在Viewpager片段的自定义操作栏布局中显示/隐藏按钮

Question

I have four fragments in my app and I intend to use a custom action bar. Two of these fragments have buttons on the action bar. I have a TabsActivity.class that has a ViewPager loading the four fragments.

In my TabsActivity and all four fragment classes i have a method setUpCustomActionBar() that i call.

I call this method in onCreate() for TabsActivity and for the 4 fragments i call them in setMenuVisibility()

private void setUpCustomActionBar(Activity activity){

    ViewGroup actionBarLayout = (ViewGroup) activity.getLayoutInflater().inflate(R.layout.actionbar_custom, null);

    RelativeLayout menupin = (RelativeLayout) actionBarLayout.findViewById(R.id.rl_menu_map);
    RelativeLayout menufilter = (RelativeLayout) actionBarLayout.findViewById(R.id.rl_menu_filter);

    ActionBar actionBar = activity.getActionBar();

    if (actionBar != null) {
        actionBar.setDisplayHomeAsUpEnabled(false);
        actionBar.setDisplayShowTitleEnabled(false);
        actionBar.setDisplayShowCustomEnabled(true);
        actionBar.setCustomView(actionBarLayout);

        menufilter.setVisibility(View.GONE);
        menupin.setVisibility(View.GONE);
    }
}

For fragments i call it like this:

@Override
public void setMenuVisibility(boolean menuVisible) {
   super.setMenuVisibility(menuVisible);

   if (menuVisible){
       if (getActivity() != null) {
           this.setUpCustomActionBar(this.getActivity());
       }
   }
}

actionbar_custom.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="4dp"
    android:paddingRight="4dp"
    android:background="@color/theme_light_blue">

  <LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:gravity="center_vertical">

    <TextView
        android:id="@+id/it_regionname"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Region_defined"
        android:textColor="@color/white"/>

    <ImageView
        android:layout_width="20dp"
        android:layout_height="20dp"
        android:src="@drawable/faq_arrow_down" />

  </LinearLayout>

  <RelativeLayout
     android:id="@+id/rl_menu_map"
     android:layout_width="wrap_content"
     android:layout_height="match_parent"
     android:visibility="gone"
     android:gravity="center_vertical">

    <ImageView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:src="@drawable/menu_icon_pin"
      android:layout_alignParentRight="true"/>

 </RelativeLayout>

 <RelativeLayout
     android:id="@+id/rl_menu_filter"
     android:layout_width="wrap_content"
     android:layout_height="match_parent"
     android:gravity="center_vertical"
     android:visibility="gone">

    <ImageView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentRight="true"
      android:src="@drawable/menu_icon_filter"/>

 </RelativeLayout>
</LinearLayout>

I have TWO questions:

1. I have to copy and repeat this method in every fragment. Is there a way to avoid repetition of code?
2. In 2nd fragment i set menupin to be visible ONLY. In 3rd fragment i set menufilter to be visible ONLY. In 1st and 4th fragment no layout SHOULD be visible BUT when i load the TabsActivity i can still see menufilter layout on fragment1. I can make it disappear by going to fragment2 and the switching to fragment1. Seems that setMenuVisiblity() is not called for the 1st default fragment when activity is loaded.

Answer 1

1. You can create class BaseFragment (and write setMenuVisibility here) -> then 4 fragments will extends from this class.

2. When creating fragment, it doesn't call setMenuVisibility method. Only when viewPager changes fragment (when we scroll viewPager), It calls setMenuVisibility. At first, the actionbar is shown with full view. So at the first time, from activity, I call to the first Fragment to hide those view on the actionbar and It work.