best practice for multiple maps

Question

I am trying to determine the best way to deal with multiple maps. Should i be adding and removing things from a single map or switching between 2 map fragments. Ideally i think it would be better to work with fragments because i can utilize the back button easily.

My problem comes when i try to show() and hide() multiple map fragments on buttonclick. The map does not change using show()/hide(). Maybe someone can shed some light on why this is happening for me so i can better understand what is actually going on with the mapviews on show and hide. Has anyone had any issues with showing and hiding map fragments?

When i click the button the mapview does not change but i lose control unless i click the button again. It seems like the fragment is switching but not actually changing its view. I am sure that it will work correctly using replace() but this defeats the purpose of loading the maps.

package com.test.googletestmaps;
public class ControlFragment extends SherlockFragmentActivity implements
    OnClickListener {

private GoogleMap mMap;
private GoogleMap mMap2;
private SupportMapFragment gmap;
private SupportMapFragment gmap2;
private ImageButton button;
private int mapShown;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_control_fragment);
    gmap = ((SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map1));
    gmap2 = ((SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map2));

    if (savedInstanceState == null) {
        // First incarnation of this activity.
        gmap.setRetainInstance(true);
    } else {
        // Reincarnated activity. The obtained map is the same map instance
        // in the previous
        // activity life cycle. There is no need to reinitialize it.
        mMap = gmap.getMap();
    }
    if (savedInstanceState == null) {
        // First incarnation of this activity.
        gmap2.setRetainInstance(true);
    } else {
        // Reincarnated activity. The obtained map is the same map instance
        // in the previous
        // activity life cycle. There is no need to reinitialize it.
        mMap2 = gmap2.getMap();
    }
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.hide(gmap2);
    ft.commit();
    button = ((ImageButton) findViewById(R.id.cacbutton));
    button.setOnClickListener(this);
    button.setVisibility(View.VISIBLE);
    mapShown = 0;
    setUpMapIfNeeded();
}

@Override
protected void onResume() {
    super.onResume();
    setUpMapIfNeeded();
}

private void setUpMapIfNeeded() {
    // Do a null check to confirm that we have not already instantiated the
    // map.
    if (mMap == null) {
        // Try to obtain the map from the SupportMapFragment.
        mMap = ((SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map1)).getMap();
        // Check if we were successful in obtaining the map.
        if (mMap != null) {
            setUpMap(0);
        }

    }
    if (mMap2 == null) {
        mMap2 = ((SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map2)).getMap();

        if (mMap2 != null) {
            setUpMap(1);
        }
    }
}

private void setUpMap(int mapNumber) {
    switch (mapNumber) {
    case 0:
        mMap.getUiSettings().setZoomControlsEnabled(true);
        mMap.addMarker(new MarkerOptions().position(new LatLng(5, 5)).title("Marker for map1"));
        break;
    case 1:
        mMap2.getUiSettings().setZoomControlsEnabled(true);
        mMap2.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker for map2"));
        break;
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu with the options to show the Map and the ListView.
    getSupportMenuInflater()
            .inflate(R.menu.activity_control_fragment, menu);
    return true;
}

@Override
public void onClick(View v) {
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.setCustomAnimations(android.R.anim.fade_in, android.R.anim.fade_out);
    if (mapShown == 0)
    {
        ft.hide(gmap);
        ft.show(gmap2);
        mapShown = 1;
    }
    else
    {
        ft.hide(gmap2);
        ft.show(gmap);
        mapShown = 0;

    }
    ft.addToBackStack(null);
    ft.commit();

}
}

EDIT: I have found this link that explains how to show and hide a map fragment and i have tried using getView().setVisibility() but i get the same result.

Edit: This is clearly not something that is easy to solve. I have looked around and i am unable to find the solution to this. For now i will be using Add/Remove to control my fragments.

This is still not solved.... I have taken a different route. show/hide fragment does not work with multiple instances of the new google map fragments. I am not sure why and if anyone finds a solution or reason to this issue please post and share.

best practice for multiple maps

Answers (1)

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