Android Problems Converting ViewGroup with Children into Bitmap

Question

I'm successfully converting a ViewGroup (RelativeLayout) into Bitmap using a Canvas. However, when the draw happens I only see the ViewGroup with its background drawable and not its children (two TextViews) who should be laid out within the RelativeLayout using rules like FILL_PARENT.

The RelativeLayout is created using the following static function:

public static RelativeLayout createProgrammeView(Context context, int width, int height, String title, String time) {
    RelativeLayout.LayoutParams params;

    // Layout Root View (RelativeLayout)
    RelativeLayout rlv = new RelativeLayout(context);
    params = new RelativeLayout.LayoutParams(width, height);
    rlv.setLayoutParams(params);
    rlv.setPadding(3, 3, 3, 3);
    rlv.setBackgroundResource(R.drawable.background);

    // Layout Title
    TextView tv = new TextView(context);
    params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
    params.addRule(RelativeLayout.ALIGN_PARENT_TOP);
    params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
    tv.setId(R.id.title);
    tv.setLayoutParams(params);
    tv.setGravity(Gravity.CENTER_VERTICAL);
    tv.setSingleLine(true);
    tv.setEllipsize(TruncateAt.END);
    tv.setTextColor(Color.parseColor("#fff"));
    tv.setTextSize(11);
    tv.setText(title);
    rlv.addView(tv);

    // Layout Start Time
    tv = new TextView(context);
    params = new RelativeLayout.LayoutParams(16, RelativeLayout.LayoutParams.WRAP_CONTENT);
    params.addRule(RelativeLayout.BELOW, R.id.title);
    params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    params.setMargins(0, 4, 0, 0);
    tv.setId(R.id.time);
    tv.setLayoutParams(params);
    tv.setGravity(Gravity.CENTER_VERTICAL);
    tv.setSingleLine(true);
    tv.setEllipsize(null);
    tv.setTextColor(Color.parseColor("#fff"));
    tv.setTextSize(10);
    tv.setText(time);
    rlv.addView(tv);
    }

    return rlv;
}

I then use the following to turn the RelativeLayout into a Bitmap:

public static Bitmap loadBitmapFromView(RelativeLayout v) {
    Bitmap b = Bitmap.createBitmap(v.getLayoutParams().width, v.getLayoutParams().height, Bitmap.Config.RGB_565);
    Canvas c = new Canvas(b);
    v.draw(c);
    return b;
}

As expected this gives me a nice Bitmap in the dimensions that I require with the background drawable, but the children are not in the bitmap. I call these functions quite a lot to build a large image which then gets drawn onto a custom view in my activity.

This is the loop which calls the static function:

public static void renderViews(final Context context) {
    largeBitmap = Bitmap.createBitmap(largeWidth, largeHeight, Bitmap.Config.RGB_565);
    Canvas largeCanvas = new Canvas(largeBitmap);

    for (int i = 0; i < items.size(); i++) {
        int leftMargin = ...SOME CALCULATIONS...;

        RelativeLayout newView = createProgrammeView(context, width, rowHeight, "Title", "21:00");
        Bitmap newViewBitmap = loadBitmapFromView(newView);

        largeCanvas.drawBitmap(newViewBitmap, leftMargin, 0, new Paint());
    }

    myCustomView.invalidate();
}

My custom view overrides the onDraw() function:

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.drawBitmap(largeBitmap, 0, 0, null);
}

From what I can see I believe this is because Android doesn't call a measure() on the child Views. I have tried calling this manually, but this doesn't solve the problem.

So, I guess what I would like to know is, how can I achieve converting a RelativeLayout with children into a Bitmap and get Android to measure the children so they respect their relative layout rules.

Many thanks to anyone who can help me work this out.

Rob