Android: right margin at Up button on the Toolbar

Question

I'm setting custom view into my Toolbar:

ActionBar actionBar = getSupportActionBar();
View customView = getLayoutInflater().inflate(resId, null);
actionBar.setCustomView(customView);
actionBar.setDisplayShowCustomEnabled(true);

It looks fine until I enabling Up button:

getSupportActionBar().setDisplayHomeAsUpEnabled(true);

Here are pictures of the toolbar with Up button and without. I've added gray color to my custom view's background to view the real element size.

Without:

With:

And here is an image of Layout inspector window. There is a space between Up button and custom view.

Answer 1

Instead of this you have to write your own Up button:

<ImageButton
    android:id="@+id/action_back"
    style="@style/Widget.AppCompat.ActionButton"
    android:layout_width="48dp"
    android:layout_height="48dp"
    android:layout_gravity="center_vertical"
    android:onClick="onClick"
    app:srcCompat="@drawable/ic_arrow_back_white"
    tools:ignore="ContentDescription" />

android:onClick="onClick" on your Button and сreate method in Java class like below way

@Override
public void onClick(View v) {
     NavUtils.navigateUpFromSameTask(TheoryActivity.this);
}