SlidingPaneLayout does not cover the left side panel

SlidingPaneLayout does not cover the left side panel

how to understand it? why the left panel is not hidden?
My xml file:
<android.support.v4.widget.SlidingPaneLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<fragment android:id="@+id/headlines"
android:layout_height="match_parent"
android:name="by.zubov.task.fragments.TitlesFragment"
android:layout_width="380dp"
/>
<FrameLayout android:id="@+id/details"
android:layout_width="500dp"
android:layout_weight="1"
android:layout_height="match_parent" />
result: Image result
testing this is code on Htc One (display 540x960).