Develop Reference

Odd behavior in adding items to listview

I have a custom photo gallery and I need to get the selected images and display their filenames in a listview
This is my custom gallery:
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
public class CustomPhotoGallery extends Activity {
private GridView grdImages;
private Button btnSelect;
private ImageAdapter imageAdapter;
private String[] arrPath;
private boolean[] thumbnailsselection;
private int ids[];
private int count;
String filename;
/**
* Overrides methods
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.custom_gallery);
grdImages= (GridView) findViewById(R.id.grdImages);
btnSelect= (Button) findViewById(R.id.btnSelect);
final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
final String orderBy = MediaStore.Images.Media._ID;
#SuppressWarnings("deprecation")
Cursor imagecursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null, null, orderBy);
int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);
this.count = imagecursor.getCount();
this.arrPath = new String[this.count];
ids = new int[count];
this.thumbnailsselection = new boolean[this.count];
for (int i = 0; i < this.count; i++) {
imagecursor.moveToPosition(i);
ids[i] = imagecursor.getInt(image_column_index);
int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
arrPath[i] = imagecursor.getString(dataColumnIndex);
}
imageAdapter = new ImageAdapter();
grdImages.setAdapter(imageAdapter);
imagecursor.close();
btnSelect.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
final int len = thumbnailsselection.length;
int cnt = 0;
String selectImages = "";
for (int i = 0; i < len; i++) {
if (thumbnailsselection[i]) {
cnt++;
selectImages = selectImages + arrPath[i] + "|";
}
}
if (cnt == 0) {
Toast.makeText(getApplicationContext(), "Please select at least one image", Toast.LENGTH_LONG).show();
} else {
Log.d("SelectedImages", selectImages);
Intent i = new Intent();
i.putExtra("data", selectImages);
setResult(Activity.RESULT_OK, i);
finish();
}
}
});
}
#Override
public void onBackPressed() {
setResult(Activity.RESULT_CANCELED);
super.onBackPressed();
}
/**
* Class method
*/
/**
* This method used to set bitmap.
* #param iv represented ImageView
* #param id represented id
*/
private void setBitmap(final ImageView iv, final int id) {
new AsyncTask<Void, Void, Bitmap>() {
#Override
protected Bitmap doInBackground(Void... params) {
return MediaStore.Images.Thumbnails.getThumbnail(getApplicationContext().getContentResolver(), id, MediaStore.Images.Thumbnails.MICRO_KIND, null);
}
#Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
iv.setImageBitmap(result);
}
}.execute();
}
/**
* List adapter
* #author tasol
*/
public class ImageAdapter extends BaseAdapter {
private LayoutInflater mInflater;
public ImageAdapter() {
mInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
return count;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
holder = new ViewHolder();
convertView = mInflater.inflate(R.layout.custom_gallery_item, null);
holder.imgThumb = (ImageView) convertView.findViewById(R.id.imgThumb);
holder.chkImage = (CheckBox) convertView.findViewById(R.id.chkImage);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.chkImage.setId(position);
holder.imgThumb.setId(position);
holder.chkImage.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v;
int id = cb.getId();
if (thumbnailsselection[id]) {
cb.setChecked(false);
thumbnailsselection[id] = false;
} else {
cb.setChecked(true);
thumbnailsselection[id] = true;
}
}
});
holder.imgThumb.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
int id = holder.chkImage.getId();
if (thumbnailsselection[id]) {
holder.chkImage.setChecked(false);
thumbnailsselection[id] = false;
} else {
holder.chkImage.setChecked(true);
thumbnailsselection[id] = true;
}
}
});
try {
setBitmap(holder.imgThumb, ids[position]);
} catch (Throwable e) {
}
holder.chkImage.setChecked(thumbnailsselection[position]);
holder.id = position;
return convertView;
}
}
/**
* Inner class
* #author tasol
*/
class ViewHolder {
ImageView imgThumb;
CheckBox chkImage;
int id;
}
}
Now the result based on selection goes to main activity where I need to display all the selected images in a listview.
This is what I'm trying to do
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if(requestCode == PICK_IMAGE_MULTIPLE){
imagesPathList = new ArrayList<String>();
String[] imagesPath = data.getStringExtra("data").split("\\|");
try{
lnrImages.removeAllViews();
}catch (Throwable e){
e.printStackTrace();
}
for (int i=0;i<imagesPath.length;i++){
//Toast.makeText(MainActivity.this,String.valueOf(imagesPath.length),Toast.LENGTH_LONG).show();
imagesPathList.add(imagesPath[i]);
//Toast.makeText(MainActivity.this,imagesPathList.toString(),Toast.LENGTH_LONG).show();
yourbitmap = BitmapFactory.decodeFile(imagesPath[i]);
ImageView imageView = new ImageView(this);
imageView.setImageBitmap(yourbitmap);
imageView.setAdjustViewBounds(true);
//lnrImages.addView(imageView);
Uri uri = (Uri.fromFile(new File(imagesPath[i])));
filename = uri.getLastPathSegment();
//Toast.makeText(MainActivity.this,filename,Toast.LENGTH_LONG).show();
Uri selectedImage = data.getData();
encodedImage= bitmapToBase64(yourbitmap);
//Toast.makeText(MainActivity.this,encodedImage,Toast.LENGTH_LONG).show();
myStringList.add(filename);
myStringArray = myStringList.toArray();
lv.setAdapter(null);
Toast.makeText(MainActivity.this,(String)myStringArray[i],Toast.LENGTH_LONG).show();
arrayAdapter = new ArrayAdapter<String>(
this,
android.R.layout.simple_list_item_1,
myStringList );
lv.setAdapter(arrayAdapter);
arrayAdapter.notifyDataSetChanged();
}
}
}
}
Now my problem is:
1) If I select one single image it's showing me the toast with the filename but not adding it to the listview
2)If I select two images its adding to the list view as normal
3) If I select more than two its appending to the old list(ie..adding the newly selected images to the previously selected images) though I have set the adapter to 'NULL'
4) Selecting large number of images takes time consumption to adding it to the listview crashing the app due to memory.
So can anyone suggest me the best way of handling this ?
Thanks in Advance!

