Android: Launch activity from clickable text

Question

Is there any way I can launch an activity from a portion of a string.

eg I have this in my strings.xml file:

<string name="clickable_string">This is a <u>clickable string</u></string>

I would like the text between the u tags to be underlined and launch an activity when clicked when inserted in to a TextView

Answer 1

Try this,

final Context context = ... // whereever your context is
CharSequence sequence = Html.fromSource(context.getString(R.string.clickable_string));
SpannableStringBuilder strBuilder = new SpannableStringBuilder(sequence);
UnderlineSpan[] underlines = strBuilder.getSpans(UnderlineSpan.class);
for(UnderlineSpan span : underlines) {
   int start = strBuilder.getSpanStart(span);
   int end = strBuilder.getSpanEnd(span);
   int flags = strBuilder.getSpanFlags(span);
   ClickableSpan myActivityLauncher = new ClickableSpan() {
     public void onClick(View view) {
       context.startActivity(getIntentForActivityToStart());
     }
   };

   strBuilder.setSpan(myActivityLauncher, start, end, flags);
}

TextView textView = ...
textView.setText(strBuilder);
textView.setMovementMethod(LinkMovementMethod.getInstance());

Basically you have to attach a Span object to the range of characters you want to be clickable. Since you are using HTML anyways, you can use the underline spans placed by the Html.fromSource() as markers for your own spans.

Alternatively you could also define a Tag within the string that only you know of. i.e. <activity> And supply your own tag handler to the Html.fromSource() method. This way your TagHandler instance could do something like, surround the tagged text with a specific color, underline, bold and make it clickable. However I would only recommend the TagHandler approach if you find yourself writing this type of code a lot.