android hide fragment on pressing back button of fragmentActivity(FragmentB)

hello all i am developing 1 app in to that

for displaying fragment 1 i have done this...(works properly)

import android.content.Context;  import android.os.Handler;  import android.util.AttributeSet;  import android.util.Log;  import android.view.MotionEvent;  import android.view.View;  import android.view.animation.Interpolator;  import android.widget.LinearLayout;  import android.widget.Scroller;    public class MainLayout extends LinearLayout {     private static final int SLIDING_DURATION = 400;// 500   private static final int QUERY_INTERVAL = 1;   int mainLayoutWidth;   public View menu;   private View content;   private static int menuRightMargin = 1;     private enum MenuState {   HIDING, HIDDEN, SHOWING, SHOWN,   };     private int contentXOffset;   private MenuState currentMenuState = MenuState.HIDDEN;   private Scroller menuScroller = new Scroller(this.getContext(),   new EaseInInterpolator());   private Runnable menuRunnable = new MenuRunnable();   private Handler menuHandler = new Handler();   int prevX = 0;   boolean isDragging = false;   int lastDiffX = 0;     public MainLayout(Context context, AttributeSet attrs) {   super(context, attrs);   }     public MainLayout(Context context) {   super(context);   }     @Override   protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {   super.onMeasure(widthMeasureSpec, heightMeasureSpec);     mainLayoutWidth = MeasureSpec.getSize(widthMeasureSpec);   menuRightMargin = mainLayoutWidth * 30 / 100;   }     @Override   protected void onAttachedToWindow() {   super.onAttachedToWindow();     menu = this.getChildAt(0);   content = this.getChildAt(1);   content.setOnTouchListener(new OnTouchListener() {   @Override   public boolean onTouch(View v, MotionEvent event) {   return MainLayout.this.onContentTouch(v, event);   }   });   menu.setVisibility(View.GONE);   }     @Override   protected void onLayout(boolean changed, int left, int top, int right,   int bottom) {   if (changed) {   LayoutParams contentLayoutParams = (LayoutParams) content   .getLayoutParams();   contentLayoutParams.height = this.getHeight();   contentLayoutParams.width = this.getWidth();   LayoutParams menuLayoutParams = (LayoutParams) menu   .getLayoutParams();   menuLayoutParams.height = this.getHeight();   menuLayoutParams.width = this.getWidth() - menuRightMargin;   }   menu.layout(left, top, right - menuRightMargin, bottom);   content.layout(left + contentXOffset, top, right + contentXOffset,   bottom);     }     public void toggleMenu() {     if (currentMenuState == MenuState.HIDING   || currentMenuState == MenuState.SHOWING)   return;     switch (currentMenuState) {   case HIDDEN:   currentMenuState = MenuState.SHOWING;   menu.setVisibility(View.VISIBLE);   menuScroller.startScroll(0, 0, menu.getLayoutParams().width, 0,   SLIDING_DURATION);   break;   case SHOWN:   currentMenuState = MenuState.HIDING;   menuScroller.startScroll(contentXOffset, 0, -contentXOffset, 0,   SLIDING_DURATION);   break;   default:   break;   }   menuHandler.postDelayed(menuRunnable, QUERY_INTERVAL);   this.invalidate();   }   public void toggleMenu1() {     if (currentMenuState == MenuState.HIDING   || currentMenuState == MenuState.SHOWING)   return;     switch (currentMenuState) {   /*case HIDDEN:   currentMenuState = MenuState.SHOWING;   menu.setVisibility(View.VISIBLE);   menuScroller.startScroll(0, 0, menu.getLayoutParams().width, 0,   SLIDING_DURATION);   break;*/   case SHOWN:   currentMenuState = MenuState.HIDING;   menuScroller.startScroll(30, 0, -30, 0,   SLIDING_DURATION);   break;   default:   break;   }   menuHandler.postDelayed(menuRunnable, QUERY_INTERVAL);   this.invalidate();   }     protected class MenuRunnable implements Runnable {   @Override   public void run() {   boolean isScrolling = menuScroller.computeScrollOffset();   adjustContentPosition(isScrolling);   }   }     private void adjustContentPosition(boolean isScrolling) {   int scrollerXOffset = menuScroller.getCurrX();     content.offsetLeftAndRight(scrollerXOffset - contentXOffset);     contentXOffset = scrollerXOffset;   this.invalidate();   if (isScrolling)   menuHandler.postDelayed(menuRunnable, QUERY_INTERVAL);   else   this.onMenuSlidingComplete();   }     private void onMenuSlidingComplete() {   switch (currentMenuState) {   case SHOWING:   currentMenuState = MenuState.SHOWN;   break;   case HIDING:   currentMenuState = MenuState.HIDDEN;   menu.setVisibility(View.GONE);   break;   default:   return;   }   }     protected class EaseInInterpolator implements Interpolator {   @Override   public float getInterpolation(float t) {   return (float) Math.pow(t - 1, 5) + 1;   }     }       public boolean isMenuShown() {   return currentMenuState == MenuState.SHOWN;   }     public boolean onContentTouch(View v, MotionEvent event) {   if (currentMenuState == MenuState.HIDING   || currentMenuState == MenuState.SHOWING)   return false;   int curX = (int) event.getRawX();   int diffX = 0;     switch (event.getAction()) {   case MotionEvent.ACTION_DOWN:     prevX = curX;   return true;     case MotionEvent.ACTION_MOVE:   if (!isDragging) {   isDragging = true;   menu.setVisibility(View.VISIBLE);   }   diffX = curX - prevX;   if (contentXOffset + diffX <= 0) {   diffX = -contentXOffset;   } else if (contentXOffset + diffX > mainLayoutWidth   - menuRightMargin) {   diffX = mainLayoutWidth - menuRightMargin - contentXOffset;   }   content.offsetLeftAndRight(diffX);   contentXOffset += diffX;   this.invalidate();     prevX = curX;   lastDiffX = diffX;   return true;     case MotionEvent.ACTION_UP:   Log.d("MainLayout.java onContentTouch()", "Up lastDiffX "   + lastDiffX);     if (lastDiffX > 0) {   currentMenuState = MenuState.SHOWING;   menuScroller.startScroll(contentXOffset, 0,   menu.getLayoutParams().width - contentXOffset, 0,   SLIDING_DURATION);   } else if (lastDiffX < 0) {   currentMenuState = MenuState.HIDING;   menuScroller.startScroll(contentXOffset, 0, -contentXOffset, 0,   SLIDING_DURATION);   }   menuHandler.postDelayed(menuRunnable, QUERY_INTERVAL);   this.invalidate();   isDragging = false;     prevX = 0;   lastDiffX = 0;   return true;     default:   break;   }     return false;   }   public void hideMenu() {   }      }

Now in Fragment B that extends FragmentActivity. on pressing BackButton of FragmentB i want to hide fragmentA how i can do this?

Answer