I want to collect all photos in pictures directory to show them in GridView, so tried with two ways.
1_ without using AsyncTask: this way worked very well but it has a problem which is that the app freezes for seconds to get all photos in specified directory and it's sub directories.
2_using AsyncTask: this way doesn't get any images and the list of images is always empty, I know that I should use Asynctask for processes that take mush time to processed and I don't know what I missed when using AsyncTask.
what I want is to find a way to collect all photos using AsyncTask with app freezing and thanks in advance.
public static class ImagesFragment extends Fragment {
static List<Image> imagesList = new ArrayList<>();
GridViewRecyclerAdapter gridViewRecyclerAdapter;
GridView gridView;
Spinner spinner;
public static File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// imagesList = loadImageData(file);
gridViewRecyclerAdapter = new GridViewRecyclerAdapter(imagesList, getContext());
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_images, container, false);
spinner = view.findViewById(R.id.spinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getContext(), R.array.spinner, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
switch (position){
case 0:
break;
case 1:
break;
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
gridView = view.findViewById(R.id.grid_view);
gridView.setAdapter(gridViewRecyclerAdapter);
return view;
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight && (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
public static List<Image> loadImageData(File file) {
String fileType;
String extension;
if(file.isDirectory()){
File[] files = file.listFiles();
for(File file1: files){
if(file1.isDirectory())
loadImageData(file1);
else{
extension = MimeTypeMap.getFileExtensionFromUrl(file1.getPath());
if (extension != null) {
fileType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
if(fileType != null)
if(fileType.contains("image")){
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = calculateInSampleSize(options, 500, 500);
options.inJustDecodeBounds = false;
Bitmap bitmap = BitmapFactory.decodeFile(file1.getAbsolutePath(), options);
// bitmap = Bitmap.createScaledBitmap(bitmap, bitmap.getWidth(), bitmap.getHeight())
imagesList.add(new Image(bitmap, file1.getName(), file1.getPath()));
}
}
}
}
}
else {
extension = MimeTypeMap.getFileExtensionFromUrl(file.getPath());
if (extension != null) {
fileType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
if(fileType != null)
if(fileType.contains("image")){
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = calculateInSampleSize(options, 500, 500);
options.inJustDecodeBounds = false;
Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath(), options);
imagesList.add(new Image(bitmap, file.getName(), file.getPath()));
}
}
}
return imagesList;
}
}
public static class GridViewRecyclerAdapter extends BaseAdapter {
List<Image> imageList;
Context context;
static int position;
public GridViewRecyclerAdapter(List<Image> imageList, Context context){
this.imageList = imageList;
this.context = context;
}
#Override
public int getCount() {
return imageList.size();
}
#Override
public Object getItem(int position) {
return imageList.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if(convertView == null){
convertView = LayoutInflater.from(context).inflate(R.layout.images_item, parent, false);
viewHolder = new ViewHolder();
viewHolder.imageView = convertView.findViewById(R.id.image_view);
viewHolder.imageView.setTag(imageList.get(position).path);
viewHolder.textView = convertView.findViewById(R.id.text_view);
convertView.setTag(viewHolder);
}
else
viewHolder = (ViewHolder) convertView.getTag();
new LoadImageAsyncTask().execute(ImagesFragment.file.getAbsolutePath());
viewHolder.imageView.setImageBitmap(imageList.get(position).bitmap);
viewHolder.textView.setText(imageList.get(position).title);
GridViewRecyclerAdapter.position = position;
return convertView;
}
public static class ViewHolder{
ImageView imageView;
TextView textView;
}
static class LoadImageAsyncTask extends AsyncTask<String, Void, List<Image>> {
#Override
protected List<Image> doInBackground(String... objects) {
ImagesFragment.imagesList = ImagesFragment.loadImageData(new File(objects[0]));
return ImagesFragment.imagesList;
}
}
}
Related
I Have problem with sliding pictures in my activity. When I slide 5-10 times I get an OutOfMemoryError. This is nothing extraordinary. My problem is related with using BitmapFactory and calculating size of image like in this page: https://android.jlelse.eu/loading-large-bitmaps-efficiently-in-android-66826cd4ad53. I don't know how it works when I'm using SlidingAdapter/PagerAdapter and my images are numbered.
