XML Europe 2002

1
WebCGM DOM - External Control for Web Graphics

• Dave Cruikshank
• Technical Fellow, The Boeing Company
• CTO, CGM Open
• Ulrich Laesche
• President, Ematek Informatik GmbH

2
Agenda

• Background
• Application Structuring
• WebCGM Application Structures
• WebCGM DOM Requirements
• Development Status
• Example

3
Background

• CGM (ISO/IEC 8632)
• Computer Graphics Metafile - interchange
• Robust 2-dimensional graphics language
• Stable 15 years as an ISO standard
• Widely supported technical documentation,
  CAD/CAM, desktop publishing, etc.
• Widely profiled Air Transport Assn, CALS,
  AECMA, automotive, telecommunications, etc.

4
Background - CGM
CGM Version 1 (1987)
Version 2 (Am11989)
Version 3 (Am31991)
Defect Corrections
Republish
CGM1992
5
Background - CGM
CGM Version 3 (1992)
ProfilesConformance (Am11994)
Version 4 (Am21995)
Defect Corrections
Republish
CGM1999
6
Background

• CGM Open
• Consortium formed in 1998 (www.cgmopen.org)

Users
Vendors
Independents
Boeing EADS Bombardier US Navy MOD
UK Xerox (AECMA)
Itedo Sys Dev Inc Larson S/W Auto-trol Ematek Bent
ley (Corel)
NIST Lofton Henderson Bruce Garner
7
Background - WebCGM

• Based on ATA GREXCHANGE
• Extensions for application structuring
• Targeted for technical illustrations
• 2D
• Line art
• Navigation functionality

8
Background - WebCGM
WebCGM V1.0 (1999)
Defect Corrections
Republish
WebCGM V1.0 Release 2 (2001)
9
Application Structuring

• Group graphical primitives by type
• Attach attributes to groups to support
• Linking
• Information retrieval
• Viewer behavior
• Etc.

10
WebCGM Application Structure Types
gdata graphical primitives opt optional rep
repeat cho choice
Picture Body
opt
rep cho
layer
gdata
para
grobject
gdata
rep cho
subpara
rep cho
grobject
gdata
para
grobject
gdata
para
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WebCGM Application Structure Attributes

• layer
• id
• layer Description
• layer Name
• grobject
• id
• region
• view Context
• linkuri
• screentip
• name

• para subpara
• id
• region
• linkuri
• screentip
• content

12
WebCGM

• What does that buy us?
• The ability to navigate through and between
  illustrations
• example

13
WebCGM

• Why a DOM?
• Control over viewer behavior externally
• Attributes of primitives (color, weight, font,
  etc.)
• Visibility of objects
• Remove some (most) of the metadata from the CGM
  file
• Context sensitive linking
• Context sensitive screen tips

14
WebCGM DOM requirements

• Metafile level
• Access to
• File name
• URL
• Metafile version
• Metafile Description

15
WebCGM DOM requirements

• Picture level
• Access to
• Picture name
• VDC extent
• Parent
• List of children
• Control over
• Links between children

16
WebCGM DOM requirements

• Graphical primitives
• Control over
• Color
• Intensity
• Line weight
• Edge weight

17
WebCGM DOM requirements

• Layer application structure type
• Access to
• Identifier
• Layer name
• Layer description
• Parent
• List of children
• Control over
• Visibility
• Links between children

18
WebCGM DOM requirements

• Grobject application structure type
• Access to
• Identifier
• Name
• Region
• View context
• Parent
• List of children
• Control over
• Linkuri
• Screentip
• visibility

19
WebCGM DOM requirements

• Para and subpara application structure type
• Access to
• Identifier
• Region
• View context
• Content
• Parent
• List of children
• Control over
• Linkuri
• Screentip
• visibility

20
WebCGM DOM requirements

• Application structure graphical primitives
• Control over
• Color
• Intensity
• Line weight
• Edge weight
• Text font
• Text size
• Text scale factor

21
WebCGM DOM requirements

• Event handling
• OnClick
• OnMouseOver
• OnMouseOut
• OnLoad
• OnUnload

22
DOM Work in Progress
Watch this space http//www.cgmopen.org