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Android Build a Self-Destructing Message Android App Using Fragments for Tabs Modifying Tabs from the Template

Ben Junya
Ben Junya
12,365 Points

Lost with imports and differences in Android Studio

Hey all,

I'm feeling really lost with the errors I'm getting in Android Studio with this module. I'm getting a couple of errors here:

SectionsPagerAdapter() cannot be applied in MainActivity.java - even when it's set as:

// primary sections of the activity. mSectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        mViewPager
                .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                    @Override
                public void onPageSelected(int position) {
                        actionBar.setSelectedNavigationItem(position);
                    }
                });

and in SectionsPagerAdapter, I'm getting a slew of errors as well. like: cannot find DummySectionFragment();

I don't know if the problem is with the imports. I downloaded the Eclipse project files and modified my code to reflect that, and I also modified the imports in the threads mentioned on the course video, but I'm still getting these errors and I can't continue because this is beyond my scope of knowledge. Does anyone know what has to be done?

Again, I'm working in Android Studio.

Here is my full MainActivity.java

package benjunya.ribbit;

import android.app.ActionBar; import android.app.Fragment; import android.app.FragmentTransaction; import android.content.Intent; import android.os.Bundle; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.app.FragmentActivity; import android.support.v4.view.ViewPager; import android.support.v4.app.FragmentManager; import android.util.Log; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.TextView;

import com.parse.ParseAnalytics; import com.parse.ParseUser;

public class MainActivity extends FragmentActivity implements ActionBar.TabListener {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link FragmentPagerAdapter} derivative, which will keep every
 * loaded fragment in memory. If this becomes too memory intensive, it
 * may be best to switch to a
 * {@link android.support.v13.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;
public static  final String TAG = MainActivity.class.getSimpleName();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ParseAnalytics.trackAppOpened(getIntent());

    ParseUser currentUser = ParseUser.getCurrentUser();
    if (currentUser == null) {

        navigateToLogin();

    }
    else {
        Log.i(TAG, currentUser.getUsername());
    }
        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(this,
                getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        mViewPager
                .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                    @Override
                public void onPageSelected(int position) {
                        actionBar.setSelectedNavigationItem(position);
                    }
                });

    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        actionBar.addTab(actionBar.newTab()
        .setText(mSectionsPagerAdapter.getPageTitle(i))
        .setTabListener(this));
    }


}
@Override
public void onTabSelected(ActionBar.Tab tab,
                          FragmentTransaction fragmentTransaction) {
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(ActionBar.Tab tab,
                            FragmentTransaction fragmentTransaction) {

}

@Override
public void onTabReselected(ActionBar.Tab tab,
                            FragmentTransaction fragmentTransaction) {

}

private void navigateToLogin() {
    Intent intent = new Intent(this, LoginActivity.class);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); //Puts this in the front of the stack
    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK); // clears previous activity
    startActivity(intent);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int itemId = item.getItemId();
    if (itemId == R.id.action_logout) {
        ParseUser.logOut();
        navigateToLogin();
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class DummySectionFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main,
                container, false);
        TextView dummyTextView = (TextView) rootView
                .findViewById(R.id.section_label);
        dummyTextView.setText(Integer.toString(getArguments().getInt(
                ARG_SECTION_NUMBER)));
        return rootView;
    }
}

}

And here is SectionsPagerAdapter.java:

package benjunya.ribbit;

import android.app.FragmentManager; import android.content.Context; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.app.FragmentActivity;

import java.util.Locale;

public class SectionsPagerAdapter { public class SectionsPagerAdapter extends FragmentPagerAdapter {

    protected Context mContext;

    public SectionsPagerAdapter(Context context, FragmentManager fm) {


        super(fm);
        mContext = context;
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        Fragment fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
        fragment.setArguments(args));
        return fragment;
    }

    @Override
    public int getCount() {
        return 2;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
            case 0:
                return mContext.getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return mContext.getString(R.string.title_section2).toUpperCase(l);
        }
        return null;
    }
}

}

Thank you! Ben