Inserting Objects

Another snippet of wisdom from Thomas Jordan's Texel bible, coming soon...

With Texel a user is not just limited to typing data on to an open document to create a working spreadsheet. Illustrations and files created in other Atari packages can quite easily be inserted on to your worksheet. For Texel to be able to insert objects onto a worksheet you need to have OLGA installed.

What is OLGA
OLGA is a system extension which improves the interaction of programs in a multi-tasking environment. Imagine that you have several running applications on your system. In one of these programs you edit an object - say, an image - all the running applications which are currently using this image will automatically update as the image is edited.

OLGA was developed by the programmer Thomas Much. He also was responsible for Texel. The letters OLGA stand for Object Linking for GEM Applications. The embedding of objects in other applictions was originally introduced to Windows and later on into System 7 on the Mac. On other systems the linking of objects in other applications is commonly known as OLE, Object Linking and Embedding. OLGA is the Atari version of OLE.

To allow the embedding of objects in a application, each appliction must follow the OLGA protocol.

Installing OLGA
To allow the interaction of applications OLGA needs to be running in parallel with your installed programs. Depending on which operating system you are using OLGA needs to be placed in either the START, APPS or AUTOGEM folder. It is also possible to have OLGA running all the time by renaming OLGA.APP to OLGA.ACC.

For those who are short of memory resources OLGA can be configured so that it is loaded and unloaded from memory. If you require OLGA to be loaded automatically your system configuration file will need to be edited to include a OLGAManager environmental variable. When an OLGA aware application is loaded OLGA is also loaded, likewise when the application is closed down OLGA will also remove itself from memory.

For MagiC users add the following line to MAGIC.INF

#_ENV OLGAMANAGER C:\GEMSYS\START\OLGA.APP

For users of other operating systems like Geneva and MTOS add the following to GEM.CNF

SETENV OLGAMANAGER C:\OLGA\OLGA.APP

The above are examples only, make sure that the paths match your computer set-up.

Creating a OLGA.INF File
The OLGA system extension allows individual programs and file types to be set up in a pre-configured script. This is known as the OLGA.INF. The INF file is placed in either the same directory as the OLGA.APP or OLGA.ACC, the same path which has been defined as the environmental variable (if it has been set up) or the root directory of your boot drive. The INF file can be edited with any ASCII text editor like Everest, QED or Luna.

The INF file has the following structure:

Extensions
.EXT = filepath + program name or alias

Objects
.EXT = a text description of available file types

Types
XY = filepath = program name or alias

Applications
Alias = filepath + program name
The INF file can either be one which you have constructed, or the one supplied with the OLGA program edited to suit your particular computer set-up. Load up the ASCII editor to construct a new document and add the following line

Extensions

For example to load GEM files into Kandinsky add the following
.GEM=$Kandinsky

The $ sign is an alias to the full program path. Either full paths can be used for the extensions or an alias. But if your application is set up to load multiple file types it makes sense to use an alias. When editing the extensions and alias full caps must be used, the individual paths can be either. Continue to add all your file types then add the following line

Objects

This is a short text description of extension file types. They must be defined in the extension. For example
GEM = GEM Metafile

Add the object descriptions. When the objects have been typed in add the following line

Types

This is where applications are matched to the file extensions which have been defined. The following file types are recognised

WP = Word Processing
DP = DTP
ED = Text editor
DB = Database
SS = Spreadsheet
RG = Raster graphic
VG = Vector program
GG = General graphic application
MU = Music application
CD = CAD
DC = Date communication
DT = Desktop
PE = Programming environment

For example to set Kandinsky as the preferred vector application add the following line

VG=$Kandinsky

The types which have been defined are case-sensitive. Add all your application programs then add the following heading

Applications

Under the application heading is where the full system path lies for each application. Make sure that case types match. Add all the file paths

Kandinsky=D:\Graphics\Kandinsky\Kandinsky.APP
Papyrus=D:\Papyrus\PAPYRUSG.APP

When the list is complete save the file as OLGA.INF

A more detailed explanation can be found in the OLGA.HYP documentation from Atari Computing issue 5. If this magazine is not available to you the OLGA application can be downloaded from www.altern.org/ta/ and then follow the links to the former Interactive software pages.

Object Inserting
Hopefully you have managed to create a OLGA.INF file using the information provided above. To insert an object in Texel you need a vector graphics program which is capable of communicating via the OLGA protocol.  

Suitable programs are Kandinsky, which is a shareware program from Ulrich Roßgoderer and also Artworx from Christian Witt a commercial release. Artworx is available in English from Atari Workshop. If you do not have any of these programs installed, do not worry demo programs are available from the WWW, should you not have a internet provider examine any Atari-specific CD-ROMs which you might have it's quite possible that they are on one of them. Finally should there still be a problem a key can be created using borders and colour shading. Close all your installed programs and reload Texel. Now from the available files reload Products11.txl. Position your mouse cursor at cell location K253 and then from the local tool bar find and select the option Object. The new window should look similar to this one.

The window illustrates the foreign file types which Texel is able to insert via the OLGA protocol. Select and choose the GEM Metafile format. When the object type was selected, Texel was asked to open the file selector. From the files displayed in the selector window select the file Key.Gem. On the product worksheet there should now be an inserted graphic of a simple key. When the graphic is displayed on your spreadsheet it indicates the OLGA script file which was created is working correctly. If no graphic is displayed examine any error message. The most common error for first-time users of OLGA is the paths typed do not match the specific file location or OLGA is unable to find its INF file. Correct any errors and try again until the errors disappear.

Examine the monitor display again. Is there anything else that was not there originally. Towards the bottom left of the screen an iconised program window.

Both Texel and your vector art program have been loaded into memory. This is  probably the first time that you have encountered inter-program communication on the Atari. The fun can now begin, just like your PC-owning friends the embedding of objects is possible on a ten year old operating system.

MyAtari magazine - Feature #5, May 2001