{"id":421,"date":"2012-08-11T16:39:49","date_gmt":"2012-08-11T11:09:49","guid":{"rendered":"http:\/\/ramkulkarni.com\/blog\/?p=421"},"modified":"2012-08-11T16:39:49","modified_gmt":"2012-08-11T11:09:49","slug":"starting-android-activity-on-device-restart","status":"publish","type":"post","link":"http:\/\/ramkulkarni.com\/blog\/starting-android-activity-on-device-restart\/","title":{"rendered":"Starting Android Activity on device restart"},"content":{"rendered":"

I finally got around to fixing a bug in my Android application, Simple Task Reminder<\/a>, which was on my to-do list for a long time.The issue was that all reminders set in this application were lost on device restart. The solution was to set reminders again after device rebooted.<\/p>\n

Android SDK provides a mechanism to receive notification for your application, after the device is booted. You need to add a broadcast receiver in the manifest file –
\n<\/p>\n

<<\/span>receiver<\/span> android:name<\/span>=<\/span>\"<\/span>BootNotificationReceiver<\/span>\"<\/span> android:exported<\/span>=<\/span>\"<\/span>false<\/span>\"<\/span>\n    android:label<\/span>=<\/span>\"<\/span>Boot Notification Receiver<\/span>\"<\/span> android:enabled<\/span>=<\/span>\"<\/span>true<\/span>\"<\/span>><\/span>\n\n    <<\/span>intent-filter<\/span>><\/span>\n        <<\/span>action<\/span> android:name<\/span>=<\/span>\"<\/span>android.intent.action.BOOT_COMPLETED<\/span>\"<\/span>\/><\/span>\n    <\/<\/span>intent-filter<\/span>><\/span>\n<\/<\/span>receiver<\/span>><\/span><\/pre>\n
Value of android:name attribute above is your class name that extends BroadcastReceiver class. In onReceive function of this class you can start the Activity of your application e.g. –<\/p>\n
public<\/span> class<\/span> BootNotificationReceiver extends<\/span> BroadcastReceiver {<\/span>\n\n    @<\/span>Override\n    public<\/span> void<\/span> onReceive(<\/span>Context context,<\/span> Intent intent)<\/span> {<\/span>\n        Intent mainIntent =<\/span> new<\/span> Intent (<\/span>context,<\/span> SimpleTaskReminderActivity.<\/span>class)<\/span>;<\/span>\n        mainIntent.<\/span>putExtra(<\/span>\"refresh_reminders\"<\/span>,<\/span> true<\/span>)<\/span>;<\/span>\n        mainIntent.<\/span>setFlags(<\/span>Intent.<\/span>FLAG_ACTIVITY_NEW_TASK)<\/span>;<\/span>\n        context.<\/span>startActivity (<\/span>mainIntent)<\/span>;<\/span>\n    }<\/span>\n}<\/span><\/pre>\n
You also need to add RECEIVE_BOOT_COMPLETED user permission in the menifest file-<\/p>\n
<<\/span>uses-permission<\/span> android:name<\/span>=<\/span>\"<\/span>android.permission.RECEIVE_BOOT_COMPLETED<\/span>\"<\/span>\/><\/span><\/pre>\n
Accessing WebView local DB from Java :<\/h3>\n
I have used WebView for this application and used local database of the WebView to store tasks. All data access code in WebView is in JavaScript. Initially, I was looking for a way to access this database from Java code in my Activity. I found that you can get path of the database file of WebView as follows –<\/p>\n
appView.getSettings().getDatabasePath();<\/span> \/\/appView is an instance of WebView.<\/span><\/pre>\n
However I did not end up using this API for refreshing reminders, because I already had all the code in JavaScript to get tasks and format data to schedule reminders. What I ended up doing was starting the Activity that had WebView, execute JavaScript function to re-schedule reminders and then hiding the Activity. Hiding Activity in an Android application is as simple as calling moveTaskToBack method on the activity –<\/p>\n
activity.moveTaskToBack(true);<\/span><\/pre>\n
-Ram Kulkarni<\/p>\n","protected":false},"excerpt":{"rendered":"
I finally got around to fixing a bug in my Android application, Simple Task Reminder, which was on my to-do list for a long time.The issue was that all reminders set in this application were lost on device restart. The solution was to set reminders again after device rebooted. Android SDK provides a mechanism to … <\/p>\n
Continue reading “Starting Android Activity on device restart”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[3,1],"tags":[2,45,46],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2g9O8-6N","jetpack-related-posts":[],"_links":{"self":[{"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/posts\/421"}],"collection":[{"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/comments?post=421"}],"version-history":[{"count":0,"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/posts\/421\/revisions"}],"wp:attachment":[{"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/media?parent=421"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/categories?post=421"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/ramkulkarni.com\/blog\/wp-json\/wp\/v2\/tags?post=421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}