There are multiple problems in your code. As in Java everything is reference, so instead of creating the adapter again and again, you should only set the new list to the adapter and then should call notifyDataSetChanged. For example, your ImageAdapter should be like this
public class ImageAdapter extends BaseAdapter {
private LayoutInflater mInflater;
private ArrayList<String> imagesList = new ArrayList<>();
public void updateImagesList(ArrayList<Strinf> newImages) {
if(newImages != null && newImages.size() > 0) {
this.imagesList.clear();
this.imagesList.addAll(newImages);
}
}
}
and then you should create global Adapter variable which we will be using for future list updates
and in your onActivityResult, you should populate the strings list in a loop and then after the loop you should update the adapter list as
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == PICK_IMAGE_MULTIPLE) {
for (int i = 0; i < imagesPath.length; i++) {
//Toast.makeText(MainActivity.this,String.valueOf(imagesPath.length),Toast.LENGTH_LONG).show();
imagesPathList.add(imagesPath[i]);
//Toast.makeText(MainActivity.this,imagesPathList.toString(),Toast.LENGTH_LONG).show();
yourbitmap = BitmapFactory.decodeFile(imagesPath[i]);
ImageView imageView = new ImageView(this);
imageView.setImageBitmap(yourbitmap);
imageView.setAdjustViewBounds(true);
//lnrImages.addView(imageView);
Uri uri = (Uri.fromFile(new File(imagesPath[i])));
filename = uri.getLastPathSegment();
//Toast.makeText(MainActivity.this,filename,Toast.LENGTH_LONG).show();
Uri selectedImage = data.getData();
encodedImage = bitmapToBase64(yourbitmap);
//Toast.makeText(MainActivity.this,encodedImage,Toast.LENGTH_LONG).show();
myStringList.add(filename);
Toast.makeText(MainActivity.this, (String) myStringArray[i], Toast.LENGTH_LONG).show();
}
arrayAdapter.updateImages(myStringList);
arrayAdapter.notifyDataSetChanged();
}
}
}
Apart the above two changes, there is great performance impact because you are all doing I/O operations on Ui Thread as you are decoding Bitmap files on Main thread which is not the good approach as It will cause OutOfMemoryError as well as It will slow down your application. You should do bitmap operations or displaying using Universal Image Loader https://github.com/nostra13/Android-Universal-Image-Loader
Hope this helps.

