Develop Reference

Android volley gridview onclick item index doesnt start with 0

I am using a custom gridview adapter to show images with volley singleton. The gridview showing the images are fine, its just that when I click the FIRST image it crashes instantly.
I have tried using URLS[i-6] but it doesnt return the right thing. There are 6 images, somehow the index of the first image is 6 thus causing the out of bound exception. I tried changing bits here and there that might cause the index starting at 6 but no result at all..
The error:
java.lang.ArrayIndexOutOfBoundsException: length=6; index=6
at com.example.user.assignmentfourtwo.MainActivity$1$1.onItemClick(MainActivity.java:80)
Which is this line:
Toast.makeText(MainActivity.this, URLS[i].toString(), Toast.LENGTH_LONG).show();
MainActivity.java:
public class MainActivity extends AppCompatActivity {
private final int THUMBNAIL_SIZE = 250;
private final String KEY = "IMAGE";
ArrayList<Bitmap> bitmaps = new ArrayList<Bitmap>();
private static final String URLS[] = {
"http://10.0.2.2/Android%20A4_1/germany.png",
"http://10.0.2.2/Android%20A4_1/indonesia.png",
"http://10.0.2.2/Android%20A4_1/japan.png",
"http://10.0.2.2/Android%20A4_1/sarawak.png",
"http://10.0.2.2/Android%20A4_1/singapore.png",
"http://10.0.2.2/Android%20A4_1/switzerland.png",
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for(int i = 0; i<URLS.length; i++) {
LoadingImages(URLS[i]);
}
}
private void LoadingImages(String url) {
ImageLoader imageLoader = MySingleton.getInstance(getApplicationContext()).getImageLoader();
imageLoader.get(url, new ImageLoader.ImageListener() {
#Override
public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) {
Bitmap image = response.getBitmap();
Bitmap thumbnail = ThumbnailUtils.extractThumbnail(image, THUMBNAIL_SIZE, THUMBNAIL_SIZE);
bitmaps.add(thumbnail);
GridView gridView = (GridView)findViewById(R.id.grid_layout);
final ImageAdapter imageAdapter = new ImageAdapter(MainActivity.this, bitmaps);
gridView.setAdapter(imageAdapter);
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Toast.makeText(MainActivity.this, URLS[i].toString(), Toast.LENGTH_LONG).show();
// Intent intent = new Intent(getApplicationContext(), Main2Activity.class);
// intent.putExtra(KEY, URLS[i]);
// startActivity(intent);
}
});
}
#Override
public void onErrorResponse(VolleyError error) {
Log.e("Do you even error?", error.getMessage());
}
});
}
}
MySingleton.java:
public class MySingleton {
private static MySingleton instance;
private RequestQueue requestQueue;
private ImageLoader imageLoader;
private static Context context;
private MySingleton(Context context){
this.context = context;
requestQueue = Volley.newRequestQueue(context);
imageLoader = new ImageLoader(requestQueue, new ImageLoader.ImageCache() {
private final LruCache<String, Bitmap> cache = new LruCache<>(6);
#Override
public Bitmap getBitmap(String url) {
Bitmap bmp = cache.get(url);
if (bmp == null) {
System.out.println("Not in cache");
} else {
System.out.println("In cache");
}
return bmp;
}
#Override
public void putBitmap(String url, Bitmap bitmap) {
System.out.println("Put in cache");
cache.put(url, bitmap);
}
});
}
public static synchronized MySingleton getInstance(Context context) {
if (instance == null) {
instance = new MySingleton(context);
}
return instance;
}
public ImageLoader getImageLoader() {
return imageLoader;
}
}
ImageAdapter.java:
public class ImageAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<Bitmap> bitmaps;
private final String KEY = "IMAGE";
public ImageAdapter(Context context, ArrayList<Bitmap> bitmaps) {
this.mContext = context;
this.bitmaps = bitmaps;
}
#Override
public int getCount() {
return bitmaps.size();
}
#Override
public Object getItem(int i) {
return bitmaps.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
if (view == null) {
final LayoutInflater layoutInflater = LayoutInflater.from(mContext);
view = layoutInflater.inflate(R.layout.griditems, null);
MyViewHolder myViewHolder = new MyViewHolder(view);
view.setTag(myViewHolder);
}
MyViewHolder myViewHolder = (MyViewHolder)view.getTag();
myViewHolder.img.setImageBitmap(bitmaps.get(i));
return view;
}
public class MyViewHolder {
public ImageView img;
public MyViewHolder(View view) {
img = view.findViewById(R.id.image1);
}
}
}

