Book Image

Appcelerator Titanium Smartphone App Development Cookbook Second Edition

Book Image

Appcelerator Titanium Smartphone App Development Cookbook Second Edition

Overview of this book

This book will take you through the process of building cross-platform, native UI applications for the mobile from scratch. You will learn how to develop apps, how to use GPS, cameras and photos and how to build socially connected apps. You will also learn how to package them for submission to the App Store and Google Play. This cookbook takes a pragmatic approach to creating applications in JavaScript from putting together basic UIs, to handling events and implementation of third party services such as Twitter, Facebook and Push notifications. The book shows you how to integrate datasources and server APIs, and how to use local databases. The topics covered will guide you to use Appcelerator Studio tools for all the mobile features such as Geolocation, Accelerometer, animation and more. You’ll also learn about Alloy, the Appcelerator MVC framework for rapid app development, and how to transfer data between applications using URLSchemes, enabling other developers to access and launch specific parts of your app. Finally, you will learn how to register developer accounts and publish your very own applications on the App Store and Google Play.
Table of Contents (21 chapters)
Appcelerator Titanium Smartphone App Development Cookbook Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Dragging an ImageView using touch events


Now that we have allowed the user to select a funny face image from our four animated ImageView controls, we need to allow them to adjust the position of their own photo so it fits within the transparent hole that makes up the face portion of our funny face. We will do this using the touch events available to us in the ImageView control.

How to do it…

The simplest way to perform this task is by capturing the x and y touch points and moving the ImageView to that location. The code for this is simple; just add the following code after your declaration of the imageViewFace control, but before you add this control to your window:

imageViewFace.addEventListener('touchmove', function(e){
  imageViewMe.left = e.x;
  imageViewMe.top = e.y;
});

Now run your app in the emulator and, after selecting a funny face image, attempt to touch and drag your photograph around the screen. You should notice that it works but it doesn't seem quite right, does it? This is because...