Browse Prior Art Database

Direct Manipulation Process Detection Via Rendering Format

IP.com Disclosure Number: IPCOM000113380D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Benge, MA: AUTHOR [+4]

Abstract

Disclosed is a process, known as rendering, by which data is transferred from the source of a Direct Manipulation operation to a target. Rendering can be optimized if the source and the target are within the same process, since both the source and target have access to the same memory address space. In this case, the target can readily access the source's data to complete the transfer. On the other hand, if the source and target are in separate processes, data transfer must be facilitated in another fashion, such as through the use of a shared memory buffer and a "hand shake" operation that involves the dispatching/processing of rendering messages.

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Direct Manipulation Process Detection Via Rendering Format

      Disclosed is a process, known as rendering, by which data is
transferred from the source of a Direct Manipulation operation to a
target.  Rendering can be optimized if the source and the target are
within the same process, since both the source and target have access
to the same memory address space.  In this case, the target can
readily access the source's data to complete the transfer.  On the
other hand, if the source and target are in separate processes, data
transfer must be facilitated in another fashion, such as through the
use of a shared memory buffer and a "hand shake" operation that
involves the dispatching/processing of rendering messages.

      Clearly, we do not want to allocate a shared memory buffer and
dispatch/process unnecessary messages, if the source and target of a
direct manipulation operation are in the same process.  However, the
PM Direct Manipulation protocol does not support process detection.
A solution has been implemented to identify the source and target
process, thereby allowing optimal data transfer between them.

      The solution involves encoding the process id into a rendering
format:  DRF_PROCESS = pid, where pid represents the process id.  The
rendering format is stored in the object, more specifically the PM
DRAGITEM structure, that is being manipulated.  When the object
enters a potential target, or when the object is dropped on a target,
the DRF_P...