[8] request for review: 7146550: [macosx] DnD test failure in createCompatibleWritableRaster()

[Andrew Brygin]

Hello,

  could you please review a fix for 7146550?

  DnD code does not check whether a toolkit image is ready to be painted
  into a buffer. We have to do this check in order to get correct image
  dimension.

  Suggested fix just delegates the conversion of toolkit image into a
  CImage instance to a helper class CImage.Creator. This helper class
  provides two ways to convert a toolkit image int CImage:

    - immediate conversion: returns valid CImage only if toolkit image
       has valid dimension, and null otherwise.
      Immediate conversion works fine for toolkit images which are
      prepared in advance, or are based on memory image source.

    - normal conversion: a toolkit image is prepared for rendering using
       a media tracker.

  We can not use the normal conversion in case of DnD, because broken
  toolkit image (whose producer never updates the image state for any
  reasons) can cause a hang in the DnD the code (test in question
  implements such scenario).

  If supplied drag image can not be conversed to CImage (either an
  exception is thrown or it is not ready, i.e. a result of conversion
  is null for any reasons) the InvalidDnDOperationException is thrown
  in order to notify user about the problem with drag image.
  Note that such approach is already used on windows platform, so with
  this fix, macosx behaves in a uniform way with windows.

  Beside this, this fix pushes the drag image (an instance of CImage)
  down to native DnD machinery in order to be able to display drag
  images.

Bug: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7146550
Webrev: http://cr.openjdk.java.net/~bae/7146550/webrev.00/

Thanks,
Andrew