Android chapter19 intent filters

11/1/2009 1 AndroidAndroid 19 Android  Android  IntentFiltersIntentFilters VictorMatos Cleveland State University Cleveland  State  University Notesarebasedon: AndroidDevelopers http://developer.android.com/index.html 19.Android–IntentFilters IntentFiltersIntentFilters AnAnalogy:RequestingActionsUsingHTTPandAndroid 1. TheHPPT 1 protocolusesanumberof<Action,resource>pairsto accomplish its work accomplish  its  work . 2. SomeoftheHTTP actionsarethewellknown(andlesserknown) operations:POST,GET,PUT,DELETE,CONNECT,HEAD,OPTIONS. 3. AndroidusesamechanismquitesimilartoHTTPforthein vocationof worktobedone. 2222 4. INTENT istheAndroid’snamefortheabstractionrequestingactions. 5. UnlikeHTTPagivenAndroid’sINTENTcouldberesolvedinmorethan onepotentialway(forinstance,wemayhaveseveralSMSappswanting toprocessanincomingtext‐message). ____ 1. Source:HypertextTransferProtocol‐‐ HTTP/1.1(1999).http://www.w3.org/Protocols/rfc2616/rfc2616‐sec9.html 11/1/2009 2 19.Android–IntentFilters IntentFiltersIntentFilters INTENTS • Anintentisan abstractdescriptionofanoperationtobeperformed. • Itsmostsignificantuseisinthelaunchingofactivities. • The primary pieces of information in an intent are action & data • The  primary  pieces  of  information  in  an  inten t  are : action &  data . ACTION DATA Misc Thegeneralactiontobe performed,suchas: ACTION _ EDIT ,  Thedatatooperateon,suchasaperson recordinthecontactsdatabase, expressedasa URI. Iam g ood f oreditin g adocument 3333 Source:http://developer.android.com/reference/android/content/Intent.html _, ACTION_VIEW, ACTION_MAIN, ACTION_LAUNCHER etc. g f g Iamgoodforviewingadocument Iamthefirstexec.Activ.ofApplication Putmeonthephone’sMenu_Pad 19.Android–IntentFilters IntentFiltersIntentFilters PartsofaTypicalIntent ACTION DATA MISC Standard URI Category Standard URI Category CATEGORY_DEFAULT CATEGORY_BROWSABLE CATEGORY_TAB CATEGORY_ALTERNATIVE CATEGORY_SELECTED_ALTERNATIVE CATEGORY_LAUNCHER CATEGORY_INFO CATEGORY_HOME CATEGORY_PREFERENCE CATEGORY_TEST ACTION_MAIN ACTION_VIEW ACTION_ATTACH_DATA ACTION_EDIT ACTION_PICK ACTION_CHOOSER ACTION_GET_CONTENT ACTION_DIAL ACTION_CALL ACTION_SEND ACTION_SENDTO ACTION_ANSWER ACTION_INSERT ACTION_DELETE ACTION_RUN ACTION_TIME_TICK ACTION_TIME_CHANGED ACTION_TIMEZONE_CHANGED ACTION_BOOT_COMPLETED ACTION_PACKAGE_ADDED ACTION_PACKAGE_CHANGED ACTION_PACKAGE_REMOVED ACTION_PACKAGE_RESTARTED ACTION_PACKAGE_DATA_CLEARED ACTION_UID_REMOVED ACTION_BATTERY_CHANGED ACTION_POWER_CONNECTED ACTION_POWER_DISCONNECTED ACTION_SHUTDOWN CONTENTS suchas: content://contacts/ content://contacts/1 SCHEME suchas: tel:123 http://aaa.bbb.ccc mailto: // aa @ bbb.ccc MIME Explicittype(aMIMEtype)of theintentdata. C 4444 ACTION_SYNC ACTION_PICK_ACTIVITY ACTION_SEARCH ACTION_WEB_SEARCH ACTION_FACTORY_TEST // @ ftp://aaa.bbb.ccc . pop:// smtp:// ssl:// C omponent Explicitnameofacomponent classtousefortheintent. Extras putExtra(String,Bundle) Flags 11/1/2009 3 19.Android–IntentFilters IntentFiltersIntentFilters Aside:MIME “…Thissetofdocuments,collectivelycalledthe M lti It tMilEt i  MIME  dfi th  M u lti purpose I n t erne tM a ilE x t ens i ons,  or MIME ,  re d e fi nes th e  formatofmessagestoallowfor (1) textualmessagebodiesincharactersetsotherthan US‐ASCII, (1) anextensiblesetofdifferentformatsfornon‐textual messagebodies, 5555 (2) multi‐partmessagebodies,and (3) textualheaderinformationincharactersetsotherthan US‐ASCII.” ____ Source:MultipurposeInternetMailExtensions.(MIME)PartTwo:MediaTypes. Availableat:http://tools.ietf.org/html/rfc2046 NOTE: CurrentusageofMIMEdescribes contenttypeingeneral. 