Android Design

Working with density-independent pixels
1px / 1dp = 160dpi / 160dpi
2px / 1dp = 320dpi / 160dpi
※ dpi = dot per inch
7inch nexus^7 1280x800pixel => 960x600dp

Density buckets
LDPI, MDPI, HDPI, XHDPI, XXHDPI, XXXHDPI

res/drawable/checkbox.xml

<selector>
	<item android:state_pressed="true"
		android:state_checked="true"
		android:drawable="@drawable/box_checked_pressed">

	<item android:state_pressed="true"
		android:drawable="@drawable/box_pressed">

	<item android:state_checked="true"
		android:drawable="@drawable/box_checked">

	<item android:drawable="@drawable/box_default">

</selector>

content, padding, margins
FrameLayout, LinearLayout, RelativeLayout, GridLayout, ScrollView, ListView, ViewPager

styles.xml

<resources>

	<!-- Base application theme. -->
	<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
		<!-- Customize theme here -->
	</style>

	<style name="MyStyle">
		<item name="android:textColor">#FF255F26</item>
	</style>

	<style name="AnotherStyle">
		<item name="android:textColor">#1D175F</item>
		<item name="android:textStyle">bold</item>
	</style>
</resources>