Code example for PopupWindow

        int heightSpec = 0;
 
        boolean noInputMethod = isInputMethodNotNeeded();
        //XXX mPopup.setAllowScrollingAnchorParent(!noInputMethod); 
 
        if (mPopup.isShowing()) {
            if (mDropDownWidth == ViewGroup.LayoutParams.MATCH_PARENT) {
                // The call to PopupWindow's update method below can accept -1 for any 
                // value you do not want to update. 
                widthSpec = -1;
            } else if (mDropDownWidth == ViewGroup.LayoutParams.WRAP_CONTENT) {
                widthSpec = mDropDownAnchorView.getWidth();
            } else { 
                widthSpec = mDropDownWidth;
            } 
 
            if (mDropDownHeight == ViewGroup.LayoutParams.MATCH_PARENT) {
                // The call to PopupWindow's update method below can accept -1 for any 
                // value you do not want to update. 
                heightSpec = noInputMethod ? height : ViewGroup.LayoutParams.MATCH_PARENT;
                if (noInputMethod) {
                    mPopup.setWindowLayoutMode(
                            mDropDownWidth == ViewGroup.LayoutParams.MATCH_PARENT ?
                                    ViewGroup.LayoutParams.MATCH_PARENT : 0, 0);
                } else { 
                    mPopup.setWindowLayoutMode(
                            mDropDownWidth == ViewGroup.LayoutParams.MATCH_PARENT ?
                                    ViewGroup.LayoutParams.MATCH_PARENT : 0,
                            ViewGroup.LayoutParams.MATCH_PARENT);
                } 
            } else if (mDropDownHeight == ViewGroup.LayoutParams.WRAP_CONTENT) {
                heightSpec = height;
            } else { 
                heightSpec = mDropDownHeight;
            } 
 
            mPopup.setOutsideTouchable(true);
 
            mPopup.update(mDropDownAnchorView, mDropDownHorizontalOffset,
                    mDropDownVerticalOffset, widthSpec, heightSpec);
        } else { 
            if (mDropDownWidth == ViewGroup.LayoutParams.MATCH_PARENT) {
                widthSpec = ViewGroup.LayoutParams.MATCH_PARENT;
            } else { 
                if (mDropDownWidth == ViewGroup.LayoutParams.WRAP_CONTENT) {
                    mPopup.setWidth(mDropDownAnchorView.getWidth());
                } else { 
                    mPopup.setWidth(mDropDownWidth);
                } 
            } 
 
            if (mDropDownHeight == ViewGroup.LayoutParams.MATCH_PARENT) {
                heightSpec = ViewGroup.LayoutParams.MATCH_PARENT;
            } else { 
                if (mDropDownHeight == ViewGroup.LayoutParams.WRAP_CONTENT) {
                    mPopup.setHeight(height);
                } else { 
                    mPopup.setHeight(mDropDownHeight);
                } 
            } 
 
            mPopup.setWindowLayoutMode(widthSpec, heightSpec);
            //XXX mPopup.setClipToScreenEnabled(true); 
 
            // use outside touchable to dismiss drop down when touching outside of it, so 
            // only set this if the dropdown is not always visible 
            mPopup.setOutsideTouchable(true);
            mPopup.setTouchInterceptor(mTouchInterceptor);
            mPopup.showAsDropDown(mDropDownAnchorView,
                    mDropDownHorizontalOffset, mDropDownVerticalOffset);
            mDropDownList.setSelection(ListView.INVALID_POSITION);
 
            if (!mModal || mDropDownList.isInTouchMode()) {
                clearListSelection(); 
            } 
            if (!mModal) {
                mHandler.post(mHideSelector);
            } 
        } 
    } 
 
    public void dismiss() { 
        mPopup.dismiss();
        if (mPromptView != null) {
            final ViewParent parent = mPromptView.getParent();
            if (parent instanceof ViewGroup) {
                final ViewGroup group = (ViewGroup) parent;
                group.removeView(mPromptView);
            } 
        } 
        mPopup.setContentView(null);
        mDropDownList = null;
        mHandler.removeCallbacks(mResizePopupRunnable);
    } 
 
    public void setOnDismissListener(PopupWindow.OnDismissListener listener) {
        mPopup.setOnDismissListener(listener);
    } 
 
    public void setInputMethodMode(int mode) {
        mPopup.setInputMethodMode(mode);
    } 
 
    public void clearListSelection() { 
        final DropDownListView list = mDropDownList;
        if (list != null) {
            // WARNING: Please read the comment where mListSelectionHidden is declared 
            list.mListSelectionHidden = true;
            //XXX list.hideSelector(); 
            list.requestLayout();
        } 
    } 
 
    public boolean isShowing() { 
        return mPopup.isShowing();
    } 
 
    private boolean isInputMethodNotNeeded() { 
        return mPopup.getInputMethodMode() == PopupWindow.INPUT_METHOD_NOT_NEEDED;
    } 
 
    public ListView getListView() {
        return mDropDownList;
    } 
 
    private int buildDropDown() { 
        ViewGroup dropDownView;
        int otherHeights = 0;
 
        if (mDropDownList == null) {
            Context context = mContext;
 
            mDropDownList = new DropDownListView(context, !mModal);
            if (mDropDownListHighlight != null) {
                mDropDownList.setSelector(mDropDownListHighlight);
            } 
            mDropDownList.setAdapter(mAdapter);
            mDropDownList.setOnItemClickListener(mItemClickListener);
            mDropDownList.setFocusable(true);
            mDropDownList.setFocusableInTouchMode(true);
            mDropDownList.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                public void onItemSelected(AdapterView<?> parent, View view,
                        int position, long id) {
 
                    if (position != -1) {
                        DropDownListView dropDownList = mDropDownList;
 
                        if (dropDownList != null) {
                            dropDownList.mListSelectionHidden = false;
                        } 
                    } 
                } 
 
                public void onNothingSelected(AdapterView<?> parent) {
                } 
            }); 
            mDropDownList.setOnScrollListener(mScrollListener);
 
            if (mItemSelectedListener != null) {
                mDropDownList.setOnItemSelectedListener(mItemSelectedListener);
            } 
 
            dropDownView = mDropDownList;
 
            View hintView = mPromptView;
            if (hintView != null) {
                // if an hint has been specified, we accomodate more space for it and 
                // add a text view in the drop down menu, at the bottom of the list 
                LinearLayout hintContainer = new LinearLayout(context);
                hintContainer.setOrientation(LinearLayout.VERTICAL);
 
                LinearLayout.LayoutParams hintParams = new LinearLayout.LayoutParams(
                        ViewGroup.LayoutParams.MATCH_PARENT, 0, 1.0f
                ); 
 
                switch (mPromptPosition) {
                case POSITION_PROMPT_BELOW:
                    hintContainer.addView(dropDownView, hintParams);
                    hintContainer.addView(hintView);
                    break; 
 
                case POSITION_PROMPT_ABOVE:
                    hintContainer.addView(hintView);
                    hintContainer.addView(dropDownView, hintParams);
                    break; 
 
                default: 
                    break; 
                } 
 
                // measure the hint's height to find how much more vertical space 
                // we need to add to the drop down's height 
                int widthSpec = MeasureSpec.makeMeasureSpec(mDropDownWidth, MeasureSpec.AT_MOST);
                int heightSpec = MeasureSpec.UNSPECIFIED;
                hintView.measure(widthSpec, heightSpec);
 
                hintParams = (LinearLayout.LayoutParams) hintView.getLayoutParams();
                otherHeights = hintView.getMeasuredHeight() + hintParams.topMargin
                        + hintParams.bottomMargin;
 
                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;