Develop Reference

How to make certain element of GridView transparent to show image underneath?

Hello there,
I'm kind of new to Android, and I'm working on a simple image gallery. I have photo that is turned into Bitmap, then I cut it into 9 square(or equal) elements. Afterwards, I'm placing it to a GridView using my version of ImageAdapter. At last I want to make an effect that this squares randomly become transparent(gradient like from visible to transparent) and reavel another image beneath them(So the process can be repeated infinitely). I want to make it OnClick later to change photo, but right now I can't figure out how to make certain elements of GridView transparent. I tried using getChildAt(int index) or getItemAtPosition(int position) but all I get was NullPointerException. Can anyone help me with this? I tried to use many code samples across the web but none of it make it possible.
My main Activity:
public class MainActivity extends AppCompatActivity {
private int screenX;
private int screenY;
private ArrayList<Bitmap> chunkedImages;
private GridView gv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
RelativeLayout rl = (RelativeLayout)findViewById(R.id.RelativeLayout1);
rl.setBackgroundColor(Color.BLACK);
loadScreenXY();
ImageView view = new ImageView(this);
view.setImageResource(R.drawable.pizza);
this.chunkedImages = this.splitImage(view,9);
gv = (GridView) findViewById(R.id.GridView);
gv.setAdapter(new GridImageAdapter(this,this.chunkedImages));
gv.setNumColumns(3);
}
private void loadScreenXY() {
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
this.screenX = size.x;
this.screenY = size.y;
}
private ArrayList<Bitmap> splitImage(ImageView image, int chunkNumbers) {
int rows,cols;
int chunkHeight;
int chunkWidth;
ArrayList<Bitmap> chunkedImages = new ArrayList<Bitmap>(chunkNumbers);
BitmapDrawable drawable = (BitmapDrawable) image.getDrawable();
Bitmap bitmap = drawable.getBitmap();
rows = cols = (int) Math.sqrt(chunkNumbers);
chunkHeight = bitmap.getHeight()/rows;
chunkWidth = bitmap.getWidth()/cols;
int yCoord = 0;
for(int x=0; x<rows; x++){
int xCoord = 0;
for(int y=0; y<cols; y++){
chunkedImages.add(Bitmap.createBitmap(bitmap, xCoord, yCoord, chunkWidth, chunkHeight));
xCoord += chunkWidth;
}
yCoord += chunkHeight;
}
return chunkedImages;
}
And my Adapter:
public class GridImageAdapter extends BaseAdapter{
private Context mContext;
private ArrayList<Bitmap> bm;
public GridImageAdapter(Context c, ArrayList<Bitmap> bm) {
mContext = c;
this.bm = bm;
}
public int getCount() {
return this.bm.size();
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(this.bm.get(position).getWidth(),this.bm.get(position).getHeight()));
imageView.setPadding(0,0,0,0);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageBitmap(this.bm.get(position));
return imageView;
}
}

Android Rebound translate up animation

I have popupWindow with some image views, which are created and added progammatically to popup window. Their position is set to bottom line with setY(). But when I use setEndValue to animate with spring, image goes from 0 to setEndValue, not from it's initial position.
How that can be fixed?
public SharePostPopupWindow(View parentView) {
super(MATCH_PARENT, MATCH_PARENT);
this.context = parentView.getContext();
this.parentView = parentView;
AndroidBlaBlaApplication.component(context).inject(this);
setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
FrameLayout container = new FrameLayout(context);
socialViews = new ArrayList<>();
socials = new ArrayList<>();
shadow = new View(context);
shadow.setId(R.id.share_view_shadow);
shadow.setBackgroundColor(Color.BLACK);
shadow.setClickable(true);
shadow.setAlpha(0.5f);
shadow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
bus.post(new ShadowClickedEvent());
spring.setEndValue(initialPosition / 2 - Utils.convertDpToPixel(imageSize, context));
dismiss();
}
});
}
public void show() {
Utils.hideKeyboard(context, getContentView());
createButtons();
SpringSystem springSystem = SpringSystem.create();
spring = springSystem.createSpring();
SpringConfig slowConfig = new SpringConfig(TENSION, DAMPER);
spring.setSpringConfig(slowConfig);
spring.addListener(new SimpleSpringListener() {
#Override
public void onSpringUpdate(Spring spring) {
float value = (float) spring.getCurrentValue();
for (int i = 0; i < socialViews.size(); i++) {
if (i % 2 != 0) {
socialViews.get(i).setY(value);
}
}
}
});
showAtLocation(parentView, Gravity.CENTER_VERTICAL, 0, 0);
getContentView().setAlpha(1f);
}

If you want to force spring animation from certain position, you need to use
spring.setCurrentValue method first.

how to set nat directory path in android gallery

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

How to get height of view inside adapter for creating sized bitmap?

