title: AppCompatPreferenceActivity strange padding on left and right in Android 4.4
body: <p>I have an SettingsActivity extending <code>AppCompatPreferenceActivity</code>.</p>
  
  <p>my pref_headers.xml looks like this:</p>
  
  <pre><code>&lt;preference-headers xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;header
          android:fragment="com.blabla.activities.fragments.ProfileFragment"
          android:icon="@drawable/ic_users"
          android:title="Profil"&gt;
      &lt;/header&gt;
  &lt;/preference-headers&gt;
  </code></pre>
  
  <p>Where the fragment code looks like this:</p>
  
  <pre><code>@TargetApi(Build.VERSION_CODES.HONEYCOMB)
  public class ProfileFragment extends PreferenceFragment {
      @BindView(R.id.email)
      TextView email;
      @BindView(R.id.username)
      TextView username;
      @BindView(R.id.loadingPanel)
      RelativeLayout loadingPanel;
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
          View rootView = inflater.inflate(R.layout.fragment_profile, container, false);
          ButterKnife.bind(this, rootView);
  
          if (setActionbarListener != null) {
              setActionbarListener.setActionbarTitle("Profil");
          }
  
          loadingPanel.setVisibility(View.VISIBLE);
          UsernameHandler uHandler = UsernameHandler.getInstance(new UsernameResult() {
              @Override
              public void finished(String uname) {
                  username.setText(uname);
                  loadingPanel.setVisibility(View.GONE);  // hide loading spinner
              }
          });
          email.setText(MainActivity.getFbUser().getEmail());
  
          return rootView;
      }
  }
  </code></pre>
  
  <p>My Problem is, that there is some space on the left and the right side to the layout I am loading. This padding definitely does not come from the layout itself. When starting the app in android 8.1 there is no such padding/margin.</p>
  
  <p>See the picture:</p>
  
  <p><a href="https://i.stack.imgur.com/kFXFi.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/kFXFi.jpg" alt="enter image description here"></a></p>
  
  <p>Finally the code of the SettingsActivity:</p>
  
  <pre><code>public class SettingsActivity extends AppCompatPreferenceActivity implements OnSetActionbarTitleListener {
  
      /**
       * A preference value change listener that updates the preference's summary
       * to reflect its new value.
       */
      private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
          @Override
          public boolean onPreferenceChange(Preference preference, Object value) {
              String stringValue = value.toString();
  
              if (preference instanceof ListPreference) {
                  // For list preferences, look up the correct display value in
                  // the preference's 'entries' list.
                  ListPreference listPreference = (ListPreference) preference;
                  int index = listPreference.findIndexOfValue(stringValue);
  
                  // Set the summary to reflect the new value.
                  preference.setSummary(
                          index &gt;= 0
                                  ? listPreference.getEntries()[index]
                                  : null);
  
              } else if (preference instanceof RingtonePreference) {
                  // For ringtone preferences, look up the correct display value
                  // using RingtoneManager.
                  if (TextUtils.isEmpty(stringValue)) {
                      // Empty values correspond to 'silent' (no ringtone).
                      preference.setSummary(R.string.pref_ringtone_silent);
  
                  } else {
                      Ringtone ringtone = RingtoneManager.getRingtone(
                              preference.getContext(), Uri.parse(stringValue));
  
                      if (ringtone == null) {
                          // Clear the summary if there was a lookup error.
                          preference.setSummary(null);
                      } else {
                          // Set the summary to reflect the new ringtone display
                          // name.
                          String name = ringtone.getTitle(preference.getContext());
                          preference.setSummary(name);
                      }
                  }
  
              } else {
                  // For all other preferences, set the summary to the value's
                  // simple string representation.
                  preference.setSummary(stringValue);
              }
              return true;
          }
      };
  
      /**
       * Helper method to determine if the device has an extra-large screen. For
       * example, 10" tablets are extra-large.
       */
      private static boolean isXLargeTablet(Context context) {
          return (context.getResources().getConfiguration().screenLayout
                  &amp; Configuration.SCREENLAYOUT_SIZE_MASK) &gt;= Configuration.SCREENLAYOUT_SIZE_XLARGE;
      }
  
      /**
       * Binds a preference's summary to its value. More specifically, when the
       * preference's value is changed, its summary (line of text below the
       * preference title) is updated to reflect the value. The summary is also
       * immediately updated upon calling this method. The exact display format is
       * dependent on the type of preference.
       *
       * @see #sBindPreferenceSummaryToValueListener
       */
      public static void bindPreferenceSummaryToValue(Preference preference) {
          // Set the listener to watch for value changes.
          preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);
  
          // Trigger the listener immediately with the preference's
          // current value.
          sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
                  PreferenceManager
                          .getDefaultSharedPreferences(preference.getContext())
                          .getString(preference.getKey(), ""));
      }
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setupActionBar();
      }
  