19.Android–IntentFilters IntentFiltersIntentFilters IntentResolution WhenIntentsareissued,Androidlooksforthemostappropriatedwayof respondingtotherequest. Thedecisionofwhattoexecuteisbasedonhowdescriptivethecallis: ExplicitIntents specifyaparticularcomponent (viasetComponent(ComponentName) orsetClass(Context,Class) ), whichprovidestheexactclasstoberun.Thisisatypicalwayforan applicationtolaunchvariousinternal activitiesithasastheuserinteracts with the application 66666 with  the  application . ImplicitIntents donotspecifiedaparticularcomponent.Howeverthey includeenoughinformationforthesystemtodeterminewhichofthe availablecomponentsareintheisbestcategorytorunforthatintent. 11/1/2009 4 19.Android–IntentFilters IntentFiltersIntentFilters IntentResolution “Theintentresolutionmechanismbasicallyrevolvesaround thi It t itll f th it t filt ma t c hi ngan I n t en t aga i ns t a ll o f  th e< i n t en t ‐ filt er> descriptionsintheinstalledapplicationpackages .” 777777 19.Android–IntentFilters IntentFiltersIntentFilters IntentResolution 88888 11/1/2009 5 19.Android–IntentFilters IntentFiltersIntentFilters IntentResolution Asshowninthepreviousillustration.Activity3hasissueageneric requestfor helpprocessinganincomingtext‐message. Assumetheuserhasinstalleda“FancySMS”applicationto(perhaps)replace thestandard“HUMBLESMS”apporiginallyincludedinAndroid. UponthearrivaloftheimplicitIntent,Androidwill(somehow)telltheuser: Youhavegotanewtext‐message.IhaveaFANCYandaHUMBLESMS application–which oneyouwantmetoexecute?Makeitadefault? 99999 Choosingcandidates: Foranactivitytobeeligibleforexecutionitmust: 1.Supportthespecifiedaction 2.SupporttheindicatedMIMEtype(ifsupplied) 3.Supportallofthecategories namedintheintent. _____________ RULEOFTHUMB:YourIntentsshouldbeasspecificaspossible 19.Android–IntentFilters IntentFiltersIntentFilters Example:IntentFilters TheManifesttellstheapplication(FancySms)isabletointerceptincomingSMS datausingitsSMSReceiver (potentialalternativetothedefaultSMSapp.) <?xmlversion="1.0"encoding="utf‐8"?> <manifestxmlns:android="http://schemas.android.com/apk/res/android" package="cis493.intentfilters"android:versionCode="1"android:versionName="1.0.0"> <uses‐permissionandroid:name="android.permission.RECEIVE_SMS"/> <applicationandroid:icon="@drawable/icon"> <activityandroid:name=".FancySms"> <intent‐filter> <actionandroid:name="android.intent.action.MAIN"/> <categoryandroid:name="android.intent.category.LAUNCHER"/> / 1010101010 < / intent‐filter> </activity> <receiverandroid:name="SMSReceiver"android:enabled="true"> <intent‐filter> <actionandroid:name="android.provider.Telephony.SMS_RECEIVED"/> </intent‐filter> </receiver> </application> </manifest> 11/1/2009 6 19.Android–IntentFilters IntentFiltersIntentFilters Commentsontheexample: • Theapplicationconsistsoftwocomponents: 1 a common Activity called FancySms (acting as the main routine) and 1 . a  common  Activity  called  FancySms (acting  as  the  main  routine)  and  2. abackgroundService(BroadcastReceiver)calledSMSService. • TheclausebelowindicatestheapplicationisallowedtoreceiveSMS <uses‐permissionandroid:name="an droid.permission.RECEIVE_SMS"/> • ThecomponentSMSService hasthefilter <intent ‐ filter> 1111111111 <intent filter> <actionandroid:name="android.provider.Telephony.SMS_RECEIVED"/> </intent‐filter> thattriggersitsexecutionwheneveranewSMSisreceived • OtherapplicationswiththesamefiltercanbealsocalledbyAndroidwhen newSMSarrives(untilaDEFAULTischosen) 19.Android–IntentFilters IntentFiltersIntentFilters Example:InterceptingIncomingSMS <?xml version="1.0" encoding="utf-8"?