Reduce Memory Consumption in In ListView with Bitmaps

I am Using this Fragment in which Song title,Artist Name, and Album art for corresponding song is being displayed in the custom ListView.
I am getting smooth Scrolling with the code. But the problem is that memory consumption for the app containing only one Activity and Fragment is very high. Can you suggest alternative approach. or help me increase efficiency of this code. thanks.
package com.vamp.playerFragments;
import android.content.ContentUris;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import com.vamp.R;
import com.vamp.adapters.AllSongsAdapter;
import com.vamp.models.AllSongsModel;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class AllSongs extends Fragment {
public AllSongsAdapter adapter;
private ListView allSongsList;
private int[] albumArts;
private String[] allSongs;
private String[] artistName;
private ArrayList<AllSongsModel> rowItems;
private OnFragmentInteractionListener mListener;
public AllSongs() {
// Required empty public constructor
}
public static AllSongs newInstance(String param1, String param2) {
AllSongs fragment = new AllSongs();
Bundle args = new Bundle();
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_all_songs, container, false);
allSongsList = (ListView) rootView.findViewById(R.id.allSongsList);
rowItems = new ArrayList<AllSongsModel>();
init_Songs_list();
adapter = new AllSongsAdapter(getActivity(), rowItems);
allSongsList.setAdapter(adapter);
return rootView;
}
public void init_Songs_list() {
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String proj[] = {
MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.ALBUM_ID
};
Cursor MainCursor = getActivity().getContentResolver().query(uri, proj, MediaStore.Audio.Media.IS_MUSIC + " =1", null, MediaStore.Audio.Media.TITLE + " ASC");
MainCursor.moveToFirst();
while (MainCursor.moveToNext()) {
String title = MainCursor.getString(MainCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));
String artistName = MainCursor.getString(MainCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
Long albumId = MainCursor.getLong(MainCursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM_ID));
Uri sArtWorkUri = Uri.parse("content://media/external/audio/albumart");
Uri albumArtUri = ContentUris.withAppendedId(sArtWorkUri, albumId);
Bitmap bitmap = null;
try {
bitmap = MediaStore.Images.Media.getBitmap(
getActivity().getContentResolver(), albumArtUri);
//bitmap = Bitmap.createScaledBitmap(bitmap, 30, 30, true);
} catch (FileNotFoundException exception) {
exception.printStackTrace();
bitmap = BitmapFactory.decodeResource(getActivity().getResources(),
R.drawable.ic_launcher);
} catch (IOException e) {
e.printStackTrace();
}
AllSongsModel allSongsModel = new AllSongsModel();
allSongsModel.setSongName(title);
allSongsModel.setArtistName(artistName);
allSongsModel.setAlbumArt(bitmap);
rowItems.add(allSongsModel);
}
}
}

I don't know if you like using third-party libraries, but I use this one in my project and it's optimized to this situations (and plenty others). Check Picasso, give it a try ! It's pretty easy to use and their docs are excellent.
Hope it helps!

You should resize your bitmaps before you load them using the following code:
Bitmap downsizeBitmap = Bitmap.createScaledBitmap(bitmap, 50, 50, false);
This will dramatically reduce memory consumption if your bitmaps are a lot bigger.

After Searching and implementing lots of method I came to find this awesome library. https://github.com/nostra13/Android-Universal-Image-Loader and implemented as per the instructions and Now the app is working fine. With no more memory issues and almost same performance as before. Check out the code below.
package com.vamp.adapters;
import...//all the imports/
public class AllSongsAdapter extends BaseAdapter {
private ArrayList<AllSongsModel> mAllSongsList;
private Context context;
private LayoutInflater mInflater;
private AllSongsModel allSongsModel;
private Bitmap bmp;
public AllSongs allSongs;
//Android Universal Image Loader Classes.
private DisplayImageOptions options;
private ImageLoadingListener animateFirstListener = new AnimateFirstDisplayListener();
public AllSongsAdapter(Context context, ArrayList<AllSongsModel> mAllSongsList) {
mInflater = LayoutInflater.from(context);
this.mAllSongsList = mAllSongsList;
this.context = context;
options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_launcher)
.showImageForEmptyUri(R.drawable.ic_launcher)
.showImageOnFail(R.drawable.ic_launcher)
.cacheInMemory(true)
.cacheOnDisk(true)
.considerExifParams(true)
.displayer(new RoundedBitmapDisplayer(20))
.build();
}
#Override
public int getCount() {
return mAllSongsList.size();
}
#Override
public Object getItem(int position) {
return mAllSongsList.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View view;
ViewHolder holder;
if (convertView == null) {
view = mInflater.inflate(R.layout.all_songs_list_row, parent, false);
holder = new ViewHolder();
holder.albumArt = (ImageView) view.findViewById(R.id.all_songs_list_row_albumart);
holder.songName = (TextView) view.findViewById(R.id.all_songs_list_row_songName);
holder.artistName = (TextView) view.findViewById(R.id.all_songs_list_row_artistName);
view.setTag(holder);
} else {
view = convertView;
holder = (ViewHolder) view.getTag();
//holder.mImageLoader.cancel();
}
AllSongsModel allSongsModel = mAllSongsList.get(position);
ImageLoader.getInstance().displayImage(Uri.decode(String.valueOf(allSongsModel.getAlbum_art_uri())),holder.albumArt,options,animateFirstListener);
holder.songName.setText(allSongsModel.getSongName());
holder.artistName.setText(allSongsModel.getArtistName());
return view;
}
private class ViewHolder {
public ImageView albumArt;
public TextView songName, artistName;
public AsyncImageSetter mImageLoader;
}
private static class AnimateFirstDisplayListener extends SimpleImageLoadingListener {
static final List<String> displayedImages = Collections.synchronizedList(new LinkedList<String>());
#Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
if (loadedImage != null) {
ImageView imageView = (ImageView) view;
boolean firstDisplay = !displayedImages.contains(imageUri);
if (firstDisplay) {
FadeInBitmapDisplayer.animate(imageView, 500);
displayedImages.add(imageUri);
}
}
}
}
}
And My AllSongs.java(Fragment) class is same as before with only One change that Instead of using Bitmap Directly to the adapter I am now passing the URI of that Bitmap to the adpater.And the app just works flawlessly.
Thanks to everyone who suggested me different approaches for the solution. I learned a lot from this.

