Creating Android Services with Delphi and RAD Studio 10 Seattle
9 likes18,233 views
Android services enable background functionality that can run even when an app is closed, supporting multiple apps. Key types include IntentService for asynchronous tasks and local vs. remote services, with specific lifecycle management. Developers must build and reference services correctly, while considering restrictions and user privacy.
Creating Android Services with Delphi and RAD Studio 10 Seattle
- 1. Android Services Jim McKeeth Lead Developer Evangelist Embarcadero Technologies
- 2. About Jim McKeeth • Lead World Wide Developer Evangelist • Host of Podcast at Delphi.org • Longtime developer – Object Pascal, Java, C#, JavaScript, Objective-C, etc. • Invented and patented swipe to unlock in 2000 – US Patent # 8352745 & 6766456, etc. • Improvisational performer with ComedySportz Boise
- 3. Why Android Services? • Provide background functionality • Can run even when app is closed • Can start on boot or other events • Can be accessible by multiple apps
- 4. Android Services vs. Threads Android Services • Cannot access the UI • Runs in main thread of host app process • Can contain multiple threads • Used for long running processes Threads • Cannot access the UI • Not accessible to other apps • Terminated with app • Used to improve responsiveness
- 5. Android Service Type Variations • IntentService – Handle asynchronous requests (onHandleIntent(Intent) event) – Otherwise are syncronous (onStartCommand(Intent) event) – Both are Bindable (onBind event) • Local vs. Remote – Local only accessible by host (exported = false in manifest) – Remote cross app access (exported = true in manifest)
- 6. Android Service Wizard • Local Service – Synchronous local access • Intent Local Service – Asynchronous local access • Remote Service – Synchronous local & remote access • Intent Remote Service – Asynchronous local & remote access
- 7. Service Class Hierarchy TDataModule TAndroidBaseService Adds OnBind, OnUnBind, OnRebind, OnTaskRemoved, OnConfigurationChanged, OnLowMemory, OnTrimMemory, OnHandleMessage*, JavaService & JavaIntentService** TAndroidService Adds OnStartCommand TAndroidIntentService Adds OnHandleIntent *OnHandleMessage only occurs in remote services **Only JavaService xor JavaIntentService will have a value, otherwise nil
- 8. Services in Delphi • The Service is a separate project • Referenced by, and included in host app • Must build service before adding to host • For best results put service in its own directory
- 9. How to use a Service • We have two ways to use a Service: 1. Sending a request (startService(Intent)) It is used to execute an unattended work in background return START_STICKY or START_REDELIVER_INTENT in OnStartCommand to restart the service in case the app is closed 2. Bound to the service (bindService) It is used to create a long-standing connection to interact with the service 3. Can use a combination of both
- 10. Service lifecycle • Lifecycle and events are different depending on how the service is started: – Started – Bound More information http://developer.android.com/guide/components/services.html
- 11. Restrictions for Services • Cannot Access UI • Not use components from the FMX namespace • Be aware of power consumption – Using a lot of CPU – Using network connection • Respect users expectations and privacy
- 12. Service Workarounds • Use RTL or low-level calls instead of FMX components. If the service fails when started, use a lower level call. • Manually edit manifest to make remote services published. • Manually edit Java Templates for Intent and Remote Services (see http://delphi.org/?p=2084)
- 14. Summary • Android services allow for execution even when app is not running. • Add a new Android Service project to your app. • Build service before adding reference. • More information: – http://delphi.org/tag/android-services/ – http://embt.co/creating_android_services – http://embt.co/android_service