I use custom CursorAdapter with custom items.
I need height of view to resize Bitmap from assets folder and set this resized bitmap to ImegeView in list item;
#Override
public void bindView(View view, final Context context, final Cursor cursor) {
final ViewHolder holder = (ViewHolder) view.getTag();
final int imgCol = cursor.getColumnIndex(TableOdelice.COLUMN_URL);
int titleCol = cursor.getColumnIndex(TableOdelice.COLUMN_TITRE);
final int themeCol = cursor.getColumnIndex(TableOdelice.COLUMN_THEME);
String tempPath = getPath(cursor.getString(themeCol), cursor.getString(imgCol));
final String path = tempPath.replace(".", "c.");
String[] arr = cursor.getString(titleCol).split("\\*");
holder.title.setText(arr[0]);
holder.subTitle.setText(arr[1]);
if (itemHeight > 0) {
showThumb(itemHeight, holder.img, path);
} else {
final ImageView v = holder.mainImage;
v.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
itemHeight = v.getHeight();
showThumb(itemHeight, holder.img, path);
}
});
}
}
private void showThumb(int height, final ImageView iv, final String path) {
if (thumbs.containsKey(path)) {
iv.setImageBitmap(thumbs.get(path));
} else {
InputStream is = null;
try {
is = context.getAssets().open(path);
} catch (IOException e) {
Log.d("no file at path", path);
e.printStackTrace();
}
if (is != null) {
Bitmap btm = btmHelper.scaleToHeight(BitmapFactory.decodeStream(is);, height);
thumbs.put(path, btm);
iv.setImageBitmap(btm);
}
}
}
For getting view height I use OnGlobalLayoutListener() of view.
But it's very slow ...
Any ideas?

I find answer for my question.
Using this construction I get a correct width or height of view inside adapter for each view.
final ImageView v = holder.mainImage;
v.post(new Runnable() {
#Override
public void run() {
itemHeight = v.getHeight();
Log.d("Height", "" + itemHeight);
}
});
}
Maybe it will help somebody :)

Just give it a try may be it will be faster
v.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
itemHeight = v.getHeight();
showThumb(itemHeight, holder.img, path);
v.getViewTreeObserver().removeGlobalOnLayoutListener( ActivityInsatance);
}
});

If you have top or bottom margins, a bug will appear. When you will scroll this listview, a height of each row will increase. In case of v.getViewTreeObserver().addOnGlobalLayoutListener it will grow infinitely. So, my solution follows.
holder.layout.post(new Runnable() {
#Override
public void run() {
int height = holder.layout.getMeasuredHeight(); // Total row height.
RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) holder.textView.getLayoutParams();
holder.textView.setHeight(height - lp.topMargin - lp.bottomMargin);
});
where holder.layout is a link to root RelativeLayout of an adapter's row.

Move an Image continously in Random position within the display in android

Can anyone help me to do this.
I am trying to build an android app but stuck in between.
i have use the following code to move a image.
iv is ImageView object
moveImage = new TranslateAnimation( 0, xDest, 0, -yDest);
moveImage.setDuration(1000);
moveImage.setFillAfter( true );
iv.startAnimation(moveImage);
code:
public class gameLogic extends Activity
{
ImageView image;
TranslateAnimation moveImage;
public void onCreate(Bundle icicle)
{
super.onCreate(icicle);
setContentView(R.layout.game_logic);
imageMoveRandom(imageList(image,0));
}
ImageView imageList(ImageView v,int i)
{
v = (ImageView) findViewById(R.id.rabbit);
int imgId;
int j = i;
TypedArray imgs = getResources().obtainTypedArray(R.array.random_imgs);
//get resourceid by index
imgId = imgs.getResourceId(j, 0);
// or set you ImageView's resource to the id
v.setBackgroundResource(imgId);
return v;
}
void imageMoveRandom(ImageView iv)throws NotFoundException
{
DisplayMetrics dm = new DisplayMetrics();
this.getWindowManager().getDefaultDisplay().getMetrics( dm );
int xDest = dm.widthPixels/2;
int yDest = dm.heightPixels/2;
// Toast.makeText(gameLogic.this, dm.widthPixels, Toast.LENGTH_SHORT).show();
// Toast.makeText(this, dm.heightPixels, 2000).show();
moveImage = new TranslateAnimation( 0, xDest, 0, -yDest);
moveImage.setDuration(1000);
moveImage.setFillAfter( true );
iv.startAnimation(moveImage);
//moveImage.reset();
}
}
Above is not full code..but part which may be helpful for references.
But i want to continuously move the image in random place but within the android display.
Can any one suggest the solution.
Thanks in Advance :)

class BitmapView extends View
{
changingX=10;
changingY=10;
public BitmapView(Context context) {
super(context);
}
#Override
public void onDraw(Canvas canvas) {
Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.yourImageName);
canvas.drawColor(Color.BLACK);
canvas.drawBitmap(bmp, changingX,changingY, null);
changingX=changingX+5;
changingY=changingY+10;
invalidate();
}
}
Try this