Package org.eclipse.swt.graphics

Class ImageData

java.lang.Object
org.eclipse.swt.graphics.ImageData
public final class ImageData extends Object
Instances of this class are device-independent descriptions of images. They are typically used as an intermediate format between loading from or writing to streams and creating an Image.

Note that the public fields x, y, disposalMethod and delayTime are typically only used when the image is in a set of images used for animation.

Since:
1.3
See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    int
    alpha
    The global alpha value to be used for every pixel.
    byte[]
    alphaData
    The alpha data of the image.
    int
    bytesPerLine
    The number of bytes per scanline.
    byte[]
    data
    The pixel data of the image.
    int
    delayTime
    The time to delay before displaying the next image in an animation (this field corresponds to the GIF89a Delay Time value).
    int
    depth
    The color depth of the image, in bits per pixel.
    int
    disposalMethod
    A description of how to dispose of the current image before displaying the next.
    int
    height
    The height of the image, in pixels.
    byte[]
    maskData
    An icon-specific field containing the data from the icon mask.
    int
    maskPad
    An icon-specific field containing the scanline pad of the mask.
    PaletteData
    palette
    The color table for the image.
    int
    scanlinePad
    The scanline padding.
    int
    transparentPixel
    The transparent pixel.
    int
    type
    The type of file from which the image was read.
    int
    width
    The width of the image, in pixels.
    int
    x
    The x coordinate of the top left corner of the image within the logical screen (this field corresponds to the GIF89a Image Left Position value).
    int
    y
    The y coordinate of the top left corner of the image within the logical screen (this field corresponds to the GIF89a Image Top Position value).

  • Constructor Summary

    Constructors
    Constructor
    Description
    ImageData(int width, int height, int depth, PaletteData palette)
    Constructs a new, empty ImageData with the given width, height, depth and palette.
    ImageData(int width, int height, int depth, PaletteData palette, int scanlinePad, byte[] data)
    Constructs a new, empty ImageData with the given width, height, depth, palette, scanlinePad and data.
    ImageData(InputStream stream)
    Constructs an ImageData loaded from the specified input stream.
    ImageData(String filename)
    Constructs an ImageData loaded from a file with the specified name.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    clone()
    Returns a new instance of the same class as the receiver, whose slots have been filled in with copies of the values in the slots of the receiver.
    int
    getAlpha(int x, int y)
    Returns the alpha value at offset x in scanline y in the receiver's alpha data.
    void
    getAlphas(int x, int y, int getWidth, byte[] alphas, int startIndex)
    Returns getWidth alpha values starting at offset x in scanline y in the receiver's alpha data starting at startIndex.
    int
    getPixel(int x, int y)
    Returns the pixel value at offset x in scanline y in the receiver's data.
    void
    getPixels(int x, int y, int getWidth, byte[] pixels, int startIndex)
    Returns getWidth pixel values starting at offset x in scanline y in the receiver's data starting at startIndex.
    void
    getPixels(int x, int y, int getWidth, int[] pixels, int startIndex)
    Returns getWidth pixel values starting at offset x in scanline y in the receiver's data starting at startIndex.
    RGB[]
    getRGBs()
    Returns an array of RGBs which comprise the indexed color table of the receiver, or null if the receiver has a direct color model.
    ImageData
    getTransparencyMask()
    Returns an ImageData which specifies the transparency mask information for the receiver.
    int
    getTransparencyType()
    Returns the image transparency type, which will be one of SWT.TRANSPARENCY_NONE, SWT.TRANSPARENCY_MASK, SWT.TRANSPARENCY_PIXEL or SWT.TRANSPARENCY_ALPHA.
    static ImageData
    internal_new(int width, int height, int depth, PaletteData palette, int scanlinePad, byte[] data, int maskPad, byte[] maskData, byte[] alphaData, int alpha, int transparentPixel, int type, int x, int y, int disposalMethod, int delayTime)
    Invokes internal SWT functionality to create a new instance of this class.
    ImageData
    scaledTo(int width, int height)
    Returns a copy of the receiver which has been stretched or shrunk to the specified size.
    void
    setAlpha(int x, int y, int alpha)
    Sets the alpha value at offset x in scanline y in the receiver's alpha data.
    void
    setAlphas(int x, int y, int putWidth, byte[] alphas, int startIndex)
    Sets the alpha values starting at offset x in scanline y in the receiver's alpha data to the values from the array alphas starting at startIndex.
    void
    setPixel(int x, int y, int pixelValue)
    Sets the pixel value at offset x in scanline y in the receiver's data.
    void
    setPixels(int x, int y, int putWidth, byte[] pixels, int startIndex)
    Sets the pixel values starting at offset x in scanline y in the receiver's data to the values from the array pixels starting at startIndex.
    void
    setPixels(int x, int y, int putWidth, int[] pixels, int startIndex)
    Sets the pixel values starting at offset x in scanline y in the receiver's data to the values from the array pixels starting at startIndex.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • width

