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Hasan Hosgel | ImmobilienScout24
Best Practices to develop for different Android Device Classifications
About me• +HasanHosgel
@alosdev
alosdev
hosgel
CO-Organizer
Developer
ImmobilienScout24
Germany’s largest real estate listing company.
> 10 Mio. Monthly unique users> 1.5 Mio. real estates> 300 Mio. detail views> 1500 Servers~ 7.5 Mio. App downloads
> 3 Mio. Android> 50% mobile traffic
Fragmentation
Fragmentation
> 5000 Android Devices
Here comes the Nightmare
Image source:http://www.flickr.com/photos/boogeyman13/4553188509/
Image source:http://www.flickr.com/photos/boogeyman13/4553188509/
Here comes the Nightmare
For developers
Let’s build the fundament
Image source:http://www.flickr.com/photos/hertenberger/1434191066/
Device Classification
Image source:https://play.google.com/store/devices
Image source:https://play.google.com/store/deviceshttp://www.htc.com
Open Automotive AllianceStarting 2014 several companies plan to bring Android platform to the cars.• Audi• GM• Google• Honda• Hyundai• Nvidiahttp://www.openautoalliance.net/
Wearables
Android Wear SDK
Google Glass
Hard Work Ahead
Image source:http://www.flickr.com/photos/16210667@N02/9172895225
Resource Folders
You can use several qualifiers in the resource folders name for serving the best matching resource.
Qualifiers• Language (-en)• Language & Region (-en-rUS)• Smallest Width (–sw600dp)• Screensize (-small, -normal, -large)• Screen Orientation (-port, -land)• Screen Pixel Densitiy (-hdpi, -xxhdpi,…)• Platform Version (-v11, -v13)
Best Matching Resource Wins1. res/values/strings.xml2. res/values-en-rUS/strings.xml3. res/values-large/strings.xml4. res/values-sw600dp/strings.xml
Best Matching Resource Wins1. res/values/strings.xml2. res/values-en-rUS/strings.xml3. res/values-large/strings.xml4. res/values-sw600dp/strings.xml
The order of the qualifiers in the previous slides gives the ranking, if two resources have the same matching number of qualifiers.
Image Resources• Use the different qualifiers for the screen pixel
density (mdpi, hdpi, etc.)• If you are forced to use text on images use
language and region (en, es-rUS, en-rUS, etc.)• Better approach is to use 9-patch drawables,
which stretches automatically depending on the content inside.
• You must provide different launcher icons for Froyo, Honeycomb and above? Use the platform version. (v4, v11, v14)
Classifications for Layouts
Platform version at least v13 (Honeycomb MR2)
Classifications for Layouts
Platform version at least v13 (Honeycomb MR2)
project-folder/res/
layout/
Classifications for Layouts
Platform version at least v13 (Honeycomb MR2)
project-folder/res/
layout/ small phones
Classifications for Layouts
Platform version at least v13 (Honeycomb MR2)
project-folder/res/
layout/ small phones
layout-sw320dp/ other phones
Classifications for Layouts
Platform version at least v13 (Honeycomb MR2)
project-folder/res/
layout/ small phones
layout-sw320dp/ other phones
layout-sw600dp/ tablets 7”
Classifications for Layouts
Platform version at least v13 (Honeycomb MR2)
project-folder/res/
layout/ small phones
layout-sw320dp/ other phones
layout-sw600dp/ tablets 7”
layout-sw720dp/ tablets 10”
* You should also use the orientation qualifier
Platform version lower v11
project-folder/res/
layout/
layout-sw320dp/ other phones
layout-sw600dp/ tablets 7”
layout-sw720dp/ tablets 10”
Platform version lower v11
project-folder/res/
layout/ phones
layout-sw320dp/ other phones
layout-sw600dp/ tablets 7”
layout-sw720dp/ tablets 10”
Platform version lower v11
project-folder/res/
layout/ phones
layout-v11/ tablets 10”
layout-sw320dp/ other phones
layout-sw600dp/ tablets 7”
layout-sw720dp/ tablets 10”
Platform version lower v11
project-folder/res/
layout/ phones
layout-v11/ tablets 10”
layout-v13/ small phones
layout-sw320dp/ other phones
layout-sw600dp/ tablets 7”
layout-sw720dp/ tablets 10”
Hint
The smallest width qualifier gets automatically platform version ”-v13” through the packager, for avoiding problems with the number of matching qualifiers.
