Android vertical tabs in fragment - Error could not find method

Question

I am trying to create a set of vertical tabs within an android project, I have been looking at a number of tutorials and posts on SO but cannot seem to piece it all together.

I created a new project with a fragment so I have a main.xml and a fragment_main.xml, a main activity class and a mainfragment class.

main.xml

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:id="@+id/fragment"
android:name="com.example.android.MainScreenActivityFragment"
tools:layout="@layout/fragment_main" android:layout_width="match_parent"
android:layout_height="match_parent" />

fragment_main.xml

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout android:orientation="horizontal"
    android:layout_width="fill_parent" android:layout_height="fill_parent">
    <FrameLayout android:layout_width="0dip"
        android:layout_height="fill_parent" android:layout_weight="0.2">
        <TabWidget android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:visibility="gone"/>
        <LinearLayout
            android:id="@+id/tab_btn_container"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="vertical">
            <Button android:layout_height="0dip"
                android:layout_width="fill_parent"
                android:layout_weight="1.0"
                android:background="@color/sunshine_blue"
                android:id="@+id/patient_tab_btn"
                android:onClick="tabHandler"/>
            <Button android:layout_height="0dip"
                android:layout_width="fill_parent"
                android:layout_weight="1.0"
                android:background="@color/sunshine_blue"
                android:id="@+id/relations_tab_btn"
                android:onClick="tabHandler"/>
            <Button android:layout_height="0dip"
                android:layout_width="fill_parent"
                android:layout_weight="1.0"
                android:background="@color/sunshine_blue"
                android:id="@+id/providers_tab_btn"
                android:onClick="tabHandler"/>
        </LinearLayout>
    </FrameLayout>
    <FrameLayout android:id="@android:id/tabcontent"
        android:layout_width="0dip"
        android:layout_height="fill_parent" android:layout_weight="0.8"/>
</LinearLayout>

The main activity doesnt do anything other than the defaults and I havent added to it as I thought I should use a fragment as the google sunshine app uses a fragment for the main screen.

main fragment class

private FragmentTabHost mTabHost;
Button patientButton, relationsButton, providersButton;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_main, container, false);
    mTabHost = new FragmentTabHost(getActivity());
    mTabHost.setup(getActivity(), getChildFragmentManager(), R.id.tab_btn_container);

    patientButton = (Button)rootView.findViewById(R.id.patient_tab_btn);
    relationsButton = (Button)rootView.findViewById(R.id.relations_tab_btn);
    providersButton = (Button)rootView.findViewById(R.id.providers_tab_btn);

    return rootView;
}

public void tabHandler(View target){
    Log.d(LOG_TAG, "Calling tabHandler() method");
    patientButton.setSelected(false);
    relationsButton.setSelected(false);
    providersButton.setSelected(false);

    if(target.getId() == R.id.patient_tab_btn){
        //mTabHost.setCurrentTab(0);
        patientButton.setSelected(true);
    } else if(target.getId() == R.id.relations_tab_btn){
        //mTabHost.setCurrentTab(1);
        relationsButton.setSelected(true);
    } else if(target.getId() == R.id.providers_tab_btn){
        //mTabHost.setCurrentTab(2);
        providersButton.setSelected(true);
    }
}

So I have added the tabHandler button and the xml is inflated inside the fragment main class but I get an error pressing any of the tab buttons:

java.lang.IllegalStateException: Could not find method tabHandler(View) in a parent or ancestor Context for android:onClick attribute

I am also not sure how I would update the tabcontent pane as all the examples seem to use an Activity and have the activity class extend from TabActivity but using a fragment my class already extends Fragment.

How do I get this to work with a fragment which contains the tabs?

Answer 1

The method that you've specified in android:onClick (tabHandler) should be located in the Activity, not the Fragment. This SO answer has more information: https://stackoverflow.com/a/4153842/3214339