Question

I want to make a compound control that is a EditText with a clear button. Since the main functionality will be the EditText functionality, I want it to be declarable in layout xmls with all the attributes of an EditText. But, it is actually going to be a LinearLayout with an EditText and an ImageButton in it.

Also, I want it to be used just like an EditText in the code, so I can just drop it in as a replacement.

I have this layout so far:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:background="@android:drawable/editbox_background" >
    <EditText 
        android:id="@+id/editText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:layout_gravity="center_vertical"
        android:background="#FFF" />
    <ImageButton
        android:id="@+id/clear"
        android:src="@drawable/clear_text"
        android:background="#FFF"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical" />
</LinearLayout>

But I am unsure how to proceed. How do I define a control that extends EditText if I need it to be a LinearLayout in order to use this layout? Or is my only option to draw the x manually in onDraw() and handle clicks myself?

Answer 1

You can declare an custom view class which extends from LinearLayout like your XML. then load the Xml and add it to your custom view.

If you want use it in the XML, you should first declare your own XML attribute by attrs.xml like below

<declare-styleable name="CustomEditText">
    <attr name="text" format="string" />
</declare-styleable>

Then override the constructor with Attributes attrs and parse the attrs like below code

TypedArray a = context.obtainStyledAttributes(attrs,R.styleable.CustomEditText);
CharSequence s = a.getString(R.styleable.CustomEditText_text);
setText(s.toString());

Use it in the XML just like this:

xmlns:anything="http://schemas.android.com/apk/res/yourpackagename" // for declare your namespace
<yourpackagename
        android:background="@drawable/blue"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        anything:text="hi"/>

To use it like the editText in the code, just wrap the custom view class.