Activity not an enclosing class

public Object instantiateItem(ViewGroup container, int position) {
Context context = FullImageActivity.this; // i get error in this line that its not an enclosing class
I simply want to call FullImageActivity to ImageAdapter class
ImageAdapter class
public class ImageAdapter extends PagerAdapter {
public String mImages[] = {("http://www.fashionlady.in/wp-content/uploads/2016/03/creative-punjabi-mehndi-design-2016.jpg"),
("https://lumiere-a.akamaihd.net/v1/images/uk_toystory_chi_woody_n_5b5a006f.png?region=0,0,300,300"),
("https://lumiere-a.akamaihd.net/v1/images/open-uri20150422-20810-10n7ovy_9b42e613.jpeg"),
("http://www.wetpaint.com/wp-content/uploads/2015/11/toy-story-20th-anniversary.jpg"),
("http://i.imgur.com/4IZMjx3.jpg")};
#Override
public int getCount() {
return mImages.length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
Context context = FullImageActivity.this;
ImageView imageView = new ImageView(context);
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
Picasso.with(context).load(mImages[position]).placeholder(R.drawable.loading2).error(R.drawable.nointernet).into(imageView);
((ViewPager) container).addView(imageView, 0);
return imageView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
}
This is my FullImageActivity class
public class FullImageActivity extends AppCompatActivity {
TouchImageView img;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("ViewPager");
setContentView(R.layout.activity_full_image);
Intent i = getIntent();
TouchImageView img = new TouchImageView(this);
int position = i.getExtras().getInt("id");
ImageAdapter adapter = new ImageAdapter();
img = (TouchImageView) findViewById(R.id.img);
img.setMaxZoom(4f);
Picasso.with(getApplicationContext()).load(adapter.mImages[position]).into(img);
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
viewPager.setAdapter(adapter);
}

Your Adapter Class
public class ImageAdapter extends PagerAdapter {
Context activity_context;
public String mImages[] = {("http://www.fashionlady.in/wp-content/uploads/2016/03/creative-punjabi-mehndi-design-2016.jpg"),
("https://lumiere-a.akamaihd.net/v1/images/uk_toystory_chi_woody_n_5b5a006f.png?region=0,0,300,300"),
("https://lumiere-a.akamaihd.net/v1/images/open-uri20150422-20810-10n7ovy_9b42e613.jpeg"),
("http://www.wetpaint.com/wp-content/uploads/2015/11/toy-story-20th-anniversary.jpg"),
("http://i.imgur.com/4IZMjx3.jpg")};
public ImageAdapter(Context context)
{
activity_context=context;
}
#Override
public int getCount() {
return mImages.length;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
ImageView imageView = new ImageView(activity_context);
imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
Picasso.with(activity_context).load(mImages[position]).placeholder(R.drawable.loading2).error(R.drawable.nointernet).into(imageView);
((ViewPager) container).addView(imageView, 0);
return imageView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
}
Your Activity class
public class FullImageActivity extends AppCompatActivity {
TouchImageView img;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("ViewPager");
setContentView(R.layout.activity_full_image);
Intent i = getIntent();
TouchImageView img = new TouchImageView(this);
int position = i.getExtras().getInt("id");
ImageAdapter adapter = new ImageAdapter(FullImageActivity.this);
img = (TouchImageView) findViewById(R.id.img);
img.setMaxZoom(4f);
Picasso.with(getApplicationContext()).load(adapter.mImages[position]).into(img);
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
viewPager.setAdapter(adapter);
}

