Preface

Lazarus is an open-source integrated development environment for the Free Pascal compiler. Lazarus provides a code editor with syntax-highlighting, a visual form designer, and the Lazarus Component Library (LCL). Lazarus is very similar to Delphi, making it ideal for Delphi programmers to utilize. Because the LCL is highly compatible with Delphi's VCL, existing Delphi projects can be easily converted to Lazarus projects.

Lazarus is cross-platform and runs on many platforms, including Linux, BSD, and Mac OS X. Lazarus applications can be created on one platform and compiled on other supporting platforms, making it suitable for many programming tasks. Besides graphical user interface and console applications, Lazarus can also support web-based applications, Android, and iOS applications.

What this book covers

Chapter 1, Installing and Configuring the Lazarus Development Environment, explains the installation and configuration of the Lazarus environment on various platforms, such as Windows, Linux, and FreeBSD.

Chapter 2, Getting to Know the Lazarus IDE – a Quick Tour, is an overview of the basics of the Lazarus IDE, such as the code editor, object inspector, and the LCL palette.

Chapter 3, Creating a Hello World Program, provides an overview of the basics of creating a GUI and console application with Lazarus using the traditional Hello World program and expanding on it.

Chapter 4, Converting Delphi, covers converting an existing Delphi project to a Lazarus project using the Delphi conversion wizard, as well as manually converting the project.

Chapter 5, Creating a Lazarus Component, covers the creation of a custom component that can be added to the component palette to be used in a GUI application.

Chapter 6, The Lazarus Documentation Editor, shows the use of LazDE, the tool for documenting a Lazarus source code unit.

Chapter 7, Rebuilding Lazarus with a GTK2 Interface, covers the rebuilding of the Lazarus interface, using one of the many supported widget sets of Lazarus.

What you need for this book

You will need to use one of the supported OS platforms, such as Windows or Linux, and the Lazarus version for that platform. Some of the source code used is available for download where indicated.

Who this book is for

This book is designed for anyone who has used Delphi in the past. It should also be useful for anyone with a basic programming experience that needs a quick overview of using Lazarus.

Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text are shown as follows: "For 32-bit Debian-based distributions, choose the Lazarus Linux i386 DEB subfolder."

A block of code is set as follows:

program Project1;
{$mode objfpc}{$H+}
uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  Classes, SysUtils, CustApp
  { you can add units after this }; 

Any command-line input or output is written as follows:

# gpg –keyserver hkp://pgp.mit.edu:11371 –recv-keys 6A11800F
# gpg -a –export 6A11800F | apt-key add -

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Unless you have a need to change the defaults, just click Next through the installation wizard's dialogs."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

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