Book Image

Building Android UIs with Custom Views

By : Raimon Ràfols Montane
Book Image

Building Android UIs with Custom Views

By: Raimon Ràfols Montane

Overview of this book

To build great user interfaces for your Android apps that go beyond the standard UI elements, you need to use custom Android views. With these, you can give your app a distinctive look and ensure that it functions properly across multiple devices. This book will help you construct a great UI for your apps by teaching you how to create custom Android views. You will start by creating your first Android custom view and go through the design considerations. You will then see how the right choices will enable your custom view to perform seamlessly across multiple platforms and Android versions. You will create custom styleable attributes that work with Android XML layouts, learn to process touch events, define custom attributes, and add properties and events to them. By the end of this book, you will be able to create apps with custom views that are responsive and adaptable to make your app distinctive and an instant hit with its users.
Table of Contents (12 chapters)

Advanced event handling

We've seen how to process onTouchEvent(), but we can also detect some gestures or more complex interactions. Android provides us with the GestureDetector to help us detect some gestures. There is even a GestureDetectorCompat on the support library to provide this support to older versions of Android.

For more information on the GestureDetector, please check the Android documentation.

Detecting gestures

Let's change the code we've been building to use GestureDetector. We'll also use a Scroller implementation to scroll smoothly between values. We can modify the constructor to create the Scroller object and the GestureDetector with an implementation of a GestureDetector.OnGestureListener...