Android drawable speech bubble

If you are creating a chat screen you are probably going to want to implement an incoming speech bubble and an outgoing speech bubble. Here is how I did that :

shape_bg_incoming_bubble.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <rotate
            android:fromDegrees="-45"
            android:pivotX="0%"
            android:pivotY="0%"
            android:toDegrees="0" >
            <shape android:shape="rectangle" >
                <solid android:color="@color/primary" />
            </shape>
        </rotate>
    </item>
    <item android:left="16dp">
        <shape android:shape="rectangle" >
            <solid android:color="@color/primary" />
            <corners android:radius="4dp" />
        </shape>
    </item>
</layer-list>

shape_bg_outgoing_bubble.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <rotate
            android:fromDegrees="45"
            android:pivotX="100%"
            android:pivotY="0%"
            android:toDegrees="0" >
            <shape android:shape="rectangle" >
                <solid android:color="@color/grey_500" />
            </shape>
        </rotate>
    </item>
    <item android:right="16dp">
        <shape android:shape="rectangle" >
            <solid android:color="@color/grey_500" />
            <corners android:radius="4dp" />
        </shape>
    </item>
</layer-list>