Android camera2 api full screen image

Displaying a single image in full screen from a click in the recyclerview thumbnail grid gallery

In this episode of the android camera2 api we implement the android camera2 api full screen image to open once one of the recyclerview grid gallery thumbnails are clicked.

Get Code

The code is now on github you can get it from here

https://github.com/mobapptuts/recyclerview_image_gallery.git Tag camera2-single-image

or else run this command

git clone –branch camera2-single-image https://github.com/mobapptuts/recyclerview_image_gallery.git

Code Samples

CamaraIntentActivity.java

Create an Key for the intent

private static final String IMAGE_FILE_LOCATION = "image_file_location";

Create an intent for starting the single image activity

@Override
   public void getRecyclerViewAdapterPosition(int position) {

       // Toast.makeText(this, Integer.toString(position), Toast.LENGTH_SHORT).show();
       Intent sendFileAddressIntent = new Intent(this, SingleImageActivity.class);
       sendFileAddressIntent.putExtra(IMAGE_FILE_LOCATION,
               sortFilesToLatest(mGalleryFolder)[position].toString());
       startActivity(sendFileAddressIntent);

   }

Create the single image activity

SingleImageActivity.java

package nigelhenshaw.com.cameraintenttutorial;

import android.app.Activity;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.widget.ImageView;
import android.widget.RelativeLayout;

import java.io.File;

/**
 * Created by nigelhenshaw on 5/10/2015.
 */
public class SingleImageActivity extends Activity {

    private static final String IMAGE_FILE_LOCATION = "image_file_location";

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

        DisplayMetrics displayMetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        int width = displayMetrics.widthPixels;
        int height = displayMetrics.heightPixels;

        ImageView imageView = new ImageView(this);
        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
                width, height
        );
        imageView.setLayoutParams(params);

        setContentView(imageView);

        File imageFile = new File(
                getIntent().getStringExtra(IMAGE_FILE_LOCATION)
        );

        SingleImageBitmapWorkerTask workerTask = new SingleImageBitmapWorkerTask(imageView, width, height);
        workerTask.execute(imageFile);

    }
}

Create the worker task for loading the image off the main ui thread

SingleImageBitmapWorkerTask.java

package nigelhenshaw.com.cameraintenttutorial;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.widget.ImageView;

import java.io.File;
import java.lang.ref.WeakReference;

/**
 * Created by nigelhenshaw on 6/07/2015.
 */

public class SingleImageBitmapWorkerTask extends AsyncTask<File, Void, Bitmap> {

    WeakReference<ImageView> imageViewReferences;
    final int TARGET_IMAGE_VIEW_WIDTH;
    final int TARGET_IMAGE_VIEW_HEIGHT;
    private File mImageFile;
    public SingleImageBitmapWorkerTask(ImageView imageView, int width, int height) {
        TARGET_IMAGE_VIEW_WIDTH = width;
        TARGET_IMAGE_VIEW_HEIGHT = height;
        imageViewReferences = new WeakReference<ImageView>(imageView);
    }

    @Override
    protected Bitmap doInBackground(File... params) {
        // return BitmapFactory.decodeFile(params[0].getAbsolutePath());
        mImageFile = params[0];
        // return decodeBitmapFromFile(params[0]);
        Bitmap bitmap = decodeBitmapFromFile(mImageFile);
        return bitmap;
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {
        /*
        if(bitmap != null && imageViewReferences != null) {
            ImageView viewImage = imageViewReferences.get();
            if(viewImage != null) {
                viewImage.setImageBitmap(bitmap);
            }
        }
        */
        if(bitmap != null && imageViewReferences != null) {
            ImageView imageView = imageViewReferences.get();
            if(imageView != null) {
                    imageView.setImageBitmap(bitmap);
            }
        }
    }

    private int calculateInSampleSize(BitmapFactory.Options bmOptions) {
        final int photoWidth = bmOptions.outWidth;
        final int photoHeight = bmOptions.outHeight;
        int scaleFactor = 1;

        if(photoWidth > TARGET_IMAGE_VIEW_WIDTH || photoHeight > TARGET_IMAGE_VIEW_HEIGHT) {
            final int halfPhotoWidth = photoWidth/2;
            final int halfPhotoHeight = photoHeight/2;
            while(halfPhotoWidth/scaleFactor > TARGET_IMAGE_VIEW_WIDTH
                    || halfPhotoHeight/scaleFactor > TARGET_IMAGE_VIEW_HEIGHT) {
                scaleFactor *= 2;
            }
        }
        return scaleFactor;
    }

    private Bitmap decodeBitmapFromFile(File imageFile) {
        BitmapFactory.Options bmOptions = new BitmapFactory.Options();
        bmOptions.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(imageFile.getAbsolutePath(), bmOptions);
        bmOptions.inSampleSize = calculateInSampleSize(bmOptions);
        bmOptions.inJustDecodeBounds = false;
        return BitmapFactory.decodeFile(imageFile.getAbsolutePath(), bmOptions);
    }

    public File getImageFile() {
        return mImageFile;
    }
}