Book Image

Delphi GUI Programming with FireMonkey

By : Andrea Magni
4 (1)
Book Image

Delphi GUI Programming with FireMonkey

4 (1)
By: Andrea Magni

Overview of this book

FireMonkey (FMX) is a cross-platform application framework that allows developers to create exciting user interfaces and deliver applications on multiple operating systems (OS). This book will help you learn visual programming with Delphi and FMX. Starting with an overview of the FMX framework, including a general discussion of the underlying philosophy and approach, you’ll then move on to the fundamentals and architectural details of FMX. You’ll also cover a significant comparison between Delphi and the Visual Component Library (VCL). Next, you’ll focus on the main FMX components, data access/data binding, and style concepts, in addition to understanding how to deliver visually responsive UIs. To address modern application development, the book takes you through topics such as animations and effects, and provides you with a general introduction to parallel programming, specifically targeting UI-related aspects, including application responsiveness. Later, you’ll explore the most important cross-platform services in the FMX framework, which are essential for delivering your application on multiple platforms while retaining the single codebase approach. Finally, you’ll learn about FMX’s built-in 3D functionalities. By the end of this book, you’ll be familiar with the FMX framework and be able to build effective cross-platform apps.
Table of Contents (18 chapters)
Section 1: Delphi GUI Programming Frameworks
Section 2: The FMX Framework in Depth
Section 3: Pushing to The Top: Advanced Topics

Subscribing and responding to messages

A messaging system is basically a mechanism to notify some observers about the firing of some event. The event may have some attached information that we call message content but the notification of the event is the crucial point of the whole thing.

We have seen so far how messages are defined and sent through the message manager. Now it is time to learn how to subscribe for notifications. Multiple observers may register themselves to be notified when the event occurs (that is, a matching message passes through the message manager).

The TMessageManager class offers a SubscribeToMessage method you can use to provide an event handler (once again, with two main options, that is, implementing the handler through an anonymous method, or using a standard method reference).

The following snippet shows how to subscribe for the TEventX message we have used in previous paragraphs:

, procedure...