How can I make the items on ActionBar to be one on the left, one in the center and one on the right?

I'm using actionbarsherlock to do it. Example of what I want in the actionbar:
[LOGIN] [COMPANY LOGO] [FILTER]

Example of what I get in the actionbar:
[LOGIN] [COMPANY LOGO] [FILTER]

I have created the login button, company logo and filter button (in the form of drawables) in the res/menu's activity_main.xml. However, those buttons on the actionbar are unable to shift fully to the left, even though I have removed the default application logo and set those to false:

getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayShowHomeEnabled (false);

here are my codes in the menu's activity_main.xml:

<item android:id="@+id/login"
      android:icon="@drawable/login_btn"
      android:layout_gravity="left"
      android:showAsAction="always"/>

<item android:id="@+id/logo"
      android:icon="@drawable/logo_btn"
      android:layout_gravity="center"
      android:showAsAction="always"/>

<item android:id="@+id/filter"
      android:icon="@drawable/filter_btn"
      android:layout_gravity="right"
      android:showAsAction="always"/>

Solution

You should create custom view for that. For example (layout/ab_custom.xml):

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:layout_gravity="fill_horizontal" >

    <ImageButton
        android:id="@+id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:src="@drawable/left" />

    <ImageButton
        android:id="@+id/btn2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:src="@drawable/center" />

    <ImageButton
        android:id="@+id/btn3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:src="@drawable/right" />

</RelativeLayout>

Then in your Activity's onCreate call this method:

private void showActionBar() {
        LayoutInflater inflator = (LayoutInflater) this
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = inflator.inflate(R.layout.ab_custom, null);
    ActionBar actionBar = getSupportActionBar();
    actionBar.setDisplayHomeAsUpEnabled(false);
    actionBar.setDisplayShowHomeEnabled (false);
    actionBar.setDisplayShowCustomEnabled(true);
    actionBar.setDisplayShowTitleEnabled(false);
    actionBar.setCustomView(v);
}

To take control on your items use this:

 @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.btn1:
            //left button, do something
            return true;
        case R.id.btn2:
            //center button
            return true;
        case R.id.btn3:
            // right button
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

EDIT: revised my answer. It's better to use RelativeLayout as parent.