Image From sd card to galleryview

In my app i want to get the Images from SD card to a specific position and i need to display in gallery,
The code i used is attaching
private Gallery gallery;
private ImageView imgView;
int position;
private byte[] data = { };
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gridview);
try{
String filepath = "/sdcard/data/Crak/";
File imagefile = new File(filepath +"abcd.jpg" );
FileInputStream fis = new FileInputStream(imagefile);
Bitmap bi = BitmapFactory.decodeStream(fis);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bi.compress(Bitmap.CompressFormat.JPEG, 100, baos);
data = baos.toByteArray();
System.out.println("cnvrtn");
}
catch(Exception e) {
e.printStackTrace();
}
final Bitmap bitmapimage = BitmapFactory.decodeByteArray(data, 0, data.length);
position = 0;
imgView = (ImageView) findViewById(R.id.ImageView01);
imgView.setImageBitmap(bitmapimage);
gallery = (Gallery) findViewById(R.id.examplegallery);
gallery.setAdapter(new AddImgAdp(this));
gallery.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView parent, View v, int position,
long id) {
imgView.setImageBitmap(bitmapimage);
DisplayImage.this.position = position;
}
});
System.out.println("Enter the activity//////////");
imgView.setOnClickListener(new View.OnClickListener() {
#SuppressWarnings("deprecation")
#Override
public void onClick(View paramView) {
// TODO Auto-generated method stub
}
});
}
public class AddImgAdp extends BaseAdapter {
int GalItemBg;
private Context cont;
#SuppressWarnings("null")
public AddImgAdp(Context c) {
cont = c;
TypedArray typArray = obtainStyledAttributes(R.styleable.GalleryTheme);
GalItemBg = typArray.getResourceId(
R.styleable.GalleryTheme_android_galleryItemBackground, 0);
typArray.recycle();
}
public int getCount() {
return data.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imgView = new ImageView(cont);
final Bitmap bitmapimage = BitmapFactory.decodeByteArray(data, 0, data.length);
imgView.setImageBitmap(bitmapimage);;
imgView.setLayoutParams(new Gallery.LayoutParams(100, 100));
imgView.setScaleType(ImageView.ScaleType.FIT_XY);
imgView.setBackgroundResource(GalItemBg);
return imgView;
}
}
The problems are
1)How can i get all image in the specific folder in SD card
2) GalleryView is indefiniite or a long one without end

here is the UPDATED code to get images from specific path...
package com.example.gall;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import com.example.gall.R;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.AdapterView.OnItemClickListener;
public class gall extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Gallery g = (Gallery) findViewById(R.id.gallery);
g.setAdapter(new ImageAdapter(this, ReadSDCard()));
g.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent,
View v, int position, long id) {
}
});
}
private List<String> ReadSDCard()
{
List<String> tFileList = new ArrayList<String>();
//It have to be matched with the directory in SDCard
File f = new File("/android/sdcard2/");
File[] files=f.listFiles();
for(int i=0; i<files.length; i++)
{
File file = files[i];
/*It's assumed that all file in the path are in supported type*/
tFileList.add(file.getPath());
}
return tFileList;
}
public class ImageAdapter extends BaseAdapter {
int mGalleryItemBackground;
private Context mContext;
private List<String> FileList;
public ImageAdapter(Context c, List<String> fList) {
mContext = c;
FileList = fList;
TypedArray a = obtainStyledAttributes(R.styleable.gall);
mGalleryItemBackground = a.getResourceId(
R.styleable.gall_android_galleryItemBackground,0);
a.recycle();
}
public int getCount() {
return FileList.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView,
ViewGroup parent) {
ImageView i = new ImageView(mContext);
Bitmap bm = BitmapFactory.decodeFile(
FileList.get(position).toString());
i.setImageBitmap(bm);
i.setLayoutParams(new Gallery.LayoutParams(150, 100));
i.setScaleType(ImageView.ScaleType.FIT_XY);
i.setBackgroundResource(mGalleryItemBackground);
return i;
}
}
public TypedArray obtainStyledAttributes(int theme) {
// TODO Auto-generated method stub
return null;
}
}