      public int width
      The width of the image, in pixels.

    • height

      public int height
      The height of the image, in pixels.

    • depth

      public int depth
      The color depth of the image, in bits per pixel.

      Note that a depth of 8 or less does not necessarily mean that the image is palette indexed, or conversely that a depth greater than 8 means that the image is direct color. Check the associated PaletteData's isDirect field for such determinations.

    • scanlinePad

      public int scanlinePad
      The scanline padding.

      If one scanline of the image is not a multiple of this number, it will be padded with zeros until it is.

    • bytesPerLine

      public int bytesPerLine
      The number of bytes per scanline.

      This is a multiple of the scanline padding.

    • data

      public byte[] data
      The pixel data of the image.

      Note that for 16 bit depth images the pixel data is stored in least significant byte order; however, for 24bit and 32bit depth images the pixel data is stored in most significant byte order.

    • palette

      public PaletteData palette
      The color table for the image.

    • transparentPixel

      public int transparentPixel
      The transparent pixel.

      Pixels with this value are transparent.

      The default is -1 which means 'no transparent pixel'.

    • maskData

      public byte[] maskData
      An icon-specific field containing the data from the icon mask.

      This is a 1 bit bitmap stored with the most significant bit first. The number of bytes per scanline is '((width + 7) / 8 + (maskPad - 1)) / maskPad * maskPad'.

      The default is null which means 'no transparency mask'.

    • maskPad

      public int maskPad
      An icon-specific field containing the scanline pad of the mask.

      If one scanline of the transparency mask is not a multiple of this number, it will be padded with zeros until it is.

    • alphaData

      public byte[] alphaData
      The alpha data of the image.

      Every pixel can have an alpha blending value that varies from 0, meaning fully transparent, to 255 meaning fully opaque. The number of bytes per scanline is 'width'.

    • alpha

      public int alpha
      The global alpha value to be used for every pixel.

      If this value is set, the alphaData field is ignored and when the image is rendered each pixel will be blended with the background an amount proportional to this value.

      The default is -1 which means 'no global alpha value'

    • type

      public int type
      The type of file from which the image was read. It is expressed as one of the following values:
      IMAGE_BMP
      Windows BMP file format, no compression
      IMAGE_BMP_RLE
      Windows BMP file format, RLE compression if appropriate
      IMAGE_GIF
      GIF file format
      IMAGE_ICO
      Windows ICO file format
      IMAGE_JPEG
      JPEG file format
      IMAGE_PNG
      PNG file format

    • x

      public int x
      The x coordinate of the top left corner of the image within the logical screen (this field corresponds to the GIF89a Image Left Position value).

    • y

      public int y
      The y coordinate of the top left corner of the image within the logical screen (this field corresponds to the GIF89a Image Top Position value).

