html and activity links in TextView

So we need to linkify a TextView.


By linkify, I mean adding links to a TextView. These links could either be html links that link to a webpage, or some url that links to an Activity (launches an activity).

TextView mTextSample = (TextView) findViewById(R.id.yourTextView);
String text = "Visit my blog sherifandroid.blogspot.com or run the myactivity callback";
mTextSample.setText(text);

Pattern pattern = Pattern.compile("sherifandroid.blogspot.com");
Linkify.addLinks(mTextSample, pattern, "http://");
Pattern pattern2 = Pattern.compile("myactivity");
Linkify.addLinks(mTextSample, pattern2, "sherif-activity://");

Now, the first pattern with the html link to my blogger page will work correctly.

However the second part should startActivity myactivity.
It will not work unless we specify that sherif-activity://myactivity is a callback url for an activity of our package.

So, for this to work and call say TestActivity!
Your TestActivity in AndroidManifest.xml should look like this:

<activity
	android:label="@string/app_name"
	android:name=".TestActivity">
	<intent-filter>
		<data android:host="myactivity" android:scheme="sherif-activity" />
		<action android:name="android.intent.action.VIEW" />
		<category android:name="android.intent.category.DEFAULT" />
		<category android:name="android.intent.category.BROWSABLE" />
	</intent-filter>
 </activity>

Congradulations, you just created a link to your website and to your activity in the same TextView.

How about sending some data to the new activity using the link!?

Lets first investigate the other way of linkifying a TextView. This would be using normal html tags, namely the <a> tag.

TextView mTextSample = (TextView) findViewById(R.id.yourTextView);
String text = "Visit my blog <a href=\"http://sherifandroid.blogspot.com/\">mysite</a> or run the <a href=\"sherif-activity://myactivity\">myactivity</a> callback";
mTextSample.setText(Html.fromHtml(text));
mTextSample.setMovementMethod(LinkMovementMethod.getInstance());

This will work perfectly like the previous approach.

Now, let us add some data to the link and ultimately the intent that will open the new activity.
We will use the normal GET parameters to add data.

so will will comment out one line of code which initializes text and change it so some data is added to linked activity.

String text = "Visit my blog <a href=\"http://sherifandroid.blogspot.com/\">mysite</a> or run the <a href=\"sherif-activity://myactivity?author=sherif&nick=king\">myactivity</a> callback";
//String text = "Visit my blog <a href=\"http://sherifandroid.blogspot.com/\">mysite</a> or run the <a href=\"sherif-activity://myactivity\">myactivity</a> callback";

So How can we retrieve these extra parameters in the TestActivity!? In this case, the parameter author and nick
It is rather simple:

String author = getIntent().getData().getQueryParameter("author");
String nick = getIntent().getData().getQueryParameter("nick");

Click here for Sample Project + Source Code (download)