Report On Portable Graphical User Interface (GUI) In Ada and GtkAda (pgag)

2005 March 12 Keith Armentrout 1

CS699: Professional Seminar in CS / Professor V. RiabovKeith Armentrout

Presentation #3 : Portable GUI in Ada and GtkAda

ReportOn

Portable Graphical User Interface (GUI)In

Ada and GtkAda(pgag)




Executive Summary:

•Portability is the “holy grail” of computer science

•a GUI is the Most Difficult Area to Make Portable

•Windows (Win32) -vs- Unix/Linux (X-Windows)

•Ada is not a dead language

•Still Widely Used Throughout the World

•A large, old, Application re-hosted from a Unisys Computer

•Fortran Converted Line-by-Line to Ada

•Remains Command Line Driven (difficult for non-programmers)

•Needs a GUI




Introduction

•Project Justification:

•Old Command Line Driven Application

•Input Formerly Specified via “JCL”

•Inputs Now Edited into a Text Input File

•Needs a GUI

•Project Software Components:

•Three Ada “Tasks”

•Nine Encapsulated Packages




Functional Specification

•Provide a GUI for the “Application”

•Input of Path/File names

•Directory Structure Browser Function

•Selection of Input/Processing Options

•Selection of Output Options

•Display of Status/Error Messages

•Control Buttons:

RUN RESET DEFAULTS

CLEAR HELP EXIT




System Design Approach

•Three Ada “Tasks”

•Nine Encapsulated Packages

•“Application” is only a simulation

call

status

startup

Setting&

Controls

status

control

GUI

pgag application

User

MainWindow

QuestionWindow

StatusWindow

HelpWindow

BrowserWindow




Object-Oriented Design Issues

•The Application (Old - Non OO)

•Re-hosted Fortran to Ada, Line-by-Line•Retains Original Functionality, Structure, & Behavior

•GtkAda (New - OO)

•Nearly All Object-Oriented in its Design•Thick Binding to X-Windows and Win32

•pgag (A Mixture of the Old and the New)

•Object-Oriented at its Highest Levels (the Ada Tasks)•Windows & Widgets Inherit from GtkAda Parents•Some Old-Time Functional Design Internally




Test Plan

•Unit Test Not Possible

•Programs Would Not Compile Without Type Definitions

•No Visible Results Until Nearly All Pieces Assembled

•The Plan:

•Formally Test Only the Final Product

•Follow Pre-Written Checklist

•Record Screen Captures




Code Implementation

•Ada

•The World’s First Standardized OO Programming Language

•GtkAda (Free Software)

•A Graphical Toolkit which uses OO Features of Ada

•A “Thick” Binding to X-Windows & Win32

•AdaGIDE (Free Software)

•An Integrated Development Environment (IDE) for Ada

•Developed by Faculty Members at US Air Force Academy

•GNAT (Free Ada Compiler for Both PC and Sun)




Code Implementation (example)

with Ada.Dynamic_Priorities; use Ada.Dynamic_Priorities;with pgag_Data; use pgag_Data;with pgag_GUI; use pgag_GUI;

procedure pgag is begin -- pgag main Task Body Set_Priority( Task_Priority_Main ); GUI.StartUp; end pgag;




Problems Solved

•Balancing the Tasks

•Selection of Task Priority

•Delay Statements

•Problem Solved by GtkAda

•500 Millisecond Master Monitor

•Dynamically Linked Libraries (DLL) on PC

•Self-extracting Installation Program (future)

•Libraries on Sun Solaris

•Installation Procedure (search path setup) (future)




Issues For Future Study

•Installation Problems (noted above)

•Porting to Other Platforms (Linux, Mac)

•The application May be Ported Soon

•Status Reporting Between pgag and Application

•Currently Implemented as a Simple/Limited Boolean Flag

•Doesn’t Distinguish Between Minor and Severe Errors

•Requires Significant Modifications to Application

•Application is Changing

•GUI Must Expand




pgag on a PC




pgag on a SUN

•SunOS (Solaris) 5.8




pgag on a PC

•with Status Window




pgag on a PC

•with Status Window

•and Question Window

•user selected “EXIT”




Conclusion

•1776 Lines of Code (3874 counting comments)

•Meets Existing Requirements of the Real Application

•Would Be Easy to Integrate with the Real Application

•Could be Easily Upgraded to Meet New Requirements

•Its Been Fun

Report On Portable Graphical User Interface (GUI) In Ada and GtkAda (pgag)

Documents

Transcript of Report On Portable Graphical User Interface (GUI) In Ada and GtkAda (pgag)