Add dot indicator to viewpager with pageradapter

I need to add dot indicator to my code for slide show so kindly help me to add this indicator and also click listner for views in page viewer
viewPager = (ViewPager) findViewById(R.id.splash);
ImageAdapter adapter = new ImageAdapter(this);
viewPager.setAdapter(adapter);
public class ImageAdapter extends PagerAdapter {
Context context;
private int[] GalImages = new int[] {
R.drawable.slider,
R.drawable.slider,
R.drawable.slider,
};
ImageAdapter(Context context){
this.context=context;
}
#Override
public int getCount() {
return GalImages.length;
// return 10;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
ImageView imageView = new ImageView(context);
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setImageResource(GalImages[position]);
new LoadImage(imageView).execute("http://www.gadgetbaazar.com/wp-content/uploads/2016/12/Top-Mobile-Phones.jpg");
new LoadImage(imageView).execute("https://pisces.bbystatic.com/BestBuy_US/store/ee/2015/com/pm/nav_desktops_1115.jpg");
container.addView(imageView, 0);
return imageView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
private class LoadImage extends AsyncTask<String, String, Bitmap> {
ImageView img=null;
public LoadImage(ImageView img){
this.img=img;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
protected Bitmap doInBackground(String... args) {
Bitmap bitmap=null;
try {
bitmap = BitmapFactory.decodeStream((InputStream)new URL(args[0]).getContent());
} catch (Exception e) {
e.printStackTrace();
}
return bitmap;
}
protected void onPostExecute(Bitmap image) {
if(image != null){
img.setImageBitmap(image);
}
}
}
}
Here i need the indicators if possible along with pageclick listner for this viewpager

I done this using following LIB PageIndicatorView
compile 'com.romandanylyk:pageindicatorview:0.1.1'
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:id="#+id/pager"
android:layout_height="match_parent">
</android.support.v4.view.ViewPager>
<com.rd.PageIndicatorView
android:id="#+id/pageIndicatorView"
android:layout_width="wrap_content"
android:layout_centerHorizontal="true"
android:layout_above="#+id/buttons"
android:layout_marginBottom="20dp"
app:piv_animationType="swap"
app:piv_viewPager="#id/pager"
android:layout_height="wrap_content" />
Java code
mViewPager = (ViewPager) findViewById(pager);
mViewPager.setAdapter(mCustomPagerAdapter);
//dots
PageIndicatorView pageIndicatorView = (PageIndicatorView) findViewById(R.id.pageIndicatorView);
pageIndicatorView.setViewPager(mViewPager);
OUTPUT

How can I use a background task within an adapter?

I have this image adapter, that is supposed to handle updating a grid of images. The problem is that I have a BackgroundImageTask running that fetches the bitmap from a URL. The getView method returns the imageView before the Background Task can finish updating it. How Can I force the Background Task to finish before it returns the imageview?
public class ImageAdapter extends BaseAdapter {
private Context mContext;
Bitmap bitmap;
List<Post> postList;
ImageView imageView;
int pos;
public ImageAdapter(Context c, List<Post> p) {
mContext = c;
postList = p;
}
public int getCount() {
return postList.size();
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
pos=position;
View convert = convertView;
if (convert == null) {
// if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(GridView.AUTO_FIT, 320));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(0, 0, 0, 0);
} else {
imageView = (ImageView) convert;
}
new BackgroundImageTask().execute();
return imageView;
}
public View SetBit(Bitmap b){
imageView.setImageBitmap(b);
return imageView;
}
class BackgroundImageTask extends AsyncTask<Void, Void, Bitmap> {
#Override
protected Bitmap doInBackground(Void... params) {
Bitmap bit1=bitmap;
try {
bit1 = BitmapFactory.decodeStream((InputStream)new URL(postList.get(pos).thumbnail).getContent());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return bit1;
}
#Override
protected void onPostExecute(Bitmap bit) {
SetBit(bit);
}
}
}

