Index for Section 4

Alphabetical listing for D

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Display(4)
CDE
NAME
  Display - display a document

SYNOPSIS
  [file] Display(in mediaType contents
	       [in title docName]);

DESCRIPTION
  The Display request causes the handler to display (present or manifest) a
  document to the user. For example, an audio manipulation utility would be
  said to ``display'' audio documents when it plays them.

  The handler must decide issues such as:

    ·  When the display operation can be deemed completed

    ·  What user gesture signals the completion of the display

    ·  What the handling tool should do with itself after replying

  The contents argument is the contents of the document. If this argument is
  unset (in other words, has a value of (char*)0 then the contents of the
  document are in the file named in the message's file attribute. The data
  type (mediaType) of the contents argument should be string, unless nulls
  are valid in the given media type, in which case the data type must be
  bytes.

  The docName argument contains the name of the document. If the docName
  argument is absent and the file attribute is set, the file name is
  considered to be the title of the document. This string would be suitable
  for display in a window title bar, for example.

APPLICATION USAGE
  The ttmedia_ptype_declare(3) function can be used to register for, and help
  process, this message.

  This message can be sent with the ttmedia_load(3) function.

  When the document to be displayed is read-only or unlikely to be modified
  the Display message is frequently used instead of the Edit message.

EXAMPLES
  To display a PostScript document, the application can send a Display
  request with a first argument whose vtype is PostScript, and whose value is
  a vector of bytes such as:

       %!\n/inch {72 mul} def...

  The \n in the example represents the newline character.  The notation is
  the same as in the .

  To display a PostScript document contained in a file, the application can
  send a Display request with the file attribute set to that file and with an
  unset first argument whose vtype is PostScript.

ERRORS
  The ToolTalk service may return one of the following errors in processing
  the Display request:

  TT_DESKTOP_ENOENT
      The file that was alleged to contain the document does not exist.

  TT_DESKTOP_ENODATA
      The in-mode contents argument had no value and the file attribute of
      the message was not set.

  TT_MEDIA_ERR_FORMAT
      The document is not a valid instance of the media type.

SEE ALSO
  ttmedia_ptype_declare(3), ttmedia_load(3); Intro, Deposit, Edit, Status
  requests

Index for Section 4

Alphabetical listing for D

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