This is my code:
public class SliderAdapter extends PagerAdapter {
static Resources res = null;
Context context;
LayoutInflater layoutInflater;
public SliderAdapter(Context context)
{
this.context = context;
slide_headings = context.getResources().getStringArray(R.array.p06_naglowek);
slide_descs = context.getResources().getStringArray(R.array.p06_opis);
}
public int [] slide_images = {
R.drawable.komputer_startowe,
R.drawable.ecu_version,
R.drawable.potrzebne_elementy,
R.drawable.co_gdzie,
R.drawable.rm11,
R.drawable.p06_finish
};
String[] slide_headings;
String[] slide_descs;
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight
&& (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
#Override
public int getCount() {
return slide_headings.length;
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view == (RelativeLayout) object;
}
#NonNull
#Override
public Object instantiateItem(#NonNull ViewGroup container, int position) {
layoutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(R.layout.slide_layout, container, false);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = false;
options.inSampleSize = calculateInSampleSize(options, 500,500);
Bitmap startImage = BitmapFactory.decodeResource(context.getResources(),R.drawable.komputer_startowe,options);
ImageView slideImageView = (ImageView) view.findViewById(R.id.slide_image);
TextView slideHeading = (TextView) view.findViewById(R.id.slide_heading);
TextView slideDescription = (TextView) view.findViewById(R.id.slide_desc);
slideImageView.setImageResource(slide_images[position]);
slideHeading.setText(slide_headings[position]);
slideDescription.setText(slide_descs[position]);
container.addView(view);
return view;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((RelativeLayout)object);
}
}
Okay, I've got solution. Maybe it'll be usable for someone.
Here is the activity:
public class SliderAdapter extends PagerAdapter {
static Resources res = null;
Context context;
LayoutInflater layoutInflater;
static Bitmap bitmap;
public SliderAdapter(Context context)
{
this.context = context;
slide_headings = context.getResources().getStringArray(R.array.p06_naglowek);
slide_descs = context.getResources().getStringArray(R.array.p06_opis);
}
public int [] slide_images = {
R.drawable.komputer_startowe,
R.drawable.ecu_version,
R.drawable.potrzebne_elementy,
R.drawable.co_gdzie,
R.drawable.rm11,
R.drawable.p06_finish
};
String[] slide_headings;
String[] slide_descs;
#Override
public int getCount() {
return slide_headings.length;
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view == (RelativeLayout) object;
}
#NonNull
BitmapFactory.Options o = new BitmapFactory.Options();
o.inSampleSize = 1;
// o.inDither = false;
o.inScaled = true;
o.inDensity = srcWidth;
o.inTargetDensity = dstWidth*o.inSampleSize;
Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), slide_images[position], o);
ImageView slideImageView = (ImageView) view.findViewById(R.id.slide_image);
TextView slideHeading = (TextView) view.findViewById(R.id.slide_heading);
TextView slideDescription = (TextView) view.findViewById(R.id.slide_desc);
slideImageView.setImageResource(slide_images[position]);
slideHeading.setText(slide_headings[position]);
slideDescription.setText(slide_descs[position]);
slideImageView.setImageBitmap(bitmap);
container.addView(view);
return view;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((RelativeLayout)object);
}
}
I created a Gallery that get the image from an External Storage, and also i decreased the height resolution of images but i got this :
I/Choreographer: Skipped 41 frames! The application may be
doing too much work on its main thread.
Also my ListView Lag.
What should to remove the Lag?
