How to instantiate a GridView or a ListView for the same Activity?

I received the answer in another forum where I also asked and received as a response a great solution, I will copy here because it can help someone else in the future. I applied to my application and it worked.

  

Suppose XML containing ListView or GridView is called layout.xml . Then:

     

• in the layout folder, there should be layout.xml with ListView .
  
• in the layout-land and layout-large folder there should be layout.xml with GridView .
  

With that done, Android will already inflate the layout.xml correct when doing:

setContentView(R.layout.layout);

     

Since both ListView and GridView are children of AbsListView, do the following:

AbsListView listOrGrid = 
    (AbsListView) findViewById(R.id.id_do_grid_e_list); 

Sent by Lucas in the GUJ (I hope there are no problems in quoting another forum)

You should work with screen sizes. The most common way I've learned was to use a resource with a boolean is property (you can put the name you want, isGrid for example), usually use isTablet.

First, you must create a values folder for each qualifier that you have to layout. For example, if you have layout-land, layout-large-land, layout-xlarge then you should also have the values-land, values-large-land, and values-xlarge folders.

Then you should create a bool.xml file with the following contents inside each of the values folders:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <bool name="isGrid">false</bool>
</resources>

The value true or false changes according to the existence of the gridView, if there is a gridView you should set true, otherwise false.

Now in the activity that calls the gridView or the ListView you add the following code:

private boolean isGrid(){
    return getResources().getBoolean(R.bool.isGrid);
}

Now in the onCreate method of the same activity you should have a code with the following:

if(this.isGrid()){
    //crie uma gridView
}
else{
    //crie uma listView
}

If you need to check orientation, you can use:

getResources().getConfiguration().orientation

which can be one of the following constants:

ORIENTATION_LANDSCAPE 
ORIENTATION_PORTRAIT

To check if the screen is large (Tablet) you can try to pick up the device's (diagonal) inches:

public static Double getPolegadas(Activity activity) {

    DisplayMetrics metrics = new DisplayMetrics();
    WindowManager wm = (WindowManager) activity.getSystemService(Context.WINDOW_SERVICE);
    wm.getDefaultDisplay().getMetrics(metrics);

    final int largura = metrics.widthPixels;
    final int altura = metrics.heightPixels;
    final double diagonal = Math.sqrt((largura * largura) + (altura * altura));

    polegadas = diagonal / metrics.densityDpi;

    return polegadas;
}

There for Tablet, you would check if it is larger than 6.5, for example:

if (polegadas >= 6.5)

I hope I have helped!