Question

Is there a way I can embed a loading progress indicator in a ListActivity or Fragment the same way that I can call setListShown() in a ListFragment? I can use a loading dialog but I would prefer to keep things consistent as I am already using setListShown() in other ListFragments.

Thanks.

Answer 1

I accomplished this by writing a wrapper for the fragment class similar to ListFragment.

public class AsyncFragment extends Fragment {

static final int INTERNAL_PROGRESS_CONTAINER_ID = 0x00ff0001;
static final int INTERNAL_CONTENT_CONTAINER_ID = 0x00ff0002;

View mProgressContainer;
View mContentContainer;
boolean mContentShown = true;

public AsyncFragment() {}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    final Context context = getActivity();

    FrameLayout root = new FrameLayout(context);

    // ------------------------------------------------------------------

    LinearLayout pframe = new LinearLayout(context);
    pframe.setId(INTERNAL_PROGRESS_CONTAINER_ID);
    pframe.setOrientation(LinearLayout.VERTICAL);
    pframe.setVisibility(View.GONE);
    pframe.setGravity(Gravity.CENTER);

    ProgressBar progress = new ProgressBar(context, null,
            android.R.attr.progressBarStyleLarge);
    pframe.addView(progress, new FrameLayout.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));

    root.addView(pframe, new FrameLayout.LayoutParams(
            ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));

    // ------------------------------------------------------------------

    FrameLayout lframe = new FrameLayout(context);
    lframe.setId(INTERNAL_CONTENT_CONTAINER_ID);

    root.addView(lframe, new FrameLayout.LayoutParams(
            ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));

    // ------------------------------------------------------------------

    root.setLayoutParams(new FrameLayout.LayoutParams(
            ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));

    return root;
}

public void setView(View v) {

    FrameLayout lframe = (FrameLayout) getView().findViewById(INTERNAL_CONTENT_CONTAINER_ID);
    lframe.addView(v, new FrameLayout.LayoutParams(
            ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT));

}

@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    mProgressContainer = getView().findViewById(INTERNAL_PROGRESS_CONTAINER_ID);
    mContentContainer = getView().findViewById(INTERNAL_CONTENT_CONTAINER_ID);
    setContentShown(false, false);
}

@Override
public void onDestroyView() {
    mContentShown = false;
    mProgressContainer = mContentContainer = null;
    super.onDestroyView();
}


public void setContentShown(boolean shown) {
    setContentShown(shown, true);
}

public void setContentShownNoAnimation(boolean shown) {
    setContentShown(shown, false);
}

private void setContentShown(boolean shown, boolean animate) {

    mProgressContainer = getView().findViewById(INTERNAL_PROGRESS_CONTAINER_ID);
    mContentContainer = getView().findViewById(INTERNAL_CONTENT_CONTAINER_ID);

    if (mContentShown == shown) {
        return;
    }
    mContentShown = shown;
    if (shown) {
        if (animate) {
            mProgressContainer.startAnimation(AnimationUtils.loadAnimation(
                    getActivity(), android.R.anim.fade_out));
            mContentContainer.startAnimation(AnimationUtils.loadAnimation(
                    getActivity(), android.R.anim.fade_in));
        } else {
            mProgressContainer.clearAnimation();
            mContentContainer.clearAnimation();
        }
        mProgressContainer.setVisibility(View.GONE);
        mContentContainer.setVisibility(View.VISIBLE);
    } else {
        if (animate) {
            mProgressContainer.startAnimation(AnimationUtils.loadAnimation(
                    getActivity(), android.R.anim.fade_in));
            mContentContainer.startAnimation(AnimationUtils.loadAnimation(
                    getActivity(), android.R.anim.fade_out));
        } else {
            mProgressContainer.clearAnimation();
            mContentContainer.clearAnimation();
        }
        mProgressContainer.setVisibility(View.VISIBLE);
        mContentContainer.setVisibility(View.GONE);
    }
}

I use this for fragments that I’m populating asynchronously. To use it, do not override onCreateView(). Instead, inflate your view in onStart() and call setView() with it. The fragment will start with a loading spinner. Call setContentShow(true) after you are done populating your view to remove the loading animation and show your content.