Get Context from Android Activiy

Question

I have implemented an Image Gallery using a GridView displaying thumbnails of images and a Fullscreen Activity which will display each of the images in fullscreen mode. The file paths are passed using Intents (putExtra) to the GridView Activity to display different GridViews depending on folder name in SDCARD.Now the problem I have is that I cannot pass those file paths to the Fullscreen Activity in order to view every image separately.

Below are my Classes ;

MainActivity.java

package info.androidhive.imageslider;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {

    private Button btn1, btn2;
    Intent intent;

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

        btn1 = (Button) findViewById(R.id.button1);
        btn2 = (Button) findViewById(R.id.button2);
        setOnClickListeners();
    }

    public void setOnClickListeners(){
        btn1.setOnClickListener(this);
        btn2.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch(v.getId()){
        case R.id.button1:
            Toast.makeText(getApplicationContext(), "Loading Gridview 1", Toast.LENGTH_LONG).show();
            intent = new Intent(MainActivity.this, GridViewActivity.class);
            intent.putExtra("folder", "folder1");
            startActivity(intent);
            break;
        case R.id.button2:
            Toast.makeText(getApplicationContext(), "Loading Gridview 2", Toast.LENGTH_LONG).show();
            intent = new Intent(MainActivity.this, GridViewActivity.class);
            intent.putExtra("folder", "folder2");
            startActivity(intent);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }



}

So in this activity am passing different folder names for each button clicks.

GridViewActivity.java

This class will receive the intent parameters for the folder names and it will list all image thumbnails for that specific folder. Until here everything is fine and I can view the images for each different folder depending on the button clicked.

package info.androidhive.imageslider;

import info.androidhive.imageslider.adapter.GridViewImageAdapter;
import info.androidhive.imageslider.helper.AppConstant;
import info.androidhive.imageslider.helper.Utils;

import java.io.File;
import java.util.ArrayList;
import java.util.Locale;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Point;
import android.os.Bundle;
import android.util.TypedValue;
import android.view.Display;
import android.view.WindowManager;
import android.widget.GridView;
import android.widget.Toast;

public class GridViewActivity extends Activity {

    private Utils utils;
    private ArrayList<String> imagePaths = new ArrayList<String>();
    private GridViewImageAdapter adapter;
    private GridView gridView;
    private int columnWidth;

    //Utils
    private Context mContext;




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

        gridView = (GridView) findViewById(R.id.grid_view);



        //utils = new Utils(this);
        mContext = this;


        // Initilizing Grid View
        InitilizeGridLayout();

        // loading all image paths from SD card
        imagePaths = getFilePaths();

        // Gridview adapter
        adapter = new GridViewImageAdapter(GridViewActivity.this, imagePaths,
                columnWidth);

        // setting grid view adapter
        gridView.setAdapter(adapter);
    }



    private void InitilizeGridLayout() {
        Resources r = getResources();
        float padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
                AppConstant.GRID_PADDING, r.getDisplayMetrics());

        columnWidth = (int) ((getScreenWidth() - ((AppConstant.NUM_OF_COLUMNS + 1) * padding)) / AppConstant.NUM_OF_COLUMNS);

        gridView.setNumColumns(AppConstant.NUM_OF_COLUMNS);
        gridView.setColumnWidth(columnWidth);
        gridView.setStretchMode(GridView.NO_STRETCH);
        gridView.setPadding((int) padding, (int) padding, (int) padding,
                (int) padding);
        gridView.setHorizontalSpacing((int) padding);
        gridView.setVerticalSpacing((int) padding);
    }

    /*
     * Reading file paths from SDCard // Utils
     */
    public ArrayList<String> getFilePaths() {
        ArrayList<String> filePaths = new ArrayList<String>();

        String folder = getIntent().getStringExtra("folder");

        File directory = new File(
                android.os.Environment.getExternalStorageDirectory()
                        + File.separator + folder);

        // check for directory
        if (directory.isDirectory()) {
            // getting list of file paths
            File[] listFiles = directory.listFiles();

            // 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();

                    // check for supported file extension
                    if (IsSupportedFile(filePath)) {
                        // Add image path to array list
                        filePaths.add(filePath);
                    }
                }
            } else {
                // image directory is empty
                Toast.makeText(
                        mContext,
                        folder
                                + " is empty. Please load some images in it !",
                        Toast.LENGTH_LONG).show();
            }

        } else {
            AlertDialog.Builder alert = new AlertDialog.Builder(mContext);
            alert.setTitle("Error!");
            alert.setMessage(folder
                    + " directory path is not valid! Please set the image directory name AppConstant.java class");
            alert.setPositiveButton("OK", null);
            alert.show();
        }

        return filePaths;
    }

    /*
     * Check supported file extensions
     * 
     * @returns boolean
     */
    private boolean IsSupportedFile(String filePath) {
        String ext = filePath.substring((filePath.lastIndexOf(".") + 1),
                filePath.length());

        if (AppConstant.FILE_EXTN
                .contains(ext.toLowerCase(Locale.getDefault())))
            return true;
        else
            return false;

    }

    /*
     * getting screen width
     */
    @SuppressLint("NewApi")
    public int getScreenWidth() {
        int columnWidth;
        WindowManager wm = (WindowManager) mContext
                .getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();

        final Point point = new Point();
        try {
            display.getSize(point);
        } catch (java.lang.NoSuchMethodError ignore) { // Older device
            point.x = display.getWidth();
            point.y = display.getHeight();
        }
        columnWidth = point.x;
        return columnWidth;
    }


}

Now Once I click on an image thumbnail my (FullScreenView Activity) cannot pickup the folder names so I can display the Image in Fullscreen mode.

FullScreenViewActivity.java

package info.androidhive.imageslider;

import info.androidhive.imageslider.adapter.FullScreenImageAdapter;
//import info.androidhive.imageslider.helper.Utils;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;

public class FullScreenViewActivity extends Activity{

    private GridViewActivity gv;
    private FullScreenImageAdapter adapter;
    private ViewPager viewPager;

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

        viewPager = (ViewPager) findViewById(R.id.pager);

        //utils = new GridViewActivity(getApplicationContext());

        Intent i = getIntent();
        int position = i.getIntExtra("position", 0);

        adapter = new FullScreenImageAdapter(FullScreenViewActivity.this,
                gv.getFilePaths());

        viewPager.setAdapter(adapter);

        // displaying selected image first
        viewPager.setCurrentItem(position);
    }
}

I want to know how can I receive the file parameters in my FullScreenActivity?

Answer 1

You can use

intent.putStringArrayListExtra("paths", getFilePaths());

when you go from GridViewActivity to FullScreenViewActivity and in onCreate of FullScreenViewActivity you can do

ArrayList<String> paths = getIntent().getStringArrayListExtra("paths");

which will give you the paths of the images