1 <HTML> 2 <BODY> 3 <p> 4 The widget package contains (mostly visual) UI elements to use 5 on your Application screen. You can also design your own. 6 </p> 7 8 <p> 9 To create your own widget, extend {@link android.view.View} or a subclass. To 10 use your widget in layout XML, there are two additional files for you to 11 create. Here is a list of files you'll need to create to implement a custom 12 widget: 13 </p> 14 <ul> 15 <li><b>Java implementation file</b> - This is the file that implements the 16 behavior of the widget. If you can instantiate the object from layout XML, 17 you will also have to code a constructor that retrieves all the attribute 18 values from the layout XML file.</li> 19 <li><b>XML definition file</b> - An XML file in res/values/ that defines 20 the XML element used to instantiate your widget, and the attributes that it 21 supports. Other applications will use this element and attributes in their in 22 another in their layout XML.</li> 23 <li><b>Layout XML</b> [<em>optional</em>]- An optional XML file inside 24 res/layout/ that describes the layout of your widget. You could also do 25 this in code in your Java file.</li> 26 </ul> 27 28 <p> 29 ApiDemos sample application has an example of creating a custom layout XML 30 tag, LabelView. See the following files that demonstrate implementing and using 31 a custom widget: 32 </p> 33 <ul> 34 <li><strong>LabelView.java</strong> - The implementation file</li> 35 <li><strong>res/values/attrs.xml</strong> - Definition file</li> 36 <li><strong>res/layout/custom_view_1.xml</strong> - Layout file</li> 37 </ul> 38 </BODY> 39 </HTML> 40
