Register a new file type in Android

I want to write a simple STL (geometrical data file) viewer application on Android, but I'm not able to make recognize a format to the system. I wrote this in my app manifest file:

<intent-filter>
    <action android:name="android.intent.action.VIEW" />
    <action android:name="android.intent.action.EDIT" />
    <action android:name="android.intent.action.PICK" />
    <category android:name="android.intent.category.DEFAULT" />
    <data android:scheme="http" />
    <data android:pathPattern=".*\\.stl" />
    <data android:mimeType="application/sla" />
    <data android:host="*" />
</intent-filter>

But the moment I launch the browser and go to download some sample STL file, the download is interrupted and I'm reported that the data file type is unknown for the system.

I have no real Android device, so I use only an emulator, and for development I use C# on MonoDroid (but I honestly don't think that is the problem).

How could I fix this problem?

Solution 1:

I'm using this manifest to register (for example) a .stl file type with my application:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="org.test.core" android:versionCode="1" android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".Testy" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity android:name="ThorActivity" android:label="@string/app_name">
        </activity>

        <activity android:name="LokiActivity" android:label="@string/app_name">
        </activity>

        <activity android:name="OdinActivity" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data android:scheme="http" android:host="*"
                    android:pathPattern=".*\\.stl" />
                <data android:scheme="https" android:host="*"
                    android:pathPattern=".*\\.stl" />
                <data android:scheme="content" android:host="*"
                    android:pathPattern=".*\\.stl" />
                <data android:scheme="file" android:host="*"
                    android:pathPattern=".*\\.stl" />
            </intent-filter>
        </activity>
    </application>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

</manifest>

As you can see, I'm linking the .stl file extension to the activity OdinActivity. Inside the OdinActivity, I use the following line to get the file path so I can open it:

filePath = getIntent().getData().getEncodedPath();

Then I just open it to read from it:

FileOutputStream out = new FileOutputStream(new File(filePath));

Solution 2:

I am surprised that gnclmorais' solution should work. Because it, having multiple data entries in one intent-filter, did not work for me. What did work in the end was multiple intent-filter in one activity:

<activity
  android:description='@string/Activity_Description'
  android:icon='@drawable/ic_launcher'
  android:label='@string/Activity_Name'
  android:name='net.sourceforge.uiq3.fx603p.Calculator_Activity'
>
  <intent-filter>
    <action
      android:name='android.intent.action.MAIN'
    ></action>
    <category
      android:name='android.intent.category.LAUNCHER'
    ></category>
  </intent-filter>
  <intent-filter
    android:icon='@drawable/ic_fx_603p_pf'
    android:label='FX-603P Simulator Program'
    android:priority='1'
  >
    <category
      android:name='android.intent.category.DEFAULT'
    ></category>
    <action
      android:name='android.intent.action.VIEW'
    ></action>
    <data
      android:host='*'
      android:pathPattern='.*\\.pf'
      android:scheme='file'
    ></data>
  </intent-filter>
  <intent-filter
    android:icon='@drawable/ic_fx_603p_df'
    android:label='FX-603P Simulator Datafile'
    android:priority='1'
  >
    <category
      android:name='android.intent.category.DEFAULT'
    ></category>
    <action
      android:name='android.intent.action.VIEW'
    ></action>
    <data
      android:host='*'
      android:pathPattern='.*\\.df'
      android:scheme='file'
    ></data>
  </intent-filter>
  <intent-filter
    android:icon='@drawable/ic_fx_603p_af'
    android:label='FX-603P Simulator Allfile (Data and Program)'
    android:priority='1'
  >
    <category
      android:name='android.intent.category.DEFAULT'
    ></category>
    <action
      android:name='android.intent.action.VIEW'
    ></action>
    <data
      android:host='*'
      android:pathPattern='.*\\.af'
      android:scheme='file'
    ></data>
  </intent-filter>
  <intent-filter
    android:icon='@drawable/ic_fx_603p_pf'
    android:label='FX-603P Simulator Program'
    android:priority='1'
  >
    <category
      android:name='android.intent.category.DEFAULT'
    ></category>
    <action
      android:name='android.intent.action.VIEW'
    ></action>
    <data
      android:host='*'
      android:mimeType='application/x-fx-602p.program'
    ></data>
  </intent-filter>
  <intent-filter
    android:icon='@drawable/ic_fx_603p_df'
    android:label='FX-603P Simulator Datafile'
    android:priority='1'
  >
    <category
      android:name='android.intent.category.DEFAULT'
    ></category>
    <action
      android:name='android.intent.action.VIEW'
    ></action>
    <data
      android:host='*'
      android:mimeType='application/x-fx-602p.data'
    ></data>
  </intent-filter>
  <intent-filter
    android:icon='@drawable/ic_fx_603p_af'
    android:label='FX-603P Simulator Allfile (Data and Program)'
    android:priority='1'
  >
    <category
      android:name='android.intent.category.DEFAULT'
    ></category>
    <action
      android:name='android.intent.action.VIEW'
    ></action>
    <data
      android:host='*'
      android:mimeType='application/x-fx-602p.all'
    ></data>
  </intent-filter>
</activity>

Note that having both pathPattern and mimeType in one data entry did not work either. Last, but not least, I would suggest a few null checks when getting the file name:

   /**
    * <p>Open calculator and load file (if one was passed).</p>
    * @see android.app.Activity#onStart()
    */
   @Override
   public void onStart ()
   {
      android.util.Log.d (Calculator_Activity.TAG, "+ onStart");
      super.onStart ();

      final android.content.Intent intent = getIntent ();

      if (intent != null)
      {
         android.util.Log.d (Calculator_Activity.TAG, "> Got intent : " + intent);

         final android.net.Uri data = intent.getData ();

         if (data != null)
         {
            android.util.Log.d (Calculator_Activity.TAG, "> Got data   : " + data);

            final String filePath = data.getEncodedPath ();

            android.util.Log.d (Calculator_Activity.TAG, "> Open file  : " + filePath);

            // File loading comes here.
         } // if
      } // if
      android.util.Log.d (Calculator_Activity.TAG, "- onStart");
      return;
   } // onStart

The actual loading of the file is missing from the sample. It should be inserted after the “Open file” log command.