    • disposalMethod

      public int disposalMethod
      A description of how to dispose of the current image before displaying the next. It is expressed as one of the following values:
      DM_UNSPECIFIED
      disposal method not specified
      DM_FILL_NONE
      do nothing - leave the image in place
      DM_FILL_BACKGROUND
      fill with the background color
      DM_FILL_PREVIOUS
      restore the previous picture
      (this field corresponds to the GIF89a Disposal Method value)

    • delayTime

      public int delayTime
      The time to delay before displaying the next image in an animation (this field corresponds to the GIF89a Delay Time value).

  • Constructor Details

    • ImageData

      public ImageData(int width, int height, int depth, PaletteData palette)
      Constructs a new, empty ImageData with the given width, height, depth and palette. The data will be initialized to an (all zero) array of the appropriate size.
      Parameters:
      width - the width of the image
      height - the height of the image
      depth - the depth of the image
      palette - the palette of the image (must not be null)
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the width or height is zero or negative, or if the depth is not one of 1, 2, 4, 8, 16, 24 or 32
      • ERROR_NULL_ARGUMENT - if the palette is null

    • ImageData

      public ImageData(int width, int height, int depth, PaletteData palette, int scanlinePad, byte[] data)
      Constructs a new, empty ImageData with the given width, height, depth, palette, scanlinePad and data.
      Parameters:
      width - the width of the image
      height - the height of the image
      depth - the depth of the image
      palette - the palette of the image
      scanlinePad - the padding of each line, in bytes
      data - the data of the image
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the width or height is zero or negative, or if the depth is not one of 1, 2, 4, 8, 16, 24 or 32, or the data array is too small to contain the image data
      • ERROR_NULL_ARGUMENT - if the palette or data is null
      • ERROR_CANNOT_BE_ZERO - if the scanlinePad is zero

    • ImageData

      public ImageData(InputStream stream)
      Constructs an ImageData loaded from the specified input stream. Throws an error if an error occurs while loading the image, or if the image has an unsupported type. Application code is still responsible for closing the input stream.

      This constructor is provided for convenience when loading a single image only. If the stream contains multiple images, only the first one will be loaded. To load multiple images, use ImageLoader.load().

      This constructor may be used to load a resource as follows: 

           static ImageData loadImageData (Class clazz, String string) {
          InputStream stream = clazz.getResourceAsStream (string);
          if (stream == null) return null;
          ImageData imageData = null;
          try {
               imageData = new ImageData (stream);
          } catch (SWTException ex) {
          } finally {
               try {
                    stream.close ();
               } catch (IOException ex) {}
          }
          return imageData;
     }
      Parameters:
      stream - the input stream to load the image from (must not be null)
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the stream is null
      SWTException -
      • ERROR_IO - if an IO error occurs while reading from the stream
      • ERROR_INVALID_IMAGE - if the image stream contains invalid data
      • ERROR_UNSUPPORTED_FORMAT - if the image stream contains an unrecognized format
      See Also:

    • ImageData

      public ImageData(String filename)
      Constructs an ImageData loaded from a file with the specified name. Throws an error if an error occurs loading the image, or if the image has an unsupported type.

      This constructor is provided for convenience when loading a single image only. If the file contains multiple images, only the first one will be loaded. To load multiple images, use ImageLoader.load().

      Parameters:
      filename - the name of the file to load the image from (must not be null)
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the file name is null
      SWTException -
      • ERROR_IO - if an IO error occurs while reading from the file
      • ERROR_INVALID_IMAGE - if the image file contains invalid data
      • ERROR_UNSUPPORTED_FORMAT - if the image file contains an unrecognized format

  • Method Details

    • internal_new

      public static ImageData internal_new(int width, int height, int depth, PaletteData palette, int scanlinePad, byte[] data, int maskPad, byte[] maskData, byte[] alphaData, int alpha, int transparentPixel, int type, int x, int y, int disposalMethod, int delayTime)
      Invokes internal SWT functionality to create a new instance of this class.

