GitLab

Detail:
  The Message_ToggleBackdrop has been introduced by ROL in one of their Select
  releases. In order to bring the RISC OS 5 API closer the ROL branch this
  changeset aims to add this message to RO5.

  Applications can broadcast Message_ToggleBackdrop to request that the backdrop
  application moves the backdrop. The message can be used to move the backdrop
  to the front, the back, toggle it or to get notified of the backdrop's
  current position.

  After the backdrop has been moved, this message is sent back to the
  application to notify it of the backdrop's new position.

  Message_ToggleBackdrop &400D1:
     +0  = 24 (Message size)
     +4  = Backdrop controlling application
     +8  = My reference number
     +12 = Your reference number
     +16 = &400D1 (Message_ToggleBackdrop)
     +20 = Flags (if not present, assumed 0)
             b0-1  = type of toggle
                      0 = toggle
                      1 = front
                      2 = back
                      3 = notify of status
             other = reserved
Admin:
  Tested on RO 5.16
Author:
  Fred Graute

Version 0.90. Tagged as 'Pinboard-0_90'