How to change EditText background color when I enter text?

Question

My EditText has some color, but when I enter some text it should change. Say it's grey, I started to enter and it's yellow. This EditText is also focused, so when this activity starts -- I already can enter the text. How I tried:

<style name="LoginEnterField">
    <item name="android:textColorHint">@color/black</item>
    <item name="android:textColor">@color/black</item>
    <item name="android:background">@drawable/selector_edittext</item>
    <item name="android:textSize">@dimen/general_text_size</item>
    <item name="android:paddingLeft">@dimen/activity_inner_horizontal_margin</item>
    <item name="android:paddingRight">@dimen/activity_inner_horizontal_margin</item>
</style>

<shape xmlns:android="http://schemas.android.com/apk/res/android"

    android:shape="rectangle">
    <solid android:color="@color/grey"/>
    <corners android:radius="5dp" />

</shape>

<shape xmlns:android="http://schemas.android.com/apk/res/android"

  android:shape="rectangle">
  <solid android:color="@color/yellow"/>
  <corners android:radius="5dp" />

</shape>

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_focused="true" android:drawable="@drawable/roundbox_active_style"/>
  <item android:drawable="@drawable/roundbox_inactive_style" />
</selector>

I think the point is in this selector. My EditText changes color, but it always yellow. How to make it became yellow only if I enter some text? I can't make any code changes! It's very important. I can't add or change only xml files.

EDIT: It's impossible to do from xml only, so make code changes.

Answer 1

Use TextWatcher.

When an object of a type is attached to an Editable, its methods will be called when the text is changed.

onTextChanged (CharSequence s, int start, int before, int count) - This method is called to notify you that, within s, the count characters beginning at start have just replaced old text that had length before.

  public void onTextChanged(CharSequence s, int start, int before, int count) {
                // Your Code // call .setBackgroundColor method here


    }