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


An important aspect of a good object-oriented design is strong separation between an abstraction and its implementation. Multiple structural patterns deal specifically with this area. so the next part of the book is dedicated to them. I'll start with the bridge pattern and then dedicate the next chapter to other patterns of this kind.

The bridge pattern introduces a strong separation between an interface and its implementation. By this approach, we define the abstraction part as one inheritance hierarchy (a group of derived classes) and the implementation part as another hierarchy. The main point is that the abstraction and implementation hierarchies have nothing in common. The only connection between them is that the abstraction part is using implementation classes through composition.


In modern cars, most controls (steering wheel, throttle, brake...) don't access hardware directly. Instead, signals from controls go to a computer that then controls the electrical motors that drive...