Fix: cannot compile problem

src/main/res/layout/item_pdf_thumb.xml

@@ -35,7 +35,7 @@
             android:layout_height="14dp"
             android:layout_alignParentRight="true"
             android:layout_marginRight="10dp"
-            android:background="@drawable/img_bookmark"/>
+            android:background="@drawable/view_pic_bookmark"/>
 
         <View
             android:id="@+id/view_pdfThumbGvItem_"