Android button actions
<p>I create 2 different state of my button and also i create selector for this buyton:
    </p>

<pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;item android:state_focused="true" android:state_pressed="false" android:drawable="@drawable/level1_calm" /&gt;
    &lt;item android:state_focused="true" android:state_pressed="true" android:drawable="@drawable/level1_on_click" /&gt;
    &lt;item android:state_focused="false" android:state_pressed="true" android:drawable="@drawable/level1_on_click" /&gt;
    &lt;item android:drawable="@drawable/level1_calm" /&gt;
&lt;/selector&gt;
</code></pre>

<p>But how can I use only one selector for all buttons, or it's prohibited.<br>
I mean can I use some variable here, something like this:</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;

&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;item android:state_focused="true" android:state_pressed="false" android:drawable="@drawable/level`$Number_button`_calm" /&gt;
    &lt;item android:state_focused="true" android:state_pressed="true" android:drawable="@drawable/level`$Number_button`_on_click" /&gt;
    &lt;item android:state_focused="false" android:state_pressed="true" android:drawable="@drawable/level`$Number_button`_on_click" /&gt;
    &lt;item android:drawable="@drawable/level`$Number_button`_calm" /&gt;
&lt;/selector&gt;
</code></pre>
