Create <shape> Equivalent at Runtime

GradientDrawableTest.java

import android.app.Activity;
import android.graphics.Color;
import android.graphics.drawable.GradientDrawable;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;

public class GradientDrawableTest extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        final int initialHue = 0;
        Button button = new Button(this);
        button.setOnClickListener(new View.OnClickListener() {
            private int mHue = initialHue;
            @Override
            public void onClick(View v) {
                mHue += 15;
                setButtonBorderHue(v, mHue %= 360);
            }
        });
        setButtonBorderHue(button, initialHue);
        addContentView(button, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
    }
    
    private void setButtonBorderHue(View view, int hue) {
        GradientDrawable drawable = new GradientDrawable();
        drawable.setShape(GradientDrawable.RECTANGLE);
        drawable.setColor(Color.WHITE);
        drawable.setStroke(
            getPixelSize(1),
            Color.HSVToColor(new float[]{ hue, 1, 1}));
        drawable.setCornerRadius(getPixelSize(8));
        view.setBackgroundDrawable(drawable);
    }
    
    private int getPixelSize(int dp) {
        return (int) (0.5f + dp * getResources().getDisplayMetrics().density);
    }
}