

Returns the byte array data backing the image allowing the image to be stored and discarded completely from RAM.

Overrides:

getImageData in class EncodedImage

Returns:

byte array used to create the image, e.g. encoded PNG, JPEG etc.

animate

public boolean animate()

Overrides:

animate in class Image

isAnimation

public boolean isAnimation()

Returns true if this is an animated image

Overrides:

isAnimation in class EncodedImage

Returns:

true if this image represents an animation

create

public static StorageImageAsync create(String fileName,
                                       Image placeholder)

Creates an encoded image that maps to a storage file thus allowing to seamlessly cache images as needed. This only works reasonably well for very small files.

Parameters:

fileName - the name of the storage file

placeholder - an image that must be of the same size as the EncodedImage

Returns:

image that will load the file seamlessly