handle textview link click in my android app

Question

I'm currently rendering HTML input in a TextView like so:

tv.setText(Html.fromHtml("<a href='test'>test</a>"));

The HTML being displayed is provided to me via an external resource, so I cannot change things around as I will, but I can, of course, do some regex tampering with the HTML, to change the href value, say, to something else.

What I want is to be able to handle a link click directly from within the app, rather than having the link open a browser window. Is this achievable at all? I'm guessing it would be possible to set the protocol of the href-value to something like "myApp://", and then register something that would let my app handle that protocol. If this is indeed the best way, I'd like to know how that is done, but I'm hoping there's an easier way to just say, "when a link is clicked in this textview, I want to raise an event that receives the href value of the link as an input parameter"

Answer 1

Another way, borrows a bit from Linkify but allows you to customize your handling.

Custom Span Class:

public class ClickSpan extends ClickableSpan {

    private OnClickListener mListener;

    public ClickSpan(OnClickListener listener) {
        mListener = listener;
    }

    @Override
    public void onClick(View widget) {
       if (mListener != null) mListener.onClick();
    }

    public interface OnClickListener {
        void onClick();
    }
}

Helper function:

public static void clickify(TextView view, final String clickableText, 
    final ClickSpan.OnClickListener listener) {

    CharSequence text = view.getText();
    String string = text.toString();
    ClickSpan span = new ClickSpan(listener);

    int start = string.indexOf(clickableText);
    int end = start + clickableText.length();
    if (start == -1) return;

    if (text instanceof Spannable) {
        ((Spannable)text).setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
    } else {
        SpannableString s = SpannableString.valueOf(text);
        s.setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        view.setText(s);
    }

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

Usage:

 clickify(textView, clickText,new ClickSpan.OnClickListener()
     {
        @Override
        public void onClick() {
            // do something
        }
    });

Answer 2

Coming at this almost a year later, there's a different manner in which I solved my particular problem. Since I wanted the link to be handled by my own app, there is a solution that is a bit simpler.

Besides the default intent filter, I simply let my target activity listen to ACTION_VIEW intents, and specifically, those with the scheme com.package.name

<intent-filter>
    <category android:name="android.intent.category.DEFAULT" />
    <action android:name="android.intent.action.VIEW" />
    <data android:scheme="com.package.name" />  
</intent-filter>

This means that links starting with com.package.name:// will be handled by my activity.

So all I have to do is construct a URL that contains the information I want to convey:

com.package.name://action-to-perform/id-that-might-be-needed/

In my target activity, I can retrieve this address:

Uri data = getIntent().getData();

In my example, I could simply check data for null values, because when ever it isn't null, I'll know it was invoked by means of such a link. From there, I extract the instructions I need from the url to be able to display the appropriate data.

Answer 3

for who looks for more options here is a one

// Set text within a `TextView`
TextView textView = (TextView) findViewById(R.id.textView);
textView.setText("Hey @sarah, where did @jim go? #lost");
// Style clickable spans based on pattern
new PatternEditableBuilder().
    addPattern(Pattern.compile("\\@(\\w+)"), Color.BLUE,
       new PatternEditableBuilder.SpannableClickedListener() {
        @Override
        public void onSpanClicked(String text) {
            Toast.makeText(MainActivity.this, "Clicked username: " + text,
                Toast.LENGTH_SHORT).show();
        }
}).into(textView);

RESOURCE : CodePath

Answer 4

I changed the TextView's color to blue by using for example:

android:textColor="#3399FF"

in the xml file. How to make it underlined is explained here.

Then use its onClick property to specify a method (I'm guessing you could call setOnClickListener(this) as another way), e.g.:

myTextView.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
    doSomething();
}
});

In that method, I can do whatever I want as normal, such as launch an intent. Note that you still have to do the normal myTextView.setMovementMethod(LinkMovementMethod.getInstance()); thing, like in your acitivity's onCreate() method.

Answer 5

public static void setTextViewFromHtmlWithLinkClickable(TextView textView, String text) {
    Spanned result;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
        result = Html.fromHtml(text, Html.FROM_HTML_MODE_LEGACY);
    } else {
        result = Html.fromHtml(text);
    }
    textView.setText(result);
    textView.setMovementMethod(LinkMovementMethod.getInstance());
}

Answer 6

This answer extends Jonathan S's excellent solution:

You can use the following method to extract links from the text:

private static ArrayList<String> getLinksFromText(String text) {
        ArrayList links = new ArrayList();

        String regex = "\(?\b((http|https)://www[.])[-A-Za-z0-9+&@#/%?=~_()|!:,.;]*[-A-Za-z0-9+&@#/%=~_()|]";
        Pattern p = Pattern.compile(regex);
        Matcher m = p.matcher(text);
        while (m.find()) {
            String urlStr = m.group();
            if (urlStr.startsWith("(") && urlStr.endsWith(")")) {
                urlStr = urlStr.substring(1, urlStr.length() - 1);
            }
            links.add(urlStr);
        }
        return links;
    }

This can be used to remove one of the parameters in the clickify() method:

public static void clickify(TextView view,
                                final ClickSpan.OnClickListener listener) {

        CharSequence text = view.getText();
        String string = text.toString();


        ArrayList<String> linksInText = getLinksFromText(string);
        if (linksInText.isEmpty()){
            return;
        }


        String clickableText = linksInText.get(0);
        ClickSpan span = new ClickSpan(listener,clickableText);

        int start = string.indexOf(clickableText);
        int end = start + clickableText.length();
        if (start == -1) return;

        if (text instanceof Spannable) {
            ((Spannable) text).setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        } else {
            SpannableString s = SpannableString.valueOf(text);
            s.setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
            view.setText(s);
        }

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

A few changes to the ClickSpan:

public static class ClickSpan extends ClickableSpan {

        private String mClickableText;
        private OnClickListener mListener;

        public ClickSpan(OnClickListener listener, String clickableText) {
            mListener = listener;
            mClickableText = clickableText;
        }

        @Override
        public void onClick(View widget) {
            if (mListener != null) mListener.onClick(mClickableText);
        }

        public interface OnClickListener {
            void onClick(String clickableText);
        }
    }

Now you can simply set the text on the TextView and then add a listener to it:

TextViewUtils.clickify(textWithLink,new TextUtils.ClickSpan.OnClickListener(){

@Override
public void onClick(String clickableText){
  //action...
}

});