Here it is my Code :
ListView mList;
ArrayList<File> list;
Bitmap firstBitmap;
private Context context;
private LayoutInflater inflater = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
list = imageReader(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES));
context = getApplicationContext();
inflater = LayoutInflater.from(context);
mList = (ListView)findViewById(R.id.listView);
mList.setAdapter(new MyListAdapter());
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight
&& (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
public static Bitmap decodeSampledBitmapFromFile (String file, int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(String.valueOf(file), options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
Log.d("Width","Bitmap : "+reqWidth);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(String.valueOf(file), options);
}
class MyListAdapter extends BaseAdapter{
#Override
public int getCount() {
return list.size();
}
#Override
public Object getItem(int i) {
return list.get(i);
}
#Override
public long getItemId(int i) {
return 0;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
final ViewHolder holder;
if (view == null){
view = inflater.inflate(R.layout.card_item_template,viewGroup,false);
holder = new ViewHolder();
holder._vw_blayer = view.findViewById(R.id.vw_blacklayer);
holder.imageView = (ImageView)view.findViewById(R.id.img_background);
holder.imageViewround = (ImageView)view.findViewById(R.id.img_cover_d);
view.setTag(holder);
}else {
holder = (ViewHolder) view.getTag();
}
firstBitmap = decodeSampledBitmapFromFile(list.get(i).getAbsolutePath(),600,316);
holder.imageView.setImageBitmap(firstBitmap);
// Picasso.with(context).load(list.get(i)).into(holder.imageView);
// Picasso.with(context).load(list.get(i)).into(holder.imageViewround);
holder.imageViewround.setImageBitmap(firstBitmap);
Log.d("getItem","I"+getItem(i));
ObjectAnimator fade = ObjectAnimator.ofFloat(holder._vw_blayer, View.ALPHA, 1f,.3f);
fade.setDuration(1500);
fade.setInterpolator(new LinearInterpolator());
fade.start();
return view;
}
}
ArrayList<File> imageReader(File root){
ArrayList<File> a = new ArrayList<>();
File[] files = root.listFiles();
for (int i = 0; i< files.length; i++){
if (files[i].isDirectory()){
a.addAll(imageReader(files[i]));
}else {
if (files[i].getName().endsWith(".jpg")){
a.add(files[i]);
}
}
}
return a;
}
private class ViewHolder {
View _vw_blayer;
ImageView imageView,imageViewround;
}
}
I'm new to android and have been working with a tutorial which loads all images from a directory on the SD card. I have the tutorial running but would like to add some code to the click listener which will load a full size version of the thumbnail in the gridview image adapter.
public class PicturesFragment extends Fragment {
public class ImageAdapter extends BaseAdapter {
private Context mContext;
ArrayList<String> itemList = new ArrayList<String>();
public ImageAdapter(Context c) {
mContext = c;
}
void add(String path) {
itemList.add(path);
}
#Override
public int getCount() {
return itemList.size();
}
#Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return itemList.get(position);
}
#Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) { // if it's not recycled, initialize some
// attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(225, 225));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(1, 1, 1, 1);
} else {
imageView = (ImageView) convertView;
}
Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220,
220);
imageView.setImageBitmap(bm);
return imageView;
}
public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth,
int reqHeight) {
Bitmap bm = null;
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth,
reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeFile(path, options);
return bm;
}
public int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
if (width > height) {
inSampleSize = Math.round((float) height
/ (float) reqHeight);
} else {
inSampleSize = Math.round((float) width / (float) reqWidth);
}
}
return inSampleSize;
}
}
ImageAdapter myImageAdapter;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.pictures_fragment, container, false);
GridView gridview = (GridView) rootView.findViewById(R.id.gridview);
myImageAdapter = new ImageAdapter(getActivity());
