Project - EML

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EML (Erdas Macro Language):

This allows the application programmers to develop window system independent GUI applications. This contains a parser, interpreter and API's. All the GUI applications define their GUI using EML Language syntax in ascii files. The parser API allows these applications to parse the GUI macro definition files and creates initial opcodes for generating GUI. The interpreter API, which is built on top of the native windowing systems (i.e. X/motif under UNIX and Microsoft Windows NT in PC) and allows the application programs to add callbacks and send messages to the graphical objects in their GUI.

The following diagram illustrates the EML system architecture.

The following is a sample EML script and the corresponding GUI generated by the EML system.

component sample {

frame sample_frame {
title "Select File Dialog";
geometry 10,10,290,36;

filename filein {
title above left "Source File:";
geometry 3,3,280,320;
select "*.img";
on filenamechoosen {
echo "Selected file: " $filein;
}
}
button stopit {
title "Quit";
geometry 105,328,82,25;
on mousedown unload;
}
}
on startup display sample_frame;

}