Instead You can pass the ImageView Object to the background Task like
new BackgroundImageTask(imageView).execute();
and
class BackgroundImageTask extends AsyncTask<Void, Void, Bitmap> {
ImageView iv;
BackgroundImageTask(ImageView imageView){
iv = imageView;
}
#Override
protected Bitmap doInBackground(Void... params) {
Bitmap bit1=bitmap;
try {
bit1 = BitmapFactory.decodeStream((InputStream)new URL(postList.get(pos).thumbnail).getContent());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return bit1;
}
#Override
protected void onPostExecute(Bitmap bit) {
iv.setImageBitmap(bit);
}
}

Android Error: type mismatch error: Cannot convert Object to Content

I am creating a simple application to share images in a grid view in Android. I have created an array but when I tried to create a gridview of those images I got an error with my code that I can't resolve.
This is my code :
public class ImageAdapter extends BaseAdapter
{
private Context context;
public ImageAdapter(Context arg2)
{
Object localObject;
this.context = localObject;
}
public int getCount()
{
return MainActivity.this.mThumbIds.length;
}
public Object getItem(int paramInt)
{
return Integer.valueOf(paramInt);
}
public long getItemId(int paramInt)
{
return paramInt;
}
public View getView(int paramInt, View paramView, ViewGroup paramViewGroup)
{
if (paramView != null)
{
MainActivity.this.imageView = ((ImageView)paramView);
}
else
{
MainActivity.this.imageView = new ImageView(this.context);
MainActivity.this.imageView.setLayoutParams(new AbsListView.LayoutParams(90, 90));
MainActivity.this.imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
MainActivity.this.imageView.setPadding(5, 5, 5, 5);
}
MainActivity.this.imageView.setImageResource(MainActivity.this.mThumbIds[paramInt].intValue());
return MainActivity.this.imageView;
}
}
}
I got the error here: Type mismatch error: Cannot convert Object to Content The error is pointing on localObject

Object localObject;
Context context;
public ImageAdapter(Context arg2)
{
this.context = arg2;
}
Instead of MainActivity.this.imageView use imageView (this is not an error)
Also use #Override where ever necessary.

Are you not using arg2?
Anyway, try to actually typecast the variable:
this.context = (Context) localObject;

You will use your Base Adapter like this and update your Grid-view like below code..
public class GridViewImageAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<String> filePaths = new ArrayList<String>();
private int imageWidth;
public GridViewImageAdapter(Activity activity,
ArrayList<String> imagePaths, int imageWidth) {
this.activity = activity;
this.filePaths = imagePaths;
this.imageWidth = imageWidth;
}
#Override
public int getCount() {
return this.filePaths.size();
}
#Override
public Object getItem(int position) {
return this.filePaths.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
imageView = new ImageView(activity);
} else {
imageView = (ImageView) convertView;
}
// get screen dimensions
Bitmap image = decodeFile(filePaths.get(position), imageWidth,
imageWidth);
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setLayoutParams(new GridView.LayoutParams(imageWidth,
imageWidth));
imageView.setImageBitmap(image);
return imageView;
}
public static Bitmap decodeFile(String filePath, int WIDTH, int HIGHT) {
try {
File f = new File(filePath);
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
final int REQUIRED_WIDTH = WIDTH;
final int REQUIRED_HIGHT = HIGHT;
int scale = 1;
while (o.outWidth / scale / 2 >= REQUIRED_WIDTH
&& o.outHeight / scale / 2 >= REQUIRED_HIGHT) {
scale *= 2;
}
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return null;
}
}
set the adapter value to the GridView,Imagepaths i have stored my images in SD-card so only i give the paths to adapter...All the best
gridView = (GridView) findViewById(R.id.gridView1);
// loading all image paths from SD card
imagePaths = utils.getFilePaths();
// Gridview adapter
adapter = new GridViewImageAdapter(GridViewActivity.this, imagePaths,columnWidth);
// setting grid view adapter
gridView.setAdapter(adapter);