Getting Android to call onActivityResult() after onSearchRequested()

Because everything is handled through the SearchManager in Android, onActivityResult() is not typically called after onSearchRequested().

What I was looking for was a clean way to get search results back to the activity that originally called onSearchRequested().

I first tried the most obvious approach of calling setResult() and finish() from the search result (searchable) activity, but because the activity isn’t launched using startActivityForResult() it doesn’t work. (Complicating things further, the SearchManager is the one launching the activity so it really doesn’t even work in theory).

Solution: I had to make the original calling activity also the searchable activity, so my entry in the manifest looks like this:

   <activity android:name=".MyBaseActivity"
             android:launchMode="singleTop">

      <!-- MyBaseActivity is also the searchable activity -->
      <intent-filter>
         <action android:name="android.intent.action.SEARCH" />
      </intent-filter>
      <meta-data android:name="android.app.searchable"
                 android:resource="@xml/searchable"/>

      <!-- enable the base activity to send searches to itself -->
      <meta-data android:name="android.app.default_searchable"
                 android:value=".MyBaseActivity" />
   </activity>

Then, as described in the android documentation, I created a handleActivity method in which I manually start the search activity for result:

   private void handleIntent(Intent intent) {
      // Get the intent, verify the action and get the query
      if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
        String query = intent.getStringExtra(SearchManager.QUERY);
        // manually launch the real search activity
        final Intent searchIntent = new Intent(getApplicationContext(),
              MySearchActivity.class);
        // add query to the Intent Extras
        searchIntent.putExtra(SearchManager.QUERY, query);
        startActivityForResult(searchIntent, ACTIVITY_REQUEST_CODE);
      }

From there it is just a matter of having the search activity perform its search as normal and, when a result is clicked, call setResult and finish. The original activity will then get the result as expected in the MyBaseActivity.onActivityResult method.

Getting started with OpenNLP 1.5.0 – Sentence Detection and Tokenizing

OpenNLP is a poorly-documented pain in the ass to figure out.  There are various scattered resources you can find on the internet, none of which are particularly thorough, accurate, or up to date.

The most useful that I’ve found is a blog post called Getting started with OpenNLP (Natural Language Processing), but it is over 4 years old and refers to version 1.4.3 (1.5.x is what I’ll discuss here).  That post is quite helpful, but still required digging into the source code to figure out the beast that is coreference resolution.

Here’s to hoping that I can add a few posts to the conversation and help both myself and, perhaps, others…

  • How to use the OpenNLP 1.5.0 Parser
  • Making Coreference Resolution your bitch with OpenNLP 1.5.0
  • Most (if not all) of the more advanced OpenNLP components rely on text that is broken into sentences and/or tokens, so I’m starting with those…

    (more…)

    Iterating over a PriorityQueue is NOT ordered

    I stumbled across a little Java gotcha recently when trying to order a collection of Java objects.  For some reason I decided to use a PriorityQueue because I wanted to maintain duplicates, so TreeSet and TreeMap were ruled out.

    Unfortunately, the PriorityQueue is only ordered when remove/peek/poll-ing objects from the collection. NOT when iterating over the collection. This fun fact is clearly identified in the PriorityQueue JavaDocs:

    The Iterator provided in method iterator() is not guaranteed to traverse the elements of the priority queue in any particular order.

    Unfortunately the JavaDocs aren’t very obvious even if you do happen to specifically access the iterator (and really isn’t obvious from a for-loop perspective).

    While it makes perfect sense in retrospect (due to the internals of the underlying heap), it was only by chance that I caught my mistake and made the fix:

    final PriorityQueue<MyObject> ordered = ...;
    while (ordered.size() > 0) {
       final MyObject next = ordered.remove();
       ...
    }
    

    Android GPS Emulator

    I was looking for a better way to set the emulator’s GPS coordinates than using geo fix and manually determining the specific latitude and longitude coordinates.

    Unable to find anything, I put together a little program that uses GWT and the Google Maps API to launch a browser-based map tool to set the GPS location in the emulator:

    android-gps-emulator