Structured Matcher

Structured Matcher

A Case Study in Object-Oriented Redesign

Introduction

Structure Matching

Truth Tables / Simple Matchers

Structured Matcher Program

Goal of Redesign

Example of Redesign

Setting Cell Editor in SimpleMatcher

Adapting QuestionAskDialog

Evaluating SimpleMatcher

Results Achieved: example

Truth Table / Simple Matcher

Higher grade	Start after fill up	Worse after fill up	Results
True	True	True	Strongly Match
False	True	False	Slightly Against
? - Don't Care	True	? - Don't Care	Neutral
? - Don't Care	? - Don't Care	? - Don't Care	Against

Design Patterns: Basic Concepts

Program for interface rather than implementation

Gain functionality through composition rather than inheritance

Set Cell Editor

Before redesign:

if ( colId instanceof Question ) { Question tempQ = (Question) colId; if ( tempQ.getType() == Boolean.class ) { tempTC.setCellEditor( booleanEditor ); } else { tempTC.setCellEditor( cellDialog ); } } else if ( colId instanceof Results ) { tempTC.setCellEditor( likelihoodEditor ); } else if ( colId instanceof SimpleMatcher.class ) { tempTC.setCellEditor( cellDialog ); } else { System.err.println("Unknown type in column identifier " + colId + " type: " + colId.getClass()); }

After redesign:

TableCellEditor cellEditor = ((ColumnIdentifierIF) colId).getCellEditor(); tempTC.setCellEditor( cellEditor );

Polymorphism pattern calls for using polymorphic operations when behavior varies dependent on the type of the object