Question

I just created class VibratingTextView. I intend to create a whole library of widgets so I want to do it the right way.

The xml for this View:

<sherif.android.textview.VibratingTextView  
    android:id="@+id/textView2"  
    android:layout_width="wrap_content"  
    android:textAppearance="?android:attr/textAppearanceLarge"  
    android:layout_height="wrap_content"  
    android:orientation="horizontal"  
    android:text="outToRight" >  
</sherif.android.textview.VibratingTextView> 

Notice it has android:orientation and android:text. It accepts the attributes of a TextView and of a LinearLayout. The class itself extends LinearLayout.

My problem is in the xml editor of eclipse. When the user types android:, eclipse’s intellisense gives the user the options available in this namespace.

In my case, it is giving the attributes of LinearLayout so, for example, Text and TextSize do not appear.

Is there a way to make them appear (using the android namespace)?

If not, should I create my own namespace with attributes that I define? or is there a way to import the android’s attributes and make them in sherif’s attributes?

Keep in mind that I am creating a TextView in the constructor of my class using the attributes passed. It is working fine and all the attributes for the TextView are being set correctly.

Since I will create many other widgets, I might need my own namespace but what is the best practice? For example, I want to create alwaysVibrate attribute. It will be something like sherif:alwaysVibrate="true". I want my library to be includable and eclipse to show the attributes of my namespace: I use the usual way using attr.xml?

Answer 1

I recently faced the exact same problem. Here are my custom attribute declarations in attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="NumberPicker">
        <attr name="rangeStart" format="integer|reference" />
        <attr name="rangeEnd" format="integer|reference" />
        <attr name="speed" format="integer|reference" />
        <attr name="current" format="integer|reference" />
        <attr name="android:orientation" />
    </declare-styleable>
</resources>

You can reuse the android attributes but you can’t teach them to suggest different values. In fact you can’t even teach eclipse to suggest your custom attribute definitions (at least at this date of post, I would love to see that feature in future).

Everything else you would want to know about defining custom attributes is in the question:
Declaring a custom android UI element using XML.