> <LinearLayout android:id="@+id/mainLayout" android:layout width = " fill parent “ android:layout height = " fill parent " android:layout_width = fill_parent android:layout_height = fill_parent android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="20px" android:textStyle="bold“ ndroid:background="#ff0000ff" android:text="Intercepting SMS messages" /> <ScrollView android:id="@+id/myScroller1" android:layout_width="fill_parent" android:layout_height="fill_parent" 1212121212 > <TextView android:id="@+id/theMessage" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#ffffffff" android:padding="4px" android:textSize="14px" android:textColor="#ff000000" /> </ScrollView> </LinearLayout> 11/1/2009 7 19.Android–IntentFilters IntentFiltersIntentFilters Example:InterceptingIncomingSMS Note: Testthefollowingapplication fromtheEclipse’sDDMS perspective.Select“Emulator Control”>“TelephonyActions”. Setphoneno.to5554,typea message,clickonSend. Alternativelyyoumaystart anotheremulatorandsend 1313131313 SMSto5554 19.Android–IntentFilters IntentFiltersIntentFilters Example:InterceptingIncomingSMS // FancySms: main screen - displays intercepted SMS package cis493.intentfilters; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class FancySms extends Activity { static TextView txtMsg; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); 1414141414 setContentView(R.layout.main); txtMsg = (TextView)findViewById(R.id.theMessage); } }// class FancySms 11/1/2009 8 19.Android–IntentFilters IntentFiltersIntentFilters Example:InterceptingIncomingSMS // SMSReceiver: listens to broadcasted SMS_RECEIVED signals package cis493.intentfilters; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.telephony.gsm.SmsMessage; import android.widget.Toast; public class SMSReceiver extends BroadcastReceiver { 1515151515 @Override public void onReceive(Context context, Intent intent) { // Android saves in a bundle the current text-message // under name "pdus" and type: Object[]. Later we cast to // SmsMessage[]. Jargon pdu stands for "protocol data unit" Bundle bundle = intent.getExtras(); 19.Android–IntentFilters IntentFiltersIntentFilters Example:InterceptingIncomingSMS Object messages[] = (Object[]) bundle.get("pdus"); SmsMessage smsMessage[] = new SmsMessage[messages.length]; // Note: long sms are broken and transmitted into various pieces String msg = ""; int smsPieces = messages.length; for (int n = 0; n < smsPieces; n++) { smsMessage[n] = SmsMessage.createFromPdu((byte[]) messages[n]); // grab all pieces of the intercepted sms msg += "\n" + (n + 1) + " -of- " + smsPieces + "\n" + "Sender:\t" + smsMessage[n].getOriginatingAddress() + "\n" + "Body: \n " + smsMessage[n].getMessageBody(); } 1616161616 } // show first part of intercepted (current) message Toast toast = Toast.makeText(context, "FANCY >>> Received SMS: " + smsMessage[0].getMessageBody(), Toast.LENGTH_LONG); toast.show(); cis493.intentfilters.FancySms.txtMsg.setText(msg); } }// class SMSReceiver 11/1/2009 9 19.Android–IntentFilters IntentFiltersIntentFilters QuestionsQuestions 171717 19.Android–IntentFilters IntentFiltersIntentFilters JARGON: PDU i htf " Pt lDt Uit " Thi t t f if ti i ss h or t  f or " P ro t oco l  D a t a U n it " . Thi srepresen t sanamoun t o f  i n f orma ti on deliveredthroughanetworklayer. VND virtualnetworkdata (todaytypicallyrepresentsabusinesscardwithname, phone,email,etc).OriginallyregisteredasMIME vnd.abcintendedfor transmissionofabc folkmelodiesinemails see:http://www.iana.org/assignments/media‐types/text/vnd.abc 181818