Book Image

Kivy: Interactive Applications in Python

By : Roberto Ulloa
4 (1)
Book Image

Kivy: Interactive Applications in Python

4 (1)
By: Roberto Ulloa

Overview of this book

Mobiles and tablets have brought with them a dramatic change in the utility of applications. Compatibility has become essential, and this has increased the kind of interaction that users expect: gestures, multi-touches, animations, and magic pens. Kivy is an open source Python solution that covers these market needs with an easy-to-learn and rapid development approach. Kivy is growing fast and gaining attention as an alternative to the established developing platforms. Kivy: Interactive Applications in Python quickly introduces you to the Kivy development methodology. You will learn some examples of how to use many of the Kivy components, as well as understand how to integrate and combine them into big projects. This book serves as a reference guide and is organized in such a way that once finished, you will have already completed your first project. You will start by learning the Kivy Language for building User Interfaces (UI) and vector figures. We then proceed to the uses of Kivy events and properties to glue the UI with the application logic. You then go on to build an entire User Interface (UI) starting from a hand-made sketch. Furthermore, you will go on to understand how to use the canvas and drawing instructions to create different types of geometrical figures. Finally, you will be introduced to a big set of interactive and smooth features: transformations (scale, rotate, and translate), gestures, animations, scheduling tasks, and multi-touch elements. Kivy: Interactive Applications in Python expands your knowledge by introducing various components that improve the User Experience (UX). Towards the end of the book, you will be confident to utilize Kivy components and strategies to start any application or game you have in mind.
Table of Contents (13 chapters)
Kivy: Interactive Applications in Python
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Combining animations with '+' and '&'


You have already learned that you can add several properties to the same animation so that they are modified together (line 69 of ammo.py).

Note

We can combine animations by using the '+' and '&' operators. The '+' operator is used to create sequenced animations (one after another). The '&' operator lets us execute two animations at the same time.

The '+' operator is similar to what we do when we bind the Animation on_complete event to a method that creates another Animation in the Invader (line 110 of invader.py). The difference is that when we use the '+' operator, there is no chance to reset the Widget properties. In the Invader case, we relocated the Invader to the top-center (lines 122 and 123) of the screen before going back to the Dock.

The '&' operator is similar to sending two properties as parameters; the difference here is that they share neither the same duration, nor the same transition. For example, we could have used one transition...