Ansicht ändern Swipe-Richtung in RTL-Ebene in Android

Question

Ich versuche RTL-Layer-Direktion in Aktivität mit Viewpager und TabLayout.aber in RTL-Layer Viewpager Swipe Richtung umgekehrt und mit CurrentItem zu ViewPager, TabLayout auch geändert werden.

Ich versuche dies nach und vor setupWithViewPager, aber Dosis funktioniert nicht.

keine Idee .. !!

ich versuche dies:

mViewPager = (ViewPager) findViewById(R.id.mViewPager); 
    mViewPager.setAdapter(Adapter); 
    mViewPager.setCurrentItem(mViewPager.getAdapter().getCount() - 1,false); 

    tabLayout = (TabLayout) findViewById(R.id.tabs); 
    tabLayout.setupWithViewPager(mViewPager); 

und diese:

mViewPager = (ViewPager) findViewById(R.id.container); 
    mViewPager.setAdapter(mSectionsPagerAdapter); 
    tabLayout = (TabLayout) findViewById(R.id.tabs); 
    tabLayout.setupWithViewPager(mViewPager); 
    mViewPager.setCurrentItem(mViewPager.getAdapter().getCount() - 1,false); 

Answer 1

Sie einen benutzerdefinierten Pager-Adapter erstellen:

public class Custom_PagerAdapter extends FragmentPagerAdapter{ 

/* 
* Attributes: 
* 
* the class attributes 
* 
* */ 

private ArrayList<Object> ItemList; 

/* 
* AutoRuns: 
* 
* these methods were called at startup 
* 
* */ 

///////////// 
//////////////////Constructor: 
////////////// 
public Custom_PagerAdapter(FragmentManager fm){ 
    super(fm); 
    ItemList = new ArrayList<>(); 
} 

/* 
* Setters: 
* 
* sets class attributes 
* 
* */ 

///////////// 
//////////////////addItem: 
////////////// 
public void addItem(Object item){ItemList.add(item);} 

/* 
* Getters: 
* 
* gets class attributes 
* 
* */ 

///////////// 
//////////////////getItem: 
////////////// 
@Override 
public Fragment getItem(int position){ 
    return (Fragment) ItemList.get(getDirectionalPagerPosition(position)); 
} 

///////////// 
//////////////////getCount: 
////////////// 
@Override 
public int getCount(){return ItemList.size();} 

/* 
* Other Functions: 
* 
* class other functions 
* 
* */ 

///////////// 
//////////////////getDirectionalPagerPosition: 
//calculates the pager position considering app direction 
public int getDirectionalPagerPosition(int virtualPosition){ 
    int actualPosition; 
    if(Core.getDirection() == Direction.LTR)//make your own if 
     actualPosition = virtualPosition; 
    else 
     actualPosition = getCount()-1-virtualPosition; 
    return actualPosition; 
} 

///////////// 
//////////////////getDirectionalTabPosition: 
//calculates the tab position considering app direction 
public int getDirectionalTabPosition(int virtualPosition){ 
    int actualPosition; 
    if(Core.getDirection() == Direction.LTR) 
     actualPosition = virtualPosition; 
    else{ 
     actualPosition = getCount()-2-virtualPosition; 
     if(actualPosition < 0) 
      actualPosition = 0; 
     if(virtualPosition > getCount()-2) 
      actualPosition = getCount()-1; 
    } 
    return actualPosition; 
} 

///////////// 
//////////////////getDirectionalTabPositionOffset: 
//calculates the tab position offset considering app direction 
public float getDirectionalTabPositionOffset(float virtualPositionOffset){ 
    float actualPositionOffset; 
    if(Core.getDirection() == Direction.LTR) 
     actualPositionOffset = virtualPositionOffset; 
    else 
     actualPositionOffset = 1-virtualPositionOffset; 
    return actualPositionOffset; 
} 

}

und die Verwendung es:

/* 
* Initializers: 
* 
* were initialize the components 
* 
* */ 

///////////// 
//////////////////initTabBar: 
////////////// 
private void initTabBar(){ 
    Main_TabLyt = (CustomTabLayout) findViewById(R.id.Main_TabLyt); 
    /** count of tabs must be equal to count of pages in {@link #initPager()} */ 
    Main_TabLyt.addTab(Main_TabLyt.newTab().setText("Tab 1")); 
    Main_TabLyt.addTab(Main_TabLyt.newTab().setText("Tab 2")); 
    Main_TabLyt.addTab(Main_TabLyt.newTab().setText("Tab 3")); 
    addTabBarOnTabSelectedListener(); 
} 

///////////// 
//////////////////initPager: 
////////////// 
private void initPager(){ 
    Main_PgrAdp = new Custom_PagerAdapter(getSupportFragmentManager()); 
    /** count of pages must be equal to count of tabs in {@link #initTabBar()} */ 
    Main_PgrAdp.addItem(new View1()); 
    Main_PgrAdp.addItem(new View2()); 
    Main_PgrAdp.addItem(new View3()); 
    Main_ViwPgr = (ViewPager) findViewById(R.id.Main_Pager); 
    Main_ViwPgr.setAdapter(Main_PgrAdp); 
    Main_ViwPgr.setCurrentItem(Main_PgrAdp.getDirectionalPagerPosition(0));//first page by considering app direction 
    addPagerOnPageChangeListener(); 
} 

/* 
* Listeners: 
* 
* these methods are called after user action 
* 
* */ 

///////////// 
//////////////////addTabBarOnTabSelectedListener: 
////////////// 
public void addTabBarOnTabSelectedListener(){ 
    Main_TabLyt.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener(){ 
     @Override 
     public void onTabSelected(Tab tab){//selects pager item by considering app direction 
      Main_ViwPgr.setCurrentItem(Main_PgrAdp.getDirectionalPagerPosition(tab.getPosition())); 
     } 
     @Override 
     public void onTabUnselected(Tab tab){} 
     @Override 
     public void onTabReselected(Tab tab){} 
    }); 
} 

///////////// 
//////////////////addPagerOnPageChangeListener: 
////////////// 
private void addPagerOnPageChangeListener(){ 
    Main_ViwPgr.addOnPageChangeListener(new ViewPager.OnPageChangeListener(){ 
     @Override 
     public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels){//sets tab bar scroll position by considering app direction 
      Main_TabLyt.setScrollPosition(Main_PgrAdp.getDirectionalTabPosition(position), Main_PgrAdp.getDirectionalTabPositionOffset(positionOffset), false); 
     } 
     @Override 
     public void onPageSelected(int position){ 
      Tab tab = Main_TabLyt.getTabAt(Main_PgrAdp.getDirectionalPagerPosition(position)); 
      if(tab != null) tab.select(); 
     } 
     @Override 
     public void onPageScrollStateChanged(int state){} 
    }); 
}