  
      /**
       * Set up the {@link android.app.ActionBar}, if the API is available.
       */
      private void setupActionBar() {
          getLayoutInflater().inflate(R.layout.pref_toolbar, (ViewGroup)findViewById(android.R.id.content));
          Toolbar toolbar = findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);
  
          if (toolbar != null) {
              getSupportActionBar().setDisplayHomeAsUpEnabled(true);
          }
  
          setActionBarBelowContent();
      }
  
      private void setActionBarBelowContent() {
          int horizontalMargin = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 2, getResources().getDisplayMetrics());
          int verticalMargin = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 2, getResources().getDisplayMetrics());
          int actionBarHeight = UserInterfaceUtils.getActionBarHeight(MainActivity.context);
          getListView().setPadding(0, actionBarHeight+10, 0, verticalMargin);
      }
  
      @Override
      public void onHeaderClick(Header header, int position) {
          setActionBarBelowContent();
          super.onHeaderClick(header, position);
      }
  
      @Override
      public boolean onMenuItemSelected(int featureId, MenuItem item) {
          int id = item.getItemId();
          if (id == android.R.id.home) {
              onBackPressed();
              return true;
          }
          return super.onMenuItemSelected(featureId, item);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public boolean onIsMultiPane() {
          return isXLargeTablet(this);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      @TargetApi(Build.VERSION_CODES.HONEYCOMB)
      public void onBuildHeaders(List&lt;Header&gt; target) {
          loadHeadersFromResource(R.xml.pref_headers, target);
      }
  
      /**
       * This method stops fragment injection in malicious applications.
       * Make sure to deny any unknown fragments here.
       */
      @Override
      protected boolean isValidFragment(String fragmentName) {
          return PreferenceFragment.class.getName().equals(fragmentName)
                  || SettingsFragment.class.getName().equals(fragmentName)
                  || FeedbackFragment.class.getName().equals(fragmentName)
                  || ProfileFragment.class.getName().equals(fragmentName)
                  || AGBFragment.class.getName().equals(fragmentName)
                  || PrivacyFragment.class.getName().equals(fragmentName)
                  || FAQFragment.class.getName().equals(fragmentName)
                  || LicenseFragment.class.getName().equals(fragmentName);
      }
  
      @Override
      public void onBackPressed() {
          super.onBackPressed();
          setActionbarTitle("Einstellungen");
      }
  
      @Override
      public void setActionbarTitle(String title) {
          getSupportActionBar().setTitle(title);
      }
  }
  </code></pre>
  
  <p><strong>Edit - added layout</strong></p>
  
  
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:id="@+id/item_list_item"
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;android.support.v7.widget.CardView
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          app:cardUseCompatPadding="true"
          app:cardElevation="4dp"
          app:cardCornerRadius="0dp"&gt;
  
          &lt;LinearLayout
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:layout_marginTop="10dp"
              android:padding="15dp"
              android:orientation="vertical"&gt;
  
              &lt;LinearLayout
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:orientation="horizontal"&gt;
  
                  &lt;TextView
                      android:id="@+id/preUsername"
                      android:layout_width="match_parent"
                      android:layout_height="wrap_content"
                      android:text="Dein Benutzername:"
                      android:textAppearance="@style/profileText"
                      android:textStyle="bold"/&gt;
  
                  &lt;TextView
                      android:id="@+id/username"
                      android:layout_width="match_parent"
                      android:layout_height="wrap_content"
                      android:textAppearance="@style/profileText"
                      android:layout_marginLeft="5dp"/&gt;
  
              &lt;/LinearLayout&gt;
  
              &lt;LinearLayout
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:orientation="horizontal"&gt;
  
                  &lt;TextView
                      android:id="@+id/preEmail"
                      android:layout_width="match_parent"
                      android:layout_height="wrap_content"
                      android:textAppearance="@style/profileText"
                      android:textStyle="bold"
                      android:text="Deine Email:"/&gt;
  
                  &lt;TextView
                      android:id="@+id/email"
                      android:layout_width="match_parent"
                      android:layout_height="wrap_content"
                      android:textAppearance="@style/profileText"
                      android:layout_marginLeft="5dp"/&gt;
  
              &lt;/LinearLayout&gt;
  
          &lt;/LinearLayout&gt;
      &lt;/android.support.v7.widget.CardView&gt;
  
      &lt;RelativeLayout
          android:id="@+id/loadingPanel"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_gravity="center_vertical|center_horizontal"
          android:gravity="center"&gt;
  
          &lt;ProgressBar
              android:id="@+id/progressBar"
              style="@style/MyProgressBarSpinner"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:indeterminate="true" /&gt;
      &lt;/RelativeLayout&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>