Bildergalerie nachbauen?

package ???.galerie.app;
import android.app.Activity;import android.content.Intent;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.provider.MediaStore;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.graphics.Bitmap;import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStream;
import java.io.File;import java.text.SimpleDateFormat;import java.util.Date;


public class MainActivity extends Activity {
    private Button open_camera_button;    private Button open_gallery_button;    private Button end_app_button;    //test    private static int TAKE_PICTURE = 1;    private Uri outputFileUri;
    private static final int REQUEST_CODE = 1;    private Bitmap bitmap;    private ImageView imageView;
    /**     * onCreate() is called as the first method of the program.     *     * @param savedInstanceState     */    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);
        final java.io.File file = new java.io.File("/gallerie_app/");        if (file.exists()) {            boolean myPath = true;        } else {            String galleryFolder = "/gallerie_app";            String extStorageDirectory = Environment.getExternalStorageDirectory().toString();            File myNewFolder = new File(extStorageDirectory + galleryFolder);            myNewFolder.mkdir();        }
        open_camera_button = (Button) findViewById(R.id.new_pic_button);        open_camera_button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {


                Intent data = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);                String timeStamp = new SimpleDateFormat("yyyyMMdd_HHss").format(new Date());
                File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath(), "/gallerie_app/Puuudel_" + timeStamp + "uhr.jpg");
                outputFileUri = Uri.fromFile(file);                data.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);                startActivityForResult(data, TAKE_PICTURE);            }
            protected void safeThePictureSafetheWorld(int requestCode, int resultCode, Intent data) {                if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK) {                    if(data.getData() != null) {                        try {                            if (bitmap != null)                            {                                bitmap.recycle();                            }
                            InputStream stream = getContentResolver().openInputStream(data.getData());                            bitmap = BitmapFactory.decodeStream(stream);                            stream.close();                            imageView.setImageBitmap(bitmap);                        }
                        catch (FileNotFoundException e) {                            e.printStackTrace();                        }                        catch (IOException e) {                            e.printStackTrace();                        }                    } else {                        bitmap=(Bitmap) data.getExtras().get("data");                        imageView.setImageBitmap(bitmap);                    }                }            }        });
        open_gallery_button = (Button) findViewById(R.id.gallery_button);        open_gallery_button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent in = new Intent(MainActivity.this,gallery.class);                startActivity(in);            }        });        end_app_button = (Button) findViewById(R.id.end_app_button);        end_app_button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                finish();            }        });    }




}

package ???.galerie.app;
import android.app.Activity;import android.database.Cursor;import android.graphics.Bitmap;import android.graphics.Point;import android.os.Bundle;import android.provider.MediaStore;import android.util.Log;import android.view.Display;import android.widget.GridView;
import java.io.File;import java.lang.reflect.Array;import java.util.ArrayList;


public class GridViewActivity extends Activity {
    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_grid_view);        getFilePaths();        getScreenWidth();    }
    public ArrayList<String> getFilePaths() {        ArrayList<String> filePaths = new ArrayList<String>();
        File directory = new File(                android.os.Environment.getExternalStorageDirectory() + "/gallerie_app/" + File.separator);        if (directory.isDirectory()) {            // getting list of file paths            File[] listFiles = directory.listFiles();            Log.i("infos_getFilePaths", Integer.toString(listFiles.length)); // just a test            // Check for count            if (listFiles.length > 0) {
                // loop through all files                for (int i = 0; i < listFiles.length; i++) {
                    // get file path                    String filePath = listFiles[i].getAbsolutePath();                }            }            Log.i("infos_getFilePaths", Integer.toString(listFiles.length)); // test        }        return filePaths;    }
    public int getScreenWidth() {        Display display = getWindowManager().getDefaultDisplay();        Point size = new Point();        display.getSize(size);        int width = size.x;        int height = size.y;        Log.i("infos", Integer.toString(size.x));        Log.i("infos", Integer.toString(size.y));        return Log.i("infos", "Test222");    }




}