      IMPORTANT: This method is not part of the public API for ImageData. It is marked public only so that it can be shared within the packages provided by SWT. It is subject to change without notice, and should never be called from application code.

      This method is for internal use, and is not described further.

    • clone

      public Object clone()
      Returns a new instance of the same class as the receiver, whose slots have been filled in with copies of the values in the slots of the receiver. That is, the returned object is a deep copy of the receiver.
      Overrides:
      clone in class Object
      Returns:
      a copy of the receiver.

    • getAlpha

      public int getAlpha(int x, int y)
      Returns the alpha value at offset x in scanline y in the receiver's alpha data. The alpha value is between 0 (transparent) and 255 (opaque).
      Parameters:
      x - the x coordinate of the pixel to get the alpha value of
      y - the y coordinate of the pixel to get the alpha value of
      Returns:
      the alpha value at the given coordinates
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if either argument is out of range

    • getAlphas

      public void getAlphas(int x, int y, int getWidth, byte[] alphas, int startIndex)
      Returns getWidth alpha values starting at offset x in scanline y in the receiver's alpha data starting at startIndex. The alpha values are unsigned, between (byte)0 (transparent) and (byte)255 (opaque).
      Parameters:
      x - the x position of the pixel to begin getting alpha values
      y - the y position of the pixel to begin getting alpha values
      getWidth - the width of the data to get
      alphas - the buffer in which to put the alpha values
      startIndex - the offset into the image to begin getting alpha values
      Throws:
      IndexOutOfBoundsException - if getWidth is too large
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if pixels is null
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      • ERROR_INVALID_ARGUMENT - if getWidth is negative

    • getPixel

      public int getPixel(int x, int y)
      Returns the pixel value at offset x in scanline y in the receiver's data.
      Parameters:
      x - the x position of the pixel to get
      y - the y position of the pixel to get
      Returns:
      the pixel at the given coordinates
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if either argument is out of bounds
      SWTException -
      • ERROR_UNSUPPORTED_DEPTH if the depth is not one of 1, 2, 4, 8, 16, 24 or 32

    • getPixels

      public void getPixels(int x, int y, int getWidth, byte[] pixels, int startIndex)
      Returns getWidth pixel values starting at offset x in scanline y in the receiver's data starting at startIndex.
      Parameters:
      x - the x position of the first pixel to get
      y - the y position of the first pixel to get
      getWidth - the width of the data to get
      pixels - the buffer in which to put the pixels
      startIndex - the offset into the byte array to begin storing pixels
      Throws:
      IndexOutOfBoundsException - if getWidth is too large
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if pixels is null
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      • ERROR_INVALID_ARGUMENT - if getWidth is negative
      SWTException -
      • ERROR_UNSUPPORTED_DEPTH - if the depth is not one of 1, 2, 4 or 8 (For higher depths, use the int[] version of this method.)

    • getPixels

      public void getPixels(int x, int y, int getWidth, int[] pixels, int startIndex)
      Returns getWidth pixel values starting at offset x in scanline y in the receiver's data starting at startIndex.
      Parameters:
      x - the x position of the first pixel to get
      y - the y position of the first pixel to get
      getWidth - the width of the data to get
      pixels - the buffer in which to put the pixels
      startIndex - the offset into the buffer to begin storing pixels
      Throws:
      IndexOutOfBoundsException - if getWidth is too large
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if pixels is null
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      • ERROR_INVALID_ARGUMENT - if getWidth is negative
      SWTException -
      • ERROR_UNSUPPORTED_DEPTH - if the depth is not one of 1, 2, 4, 8, 16, 24 or 32

    • getRGBs

      public RGB[] getRGBs()
      Returns an array of RGBs which comprise the indexed color table of the receiver, or null if the receiver has a direct color model.
      Returns:
      the RGB values for the image or null if direct color
      See Also:

