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


Reusing existing components (objects, subsystems) is a common part of software development. Usually, it is better to reuse an existing solution than rewriting it from scratch, as the latter will inevitably take longer and introduce new bugs.

Using old components in new code, however, brings its own set of problems. Quite frequently, the newer code works against an abstract interface that does not exactly match the existing functionality. We have to write an intermediate object, a kind of translator from the new interface to the old one. This object is called an adapter.



Adapters are used in everyday life. For example, a cable with a USB type A connector on one side and a USB micro connector on the other is an adapter that allows us to plug a mobile phone into a personal computer. Another kind of adapter allows you to plug a device with a German power plug into a UK wall socket, or a device that uses 110 V power into a socket that provides 230 V.

Keep in mind that adapters should...