I am “amused” to discover that HTC sense has changed even the way android breaks to access of a WebView from outside the UI thread.

Since I don’t own a phone with HTC sense, it took me months to understand this and I only fixed the issue thanks to a kind user who sent me logs.

For example, calling this outside from a UI thread works on the normal android SDK’s:
webSettingsObj.setBuiltInZoomControls(true);

Instead, on HTC Sense phones it breaks here:

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
 at android.os.Handler.(Handler.java:121)
 at com.htc.multitouch.MultiTouchDetector$MultiTouchHandler.(MultiTouchDetector.java:180)
 at com.htc.multitouch.MultiTouchDetector.(MultiTouchDetector.java:242)
 at android.webkit.WebView$HTCMultiTouch.fnCreateMultiTouchListener(WebView.java:11781)
 at android.webkit.WebView.enableMultiTouch(WebView.java:10893)
 at android.webkit.WebView.updateMultiTouchSupport(WebView.java:905)
 at android.webkit.WebSettings.setBuiltInZoomControls(WebSettings.java:474)

Now, I know know that anything that changes the UI shouldn’t be executed outside of the UI Thread, but still..

A very common caveat, when doing android applications, is fighting to keep the APK size small.

Many applications need the ability to upload binary data to their server and when you arrive there you see that the android SDK doesn’t have the http-client libraries to send multipart posts.

The easiest way is to include the JAR for httpmime and apache_mime4j, but it takes way too much space; 300kb.

We overcome this by implementing our own HttpEntity. In this way the code is:

public class SimpleMultipartEntity implements HttpEntity {

    private final static char[] MULTIPART_CHARS = "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
        .toCharArray();

    private String boundary = null;

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    boolean isSetLast = false;
    boolean isSetFirst = false;

    public SimpleMultipartEntity() {
        final StringBuffer buf = new StringBuffer();
        final Random rand = new Random();
        for (int i = 0; i < 30; i++) {
            buf.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]);
        }
        this.boundary = buf.toString();

    }

    public void writeFirstBoundaryIfNeeds(){
        if(!isSetFirst){
            try {
                out.write(("--" + boundary + "\r\n").getBytes());
            } catch (final IOException e) {
                Log.e(Constants.TAG, e.getMessage(), e);
            }
        }
        isSetFirst = true;
    }

    public void writeLastBoundaryIfNeeds() {
        if(isSetLast){
            return ;
        }
        try {
            out.write(("\r\n--" + boundary + "--\r\n").getBytes());
        } catch (final IOException e) {
            Log.e(Constants.TAG, e.getMessage(), e);
        }
        isSetLast = true;
    }

    public void addPart(final String key, final String value) {
        writeFirstBoundaryIfNeeds();
        try {
            out.write(("Content-Disposition: form-data; name=\"" +key+"\"\r\n").getBytes());
            out.write("Content-Type: text/plain; charset=UTF-8\r\n".getBytes());
            out.write("Content-Transfer-Encoding: 8bit\r\n\r\n".getBytes());
            out.write(value.getBytes());
            out.write(("\r\n--" + boundary + "\r\n").getBytes());
        } catch (final IOException e) {
            Log.e(Constants.TAG, e.getMessage(), e);
        }
    }

    public void addPart(final String key, final String fileName, final InputStream fin){
        addPart(key, fileName, fin, "application/octet-stream");
    }

    public void addPart(final String key, final String fileName, final InputStream fin, String type){
        writeFirstBoundaryIfNeeds();
        try {
            type = "Content-Type: "+type+"\r\n";
            out.write(("Content-Disposition: form-data; name=\""+ key+"\"; filename=\"" + fileName + "\"\r\n").getBytes());
            out.write(type.getBytes());
            out.write("Content-Transfer-Encoding: binary\r\n\r\n".getBytes());

            final byte[] tmp = new byte[4096];
            int l = 0;
            while ((l = fin.read(tmp)) != -1) {
                out.write(tmp, 0, l);
            }
            out.flush();
        } catch (final IOException e) {
            Log.e(Constants.TAG, e.getMessage(), e);
        } finally {
            try {
                fin.close();
            } catch (final IOException e) {
                Log.e(Constants.TAG, e.getMessage(), e);
            }
        }
    }

    public void addPart(final String key, final File value) {
        try {
            addPart(key, value.getName(), new FileInputStream(value));
        } catch (final FileNotFoundException e) {
            Log.e(Constants.TAG, e.getMessage(), e);
        }
    }

    @Override
    public long getContentLength() {
        writeLastBoundaryIfNeeds();
        return out.toByteArray().length;
    }

    @Override
    public Header getContentType() {
        return new BasicHeader("Content-Type", "multipart/form-data; boundary=" + boundary);
    }

    @Override
    public boolean isChunked() {
        return false;
    }

    @Override
    public boolean isRepeatable() {
        return false;
    }

    @Override
    public boolean isStreaming() {
        return false;
    }

    @Override
    public void writeTo(final OutputStream outstream) throws IOException {
        outstream.write(out.toByteArray());
    }

    @Override
    public Header getContentEncoding() {
        return null;
    }

    @Override
    public void consumeContent() throws IOException,
    UnsupportedOperationException {
        if (isStreaming()) {
            throw new UnsupportedOperationException(
            "Streaming entity does not implement #consumeContent()");
        }
    }

    @Override
    public InputStream getContent() throws IOException,
    UnsupportedOperationException {
        return new ByteArrayInputStream(out.toByteArray());
    }

}

I have been googling to find the Twitter native app intent that enables to share through it directly, but I couldn’t find any.

ATTENTION: This is just a hack. It’s better to just open the android popup with the Intent.ACTION_SEND intent.

I didn’t had time to test other ways, but the only way to launch the twitter PostActivity directly was to get the ActivityInfo instance of it. Please, give me feedback if you know a better way.

What this code does is to query all activities that match with the Intent.ACTION_SEND and then it searches for the “com.twitter.android.PostActivity” intent.

try{
    intent = new Intent(Intent.ACTION_SEND);
    intent.putExtra(Intent.EXTRA_TEXT, message);
    intent.setType("text/plain");
    final PackageManager pm = context.getPackageManager();
    final List activityList = pm.queryIntentActivities(intent, 0);
        int len =  activityList.size();
    for (int i = 0; i < len; i++) {
        final ResolveInfo app = activityList.get(i);
        if ("com.twitter.android.PostActivity".equals(app.activityInfo.name)) {
            final ActivityInfo activity=app.activityInfo;
            final ComponentName name=new ComponentName(activity.applicationInfo.packageName, activity.name);
            intent=new Intent(Intent.ACTION_SEND);
            intent.addCategory(Intent.CATEGORY_LAUNCHER);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
            intent.setComponent(name);
            intent.putExtra(Intent.EXTRA_TEXT, message);
            context.startActivity(intent);
            break;
        }
    }
}
catch(final ActivityNotFoundException e) {
    Log.i("mufumbo", "no twitter native",e );
}