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)

Drawing operations

As we've just mentioned, we have already seen and used some drawing operations, but that was only the envelope of what's inside. We'll see new drawing operations and how to combine them.

Bitmaps

Let's start by drawing bitmaps or images. Instead of having a white background, we'll use an image as background for our custom view. Using the source code from our previous example, we could do some very simple modifications to draw an image:

First, let's define a Bitmap object that will hold a reference to the image:

private Bitmap backgroundBitmap; 

To start, let's initialize it with the application icon we already have on our application:

public CircularActivityIndicator(Context...