update image when list element is touched

this is required from introduction of project butter
before that view was invalidated on any action, which
was slowing down UI

src/com/owncloud/android/ui/adapter/FileListListAdapter.java

@@ -154,12 +154,12 @@ public class FileListListAdapter implements ListAdapter {
                 if (parentList.getChoiceMode() == ListView.CHOICE_MODE_NONE) { 
                     checkBoxV.setVisibility(View.GONE);
                 } else {
-                    checkBoxV.setVisibility(View.VISIBLE);
                     if (parentList.isItemChecked(position)) {
                         checkBoxV.setImageResource(android.R.drawable.checkbox_on_background);
                     } else {
                         checkBoxV.setImageResource(android.R.drawable.checkbox_off_background);
                     }
+                    checkBoxV.setVisibility(View.VISIBLE);
                 }
                 
             } else {

src/com/owncloud/android/ui/adapter/LocalFileListAdapter.java

@@ -123,12 +123,12 @@ public class LocalFileListAdapter extends BaseAdapter implements ListAdapter {
                 if (parentList.getChoiceMode() == ListView.CHOICE_MODE_NONE) { 
                     checkBoxV.setVisibility(View.GONE);
                 } else {
-                    checkBoxV.setVisibility(View.VISIBLE);
                     if (parentList.isItemChecked(position)) {
                         checkBoxV.setImageResource(android.R.drawable.checkbox_on_background);
                     } else {
                         checkBoxV.setImageResource(android.R.drawable.checkbox_off_background);
                     }
+                    checkBoxV.setVisibility(View.VISIBLE);
                 }
 
             } else {

src/com/owncloud/android/ui/fragment/LocalFileListFragment.java

@@ -31,6 +31,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
+import android.widget.ImageView;
 import android.widget.ListView;
 
 import com.owncloud.android.R;
@@ -116,6 +117,14 @@ public class LocalFileListFragment extends FragmentListView {
                 mContainerActivity.onDirectoryClick(file);
             
             } else {    /// Click on a file
+                ImageView checkBoxV = (ImageView) v.findViewById(R.id.custom_checkbox);
+                if (checkBoxV != null) {
+                    if (getListView().isItemChecked(position)) {
+                        checkBoxV.setImageResource(android.R.drawable.checkbox_on_background);
+                    } else {
+                        checkBoxV.setImageResource(android.R.drawable.checkbox_off_background);
+                    }
+                }
                 // notify the change to the container Activity
                 mContainerActivity.onFileClick(file);
             }