@Override
 public void onBackPressed() {
   adapter.clear();
   adapter.clearCache();
   setResult(RESULT_CANCELED);
   super.onBackPressed();
 }
 @Override
 public void onClick(View v) {
   // clear adapter
   adapter.clear();
   adapter.clearCache();
   setResult(RESULT_CANCELED);
   finish();
 }
        @Override
        public void onClick(View v) {
          ArrayList<CustomGallery> selected = adapter.getSelected();

          String[] allPath = new String[selected.size()];
          for (int i = 0; i < allPath.length; i++) {
            allPath[i] = selected.get(i).sdcardPath;
          }

          // clear adapter
          adapter.clear();
          adapter.clearCache();
          Intent data = new Intent().putExtra("all_path", allPath);
          try {
            setResult(RESULT_OK, data);
          } catch (Exception e) {
            e.printStackTrace();
          }
          finish();
        }