Book Image

Hands-On Design Patterns with Delphi

By : Primož Gabrijelčič
Book Image

Hands-On Design Patterns with Delphi

By: Primož Gabrijelčič

Overview of this book

Design patterns have proven to be the go-to solution for many common programming scenarios. This book focuses on design patterns applied to the Delphi language. The book will provide you with insights into the language and its capabilities of a runtime library. You'll start by exploring a variety of design patterns and understanding them through real-world examples. This will entail a short explanation of the concept of design patterns and the original set of the 'Gang of Four' patterns, which will help you in structuring your designs efficiently. Next, you'll cover the most important 'anti-patterns' (essentially bad software development practices) to aid you in steering clear of problems during programming. You'll then learn about the eight most important patterns for each creational, structural, and behavioral type. After this, you'll be introduced to the concept of 'concurrency' patterns, which are design patterns specifically related to multithreading and parallel computation. These will enable you to develop and improve an interface between items and harmonize shared memories within threads. Toward the concluding chapters, you'll explore design patterns specific to program design and other categories of patterns that do not fall under the 'design' umbrella. By the end of this book, you'll be able to address common design problems encountered while developing applications and feel confident while building scalable projects.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
About Packt


Structural patterns tell us how to put objects together. Their focus is mostly on organizing software components. They help us to maintain order in our code. That, however, is not true for each and every one of them. A case in point, for example, is the flyweight pattern.

The flyweight pattern helps us to reduce memory usage. As such, it is less and less important in modern times, where we are dealing with gigabyte memories. Sometimes, however, we will still significantly decrease memory usage by implementing it. Also, sometimes, it will help speed up the program.

This pattern works best when part of each object contains data that is also used in other objects. Instead of duplicating that data in every object, we can extract shared data into another object. We can then replace original data in an object with a pointer to the shared data. This allows multiple objects to share one copy of the data, hence reducing memory usage.


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