Android - Basic Gesture Detection

//Implement the following events in your class


public class ActivitySwipeDetector implements View.OnTouchListener {
static final String logTag = "ActivitySwipeDetector";
static final int MIN_DISTANCE = 100;
private float downX, downY, upX, upY;

public void onRightToLeftSwipe(){
    Log.i(logTag, "RightToLeftSwipe!");
    activity.doSomething();
}
public void onLeftToRightSwipe(){
    Log.i(logTag, "LeftToRightSwipe!");
    activity.doSomething();
}
public void onTopToBottomSwipe(){
    Log.i(logTag, "onTopToBottomSwipe!");
    activity.doSomething();
}
public void onBottomToTopSwipe(){
    Log.i(logTag, "onBottomToTopSwipe!");
    activity.doSomething();
}
public boolean onTouch(View v, MotionEvent event) {
    switch(event.getAction()){
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

            // swipe horizontal?
            if(Math.abs(deltaX) > MIN_DISTANCE){
                // left or right
                if(deltaX < 0) { this.onLeftToRightSwipe(); return true; }
                if(deltaX > 0) { this.onRightToLeftSwipe(); return true; }
            }
            else {
                    Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                    return false; // We don't consume the event
            }

            // swipe vertical?
            if(Math.abs(deltaY) > MIN_DISTANCE){
                // top or down
                if(deltaY < 0) { this.onTopToBottomSwipe(); return true; }
                if(deltaY > 0) { this.onBottomToTopSwipe(); return true; }
            }
            else {
                    Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                    return false; // We don't consume the event
            }

            return true;
        }
    }
    return false;
}
}



//To Bind the touch events on your controls

ActivitySwipeDetector activitySwipeDetector = new ActivitySwipeDetector(this);
lowestLayout = (RelativeLayout)this.findViewById(R.id.lowestLayout);
lowestLayout.setOnTouchListener(activitySwipeDetector);


Android - Open Gallery For Image

//Open Gallery To Select Image
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent, 0);


//To Show Image After Selection or Get its Path
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

    switch(requestCode) {
    case 0:
        if(resultCode == RESULT_OK){ 
            Uri selectedImage = imageReturnedIntent.getData();
            String[] filePathColumn = {MediaStore.Images.Media.DATA};

            Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String filePath = cursor.getString(columnIndex); // file path of selected image
            cursor.close();
                   //  Convert file path into bitmap image using below line.
            Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);
          
                   // put  bitmapimage in your imageview
            yourimgView.setImageBitmap(yourSelectedImage);
        }
    }
}

Android - Adding External JARS in Your Project

A Best way to add External Jars to your Anroid Project or any Java project is:

1. Create a folder call 'lib' into you project root folder
2. Copy your Jar files to the lib folder
3. Now right click on the Jar file and Build Path > Add to Build Path, this will create a folder called 'Refrenced Library' into you project, and your are done

By do doing like this, whenever you transfer you project, you will not miss you libraries which are being referenced to some space on your Hard drive.