How to Classify In Code• Read configuration from the device
How to Classify In Code• Read configuration from the device• Smarter approach is to use boolean
resources
project-folder/res/values/layouts.xml
<resources>
</resources>
project-folder/res/values/layouts.xml
<resources>
<bool > </bool>
</resources>
project-folder/res/values/layouts.xml
<resources>
<bool name="is_phone_small"> </bool>
</resources>
project-folder/res/values/layouts.xml
<resources>
<bool name="is_phone_small">true</bool>
</resources>
project-folder/res/values/layouts.xml
<resources>
<bool name="is_phone_small">true</bool>
<bool name="is_phone_other">false</bool>
<bool name="is_tablet_7">false</bool>
<bool name="is_tablet_10">false</bool>
</resources>
project-folder/res/values/layouts.xml
<resources>
<bool name="is_phone_small">true</bool>
<bool name="is_phone_other">false</bool>
<bool name="is_tablet_7">false</bool>
<bool name="is_tablet_10">false</bool>
</resources>
Usage in code: getResources().getBoolean(R.bool.is_phone_small)
Current Layout File Structureproject-folder/res/
layout/main.xmllayout-v11/main.xmllayout-v13/main.xmllayout-sw320dp/main.xmllayout-sw600dp/main.xmllayout-sw720dp/main.xml
Current Layout File Structureproject-folder/res/
layout/main.xmllayout-v11/main.xmllayout-v13/main.xmllayout-sw320dp/main.xmllayout-sw600dp/main.xmllayout-sw720dp/main.xml
Fixing one bug in the 10“ layout has to be done in two files.
Current Layout File Structureproject-folder/res/
layout/main.xmllayout-v11/main.xmllayout-v13/main.xmllayout-sw320dp/main.xmllayout-sw600dp/main.xmllayout-sw720dp/main.xml
Fixing one bug in the 10“ layout has to be done in two files. error prone
Resource Alias
Put your layout files in the default folder.project-folder/res/
layout/main_phone_small.xml
layout/main_phone_other.xml
layout/main_tablet_7.xml
layout/main_tablet_10.xml
Create an item with the needed classification in the previously defined values folder.
project-folder/res/values-sw720dp/layouts.xml
<resources>
</resources>
Create an item with the needed classification in the previously defined values folder.
project-folder/res/values-sw720dp/layouts.xml
<resources>
<item name="main" >
</item>
</resources>
Create an item with the needed classification in the previously defined values folder.
project-folder/res/values-sw720dp/layouts.xml
<resources>
<item name="main" type="layout">
</item>
</resources>
Create an item with the needed classification in the previously defined values folder.