Getting all the images will cause a memory overflow the best way is to keep a list of paths in string form and supply that to the gallery. If you are making a custom gallery you will have to create bitmaps and garbage collect them.
This is a good way to access sd-card:
String path = Environment.getExternalStorageDirectory().getPath()+ "/yourFolder/"
This is how to get the list
File directory = new File(path);
if(directory.isDirectory)
{
if(directory.list().length > 0 /*&& check if its an img etc*/)
{
for(String s: directory.list())
{
Log.d(TAG, "adding " + s);
fileNames.add(s);
}
}
}
you should make sure to check sd-card is loaded

//YOUR CODE HERE...
String[] projection = new String[]{
MediaStore.Images.Media._ID,
MediaStore.Images.Media.DATA, // add DATA column
MediaStore.Images.Media.BUCKET_DISPLAY_NAME,
MediaStore.Images.Media.DATE_TAKEN,
MediaStore.Images.Media.TITLE,
};
// Get the base URI for the People table in the Contacts content provider.
Uri images = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
Log.i("URI", images.toString());
// Make the query.
Cursor cur = managedQuery(
MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
projection, // Which columns to return
null, // Which rows to return (all rows)
null, // Selection arguments (none)
MediaStore.Images.Thumbnails.IMAGE_ID // Ordering
);
Log.i("ListingImages"," query count="+cur.getCount());
if (cur.moveToFirst()) {
String bucket;
String date;
String name;
int bucketColumn = cur.getColumnIndex(
MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
int dateColumn = cur.getColumnIndex(
MediaStore.Images.Media.DATE_TAKEN);
int nameColumn = cur.getColumnIndex(
MediaStore.Images.Media.TITLE);
// Get the field values
bucket = cur.getString(bucketColumn);
date = cur.getString(dateColumn);
name = cur.getString(nameColumn);
int columnIndex = cur.getColumnIndex(MediaStore.Images.Media.DATA);
String picPath = cur.getString(columnIndex);
imageView.setImageBitmap(BitmapFactory.decodeFile(picPath));
// Do something with the values.
Log.i("ListingImages", " bucket=" + bucket
+ " name_taken=" + name);
}
}

Loading image bitmap from content providers using asynctask

I have been trying to query for all images on sd card through MediaStore content provider and display their thumbnail on a GridView.
However, if i load the image thumbnail on the main thread, the scrolling gets incredibly slow...
So i tried to load the bitmap through asynctasks:
Scrolling performance got better, but now the grid items keep reloading their thumbnail until it gets the correct bitmap...
Here is my asynctask, which loads the bitmaps:
package x.y;
import java.lang.ref.WeakReference;
import android.content.ContentResolver;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory.Options;
import android.os.AsyncTask;
import android.provider.MediaStore;
import android.widget.ImageView;
public class ImageThumbnailLoader extends AsyncTask<Long, Void, Bitmap> {
private final Options mOptions;
private WeakReference<ImageView> mImageViewWeakReference;
private ContentResolver mContentResolver;
public ImageThumbnailLoader(ImageView imageView,
ContentResolver cr) {
mContentResolver = cr;
mImageViewWeakReference = new WeakReference<ImageView>(imageView);
mOptions = new Options();
mOptions.inSampleSize = 4;
}
#Override
protected Bitmap doInBackground(Long... params) {
Bitmap result;
result = MediaStore.Images.Thumbnails.getThumbnail(
mContentResolver, params[0],
MediaStore.Images.Thumbnails.MINI_KIND, mOptions);
return result;
}
#Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
if (mImageViewWeakReference != null
&& mImageViewWeakReference.get() != null)
mImageViewWeakReference.get().setImageBitmap(result);
}
}
And here is my custom cursor adapter:
package x.y;
import android.content.Context;
import android.database.Cursor;
import android.graphics.BitmapFactory.Options;
import android.provider.MediaStore;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.ImageView;
public class MediaCursorAdapter extends CursorAdapter {
private LayoutInflater mInflater;
private final static int mColumnID = 0;
private Options mOptions;
public MediaCursorAdapter(Context context, Cursor c) {
super(context, c);
mInflater = LayoutInflater.from(context);
mOptions = new Options();
mOptions.inSampleSize = 4;
}
#Override
public void bindView(View view, Context context, Cursor cursor) {
ViewHolder holder = (ViewHolder) view.getTag();
ImageThumbnailLoader imageLoader = new ImageThumbnailLoader(holder.thumbImg,
context.getContentResolver());
imageLoader.execute(cursor.getLong(mColumnID));
// holder.thumbImg.setImageBitmap(MediaStore.Images.Thumbnails.getThumbnail(
// context.getContentResolver(), cursor.getLong(mColumnID),
// MediaStore.Images.Thumbnails.MINI_KIND, mOptions));
Log.i("Prototype", "bindView : " + cursor.getPosition());
}
#Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
Log.i("Prototype", "newView : " + cursor.getPosition());
View view = mInflater.inflate(R.layout.grid_item, null);
ViewHolder holder = new ViewHolder(view);
view.setTag(holder);
return view;
}
private static class ViewHolder {
ImageView thumbImg, dragImg;
ViewHolder(View base) {
thumbImg = (ImageView) base.findViewById(R.id.thumbImage);
dragImg = (ImageView) base.findViewById(R.id.dragImage);
}
}
}
I query the cursor with this code and send it to the adapter:
query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new String[] { MediaStore.Images.Media._ID,
MediaStore.Images.Media.DATA }, null, null,
MediaStore.Images.Media._ID);
Looks like the bindview() on my custom cursor adapter gets called more often than it is supposed to... Anyone knows how can i make the images on my gridview stop reloading while mantaining the scrolling performance??
Thanks in advance.

