Code example for PopupWindow

                dropDownView = hintContainer;
            } 
 
            mPopup.setContentView(dropDownView);
        } else { 
            dropDownView = (ViewGroup) mPopup.getContentView();
            final View view = mPromptView;
            if (view != null) {
                LinearLayout.LayoutParams hintParams =
                        (LinearLayout.LayoutParams) view.getLayoutParams();
                otherHeights = view.getMeasuredHeight() + hintParams.topMargin
                        + hintParams.bottomMargin;
            } 
        } 
 
        // getMaxAvailableHeight() subtracts the padding, so we put it back 
        // to get the available height for the whole window 
        int padding = 0;
        Drawable background = mPopup.getBackground();
        if (background != null) {
            background.getPadding(mTempRect);
            padding = mTempRect.top + mTempRect.bottom;
 
            // If we don't have an explicit vertical offset, determine one from the window 
            // background so that content will line up. 
            if (!mDropDownVerticalOffsetSet) {
                mDropDownVerticalOffset = -mTempRect.top;
            } 
        } 
 
        // Max height available on the screen for a popup. 
        boolean ignoreBottomDecorations =
                mPopup.getInputMethodMode() == PopupWindow.INPUT_METHOD_NOT_NEEDED;
        final int maxHeight = /*mPopup.*/getMaxAvailableHeight(
                mDropDownAnchorView, mDropDownVerticalOffset, ignoreBottomDecorations);
 
        if (mDropDownHeight == ViewGroup.LayoutParams.MATCH_PARENT) {
            return maxHeight + padding;
        } 
 
        final int listContent = /*mDropDownList.*/measureHeightOfChildren(MeasureSpec.UNSPECIFIED,
                0, -1/*ListView.NO_POSITION*/, maxHeight - otherHeights, -1);
        // add padding only if the list has items in it, that way we don't show 
        // the popup if it is not needed 
        if (listContent > 0) otherHeights += padding;
 
        return listContent + otherHeights;
    } 
 
    private int getMaxAvailableHeight(View anchor, int yOffset, boolean ignoreBottomDecorations) {
        final Rect displayFrame = new Rect();
        anchor.getWindowVisibleDisplayFrame(displayFrame);
 
        final int[] anchorPos = new int[2];
        anchor.getLocationOnScreen(anchorPos);
 
        int bottomEdge = displayFrame.bottom;
        if (ignoreBottomDecorations) {
            Resources res = anchor.getContext().getResources();
            bottomEdge = res.getDisplayMetrics().heightPixels;
        } 
        final int distanceToBottom = bottomEdge - (anchorPos[1] + anchor.getHeight()) - yOffset;
        final int distanceToTop = anchorPos[1] - displayFrame.top + yOffset;
 
        // anchorPos[1] is distance from anchor to top of screen 
        int returnedHeight = Math.max(distanceToBottom, distanceToTop);
        if (mPopup.getBackground() != null) {
            mPopup.getBackground().getPadding(mTempRect);
            returnedHeight -= mTempRect.top + mTempRect.bottom;
        } 
 
        return returnedHeight;
    }