android_lifecycle_app_note.pdf

ANDROID LIFECYCLE FOR APPLICATION DEVELOPERS: GUIDELINES AND TIPS May 2012 Developer Whitepaper DOCUMENT CHANGE HISTORY Document Number Version Date Authors Description of Change 01 30 May, 2011 Lbishop Initial release 02 21 Sept, 2011 Lbishop Update for NativeActivity 03 4 march, 2012 Lbishop Update for new samples pack 04 16 May, 2012 Lbishop Update for suspend/resume with no lock screen Android Lifecycle for application developers: Guidelines and Tips ii TABLE OF CONTENTS Android Lifecycle Basics in Practice 4 Top-Level Items 4 NativeActivity and native_app_glue 5 The Lifecycle Hierarchy Events 6 The non-Hierarchy Events 6 Mapping Lifecycle to Native Code 8 Additional Lifecycle Concepts and Realities 9 Being “Killable” 9 Callback-Handling AND ANR’s 9 onPause versus onStop 9 Rendering and Threading 10 User Actions and Callback Sequences 10 Sequencing Differences 10 Launching a New Application 11 Pressing the Back Button 11 Pressing the Home Button 12 Resuming a “Home’d” Application 12 Opening a Status Icon Pop-up 12 Closing a Status Icon Pop-up 13 Suspend/Resume 13 Basic Android Lifecycle Recommendations 15 All a Game Needs 16 Common Steps and when they can be done 16 Loading and Deleting Game Data 16 Initializing and Deleting EGL, Contexts, Surfaces and Rendering Resources 16 Rendering 18 Auto-pause 19 Handling Input 20 Exiting and Native Apps 20 Saving Game Progress 21 Resuming versus Restarting 21 Some Simple Mappings 21 Surprising Application Lifecycle Events an