Problem solved, had to check if image at the start of async task was the same as the image at the end of it, on onPostExecute().
new bindView:
#Override
public void bindView(View view, Context context, Cursor cursor) {
ViewHolder holder = (ViewHolder) view.getTag();
holder.thumbImg.setId(cursor.getPosition());
ImageThumbnailLoader imageLoader = new ImageThumbnailLoader(holder.thumbImg,
context.getContentResolver());
imageLoader.execute(cursor.getLong(mColumnID));
Log.i("Prototype", "bindView : " + cursor.getPosition());
}
new Async:
public class ImageThumbnailLoader extends AsyncTask<Long, Void, Bitmap> {
private final Options mOptions;
private WeakReference<ImageView> mImageViewWeakReference;
private ContentResolver mContentResolver;
private int mPosition;
public ImageThumbnailLoader(ImageView imageView,
ContentResolver cr) {
mContentResolver = cr;
mImageViewWeakReference = new WeakReference<ImageView>(imageView);
mOptions = new Options();
mOptions.inSampleSize = 4;
mPosition = imageView.getId();
}
#Override
protected Bitmap doInBackground(Long... params) {
Bitmap result;
result = MediaStore.Images.Thumbnails.getThumbnail(
mContentResolver, params[0],
MediaStore.Images.Thumbnails.MINI_KIND, mOptions);
return result;
}
#Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
if (mImageViewWeakReference != null
&& mImageViewWeakReference.get() != null
&& mPosition == mImageViewWeakReference.get().getId())
mImageViewWeakReference.get().setImageBitmap(result);
}
}

