Mobile Programming Practice Explicit intent Implicit intent Intent filter Lab#4 PA #1

Transcription

1 1 Mobile Programming Practice Explicit intent Implicit intent Intent filter Lab#4 PA #1 Prof. Hwansoo Han T.A. Sung-in Hong T.A. Minseop Jeong

2 2 Lecture schedule Spring 2019 (Tuesday) This schedule can be changed M A R C H A P R I L M A Y Introduction Android overview & basic layout Layout Advanced UI Intent / filter PA#1 Broadcast receivers and Services Project proposal Advanced concepts (1) APIs (1) PA#2 APIs (2) MID TERM (no exam) Profile Content providers J U N E Intro. to the Kotlin Project Final Presentation END TERM (no class)

3 3 Proposal presentation 16 th Apr. 5 min presentation (you can change contents) Ex)Team members Idea Goals Please upload your presentation material on i-campus until Proposal day

4 4 Intent An Intent is a messaging object you can use to request an action from another app component Three fundamental use cases: 1. Starting an activity : Context.startActivity() 2. Starting a service : Context.startService() 3. Delivering a broadcast : Context.sendBroadcast()

5 5 Intent types Explicit intents specify which application will satisfy the intent, by supplying either the target app's package name or a fully-qualified component class name Implicit intents do not name a specific component, but instead declare a general action to perform, which allows a component from another app to handle it

6 6 Primary info. of intent Component name The name of the component to start Optional, but it s the critical piece of info. that makes an intent explicit Action A string that specifies the generic action to perform Ex) ACTION_IMAGE_CAPTURE Data The URI(a Uri object) that references the data to be acted on and/or the MIME type of that data. URI : Uniform Resource Identifier MIME : type/subtype (e.g. image/jpeg)

7 7 Primary info. of intent Category A string containing additional information about the kind of component that should handle the intent Extras Key-value pairs that carry additional information required to accomplish the requested action Flags defined in the Intent class that function as metadata for the intent

8 8 Explicit intent // Explicit Intent by specifying its class name Intent i = new Intent(FirstActivity.this, SecondActivity.class); // Starts TargetActivity startactivity(i); *

9 9 Creating explicit intent Constructor Public Intent(Context packagecontext, class<?> cls); packagagecontext : the Context of current Activity cls : the class of target Activity Set parameter to Intent putextra(string name, ); //key, value // Explicit Intent by specifying its class name Intent i = new Intent(FirstActivity.this, SecondActivity.class); // Explicit Intent by specifying its class name i.putextra( mydata,edittext.gettext().tostring()); startactivity(i);

10 10 Receiving an explicit intent public Intent getintent(); Get Intent object which is submitted from previous Component public bundle getextra(); public String getstringextra() : to get String data public String getintextra() : to get Int data Intent i = getintent(); bundle extras = i.getextras(); String text = extras.getstring( mydata ); Or String text = i.getstringextra( mydata );

11 11 Implicit intent An implicit intent specifies an action that can invoke any app on the device able to perform the action. Using an implicit intent is useful when your app cannot perform the action, but other apps probably can and you'd like the user to pick which app to use. *

12 12 Creating implicit intent Constructor public Intent(String action) public Intent(String action, Uri, uri) Action strings for instantiating Intent is statically defined in Intent class Please refer APPENDIX A LIST OF COMMON INTENTS

13 13 Example of implicit intent String query = "android"; Intent intent = new Intent(Intent.ACTION_WEB_SEARCH); intent.putextra(searchmanager.query,query); startactivity(intent);

14 14 Intent filter Define the actions which Component will receive in AndroidManifest <activity android:name=".mainactivity" <intent-filter> <action android:name="android.intent.action.main" /> <action android:name="android.intent.action.view" /> <category android:name="android.intent.category.launcher" /> </intent-filter> </activity>

15 15 Example of filters <activity android:name="mainactivity"> <!-- This activity is the main entry, should appear in app launcher --> <intent-filter> <action android:name="android.intent.action.main" /> <category android:name="android.intent.category.launcher" /> </intent-filter> </activity> <activity android:name="shareactivity"> <!-- This activity handles "SEND" actions with text data --> <intent-filter> <action android:name="android.intent.action.send"/> <category android:name="android.intent.category.default"/> <data android:mimetype="text/plain"/> </intent-filter> <!-- This activity also handles "SEND" and "SEND_MULTIPLE" with media data --> <intent-filter> <action android:name="android.intent.action.send"/> <action android:name="android.intent.action.send_multiple"/> <category android:name="android.intent.category.default"/> <data android:mimetype="application/vnd.google.panorama360+jpg"/> <data android:mimetype="image/*"/> <data android:mimetype="video/*"/> </intent-filter> </activity>

16 16 Receiving an implicit intent public Intent getintent(); Get Intent object which is submitted from previous Component public bundle getextra(); public String getstringextra() : to get String data public String getintextra() : to get Int data Intent i = getintent(); bundle extras = i.getextras(); String text = extras.getstring( mydata ); Or String text = i.getstringextra( mydata );

17 17 [Lab Practice #4] Create two Activities The first Activity has One edittext to input user name One button to deliver user name to next activity The second Activity has Welcome message with user name One (or more) function to invoke any other app Ex) set alarm, capture a picture, send and etc. (excepts web_search) You can add any view what you need

18 18 PA#1 To do list Implement to do list app. Login activity Enter the user id and password from the user The password should be covered on display Check user id and password are matched User id and password were predefined in your app ToDoList activity *Trello Has three vertical lists, named TASK, DOING and DONE Each card represents job includes Job name, dead line, and description Belonging in one of lists Can move to another list Can be deleted, added and modified

19 19 PA#1 To do list Individual programming assignment Recommend to use Android 8.1 Oreo (API level 27) Please upload your zipped project on i-campus Due : 23:59, 18 th Apr. A Chance to earn extra 10 credit : User familiar interface or extra functionality Late submission : 10% penalty per day, up to 5days 50% of the full score is the maximum, if you delay more than 5 days Submitting all PA is mandatory to earn your grade

20 20 APPENDIX A LIST OF COMMON INTENTS uide/components/intentscommon

21 21 Common intents Alarm clock Calendar Camera Contacts/People App File Storage Local Actions Maps Music or Video New Note Phone Search Settings Text Messaging Web Browser

22 22 APPENDIX B Forcing an app chooser uide/components/intentsfilters#forcechooser