AOSP implementation of Toolbar.setTitle()

Toolbar#setTitle.java

/**
 * Set the title of this toolbar.
 *
 * <p>A title should be used as the anchor for a section of content. It should
 * describe or name the content being viewed.</p>
 *
 * @param title Title to set
 */
public void setTitle(CharSequence title) {
    if (!TextUtils.isEmpty(title)) {
        if (mTitleTextView == null) {
            final Context context = getContext();
            mTitleTextView = new AppCompatTextView(context);
            mTitleTextView.setSingleLine();
            mTitleTextView.setEllipsize(TextUtils.TruncateAt.END);
            if (mTitleTextAppearance != 0) {
                mTitleTextView.setTextAppearance(context, mTitleTextAppearance);
            }
            if (mTitleTextColor != null) {
                mTitleTextView.setTextColor(mTitleTextColor);
            }
        }
        if (!isChildOrHidden(mTitleTextView)) {
            addSystemView(mTitleTextView, true);
        }
    } else if (mTitleTextView != null && isChildOrHidden(mTitleTextView)) {
        removeView(mTitleTextView);
        mHiddenViews.remove(mTitleTextView);
    }
    if (mTitleTextView != null) {
        mTitleTextView.setText(title);
    }
    mTitleText = title;
}