HyperlinkTextView.java

HyperlinkTextView.java

package audio.rabid.dev.utils;

import android.content.Context;
import android.text.SpannableString;
import android.text.Spanned;
import android.text.method.LinkMovementMethod;
import android.text.method.MovementMethod;
import android.text.style.ClickableSpan;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Created by Charles Julian Knight, charles@rabidaudio.com on 9/25/15.
 *
 * A text view that you can attach callbacks to.
 *
 * Links are surrounded by double square brackets. For example:
 *
 * <code>[[This]] is a link</code>
 *
 * Use {@link #setOnLinkClickListener(OnLinkClickListener)} to get a callback with both the link text
 * and its index in the string so that you can handle it as you like.
 *
 * A lot of this was gathered from <a href="This stackoverflow answer">http://stackoverflow.com/a/5681946</a>.
 */
public class HyperlinkTextView extends TextView {

    private OnLinkClickListener linkClickListener;

    private static final Pattern URL_PATTERN = Pattern.compile("\\[\\[(.*?)\\]\\]");

    public HyperlinkTextView(Context context) {
        super(context);
    }

    public HyperlinkTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public HyperlinkTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        if(type==BufferType.NORMAL) {
            setText(text.toString());
        }else{
            super.setText(text, type);
        }
    }

    private void setText(String text) {
        String[] regularText = URL_PATTERN.split(text);
        Matcher m = URL_PATTERN.matcher(text);

        int index = 0;
        while(m.find()){
            append(regularText[index]);

            final String hyperlink = m.group(1);
            SpannableString ss = SpannableString.valueOf(hyperlink);
            final int finalIndex = index;
            ss.setSpan(new ClickableSpan() {
                @Override
                public void onClick(View widget) {
                    if(linkClickListener != null){
                        linkClickListener.onLinkClick(hyperlink, finalIndex);
                    }
                }
            }, 0, hyperlink.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

            append(ss);
            index++;
        }
        if(regularText.length > m.groupCount()){
            //need to add that last regular text
            append(regularText[regularText.length-1]);
        }

        MovementMethod mm = getMovementMethod();
        if ((mm == null) || !(mm instanceof LinkMovementMethod)) {
            setMovementMethod(LinkMovementMethod.getInstance());
        }
    }

    public void setOnLinkClickListener(OnLinkClickListener linkClickListener){
        this.linkClickListener = linkClickListener;
    }

    public interface OnLinkClickListener {
        void onLinkClick(String linkText, int id);
    }
}