Android:Design

lastmod 2018-08-17created 2016-11-024 edits

Terms

dpi: Dots Per Inch, the number of pixels in 1 inch (2.54 centimeters) (density)
dip: Density-independent Pixels, a pixel unit independent of density. Abbreviated as dp.
- Low density (120dpi) (0.75x): ldpi.
- Medium density (160dpi) (baseline): mdpi Optimus One.
- High density (240dpi) (1.5x): hdpi : Galaxy S, Galaxy S2.
- Extra High density (320dpi) (2.0x): xhdpi Galaxy S3.
- Extra Extra High density (480dpi) (3.0x): xxhdpi Galaxy S4 (unconfirmed).
- xlarge screens are at least 960dp x 720dp
- large screens are at least 640dp x 480dp
- normal screens are at least 470dp x 320dp
- small screens are at least 426dp x 320dp
sip: Scale-independent Pixels, i.e. a pixel unit independent of scale. Abbreviated as sp.

A few tips for collaborating with designers on Android

Understand the terms precisely.
Development/design generally targets the Galaxy S, which has 240 density and 480x800 resolution.
The only units used in all development are dp (Image) and sp (Font).
For every px size notation (based on 240 density), the designer divides by 3, multiplies by 2, and then uses the unit dp.
The designer refers to the sp table image for the font sizes used.
(The table image is provided by the developer. See: #SP Reference)
The designer creates all images at sizes targeting 480x800, without any special calculation.
Developers are recommended to use drawable-hdpi among the Resource Identifiers. Making icons for mdpi is also recommended.
Android image file name restriction: must use only [a-z], [~A-Z], [0-9], _.
Icon Sizes & scale
- Launcher icons on a mobile device must be 48x48 dp.
- Launcher icons for display on Google Play must be 512x512 pixels.

240dpi-sp_list.png	160dpi-sp_list.png
240dpi	160dpi

A summary of what designers should know when moving from the web to the mobile (Android platform) environment.