Concept, Tips and Best Practices for Supporting Multiple Screens

Supporting multiple screens is the most important issue to provide user-friendly apps to your users. So, if you want your users to continue to use your apps, you must serve them apps that have a nice seeming screen. Consequently, you have to familiar with supporting multiple screens terms and concepts.

Terms and concepts

• Screen size
• Screen density
• Orientation
• Resolution
• Density-independent pixel (dp)
• Range of supported screens
  • Small
  • Normal
  • Large
  • Xlarge

You should learn these terms from Android developer website under “Device Capability”  especially  under this link “https://developer.android.com/training/multiscreen/screensizes”

How to Support Multiple Screens

 

• At first, you have to declare explicitly in the manifest which screen sizes your application supports

<supports-screens

android:smallScreens=”true”

android:normalScreens=”true”

android:largeScreens=”true”

android:xlargeScreens=”true”

android:anyDensity=”true” />

 

• You have to provide different layouts for different screen sizes

res/layout/my_layout.xml //layout for normal screen size (“default”)
res/layout-small/my_layout.xml   // layout for small screen size
res/layout-large/my_layout.xml       // layout for large screen size
res/layout-xlarge/my_layout.xml      // layout for extra large screen size
res/layout-xlarge-land/my_layout.xml // layout for extra-large in landscape orientation

 

• You have to provide different bitmap drawables for different screen densities

res/drawable-mdpi/my_icon.png        // bitmap for medium density
res/drawable-hdpi/my_icon.png        // bitmap for high density
res/drawable-xhdpi/my_icon.png       // bitmap for extra high density

• Use configuration qualifiers

 

• Size
  • small, normal, large, xlarge

 

• Density
  • ldpi, mdpi, hdpi, xhdpi, nodpi, tvdpi

 

• Orientation
  • land, port

 

• Aspect Ratio
  • Long, notlong

 

• Design Alternative Layouts and Drawable

Best Practices

To sum up;

• Use wrap_content, match_parent, or dp units when specifying dimensions in an XML layout file

 

• android:layout_width = ”wrap_content”
• android:layout_height = ”match_content”
• android:layout_width = ”100dp”

 

• Do not use hard coded pixel values in your application code

 

• Use sp for text size

 

• android:textSize= ”12sp”

 

• Avoid hardcoding

 

• Do not use AbsoluteLayout(it’s deprecated) or ConstarintLayout

 

• Use RelativeLayout or
• Look for layouts which are suitable for your app

 

• Supply alternative bitmap drawable for different screen densities

 

o   res/drawable-mdpi/icon.png   //for medium-density screenso   res/drawable-hdpi/icon.png   //for high-density screens

Aytunç BAKIR, Computer Engineer

Kaynak : https://developer.android.com