how to implement in endless gallery in android gallery application

Question

hi sir

Hi I am using gallary layout my application is running when gallary moving from left ti right it is infinite that means elements are repeated again,Here is no problem,But when we move from right to left i am reached the first position after then no elements are coming.But i want to repeat elemts from this side also.Give me some suggestions

 Gallery g = (Gallery) findViewById(R.id.gallery);
        g.setAdapter(new ImageAdapter(this));
        g.setFocusable(true);
        g.setSelection((int)(Integer.MAX_VALUE / 2) - (Integer.MAX_VALUE / 2)% mImageIds.length);        
        g.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) 
            {
                try {
                    imageid=position;
                    ((ImageView)findViewById(R.id.ImageViewlarge)).setImageResource(mImageIds[position]);
                    ((TextView)findViewById(R.id.TextViewImageName)).setText(imgNames[position]);
                     mp = MediaPlayer.create(SeaSpell.this,audioTrack[position]);

                        } catch (Exception e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                            }

                }
            });


        }

    @Override
    protected void onStart() {
        super.onStart();
        imageid=getSharedPreferences("ResultInfo", 0).getInt("Result", 0);
        Log.v("Gallary","Imageid"+imageid);
        isUpdateUI = true;
        mRedrawHandler.handleMessage(new Message());

    } 
    @Override
    protected void onPause()
    {
        super.onPause();
        isUpdateUI = false;
    }

     class RefreshHandler extends Handler {


        @Override
        public void handleMessage(Message msg) {            
            SeaSpell.this.updateUI();
        }

        public void sleep(long delayMillis) {

            this.removeMessages(0);         
            if(isUpdateUI)
                sendMessageDelayed(obtainMessage(0), delayMillis);
        }
}
public void updateUI(){
    try
    {
     getImages();
        mRedrawHandler.sleep(3000);

    }
    catch (Exception e) {
        e.printStackTrace();
    }
    }
      private void getImages() 
  { 
      if(imageid>=22)
          imageid=0;
      //((Gallery) findViewById(R.id.gallery));
       ((ImageView)findViewById(R.id.ImageViewlarge)).setImageResource(mImageIds[imageid]);
        ((TextView)findViewById(R.id.TextViewImageName)).setText(imgNames[imageid]);

            imageid++;

}  

screenshot frontgallery http://www.freeimagehosting.net/image.php?d816500473.png how can i make gallery view as circular.i am able to done left to right infinite when i drag right to left.it is showing end point i am new in android give me some suggestion

Answer 1

In getView:

if(position>21){
    position=0;
}

this should be removed as it should be handled by the checkPosition function.

In checkPosition:

For the modulus operator (%), given a % b if 0 <= a < b then the result will be a. For b <= a < 2*b then the result will be a-b, so if b == a, then the result is 0. This continues for any positive integer, so the check should be:

if (position > 0)
    position = position % mImageIds.length;

Now, what you are missing from this is handling the case where position < 0.

a    a%3    a    a%3    f(a)
0    0      0    0      0
1    1     -1   -1      2
2    2     -2   -2      1
3    0     -3    0      0
4    1     -4   -1      2
5    2     -5   -2      1
6    0     -6    0      0

What we want in this case is for it to wrap back around to the end of the list -- the f(a) in the table above.

As can be seen in the table above, if a is negative then -b < a <= 0. Also, if we make f(a) = (a % b) + b we get our desired result.

This means that the logic in checkPosition becomes:

position = position % mImageIds.length;
if (position < 0)
    position = position + mImageIds.length;

which should work for all values of position irrespective of the value of mImageIds.length.

Answer 2

If anyone wanted to make it also go backwards, you can implement this. All it really does it is start the gallery in the middle.

GalleryName.setSelection((int)( Integer.MAX_VALUE / 2 ) - ( Integer.MAX_VALUE / 2 ) % mImageIds.length);

Answer 3

Hello, Where to put the if condition ?