Android Boot Camp for Developers Using Java Comprehensive

Android Boot Camp for Developers Using Java, Comprehensive: A Guide to Creating Your First Android Apps Chapter 10: Move! Creating Animation Android Boot Camp for Developers Using Java, 2 nd Ed. 1

Objectives In this chapter, you learn to: • Create an Android application with Frame and Tween animation • Understand Frame animation • Understand Tween animation • Add an animation-list XML file • Code the Animation. Drawable object • Set the background Drawable resource • Launch the start( ) and stop( ) methods Android Boot Camp for Developers Using Java, 2 nd Ed. 2

Objectives (continued) • Add Tween animation to the application • Create a Tween XML file that rotates an image • Determine the rotation pivot, duration, and repeat count of a Tween animation • Load the start. Activity Tween animation in a second Activity • Change the orientation of the emulator Android Boot Camp for Developers Using Java, 2 nd Ed. 3

Creating Animation • Animation is everywhere – Words with Friends – Angry Birds – Cut the Rope – Candy Crush • A motion tween is used to animate the object – Specifies start state – Transition type – Number of times to animate Android Boot Camp for Developers Using Java, 2 nd Ed. 4

Creating Animation (continued) Steps to complete the App: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Add the five images to the drawable folder. Add a Frame animation XML file to the project. Add the layout for the image and button objects in main. xml. Set the duration between frames in the frame-by-frame animation. Declare and instantiate the Image. View, Button, and Animation. Drawable controls. Code the On. Click. Listeners for the Button controls. Run the Frame animation application. Add a layout for an Image. View control for the Tween animation. Add a Tween animation XML file to rotate the last surfing image. Create a second Activity named Tween. java to launch the rotation Tween animation. When the application executes, change the orientation of the emulator. Android Boot Camp for Developers Using Java, 2 nd Ed. 5

Android Animation • Two types of animation for Android: – Frame animation • A sequence of photos playing as a slide show • Similar to cartoon animation • Images rapidly replaced by new, similar images – Tween animation • Created by a series of transformations on a single image • Transformations include position, size, shape rotation, color, and transparency Android Boot Camp for Developers Using Java, 2 nd Ed. 6

Adding the Layout for the Frame Image and Button Controls • This app requires nested layout – relative layout within a linear layout – Linear layout • Image. View control displays the animation images – Relative layout • Buttons arranged side by side (not allowed in linear layout) Android Boot Camp for Developers Using Java, 2 nd Ed. 7

Adding the Layout for the Frame Image and Button Controls (continued) Android Boot Camp for Developers Using Java, 2 nd Ed. 8

Adding the Layout for the Frame Image and Button Controls (continued) Android Boot Camp for Developers Using Java, 2 nd Ed. 9

Adding the Layout for the Frame Image and Button Controls (continued) • Creating Frame-by-frame Animation – Animation-list root element is needed to reference images stored in the drawable folders • Set the android: oneshot property to false for the animation plays repeatedly <? xml version="1. 0" encoding="utf-8"? > <animation-list xmlns: android="http: //schemas. android. com/apk/res/android" android: oneshot="false" > <item android: drawable="@drawable/surf 1" android: duration="100"/> <item android: drawable="@drawable/surf 2" android: duration="100"/> <item android: drawable="@drawable/surf 3" android: duration="100"/> <item android: drawable="@drawable/surf 4" android: duration="100"/> </animation-list> Android Boot Camp for Developers Using Java, 2 nd Ed. 10

Coding the Animation. Drawable Object • The Animation. Drawable class – Contains methods to sequence frame-by-frame images Android Boot Camp for Developers Using Java, 2 nd Ed. 11

Setting the Background Resource • Image backgrounds can be set to: – A 9 -patch image • Contains pre-defined stretching areas that maintain the same look on different screen sizes • Named for the nine areas, called patches, that scale separately – A solid color background Android Boot Camp for Developers Using Java, 2 nd Ed. 12

Setting the Background Resource Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 13

Setting the Background Resource Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 14

Adding Two Button Controls Android Boot Camp for Developers Using Java, 2 nd Ed. 15

Adding Two Button Controls Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 16

Adding Two Button Controls Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 17

Using the Start and Stop Methods Android Boot Camp for Developers Using Java, 2 nd Ed. 18

Using the Start and Stop Methods (continued) • Adding the Layout for the Tween Image Android Boot Camp for Developers Using Java, 2 nd Ed. 19

Creating Tween Animation Tween effects are transitions that change objects from one state to another Android Boot Camp for Developers Using Java, 2 nd Ed. 20

Creating Tween Animation (continued) • Coding a Tween Rotation XML File Android Boot Camp for Developers Using Java, 2 nd Ed. 21

Creating Tween Animation (continued) Coding a Second Activity to Launch the Tween Animation Android Boot Camp for Developers Using Java, 2 nd Ed. 22

Creating Tween Animation (continued) Coding a Start. Animation • The Start. Animation method begins animating a View object by calling the Animation. Utils class utilities to access the resources necessary to load the animation Android Boot Camp for Developers Using Java, 2 nd Ed. 23

Creating Tween Animation Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 24

Creating Tween Animation Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 25

Creating Tween Animation (continued) Updating the Android Manifest File Android Boot Camp for Developers Using Java, 2 nd Ed. 26

Creating Tween Animation Android Boot Camp for Developers Using Java, 2 nd Ed. (continued) 27

Changing the Emulator to Landscape Orientation • Most Android devices automatically rotate the display from portrait to landscape when the user turns the device • The default screen orientation layout is vertical • Ctrl + F 12 rotates the phone emulator to landscape orientation • You can also press the 7 key on the keypad when Num Lock is turned off Android Boot Camp for Developers Using Java, 2 nd Ed. 28

Running and Testing the Application • • • Click Run on the menu bar Select Android Application from the dialog box Save all the files when prompted Unlock the emulator (if necessary) Click the Start Frame Animation and begin the rotation – The animation should rotate six times and then end Android Boot Camp for Developers Using Java, 2 nd Ed. 29

Summary (continued) • Use the start( ) and stop( ) methods of the drawable objects to control a Frame animation • A Tween animation manipulates a Drawable image by adding tween effects, which are predefined transitions that change an object from one state to another • The XML file for a Tween animation defines rotate attributes such as the number of degrees to spin, the pivot location, the rotation duration, and the number of times to repeat the rotation Android Boot Camp for Developers Using Java, 2 nd Ed. 30

Summary (continued) • Frame animation and Tween animation are the two types of animation provided by Android • Nest a relative layout within a linear layout to display two controls side by side • To create frame animation, load images in a drawable folder and then create an animation list • Set the oneshot property of the animation-list to false to repeatedly play the animation • In the XML file, select drawable as the resource type and animation-list as the root element Android Boot Camp for Developers Using Java, 2 nd Ed. 31

Summary (continued) • Frame-based animations and image transitions are defined as drawables in Android Development • The Background property can be set to any full drawable resource • Main. java includes an instance of Animation. Drawable and assigns it as the background of the animation images. Android constructs an Animation. Drawable Java object before setting it as the background Android Boot Camp for Developers Using Java, 2 nd Ed. 32

Summary (continued) • To launch a Tween animation, use the start. Animation method, which begins animating a View object by calling the Animation. Utils class utilities to access the resources it needs to play the animation • To switch the emulator to use a landscape orientation on a PC, press the Ctrl+F 12 keys. To rotate the emulator to the original portrait position, press the Ctrl+F 12 keys again. Mac users can press the Fn+Ctrl+F 12 keys to change the orientation Android Boot Camp for Developers Using Java, 2 nd Ed. 33