    • getTransparencyMask

      public ImageData getTransparencyMask()
      Returns an ImageData which specifies the transparency mask information for the receiver. If the receiver has no transparency or is not an icon, returns an opaque mask.
      Returns:
      the transparency mask

    • getTransparencyType

      public int getTransparencyType()
      Returns the image transparency type, which will be one of SWT.TRANSPARENCY_NONE, SWT.TRANSPARENCY_MASK, SWT.TRANSPARENCY_PIXEL or SWT.TRANSPARENCY_ALPHA.
      Returns:
      the receiver's transparency type

    • scaledTo

      public ImageData scaledTo(int width, int height)
      Returns a copy of the receiver which has been stretched or shrunk to the specified size. If either the width or height is negative, the resulting image will be inverted in the associated axis.
      Parameters:
      width - the width of the new ImageData
      height - the height of the new ImageData
      Returns:
      a scaled copy of the image

    • setAlpha

      public void setAlpha(int x, int y, int alpha)
      Sets the alpha value at offset x in scanline y in the receiver's alpha data. The alpha value must be between 0 (transparent) and 255 (opaque).
      Parameters:
      x - the x coordinate of the alpha value to set
      y - the y coordinate of the alpha value to set
      alpha - the value to set the alpha to
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds

    • setAlphas

      public void setAlphas(int x, int y, int putWidth, byte[] alphas, int startIndex)
      Sets the alpha values starting at offset x in scanline y in the receiver's alpha data to the values from the array alphas starting at startIndex. The alpha values must be between (byte)0 (transparent) and (byte)255 (opaque)
      Parameters:
      x - the x coordinate of the pixel to being setting the alpha values
      y - the y coordinate of the pixel to being setting the alpha values
      putWidth - the width of the alpha values to set
      alphas - the alpha values to set
      startIndex - the index at which to begin setting
      Throws:
      IndexOutOfBoundsException - if putWidth is too large
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if pixels is null
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      • ERROR_INVALID_ARGUMENT - if putWidth is negative

    • setPixel

      public void setPixel(int x, int y, int pixelValue)
      Sets the pixel value at offset x in scanline y in the receiver's data.
      Parameters:
      x - the x coordinate of the pixel to set
      y - the y coordinate of the pixel to set
      pixelValue - the value to set the pixel to
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      SWTException -
      • ERROR_UNSUPPORTED_DEPTH if the depth is not one of 1, 2, 4, 8, 16, 24 or 32

    • setPixels

      public void setPixels(int x, int y, int putWidth, byte[] pixels, int startIndex)
      Sets the pixel values starting at offset x in scanline y in the receiver's data to the values from the array pixels starting at startIndex.
      Parameters:
      x - the x position of the pixel to set
      y - the y position of the pixel to set
      putWidth - the width of the pixels to set
      pixels - the pixels to set
      startIndex - the index at which to begin setting
      Throws:
      IndexOutOfBoundsException - if putWidth is too large
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if pixels is null
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      • ERROR_INVALID_ARGUMENT - if putWidth is negative
      SWTException -
      • ERROR_UNSUPPORTED_DEPTH if the depth is not one of 1, 2, 4, 8 (For higher depths, use the int[] version of this method.)

    • setPixels

      public void setPixels(int x, int y, int putWidth, int[] pixels, int startIndex)
      Sets the pixel values starting at offset x in scanline y in the receiver's data to the values from the array pixels starting at startIndex.
      Parameters:
      x - the x position of the pixel to set
      y - the y position of the pixel to set
      putWidth - the width of the pixels to set
      pixels - the pixels to set
      startIndex - the index at which to begin setting
      Throws:
      IndexOutOfBoundsException - if putWidth is too large
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if pixels is null
      • ERROR_INVALID_ARGUMENT - if x or y is out of bounds
      • ERROR_INVALID_ARGUMENT - if putWidth is negative
      SWTException -
      • ERROR_UNSUPPORTED_DEPTH if the depth is not one of 1, 2, 4, 8, 16, 24 or 32