How to set the width of the ListView in a PopupWindow on Android?

Question

I inflated a ListView as the contentView in a PopupWindow. If I don't set the width & height, I can't see the PopupWindow. If I set them like this:

setWindowLayoutMode(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);

The layout is being set like "fill_parent". Why?

The layout attributes of the ListView and ListView item are all set to "wrap_content". Any suggestion? Thanks.

Answer 1

This is how to do it:

// Don't use this. It causes ListView's to have strange widths, similar to "fill_parent"
//popupWindow.setWindowLayoutMode(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT);

// Instead, use this:
final int NUM_OF_VISIBLE_LIST_ROWS = 4;
listView.measure(View.MeasureSpec.UNSPECIFIED, View.MeasureSpec.UNSPECIFIED);
popupWindow.setWidth(listView.getMeasuredWidth());
popupWindow.setHeight((listView.getMeasuredHeight() + 10) * NUM_OF_VISIBLE_LIST_ROWS);

Note that setWidth() and setHeight() use raw pixel values, so you need to adjust for different screen sizes and different densities.

Answer 2

My solution is override onMeasure of ListView like this:

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    int maxWidth = meathureWidthByChilds() + getPaddingLeft() + getPaddingRight();
    super.onMeasure(MeasureSpec.makeMeasureSpec(maxWidth, MeasureSpec.EXACTLY), heightMeasureSpec);     
}

public int meathureWidthByChilds() {
    int maxWidth = 0;
    View view = null;
    for (int i = 0; i < getAdapter().getCount(); i++) {
        view = getAdapter().getView(i, view, this);
        view.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
        if (view.getMeasuredWidth() > maxWidth){
            maxWidth = view.getMeasuredWidth();
        }
    }
    return maxWidth;
}