Book Image

Delphi Cookbook - Second Edition

By : Daniele Teti
Book Image

Delphi Cookbook - Second Edition

By: Daniele Teti

Overview of this book

Delphi is a cross-platform Integrated Development Environment (IDE) that supports rapid application development for Microsoft Windows, Apple Mac OS X, Google Android, and Apple iOS. It helps you to concentrate on the real business and save yourself the pain of wandering amid GUI widget details, or having to tackle inter-platform incompatibilities. It also has a wide range of drag-and-drop controls, helping you code your business logic into your business model, and it compiles natively for desktop and mobile platforms. This book will teach you how to design and develop applications, deploy them on the cloud platform, and distribute them within an organization via Google Play and other similar platforms. You will begin with the basics of Delphi and get acquainted with JSON format strings, XSLT transformations, unicode encodings and various types of streams. We then move on to more advanced topics such as developing higher-order functions and using enumerators and RTTI. You will get an understanding of how Delphi RTL functions and how to use FireMonkey in a VCL application. We will then cover topics such as multithreading, using the parallel programming library and putting Delphi on a server. We will also take a look at the new feature of WebBroker Apache modules and then ride the mobile revolution with FireMonkey. By the end of the book, you will be able to develop and deploy cross-platform applications using Delphi .
Table of Contents (10 chapters)
9
Index

Displaying a measure on a 2D graph like an oscilloscope


An oscilloscope is a type of electronic test instrument that allows the observation of constantly varying signal voltages. Usually, information is shown as a two-dimensional plot graph of one or more signals as a function of time. In this recipe, you'll implement a type of oscilloscope to display data generated by a background thread. Obviously, in this recipe, you'll not create an accurate oscilloscope, rather a nice real-world utilization of retrieving data and using it continuously in the GUI.

Getting ready

You'll use the TThreadedQueue<Extended> class to bring out data from the background thread to the main thread. The approach is similar to that shown in the recipe Talking with the main thread using a thread-safe queue, but in this case, we've to show data in a complex way—on a 2D graph showing only the last n data retrieved.

How to do it…

This recipe has a background thread acting like an analogic signal generator that is able...