Set an image to wallpaper

I am new to coding and never worked with it before! We are working with Android and Java eclipse, it's a school project. Now I am working with a band application were I am supposed to create the gallery. This I managed, but to create a function were the user can set an image to a wallpaper, I couldn't. I need some help with this! I believe I found good code, but I don't know how to implement it in my work.
Does anyone know how I should connect these to each other? Really thankful for help,
Sandra
My Gallery code:
package com.Lavin;
import com.Lavin.R;
import java.io.IOException;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.Gallery.LayoutParams;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.app.WallpaperManager;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
public class Lavin extends Activity implements
AdapterView.OnItemSelectedListener, ViewSwitcher.ViewFactory {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
mSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
mSwitcher.setFactory(this);
mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_in));
mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
android.R.anim.fade_out));
Gallery g = (Gallery) findViewById(R.id.gallery);
g.setAdapter(new ImageAdapter(this));
g.setOnItemSelectedListener(this);
}
public void onItemSelected(AdapterView parent, View v, int position, long id) {
mSwitcher.setImageResource(mImageIds[position]);
}
public void onNothingSelected(AdapterView parent) {
}
public View makeView() {
ImageView i = new ImageView(this);
i.setBackgroundColor(0xFF000000);
i.setScaleType(ImageView.ScaleType.FIT_CENTER);
i.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));
return i;
}
private ImageSwitcher mSwitcher;
public class ImageAdapter extends BaseAdapter {
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(mContext);
i.setImageResource(mThumbIds[position]);
i.setAdjustViewBounds(true);
i.setLayoutParams(new Gallery.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
i.setBackgroundResource(R.drawable.picture_frame);
return i;
}
private Context mContext;
}
private Integer[] mThumbIds = {
R.drawable.lavin_thumb_0, R.drawable.lavin_thumb_1,
R.drawable.lavin_thumb_2, R.drawable.lavin_thumb_3,
R.drawable.lavin_thumb_4, R.drawable.lavin_thumb_5,
R.drawable.lavin_thumb_6, R.drawable.lavin_thumb_7,
R.drawable.lavin_thumb_8, R.drawable.lavin_thumb_9,
R.drawable.lavin_thumb_10, R.drawable.lavin_thumb_11,
R.drawable.lavin_thumb_12};
private Integer[] mImageIds = {
R.drawable.lavin_0, R.drawable.lavin_1, R.drawable.lavin_2,
R.drawable.lavin_3, R.drawable.lavin_4, R.drawable.lavin_5,
R.drawable.lavin_6, R.drawable.lavin_7, R.drawable.lavin_8,
R.drawable.lavin_9, R.drawable.lavin_10,
R.drawable.lavin_11, R.drawable.lavin_12};
}
My Wallpaper code:
package com.Lavin;
import android.app.Activity;
import android.os.Bundle;
import java.io.IOException;
import android.app.Activity;
import android.app.WallpaperManager;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class Wallpaper extends Activity {
final static private int[] mColors =
{Color.BLUE, Color.GREEN, Color.RED, Color.LTGRAY, Color.MAGENTA, Color.CYAN,
Color.YELLOW, Color.WHITE};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final WallpaperManager wallpaperManager = WallpaperManager.getInstance(this);
final Drawable wallpaperDrawable = wallpaperManager.getDrawable();
final ImageView imageView = (ImageView) findViewById(R.id.imageview);
imageView.setDrawingCacheEnabled(true);
imageView.setImageDrawable(wallpaperDrawable);
Button randomize = (Button) findViewById(R.id.randomize);
randomize.setOnClickListener(new OnClickListener() {
public void onClick(View view) {
int mColor = (int) Math.floor(Math.random() * mColors.length);
wallpaperDrawable.setColorFilter(mColors[mColor], PorterDuff.Mode.MULTIPLY);
imageView.setImageDrawable(wallpaperDrawable);
imageView.invalidate();
}
});
Button setWallpaper = (Button) findViewById(R.id.setwallpaper);
setWallpaper.setOnClickListener(new OnClickListener() {
public void onClick(View view) {
try {
wallpaperManager.setBitmap(imageView.getDrawingCache());
finish();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}
}