gridview.setAdapter(myImageAdapter);
String ExternalStorageDirectoryPath = Environment
.getExternalStorageDirectory().getAbsolutePath();
String targetPath = ExternalStorageDirectoryPath + "/myfilepath/Images";
Toast.makeText(getActivity().getApplicationContext(), targetPath, Toast.LENGTH_LONG)
.show();
File targetDirector = new File(targetPath);
File[] files = targetDirector.listFiles();
for (File file : files) {
myImageAdapter.add(file.getAbsolutePath());
}
gridview.setOnItemClickListener(myOnItemClickListener);
Button camerabtn = (Button) rootView.findViewById(R.id.camerabtn);
camerabtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), CameraActivity.class);
startActivityForResult(intent, 0);
}
});
return rootView;
}
Here's the click listener where I believe I should be implementing the code to solve this problem. I think I should be launching another activity (FullImageActivity.class) which just contains a layout with an imageview and pass the image which has been clicked to this new activity , but I have little know how to go about this
OnItemClickListener myOnItemClickListener = new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
String prompt = (String) parent.getItemAtPosition(position);
Toast.makeText(getActivity().getApplicationContext(), prompt, Toast.LENGTH_LONG)
.show();
//Intent i = new Intent(getActivity().getApplicationContext(), FullImageActivity.class);
// startActivity(i);
}
};
}
Any help would be greatly appreciated.
Yes, change the onItemClick like this..
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
String path = (String) myImageAdapter.getItem(position);
Intent intent = new Intent(this, FullImageActivity.class);
intent.putExtra("IMAGEPATH",path);
startActivity(intent);
}
And in FullImageActivity have a layout to show the full image from the path.
you can get the path in the FullImageActivity onCreate()
public class FullImageActivity extends ActionBarActivity{
#Override
public void onCreate(Bundle bundle){
super.onCreate(bundle);
setContentView(R.layout.image_layout);
String path = getIntent().getStringExtra("IMAGEPATH");
// load the image from the path and set it to the imageview in layout
}
}
I found a tutorial on the Internet for an image slider but I don't know how to make it work on my phone. In the emulator it is giving me a message about setting nat directory path. I don't know how to do that. . .
Could anyone help me, please?
Code for Activities are:
Code for FullScreenViewActivity.java:
public class FullScreenViewActivity extends Activity{
private Utils utils;
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 Utils(getApplicationContext());
Intent i = getIntent();
int position = i.getIntExtra("position", 0);
adapter = new FullScreenImageAdapter(FullScreenViewActivity.this,
utils.getFilePaths());
viewPager.setAdapter(adapter);
// displaying selected image first
viewPager.setCurrentItem(position);
}
}
Code for GridViewActivity.java:
public class GridViewActivity extends Activity {
private Utils utils;
private ArrayList<String> imagePaths = new ArrayList<String>();
private GridViewImageAdapter adapter;
private GridView gridView;
private int columnWidth;
#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);
// Initilizing Grid View
InitilizeGridLayout();
// 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);
}
private void InitilizeGridLayout() {
Resources r = getResources();
float padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
AppConstant.GRID_PADDING, r.getDisplayMetrics());
columnWidth = (int) ((utils.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);
}
}
Code for FullScreenImageAdapter.java:
public class FullScreenImageAdapter extends PagerAdapter {
private Activity _activity;
private ArrayList<String> _imagePaths;
private LayoutInflater inflater;
// constructor
public FullScreenImageAdapter(Activity activity,
ArrayList<String> imagePaths) {
this._activity = activity;
this._imagePaths = imagePaths;
}
#Override
public int getCount() {
return this._imagePaths.size();
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view == ((RelativeLayout) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
TouchImageView imgDisplay;
Button btnClose;
inflater = (LayoutInflater) _activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image, container,
false);
imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
btnClose = (Button) viewLayout.findViewById(R.id.btnClose);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
imgDisplay.setImageBitmap(bitmap);
// close button click event
btnClose.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
_activity.finish();
}
});
((ViewPager) container).addView(viewLayout);
return viewLayout;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((RelativeLayout) object);
}
}
public class GridViewImageAdapter extends BaseAdapter {
private Activity _activity;
private ArrayList<String> _filePaths = new ArrayList<String>();
private int imageWidth;
public GridViewImageAdapter(Activity activity, ArrayList<String> filePaths,
int imageWidth) {
this._activity = activity;
this._filePaths = filePaths;
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);
// image view click listener
imageView.setOnClickListener(new OnImageClickListener(position));
return imageView;
}
class OnImageClickListener implements OnClickListener {
int _postion;
// constructor
public OnImageClickListener(int position) {
this._postion = position;
}
#Override
public void onClick(View v) {
// on selecting grid view image
// launch full screen activity
Intent i = new Intent(_activity, FullScreenViewActivity.class);
i.putExtra("position", _postion);
_activity.startActivity(i);
}
}
/*
* Resizing image size
*/
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;
}
}
Code for GridViewImageAdapter.java:
public class GridViewImageAdapter extends BaseAdapter {
private Activity _activity;
private ArrayList<String> _filePaths = new ArrayList<String>();
private int imageWidth;
public GridViewImageAdapter(Activity activity, ArrayList<String> filePaths,
int imageWidth) {
this._activity = activity;
this._filePaths = filePaths;
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);
// image view click listener
imageView.setOnClickListener(new OnImageClickListener(position));
return imageView;
}
class OnImageClickListener implements OnClickListener {
int _postion;
// constructor
public OnImageClickListener(int position) {
this._postion = position;
}
#Override
public void onClick(View v) {
// on selecting grid view image
// launch full screen activity
Intent i = new Intent(_activity, FullScreenViewActivity.class);
i.putExtra("position", _postion);
_activity.startActivity(i);
}
}
/*
* Resizing image size
*/
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;
}
}
util.java
public class Utils {
private Context _context;
// constructor
public Utils(Context context) {
this._context = context;
}
/*
* Reading file paths from SDCard
*/
public ArrayList<String> getFilePaths() {
ArrayList<String> filePaths = new ArrayList<String>();
File directory = new File(
android.os.Environment.getExternalStorageDirectory()
+ File.separator + AppConstant.PHOTO_ALBUM);
// 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(
_context,
AppConstant.PHOTO_ALBUM
+ " is empty. Please load some images in it !",
Toast.LENGTH_LONG).show();
}
} else {
AlertDialog.Builder alert = new AlertDialog.Builder(_context);
alert.setTitle("Error!");
alert.setMessage(AppConstant.PHOTO_ALBUM
+ " 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
*/
public int getScreenWidth() {
int columnWidth;
WindowManager wm = (WindowManager) _context
.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;
}
}
AppConstant.java
public class AppConstant {
// Number of columns of Grid View
public static final int NUM_OF_COLUMNS = 3;
// Gridview image padding
public static final int GRID_PADDING = 8; // in dp
// SD card image directory
public static final String PHOTO_ALBUM = "NAT";
// supported file formats
public static final List<String> FILE_EXTN = Arrays.asList("jpg", "jpeg",
"png");
}
The only problem is setting the nat directory path so that it works on my phone.
I had the same problem (same tutorial :D), the problem is that you need a place to store all the wallpapers, so just change
// SD card image directory
public static final String PHOTO_ALBUM = "NAT";
to
// SD card image directory
public static final String PHOTO_ALBUM = "Camera";
for example to show the cameras pics.
public static final String PHOTO_ALBUM =Environment.getExternalStorageDirectory().getPath()+ "/DCIM/"+"/100ANDRO/";
"/DCIM/100ANDRO/" is a path where my Pictures are stored.
