Set Imageview as wallpaper with a Button

Question

I have a problem with my code, I want to set an image from an ImageView as the wallpaper, I have a gallery and when I press an image from there the ImageView changes, so I don't know where to put the code for onClick to my button.

This is my code:

public class MainActivity extends Activity{

    final Integer[] mThumbIds = {
            R.drawable.a_compressed, R.drawable.b_compressed,
            R.drawable.c_compressed, R.drawable.d_compressed,
           };
    final Integer[] mFullSizeIds = {
            R.drawable.a, R.drawable.b,
            R.drawable.c, R.drawable.d,
           };

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

        Gallery galeria = (Gallery) findViewById(R.id.gallery);
        galeria.setAdapter(new ImageAdapter(this));
        galeria.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
                ImageView laimagen = (ImageView) findViewById(wallpaper);
                laimagen.setImageResource(mFullSizeIds[position]);
            }
        });
    }


    public class ImageAdapter extends BaseAdapter {
        private Context mContext;

        public ImageAdapter(MainActivity inicio) {
            mContext = inicio;
        }

        public int getCount() {
            return mThumbIds.length;
        }

        public Object getItem(int position) {
             return null;
        }

        public long getItemId(int position) {
             return mFullSizeIds[position];
        }

        // create a new ImageView for each item referenced by the Adapter
        public View getView(int position, View convertView, ViewGroup parent) {

            ImageView  imageView = new ImageView(mContext);
            imageView.setImageResource(mThumbIds[position]);
            imageView.setLayoutParams(new Gallery.LayoutParams(180, 170));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            return imageView;

        }
    }
}

I tried this but it did not work

private void onClick() {
    Bitmap bitmap;
    bitmap = BitmapFactory.decodeResource(getResources(),mFullSizeIds[position]);

    try {
        getApplicationContext().setWallpaper(bitmap);
        Toast.makeText(MainActivity.this, "Wallpaper set", Toast.LENGTH_LONG).show();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

This is my layout:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
android:background="#222222"
android:orientation="vertical">


<ImageView android:id="@id/wallpaper"
    android:layout_width="fill_parent"
    android:layout_height="0dp"
    android:scaleType="centerInside"
    android:layout_weight="1.0"
    android:src="@drawable/a" />

<Gallery android:id="@id/gallery"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

<Button android:layout_gravity="center_horizontal"
    android:id="@id/set"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/SetWallpaper"
    android:background="@color/Esmeralda"
    android:textColor="@color/Clouds"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true" />

</LinearLayout>

Answer 1

First of all you should take an int variable which specifies basically the index of drawableIds present in your mFullSizeIds[] and intialise it to -1 intitially like this

private int index=-1;

and in your galeria.setOnItemClickListener(), assign the position to your index variable like this.

 galeria.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
            index=position;
            laimagen.setImageResource(mFullSizeIds[position]);
        }
    });

and then in your Button click, do something like this

private void onClick() {

  try {
       WallpaperManager wallpaperManager = WallpaperManager.getInstance(MainActivity .this); 
       Drawable drawable = getResources().getDrawable(mFullSizeIds[index]);// here index is position of selected drawable in your mFullSizeIds[] that you have set in galeria.setOnItemClickListener()
            Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
            wallpaperManager.setBitmap(bitmap);
    } catch (IOException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
    }
}

your onCreate() will look like this

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

    ImageView laimagen = (ImageView) findViewById(R.id.wallpaper);
    Gallery galeria = (Gallery) findViewById(R.id.gallery);
    galeria.setAdapter(new ImageAdapter(this));
    galeria.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
              index=position;
              laimagen.setImageResource(mFullSizeIds[position]);
        }
    });
    Button setButton=(Button)findViewById(R.id.set);
     setButton.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                onClick();
            }
        });
}