public class LoadImagesFromSDCardActivity extends Activity implements
OnItemClickListener {
/**
* Grid view holding the images.
*/
private GridView sdcardImages;
/**
* Image adapter for the grid view.
*/
private ImageAdapter imageAdapter;
/**
* Display used for getting the width of the screen.
*/
private Display display;
/**
* Creates the content view, sets up the grid, the adapter, and the click listener.
*
* #see android.app.Activity#onCreate(android.os.Bundle)
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Request progress bar
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.sdcard);
display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
setupViews();
setProgressBarIndeterminateVisibility(true);
loadImages();
}
/**
* Free up bitmap related resources.
*/
protected void onDestroy() {
super.onDestroy();
final GridView grid = sdcardImages;
final int count = grid.getChildCount();
ImageView v = null;
for (int i = 0; i < count; i++) {
v = (ImageView) grid.getChildAt(i);
((BitmapDrawable) v.getDrawable()).setCallback(null);
}
}
/**
* Setup the grid view.
*/
private void setupViews() {
sdcardImages = (GridView) findViewById(R.id.sdcard);
sdcardImages.setNumColumns(display.getWidth()/95);
sdcardImages.setClipToPadding(false);
sdcardImages.setOnItemClickListener(LoadImagesFromSDCardActivity.this);
imageAdapter = new ImageAdapter(getApplicationContext());
sdcardImages.setAdapter(imageAdapter);
}
/**
* Load images.
*/
private void loadImages() {
final Object data = getLastNonConfigurationInstance();
if (data == null) {
new LoadImagesFromSDCard().execute();
} else {
final LoadedImage[] photos = (LoadedImage[]) data;
if (photos.length == 0) {
new LoadImagesFromSDCard().execute();
}
for (LoadedImage photo : photos) {
addImage(photo);
}
}
}
/**
* Add image(s) to the grid view adapter.
*
* #param value Array of LoadedImages references
*/
private void addImage(LoadedImage... value) {
for (LoadedImage image : value) {
imageAdapter.addPhoto(image);
imageAdapter.notifyDataSetChanged();
}
}
/**
* Save bitmap images into a list and return that list.
*
* #see android.app.Activity#onRetainNonConfigurationInstance()
*/
#Override
public Object onRetainNonConfigurationInstance() {
final GridView grid = sdcardImages;
final int count = grid.getChildCount();
final LoadedImage[] list = new LoadedImage[count];
for (int i = 0; i < count; i++) {
final ImageView v = (ImageView) grid.getChildAt(i);
list[i] = new LoadedImage(((BitmapDrawable) v.getDrawable()).getBitmap());
}
return list;
}
/**
* Async task for loading the images from the SD card.
*
* #author Mihai Fonoage
*
*/
class LoadImagesFromSDCard extends AsyncTask<Object, LoadedImage, Object> {
/**
* Load images from SD Card in the background, and display each image on the screen.
*
* #see android.os.AsyncTask#doInBackground(Params[])
*/
#Override
protected Object doInBackground(Object... params) {
//setProgressBarIndeterminateVisibility(true);
Bitmap bitmap = null;
Bitmap newBitmap = null;
Uri uri = null;
// Set up an array of the Thumbnail Image ID column we want
String[] projection = {MediaStore.Images.Thumbnails._ID};
// Create the cursor pointing to the SDCard
Cursor cursor = managedQuery( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
projection, // Which columns to return
null, // Return all rows
null,
null);
int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID);
int size = cursor.getCount();
// If size is 0, there are no images on the SD Card.
if (size == 0) {
//No Images available, post some message to the user
}
int imageID = 0;
for (int i = 0; i < size; i++) {
cursor.moveToPosition(i);
imageID = cursor.getInt(columnIndex);
uri = Uri.withAppendedPath(MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + imageID);
try {
bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri));
if (bitmap != null) {
newBitmap = Bitmap.createScaledBitmap(bitmap, 70, 70, true);
bitmap.recycle();
if (newBitmap != null) {
publishProgress(new LoadedImage(newBitmap));
}
}
} catch (IOException e) {
//Error fetching image, try to recover
}
}
cursor.close();
return null;
}
/**
* Add a new LoadedImage in the images grid.
*
* #param value The image.
*/
#Override
public void onProgressUpdate(LoadedImage... value) {
addImage(value);
}
/**
* Set the visibility of the progress bar to false.
*
* #see android.os.AsyncTask#onPostExecute(java.lang.Object)
*/
#Override
protected void onPostExecute(Object result) {
setProgressBarIndeterminateVisibility(false);
}
}
/**
* Adapter for our image files.
*
* #author Mihai Fonoage
*
*/
class ImageAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<LoadedImage> photos = new ArrayList<LoadedImage>();
public ImageAdapter(Context context) {
mContext = context;
}
public void addPhoto(LoadedImage photo) {
photos.add(photo);
}
public int getCount() {
return photos.size();
}
public Object getItem(int position) {
return photos.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
final ImageView imageView;
if (convertView == null) {
imageView = new ImageView(mContext);
} else {
imageView = (ImageView) convertView;
}
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
imageView.setPadding(8, 8, 8, 8);
imageView.setImageBitmap(photos.get(position).getBitmap());
return imageView;
}
}
/**
* A LoadedImage contains the Bitmap loaded for the image.
*/
private static class LoadedImage {
Bitmap mBitmap;
LoadedImage(Bitmap bitmap) {
mBitmap = bitmap;
}
public Bitmap getBitmap() {
return mBitmap;
}
}
/**
* When an image is clicked, load that image as a puzzle.
*/
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
int columnIndex = 0;
String[] projection = {MediaStore.Images.Media.DATA};
Cursor cursor = managedQuery( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
projection,
null,
null,
null);
if (cursor != null) {
columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToPosition(position);
String imagePath = cursor.getString(columnIndex);
FileInputStream is = null;
BufferedInputStream bis = null;
try {
is = new FileInputStream(new File(imagePath));
bis = new BufferedInputStream(is);
Bitmap bitmap = BitmapFactory.decodeStream(bis);
Bitmap useThisBitmap = Bitmap.createScaledBitmap(bitmap, parent.getWidth(), parent.getHeight(), true);
bitmap.recycle();
//Display bitmap (useThisBitmap)
}
catch (Exception e) {
//Try to recover
}
finally {
try {
if (bis != null) {
bis.close();
}
if (is != null) {
is.close();
}
cursor.close();
projection = null;
} catch (Exception e) {
}
}
}
}
}
The sdcard.xml file:
<GridView
android:id="#+id/sdcard"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center" />