just change NAT by DCIM/Camera here your internal phone memory pics. i tried this and its work but some other problem occurs, when i click any pic then application is force stop if you resolve this problem then let m know. thank you
i have been working on wallpaper app for a while and it's almost done but the size of app is pretty big cause i use .png extension so currently i'm trying to load jpg via assets instead of png in res
i tried to implement this answer
Images from Assets folder in a GridView
i get an error while loading the imageadapter
02-21 23:13:05.883: E/AndroidRuntime(17634): FATAL EXCEPTION: main
02-21 23:13:05.883: E/AndroidRuntime(17634): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.imagieview05/com.example.imagieview05.MainActivity}: java.lang.NullPointerException
here is my code
public class MainActivity extends Activity {
private GridView mGridView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mGridView = (GridView) findViewById(R.id.GridView1);
Bitmap[] mBitArray = new Bitmap[4];
try {
mBitArray[0] = getBitmapFromAssets("g1p2.jpg");
mBitArray[1] = getBitmapFromAssets("g1p1.jpg");
mBitArray[2] = getBitmapFromAssets("g1p3.jpg");
mBitArray[3] = getBitmapFromAssets("g1p4.jpg");
} catch (Exception e) {
e.printStackTrace();
}
mGridView.setAdapter(new ImageAdapter(this ,mBitArray));
}
public Bitmap getBitmapFromAssets (String filename) throws IOException{
AssetManager assetManager = getAssets();
InputStream istr = assetManager.open(filename);
Bitmap bitmap = BitmapFactory.decodeStream(istr);
return bitmap;
}
public class ImageAdapter extends BaseAdapter{
private Context mContext;
private Bitmap[] mImageArray;
public GallaryAdapter(Context c, Bitmap[] mBitArray) {
c = mContext;
mBitArray = mImageArray;
}
public int getCount() {
return mImageArray.length;
}
public Object getItem(int position) {
// TODO Auto-generated method stub
return mImageArray[position];
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imgView = new ImageView(mContext);
imgView.setImageBitmap(mImageArray[position]);
//put black borders around the image
imgView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imgView.setLayoutParams(new GridView.LayoutParams(120, 120));
return imgView;
}
here is the original working code without Assets reference
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GridView gridView = (GridView) findViewById(R.id.GridView1);
gridView.setAdapter(new ImageAdapter(this));
public class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
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) {
ImageView imageView;
if (convertView == null) { // if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(150, 150));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
return imageView;
}
// references to our images
private Integer[] mThumbIds = {
R.drawable.g1p1, R.drawable.g1p2,
R.drawable.g1p3, R.drawable.g1p4,
R.drawable.g1p5, R.drawable.g1p6,
R.drawable.g1p22, R.drawable.g1p33,
R.drawable.g1p44, R.drawable.g1p55,
R.drawable.g1p5, R.drawable.g1p6,
R.drawable.g1p22, R.drawable.g1p33,
R.drawable.g1p44, R.drawable.g1p55
};
};
thanks for help in advance
mBitArray = mImageArray; its pointing mBitArray toward mImageArray witch is nothing, maybe?
i dont think it really matters if you use jpeg or png memory wise anyway, in the program its going to completely uncompress the jpeg anyway
I wrote the code loader images from assets folder following the example code
private Bitmap decodeStreamFromAssets(String path, int reqWidth, int reqHeight) {
InputStream ims = null;
try {
ims = getAssets().open(path);
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(ims, null, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeStream(ims, null, options);
}
catch (IOException e) {
e.printStackTrace();
}
finally {
if (ims != null) {
try {
ims.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
private int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
Load *.jpg work, but *.png not work for ex.
IMG // work
Bitmap bitmap = decodeStreamFromAssets("test.jpg", 64, 64);
if(bitmap1 != null){
imageViewTest.setImageBitmap(bitmap);
}
else {
Log.e("ERROR", "error");
}
PNG // not work ( is error )
Bitmap bitmap = decodeStreamFromAssets("test.png", 64, 64);
if(bitmap1 != null){
imageViewTest.setImageBitmap(bitmap);
}
else {
Log.e("ERROR", "error");
}