How do I apply mathematical operations to Android dimensions?

Question

How do I avoid this hardcoded math...

 10dip
 6dip
 

        

Answer 1

Using databinding:

android:layout_marginTop="@{@dimen/uno + @dimen/dos}"

IFAIK margins adapters are not provided by the sdk. You will need to define it yourself:

@BindingAdapter("android:layout_marginTop")
public static void setBottomMargin(View view, int bottomMargin) {
    ViewGroup.MarginLayoutParams layoutParams = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
    layoutParams.setMargins(layoutParams.leftMargin, layoutParams.topMargin,
            layoutParams.rightMargin, bottomMargin);
    view.setLayoutParams(layoutParams);
}

Make sure databinding is enabled for your project :

dataBinding {
    enabled = true
}

in your build.gradle.

The databinding doc is worth reading.