javax.microedition.lcdui
Class Image

java.lang.Object
  extended by javax.microedition.lcdui.Image

public class Image
extends Object

Provides support for in memory images. The format of the bitmap is in standard leJOS format (so aligned for use on NXT LCD display). There is one bit per pixel. The pixels are packed into bytes with each byte spanning 8 scan lines. The least significant bit of each byte is the pixel for the top most scan line, the most significant bit is the 8th scan line. Values of 1 represent black. 0 white. This class implements a sub set of the standard lcdui Image class. Only mutable images are supported and the ARGB methods are not available.

Author:
Andre Nijholt & Andy Shaw

Constructor Summary
Image(int width, int height, byte[] data)
          Create an image using an already existing byte array.
 
Method Summary
static Image createImage(Image image, int x, int y, int w, int h, int transform)
          Creates a new image based upon the transformed region of another image
static Image createImage(InputStream s)
          Read image from file.
static Image createImage(int width, int height)
          Create ablank image of the requested size.
 byte[] getData()
          Return the byte array used to hold the image data.
 Graphics getGraphics()
          Returns a graphics object that can be used to draw to the image.
 int getHeight()
          return the height of the image.
 int getWidth()
          Return the width of the image.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Image

public Image(int width,
             int height,
             byte[] data)
Create an image using an already existing byte array. The byte array is used to store the image data. The array may already be initialized with image data.
Note: This is a non standard constructor.

Parameters:
width - width of the image
height - height of the image
data - The byte array to be used for image store/
Method Detail

createImage

public static Image createImage(int width,
                                int height)
Create ablank image of the requested size.

Parameters:
width -
height -
Returns:
Returns the new image.

createImage

public static Image createImage(InputStream s)
                         throws IOException
Read image from file. An image file has the following format:
1st byte - 4th byte 5th byte - 8th byte 9th byte 10th byte ....
image-width (int) image-height (int) 0x00(image data delimit) byte image data....

For example:

After a file with content
width (int) height (int) delimit byte data
00 00 00 03 00 00 00 05 00 00 02 1f
was read, this method will return an object which is equivalent to
new Image(3, 5, new byte[] {(byte)0x00, (byte)0x02, (byte)0x1f})

Parameters:
s - The input stream for the image file.
Returns:
an nxt image object.
Throws:
IOException - if an input or output error occurs or file format is not correct.
See Also:
Image, Image(int, int, byte[])

createImage

public static Image createImage(Image image,
                                int x,
                                int y,
                                int w,
                                int h,
                                int transform)
Creates a new image based upon the transformed region of another image

Parameters:
image - Source image
x - x co-ordinate of the source region
y - y co-ordinate of the source region
w - width of the source region
h - height of the source region
transform - Transform to be applied
Returns:
New image
See Also:
#see game.Sprite

getWidth

public int getWidth()
Return the width of the image.

Returns:
Image width

getHeight

public int getHeight()
return the height of the image.

Returns:
image height

getData

public byte[] getData()
Return the byte array used to hold the image data.
Note: This is a non standard method.

Returns:
The image byte array.

getGraphics

public Graphics getGraphics()
Returns a graphics object that can be used to draw to the image.

Returns:
graphics object.
See Also:
Graphics