This talk gives a brief overview of the options Android offers you to integrate with other apps.

1. DevFest Berlin 2013
You are not alone
on this
phone
+Christian Ketterer / cketti

2. Christian Ketterer
cketti
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Freelancer, Android!
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K-9 Mail core contributor
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Open source enthusiast
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Co-Organizer:
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Android Stammtisch Berlin
–
Google I/O Extended Berlin
–
DevFest Berlin
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3. What's this all about?
Android offers a lot of opportunities to integrate
with other apps → use them!
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use functionality provided by other apps
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provide functionality other apps can use
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4. Application components
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Activities
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Services
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Content providers
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Broadcast receivers
All application components can be used across
app boundaries
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5. What are Intents again?
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„An intent is an abstract description of an
operation to be performed.“
→ stores data that is interpreted by others
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Contains:
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Action
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Data (URI)
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Type
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Extras („simple“ data types)
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6. Activity
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„An activity is a single, focused thing that the
user can do.“
You can start activities of other apps
–
startActivity(Intent)
–
startActivityForResult(Intent, int)
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7. Expose your activity
<activity android:name=".ShareActivity">
<intent-filter>
<action android:name="android.intent.action.SEND"/>
<category android:name="android.intent.category.DEFAULT"/>
<data android:mimeType="text/plain"/>
<data android:mimeType="image/*"/>
</intent-filter>
</activity>
<activity
android:name=".InterestingActivity"
android:label="Do something"
android:exported="true">
</activity>
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8. Service
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„A Service is an application component that
can perform long-running operations in the
background and does not provide a user
interface.“
Can be used for interprocess communication
(IPC) → Context.bindService()
Allows you to call exposed methods in another
app
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9. AIDL
package com.example.aidl;
interface IRemoteService {
int giveMeAnInt();
void basicTypes(int anInt, long aLong, boolean aBoolean,
float aFloat, double aDouble, String aString);
}
oneway void setCallback(in ICallback callback);
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10. Examples
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DashClock Widget (extensions)
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OpenPGP Keychain
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OpenIntents Safe
If you know of any other (open source) app
making use of this functionality, please let me
know.
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11. Content provider
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●
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„Content providers are the standard interface
that connects data in one process with code
running in another process.“
Exposes structured set of data (think: table in
an SQL database)
Read and write data blobs
Notification mechanism when data has
changed
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12. Give me your content://
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ContentResolver is used to access a content
provider
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Needs a content:// URI
–
–
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Authority: specifies which content provider to use
Path: specifies what data to access
Example:
content://com.fsck.k9.messageprovider/inbox_messages
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13. Structured data
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CRUD
–
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Retrieve (query)
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Update
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_id
1
2
Create (insert)
Delete
name
keyboardsurfer
cketti
DevFest Berlin 2013
title
Señor Developer
Procrastinator extraordinaire
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14. Notification mechanism
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Be notified when data managed by the content
provider changes:
ContentResolver.registerContentObserver()
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Notify when data was changed:
ContentResolver.notifyChange(Uri, …)
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15. Examples
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Gmail (labels only)
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K-9 Mail
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Android
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Contacts
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Calendar
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Call log
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android.provider.*
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16. Broadcast receiver
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Receives Intents broadcasted via
Context.sendBroadcast()
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Examples:
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SMS received
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Time changed
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Boot complete
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Connectivity change
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Email received
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17. Finding components to talk to
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Use PackageManager.queryIntent*()
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<intent-filter>
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<meta-data>
<service android:name=".FancyService">
<intent-filter>…</intent-filter>
<meta-data android:name="protocolVersion"
android:value="1"/>
<meta-data android:name="settingsActivity"
android:value="com.example.app.SettingsActivity"/>
</service>
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18. Important
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Protect components exposing sensitive data
using Android permissions
It's a public API!
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Use versioning
If you make a mistake not only your app will break
Make sure you read the official documentation
when adding support for standard intent
actions*
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19. Summary
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Expose an Activity to provide some
functionality requiring an user interface
Use a Service to allow performing
(background) actions
Allow others to read/write your data using a
content provider
Send broadcast intents to notify others of
important events
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20. Take-away
Make the Android experience
more awesome by allowing
other apps to integrate with
yours
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21. Questions?
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22. Storage Access Framework
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