project-folder/res/values-sw720dp/layouts.xml
<resources>
<item name="main" type="layout">
@layout/main_tablet_10.xml
</item>
</resources>
Scenario
Use <includes>
Usage include<LinearLayout … >
…< />…
</LinearLayout>
Usage include<LinearLayout … >
…<include />…
</LinearLayout>
Usage include<LinearLayout … >
…<include layout="@layout/footer"/>…
</LinearLayout>
Use <includes>
Use <includes>
Custom Viewpublic class CustomView extends LinearLayout {…
public CustomView(Context context, AttributeSet attrs) {
…
addView(createTextView(context, "label"), lp);
addView(createTextView(context, "desc"), lp);
if(getResources().getBoolean(R.bool.is_phone)){setOrientation(VERTICAL);
} else {setOrientation(HORIZONTAL);
}}
…
}
Usage In Layout Files<LinearLayout … >
…<de.alosdev.CustomViewandroid:layout_width="wrap_content" android:layout_height="wrap_content"/>…
</LinearLayout>
Use <includes>
Create custom view
Custom XML Attribute<resources> <resources>
Custom XML Attribute<resources> <declare-styleable > </declare-styleable><resources>
Custom XML Attribute<resources> <declare-styleable name=”CustomView"> </declare-styleable><resources>
Custom XML Attribute<resources> <declare-styleable name=”CustomView"> <attr /> </declare-styleable><resources>
Custom XML Attribute<resources> <declare-styleable name=”CustomView"> <attr name="label" /> </declare-styleable><resources>
Custom XML Attribute<resources> <declare-styleable name=”CustomView"> <attr name="label" format="reference|string"/> </declare-styleable><resources>
Custom XML Attribute<resources> <declare-styleable name=”CustomView"> <attr name="label" format="reference|string"/> <attr name="value" format="reference|string"/> </declare-styleable><resources>
Custom XML Attribute<resources> <declare-styleable name=”CustomView"> <attr name="label" format="reference|string"/> <attr name="value" format="reference|string"/> <attr name="orientation" format="enum"> <enum name="horizontal" value="0"/> <enum name="vertical" value="1"/> </attr> </declare-styleable><resources>
Usage In Layout Files
1. Add to root XML nodexmlns:app="http://schemas.android.com/apk/res-auto"
Usage In Layout Files
1. Add to root XML nodexmlns:app="http://schemas.android.com/apk/res-auto"
2. Usage in custom view<de.alosdev.CustomView android:id="@+id/customView" android:layout_width="wrap_content" android:layout_height="wrap_content" app:label="label 1" app:orientation="vertical" app:value="value 1" />
public class CustomView extends LinearLayout { static final int[] ORIENTATION = new int[] { HORIZONTAL, VERTICAL }; public CustomView(Context context, AttributeSet attrs) { super(context, attrs); …
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CustomView); try { setOrientation(ORIENTATION[ a.getInt(R.styleable.CustomView_orientation, 0)]); } finally { a.recycle(); } } …
}
If custom view has much more business logic and need lifecycles Create a Fragment
Code
Best Practices
You have already an application Remove orientation fixation and suppressing of orientation change from manifest to avoid long bug analyzing.
You start from the scratch Focus on main classification for faster time to market But create an overall concept for better modularization
If you support both orientations, save the instance state while orientation changes for more responsiveness
Especially for states, that need a long computation for creation.Make the state object Parcelable for faster write & read and also to have a smaller memory footprint
Developer Hints• You can start an activity for result from a
fragment, so the response can be handled in the fragment.
• If you want to register a special service on every onCreate method of an activity give the ActivityLivecycleCallbacks a try. You can register them in the onCreate method of the application. (minSDK -v14)
If you get a BadParcelableException with the cause ClassNotFound-Exception, the source can be a NullPointerException during the read or write of the Parcelable. Exceptions are hidden during the parcel process.
If you want to use “match_parent” or “wrap_content” in a dimension alias, you should use “-1px” or “-2px”
project-folder/res/values/dimen.xml<resources> <dimen name="my_dimen>@dimen/match_parent</dimen> <dimen name="match_parent">-1px</dimen> <dimen name="wrap_content">-2px</dimen></resources>
project-folder/res/values-sw600dp/layout.xml<resources> <dimen name="my_dimen>300dp</dimen></resources>
Listener HellIf you have to many listeners or you think the programming model is old school like the “goto statements”. Give message/ event/ service bus a try. For Android:• Otto from Square• EventBus from greenrobot
See also: Callbacks as our Generations' Go To Statement
Custom Theme & StyleAndroid Ui Utils
Mission Accomplished?
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Mission Accomplished
cleared
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Q & A
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www.immobilienscout24.dewww.immobilienscout24.de
Thanks for your attention!
Contact:+HasanHosgel
@alosdev
alosdev
Best Practices to develop for different Android Device Classificationshttps://github.com/alosdev/multidevice-nightmare-demohttp://www.slideshare.net/hosgel/mtc-spring-2014-best-practices-to-develop-for-different-android-device-classifications
