spoton game app android how to program ©1992-2013 by pearson education, inc. all rights reserved

©1992-2013 by Pearson Education, Inc. All Rights

Reserved.

•Android 3.x ▫First app to use features of Android 3.0+▫Using it to animate properties▫Actually this is an Android 3.1 app

•AVDs for Android 3.0+ apps are extremely slow▫Run on an Android device, if possible


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Test driving the app©1992-2013 by Pearson Education, Inc. All Rights

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Technologies Overview

•Prior to Android 3.0 animation done three ways:▫Tweened View animations to change View’s

appearance, such as where it is displayed, rotation, size the way we did in FlagQuizGame

▫Frame View animations for sequence of images▫Create animations the way we did it with

CannonGame

•Problem: if you animate a button, can only initiate Button’s click event where the Button was originally


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Technologies Overview• Property Animators

▫Used to move and scale ImageViews dynamically▫Can animate ANY property of ANY object▫Not limited to Views▫Can interact with a Button after it has moved

• Property Animators animate values over time• Specify

▫Target object▫Property to animate▫Duration of animation▫Values to animate between for each property▫How to change the values over time

(interpolator)


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Two property animation classes: Value Animator and Object Animator

•ValueAnimator▫Calculates property values over time▫Must specify AnimatorUpdateListener▫Programmatically modigy target object’s

property values▫Useful if target object does not have

standard set methods for changing property values


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Two property animation classes

•ObjectAnimator▫Subclass of ValueAnimator▫Uses target object’s set methods to modify

object’s animated properties as their values change over time


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New Utility class

•Added by Android 3.1•ViewPropertyAnimator

▫Simplifies property animation for Views▫Allows multiple properties to be animated

in parallel▫Now each View contains an animate method

Returns a ViewPropertyAnimator on which you can chain method calls to configure the animation

When last method call on chain finishes, the animation starts

Used to animate spots in this game


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Two ways to listening for Animation Lifecycle Events

•Implement interface AnimatorListener▫Defines methods called when animation

starts, ends, repeats or is cancelled•Extend class AnimatorListenerAdapter

▫If you do not need all four methods▫Override only the listener method(s) you

need


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•Touch Handling▫Introduced in CannonGame – overrode

Activity method onTouchEvent▫Two types of touches in the SpotOn game

Touching a spot Touching elsewhere on the screen

•Register onClickListeners for each spot (i.e. ImageView) to process touching a spot

•Use onTouchEvent to process all other screen touches


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Building the App’s GUI

• Set attributes in string.xml (not shown and not discussed)

• Set attributes in AndroidManifest.xml file• App’s main.xml layout file contains two layouts

▫RelativeLayout Positions the app’s TextViews for displaying

High score, level and current score

▫LinearLayout (nested inside RelativeLayout) Display’s lives remaining

• The layouts and GUI components in this app have all been seen before

• …and two other XML files


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This ImageView will be inflated and configured dynamically for each new spot in the game.


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This ImageView will be inflated and configured dynamically each time a new life is added to the Screen during the game.

Building the App

•Consists of two classes▫SpotOn – app’s main Activity▫SpotOnView – subclass of View, it defines

the game logic and spot animations


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Construct the SpotOnViewRequires 3 arguments:•Context in which GUI component is displayed (this Activity)•A SharedPreference object•The RelativeLayout (so SpotOnView can interact with other GUI components in the layout)

layout);

Ch5 showed how to read from a SharedPreferences file, here we use default one associated with this Activity


Reserved.Add the SpotOnView to the RelativeLayout at position 0 – that is, behind all the other elements in the layout

Call the SpotOnView’s pauseAnd resume methods

OnPause and OnResume• onPause releases SoundPool resources and

cancels running animations.

• When an Activity begins executing,▫ The method OnCreate is executed, followed by

OnStart, then onResume• onResume is also called when an Activity in the

background returns to the foreground

• In this app’s Activity, SpotOnView’s resume method obtains (or re-obtains) SoundPool resources and starts (or restarts) the game

• This app does not save the game’s state when the app is not on the screen.


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SpotOnView Subclass of View©1992-2013 by Pearson Education, Inc. All Rights

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OnCreate OnResumeOnPause

+SpotOnViewconstructor

+pause +resume

+cancelAnimations

+initializeSoundEffects +resetGame

+displayScores+addSpotRunnable

+addNewSpot

+touchedSpot

+missedSpot onTouchEvent

+displayScores

onClickListener


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For collection of spots and animators


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Call to this from OnCreate view = new SpotOnView (this, getPreferences(Context.MODE_PRIVATE), layout);


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For each loops

Do not want animationsto continue executing whenapp not on screen


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If dialogDisplayed is true, it is because the end-of-game dialog is still displayed on the screen and user can click the Reset Game button to start over; otherwise, it willcall resetGame.


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Inflate the life.xml file


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Schedule game’s first few spots


Reserved.Uses CannonGame’s same technique to prepare game’s sound effects


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resetGame’s spotHandler’s postDelayed method receives theaddSpotRunnable as an argument. This Runnable’s run method simply calls addNewSpot.


Reserved.Called-Several times near the beginning of game to display initial spots-Whenever the user touches a spot-When a spot’s animation ends without the spot being touched

Set spot’s values


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Each new added spot has a listener


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Chained methods

Only override two of thefour AnimatorListener’smethods


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Wrap-up

•Be able to describe three animation mechanisms

•Know what was added in Android 3.0 and 3.1 that was used in the SpotOn game

•Know what 4 methods are available in AnimatorListenerAdapter

•Know how to chain methods to configure an animation

•Know how to cancel animations•Know the methods of the

ConcurrentLinkedQueue class and what it is used for


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spoton game app android how to program ©1992-2013 by pearson education, inc. all rights reserved

Documents

pearson education

animation startsused

android device

features of android

animate methodreturns

technologies overviewtwo

changing property values1992

technologies overviewprior