Question: I am looking at the Honeycomb Gallery sample code ([here](http://developer.android.com/resources/samples/HoneycombGallery/index.html)) and I ran across the following code while trying to add action items in my own app:

```
<item android:id="@+id/camera"
    android:title="Camera"
    android:icon="?attr/menuIconCamera"
    android:showAsAction="ifRoom" />

```

The `?attr` is throwing me for a loop. Can someone please explain what this is doing? How is this related to a drawable? I can't seem to find any good information on Google. Also is there a listing or gallery of attributes we can use for icons instead of just `menuIconCamera`?

Thanks

Edit:
I did some more looking around and found that attrs.xml looks like this:

```
<resources>
<declare-styleable name="AppTheme">
    <attr name="listDragShadowBackground" format="reference" />
    <attr name="menuIconCamera" format="reference" />
    <attr name="menuIconToggle" format="reference" />
    <attr name="menuIconShare" format="reference" />
</declare-styleable>

```

Unfortunately that just makes it even more confusing for me. What is this doing?

Answer: 
The `?attr:` syntax is used for accessing attributes of current theme. See [referencing style attributes](http://developer.android.com/guide/topics/resources/accessing-resources.html#ReferencesToThemeAttributes).
This is for refering style Attributes. see R.attr

```
?[<package_name>:][<resource_type>/]<resource_name>

```

[Referencing style attributes](http://developer.android.com/guide/topics/resources/accessing-resources.html#ReferencesToThemeAttributes)