Is there any way to make custom Spannables on Android?

Question

In my Android app I've got text views with links. Each of them is toggling a particular event (opening browser, starting another activity, etc...). To handle that, I haven't found any better solution than doing this:

hi there!, this is <u>a action</u> and this is <b>another action</b>. This third one goes to <a href="http://google.com>Google</a>

Then, when displaying the textview, I convert each link to a custom spannable with a SpannableStringBuilder.

I know this is hacky. And this is why I want to know if there's any other better way?

I've got two ideas:

• Is it possible to implement custom spannables with their own marshalling system? For example a custom spannable matching tags like:

  <div class="foo"></div>

Then I'd have a FooClickableSpannable extending ClickableSpan automatically detected with fromHtml()

• I could use custom url schemes to open my activities but I'm not sure how to force it not to display an app chooser if there are other alternatives.

Answer 1

Is it possible to implement custom spannables with their own marshalling system?

Can you create custom subclasses of CharacterStyle, particularly ClickableSpan? Yes.

I have no idea what "their own marshalling system" means, though.

I could use custom url schemes to open my activities but I'm not sure how to force it not to display an app chooser if there are other alternatives.

Well, a true custom scheme (e.g., piel:// instead of http:// or content://) is unlikely to present a chooser, since it is unlikely that there will be another alternative.

Beyond that, what I have done in the past is:

• Use Html.fromHtml() for a basic conversion
• Use getSpans() on the results to find all the URLSpan objects
• replaced those URLSpan objects with other sorts of custom spans where needed via removeSpan() and setSpan()

Another approach would be to create a workalike for Html.fromHtml(). This is something that's rattling around the lower levels of my own TODO list, to create something that is more extensible, handles more HTML constructs, etc.