java - Can't get swipe working for swipeable tabs -

i following http://www.android4devs.com/2015/01/how-to-make-material-design-sliding-tabs.html , have same code. can't tabs swipe each other , can't view content in tabs. code below. help!

activity_main.xml

<relativelayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     xmlns:fab="http://schemas.android.com/apk/res-auto"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical"     tools:context="activity.mainactivity">      <include         android:id="@+id/toolbar"         layout="@layout/tool_bar" />      <slidingmodel.slidingtablayout         android:layout_below="@+id/toolbar"         android:id="@+id/tabs"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:elevation="4dp"         android:background="@color/primary_color"          />      <android.support.v4.view.viewpager         android:layout_below="@id/tabs"         android:id="@+id/pager"         android:layout_height="0dp"         android:layout_width="match_parent"          />       <com.melnykov.fab.floatingactionbutton         android:id="@+id/fab"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_gravity="bottom|end"         android:layout_margin="16dp"         fab:fab_colornormal="@color/fab_normal"         fab:fab_colorpressed="@color/fab_pressed"         fab:fab_colorripple="@color/fab_ripple"         android:layout_marginleft="16dp"         android:layout_marginright="16dp"         android:layout_alignparentbottom="true"         android:layout_alignparentend="true" />   </relativelayout> 

mainactivity.java

package activity;  import android.support.v4.view.viewpager; import android.support.v7.app.appcompatactivity; import android.os.bundle; import android.support.v7.widget.toolbar; import android.view.menu; import android.view.menuitem;  import com.gursimran.bei.forte.r;  import adapter.viewpageradapter; import slidingmodel.slidingtablayout;  public class mainactivity extends appcompatactivity {      toolbar mtoolbar;      viewpager pager;     viewpageradapter adapter;     slidingtablayout tabs;     charsequence titles[] = {"factorial", "permutation", "random"};     int numboftabs = 3;       @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          mtoolbar = (toolbar) findviewbyid(r.id.toolbar);         setsupportactionbar(mtoolbar);          // creating viewpageradapter , passing fragment manager, titles fot tabs , number of tabs.         adapter =  new viewpageradapter(getsupportfragmentmanager(),titles,numboftabs);          // assigning viewpager view , setting adapter         pager = (viewpager) findviewbyid(r.id.pager);         pager.setadapter(adapter);          // assiging sliding tab layout view         tabs = (slidingtablayout) findviewbyid(r.id.tabs);         tabs.setdistributeevenly(true); // make tabs fixed set true, makes tabs space evenly in available width          // setting custom color scroll bar indicator of tab view         tabs.setcustomtabcolorizer(new slidingtablayout.tabcolorizer() {             @override             public int getindicatorcolor(int position) {                 return getresources().getcolor(r.color.fab_pressed);             }         });          // setting viewpager slidingtabslayout         tabs.setviewpager(pager);      }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.menu_main, menu);         return true;     }      @override     public boolean onoptionsitemselected(menuitem item) {         // handle action bar item clicks here. action bar         // automatically handle clicks on home/up button, long         // specify parent activity in androidmanifest.xml.         int id = item.getitemid();          //noinspection simplifiableifstatement         if (id == r.id.action_settings) {             return true;         }          return super.onoptionsitemselected(item);     } } 

viewpageradapter.java

package adapter;  import android.support.v4.app.fragment; import android.support.v4.app.fragmentmanager; import android.support.v4.app.fragmentstatepageradapter;  import fragment.factorialtab; import fragment.permutationtab; import fragment.randomtab;  public class viewpageradapter extends fragmentstatepageradapter {      charsequence titles[]; // store titles of tabs going passed when viewpageradapter created     int numboftabs; // store number of tabs, passed when viewpageradapter created      // build constructor , assign passed values appropriate values in class     public viewpageradapter(fragmentmanager fm,charsequence mtitles[], int mnumboftabsumb) {         super(fm);          this.titles = mtitles;         this.numboftabs = mnumboftabsumb;      }      //this method return fragment every position in view pager     @override     public fragment getitem(int position) {          if(position == 0) // if position 0 returning first tab         {             factorialtab factorialtab = new factorialtab();             return factorialtab;          } else if(position == 1)             // having 2 tabs if position 0 must 1 returning second tab         {             permutationtab permutationtab = new permutationtab();             return permutationtab;         }         else {             randomtab randomtab = new randomtab();             return randomtab;         }     }      // method return titles tabs in tab strip     @override     public charsequence getpagetitle(int position) {         return titles[position];     }      // method return number of tabs tabs strip     @override     public int getcount() {         return numboftabs;     } } 

swipe function control viewpager .your viewpager layout_height 0dp in here that's why have problem .

so set way

android:layout_width="match_parent" android:layout_height="wrap_content"