android - How to: Define theme (style) item for custom widget -

i've written custom widget control use throughout our application. widget class derives imagebutton , extends in couple of simple ways. i've defined style can apply widget it's used, i'd prefer set through theme. in r.styleable see widget style attributes imagebuttonstyle , textviewstyle. there way create custom widget wrote?

yes, there's 1 way:

suppose have declaration of attributes widget (in attrs.xml):

<declare-styleable name="customimagebutton">     <attr name="customattr" format="string"/> </declare-styleable> 

declare attribute use style reference (in attrs.xml):

<declare-styleable name="customtheme">     <attr name="customimagebuttonstyle" format="reference"/> </declare-styleable> 

declare set of default attribute values widget (in styles.xml):

<style name="widget.imagebutton.custom" parent="android:style/widget.imagebutton">     <item name="customattr">some value</item> </style> 

declare custom theme (in themes.xml):

<style name="theme.custom" parent="@android:style/theme">     <item name="customimagebuttonstyle">@style/widget.imagebutton.custom</item> </style> 

use attribute third argument in widget's constructor (in customimagebutton.java):

public class customimagebutton extends imagebutton {     private string customattr;      public customimagebutton( context context ) {         this( context, null );     }      public customimagebutton( context context, attributeset attrs ) {         this( context, attrs, r.attr.customimagebuttonstyle );     }      public customimagebutton( context context, attributeset attrs,             int defstyle ) {         super( context, attrs, defstyle );          final typedarray array = context.obtainstyledattributes( attrs,             r.styleable.customimagebutton, defstyle,             r.style.widget_imagebutton_custom ); // see below         this.customattr =             array.getstring( r.styleable.customimagebutton_customattr, "" );         array.recycle();     } } 

now have apply theme.custom activities use customimagebutton (in androidmanifest.xml):

<activity android:name=".myactivity" android:theme="@style/theme.custom"/> 

that's all. customimagebutton tries load default attribute values customimagebuttonstyle attribute of current theme. if no such attribute found in theme or attribute's value @null final argument obtainstyledattributes used: widget.imagebutton.custom in case.

you can change names of instances , files (except androidmanifest.xml) better use android naming convention.