Make a substring of a string stylable

StyledString.java

import android.content.Context;
import android.support.annotation.ColorRes;
import android.support.annotation.Nullable;
import android.support.annotation.StringRes;
import android.support.annotation.StyleRes;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.method.LinkMovementMethod;
import android.text.style.ClickableSpan;
import android.text.style.ForegroundColorSpan;
import android.text.style.TextAppearanceSpan;
import android.view.View;
import android.widget.TextView;

/**
 * Created by jan on 01/04/16.
 * enables making a string stylable by giving multiple substrings a style
 * capable of method chaining
 */


public class StyledString {

    public interface OnSpanClickListener {
        void onSpanClicked();
    }

    private SpannableStringBuilder fullStringBuilder;
    private String fullString;
    private Context context;

    private int startingIndex;
    private int endingIndex;


    /**
     * constructor for string
     * @param context Context
     * @param fullString full length string
     */
    public StyledString(Context context, String fullString){
        fullStringBuilder = new SpannableStringBuilder(fullString);
        this.fullString = fullString;
        this.context = context;
    }

    /**
     * constructor for string resource
     * @param context Context
     * @param fullStringRes full length string resource
     */
    public StyledString(Context context, @StringRes int fullStringRes){
        String fullString = context.getString(fullStringRes);
        fullStringBuilder = new SpannableStringBuilder(fullString);
        this.fullString = fullString;
    }


    /**
     * give a substring a styling
     * @param subString substring of the fullstring
     * @param textAppearance text style
     * @return Styledstring
     */
    public StyledString put(String subString, @StyleRes int textAppearance){
        if(getStartEnd(subString)){
            TextAppearanceSpan textAppearanceSpan = new TextAppearanceSpan(context, textAppearance);
            fullStringBuilder.setSpan(textAppearanceSpan, startingIndex, endingIndex, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        return this;
    }


    /**
     * give a substring a clickable link
     * add this to textview: textView.setMovementMethod(LinkMovementMethod.getInstance());
     *
     * @param subString to make clickable
     * @param spanClickListener listener to listen for cliks, can be null
     * @return StyledString
     */
    public StyledString putLink(String subString, @Nullable final OnSpanClickListener spanClickListener){
        if(getStartEnd(subString)){
            //clickable span with listener
            ClickableSpan clickableSpan = new ClickableSpan() {

                @Override
                public void onClick(View widget) {
                    if (spanClickListener != null) {
                        spanClickListener.onSpanClicked();
                    }
                }
            };
            fullStringBuilder.setSpan(clickableSpan,startingIndex, endingIndex, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }

        return this;
    }


    /**
     * give a substring a color
     * @param subString Substring
     * @param colorRes color resource
     * @return StyledString with color
     */
    public StyledString putColor(String subString, @ColorRes int colorRes){
        if(getStartEnd(subString)){
            int color = ColorUtil.getColor(context, colorRes);
            ForegroundColorSpan foregroundColorSpan = new ForegroundColorSpan(color);
            fullStringBuilder.setSpan(foregroundColorSpan, startingIndex, endingIndex, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        return this;
    }


    /**
     * show directly in the given textview
     * @param textView TextView
     */
    public StyledString toView(TextView textView){
        textView.setMovementMethod(LinkMovementMethod.getInstance()); //make links clickable
        textView.setText(getStringBuilder(), TextView.BufferType.SPANNABLE);
        return this;
    }

    public SpannableStringBuilder getStringBuilder(){
        return fullStringBuilder;
    }


    /**
     * calculate the beginning and end index of the substring
     * @param subString String
     * @return boolean true if index calculations are correctly done
     */
    private boolean getStartEnd(String subString){
        if(subString.length() > 0 && !subString.trim().equals("")) {
            //for counting start/end indexes
            startingIndex = fullString.indexOf(subString);
            endingIndex = startingIndex + subString.length();

            if(startingIndex < 0 || endingIndex <0){
                return false;
            }

            return true;
        }

        return false;
    }

}