opening an image from a gridview into a new activity

Question

I created a gridview that show images from specific folder in SD card. I am able to get the item position but unfortunatly, I am facing a problem of displaying selected images in full screen image activity. I think there is an issue in getting image path using its position. I would appreciate your help.

This is Gridview Activity

public class print extends AppCompatActivity {

public class ImageAdapter extends BaseAdapter {

    private Context mContext;
    ArrayList<String> itemList = new ArrayList<String>();

    public ImageAdapter(Context c) {
        mContext = c;
    }

    void add(String path){
        itemList.add(path);
    }

    @Override
    public int getCount() {
        return itemList.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {  // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(700, 1150));
            imageView.setScaleType(ImageView.ScaleType.FIT_XY);
            imageView.setPadding(1, 1, 1, 1);
        } else {
            imageView = (ImageView) convertView;
        }

        Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220, 220);

        imageView.setImageBitmap(bm);
        return imageView;
    }



    public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) {

        Bitmap bm = null;
        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        bm = BitmapFactory.decodeFile(path, options);

        return bm;
    }

    public int calculateInSampleSize(

            BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {
            if (width > height) {
                inSampleSize = Math.round((float)height / (float)reqHeight);
            } else {
                inSampleSize = Math.round((float)width / (float)reqWidth);
            }
        }

        return inSampleSize;
    }

}

ImageAdapter myImageAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ActionBar actionBar = getSupportActionBar();
    actionBar.hide();
    setContentView(R.layout.activity_print);

    GridView gridView = (GridView) findViewById(R.id.gridView);
    myImageAdapter = new ImageAdapter(this);
    gridView.setAdapter(myImageAdapter);

    String ExternalStorageDirectoryPath = Environment
            .getExternalStorageDirectory()
            .getAbsolutePath();

    String targetPath = ExternalStorageDirectoryPath + "/sdfolder/";


    File targetDirector = new File(targetPath);

    File[] files = targetDirector.listFiles();
    for (File file : files){
        myImageAdapter.add(file.getAbsolutePath());
    }

    gridView.setOnItemClickListener(myOnItemClickListener);
}

AdapterView.OnItemClickListener myOnItemClickListener
        = new AdapterView.OnItemClickListener(){

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
                            long id) {
       // String prompt = (String)parent.getItemAtPosition(position).toString();


        Intent i = new Intent(print.this, DetailsActivity.class);
        Toast.makeText(print.this, "Position " + position,
                Toast.LENGTH_SHORT).show();
        i.putExtra("id", id);
         startActivity(i);
    }};

}

This is the Full Screen Activity

public class DetailsActivity extends AppCompatActivity {

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

    // Get position from intent passed from MainActivity.java
    Intent i = getIntent();

    int position = i.getExtras().getInt("id");

    // Open the Image adapter

    // Locate the ImageView in single_item_view.xml
    ImageView imageView = (ImageView) findViewById(R.id.image);

    // Get image and position from ImageAdapter.java and set into ImageView
    imageView.setImageResource(position);

}
}

Answer 1

The integer you pass to ImageView.setImageResource() needs to be a valid drawable resource id. What you actually pass to the details activity is an adapter-specific item id, moreover in your case it is always 0, according to your code:

// ...
@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return 0;
}
// ...

Solution: If you only need to show the image, you could simply pass the image URI to the details activity:

GridViewActivity.java

    Intent intent = new Intent(print.this, DetailsActivity.class);
    intent.putExtra("uri", myImageAdapter.itemList.get(position));
    startActivity(intent);

DetailsActivity.java

// ...
setContentView(R.layout.details_activity);

// Get position from intent passed from MainActivity.java
Intent intent = getIntent();
String imageUri = intent.getExtras().getString("uri");

Bitmap image = ...; // load the full size image using the imageUri

ImageView imageView.setImageBitmap(image);

There's no need to share the list between your activities.