/*
 * Copyright 2011 Vaadin Ltd.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.vaadin.client.ui.combobox;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Style;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.BlurEvent;
import com.google.gwt.event.dom.client.BlurHandler;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.FocusEvent;
import com.google.gwt.event.dom.client.FocusHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.event.dom.client.LoadEvent;
import com.google.gwt.event.dom.client.LoadHandler;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.PopupPanel.PositionCallback;
import com.google.gwt.user.client.ui.SuggestOracle.Suggestion;
import com.google.gwt.user.client.ui.TextBox;
import com.vaadin.client.ApplicationConnection;
import com.vaadin.client.BrowserInfo;
import com.vaadin.client.ComponentConnector;
import com.vaadin.client.ConnectorMap;
import com.vaadin.client.Focusable;
import com.vaadin.client.UIDL;
import com.vaadin.client.Util;
import com.vaadin.client.VConsole;
import com.vaadin.client.ui.Field;
import com.vaadin.client.ui.SubPartAware;
import com.vaadin.client.ui.VLazyExecutor;
import com.vaadin.client.ui.VOverlay;
import com.vaadin.client.ui.menubar.MenuBar;
import com.vaadin.client.ui.menubar.MenuItem;
import com.vaadin.shared.ComponentState;
import com.vaadin.shared.EventId;
import com.vaadin.shared.ui.ComponentStateUtil;
import com.vaadin.shared.ui.combobox.FilteringMode;

/**
 * Client side implementation of the Select component.
 * 
 * TODO needs major refactoring (to be extensible etc)
 */
@SuppressWarnings("deprecation")
public class VFilterSelect extends Composite implements Field, KeyDownHandler,
        KeyUpHandler, ClickHandler, FocusHandler, BlurHandler, Focusable,
        SubPartAware {

    /**
     * Represents a suggestion in the suggestion popup box
     */
    public class FilterSelectSuggestion implements Suggestion, Command {

        private final String key;
        private final String caption;
        private String iconUri;

        /**
         * Constructor
         * 
         * @param uidl
         *            The UIDL recieved from the server
         */
        public FilterSelectSuggestion(UIDL uidl) {
            key = uidl.getStringAttribute("key");
            caption = uidl.getStringAttribute("caption");
            if (uidl.hasAttribute("icon")) {
                iconUri = client.translateVaadinUri(uidl
                        .getStringAttribute("icon"));
            }
        }

        /**
         * Gets the visible row in the popup as a HTML string. The string
         * contains an image tag with the rows icon (if an icon has been
         * specified) and the caption of the item
         */

        @Override
        public String getDisplayString() {
            final StringBuffer sb = new StringBuffer();
            if (iconUri != null) {
                sb.append("<img src=\"");
                sb.append(Util.escapeAttribute(iconUri));
                sb.append("\" alt=\"\" class=\"v-icon\" />");
            }
            String content;
            if ("".equals(caption)) {
                // Ensure that empty options use the same height as other
                // options and are not collapsed (#7506)
                content = "&nbsp;";
            } else {
                content = Util.escapeHTML(caption);
            }
            sb.append("<span>" + content + "</span>");
            return sb.toString();
        }

        /**
         * Get a string that represents this item. This is used in the text box.
         */

        @Override
        public String getReplacementString() {
            return caption;
        }

        /**
         * Get the option key which represents the item on the server side.
         * 
         * @return The key of the item
         */
        public int getOptionKey() {
            return Integer.parseInt(key);
        }

        /**
         * Get the URI of the icon. Used when constructing the displayed option.
         * 
         * @return
         */
        public String getIconUri() {
            return iconUri;
        }

        /**
         * Executes a selection of this item.
         */

        @Override
        public void execute() {
            onSuggestionSelected(this);
        }
    }

    /**
     * Represents the popup box with the selection options. Wraps a suggestion
     * menu.
     */
    public class SuggestionPopup extends VOverlay implements PositionCallback,
            CloseHandler<PopupPanel> {

        private static final String Z_INDEX = "30000";

        protected final SuggestionMenu menu;

        private final Element up = DOM.createDiv();
        private final Element down = DOM.createDiv();
        private final Element status = DOM.createDiv();

        private boolean isPagingEnabled = true;

        private long lastAutoClosed;

        private int popupOuterPadding = -1;

        private int topPosition;

        /**
         * Default constructor
         */
        SuggestionPopup() {
            super(true, false, true);
            menu = new SuggestionMenu();
            setWidget(menu);
            setStyleName(CLASSNAME + "-suggestpopup");
            DOM.setStyleAttribute(getElement(), "zIndex", Z_INDEX);

            final Element root = getContainerElement();

            DOM.setInnerHTML(up, "<span>Prev</span>");
            DOM.sinkEvents(up, Event.ONCLICK);
            DOM.setInnerHTML(down, "<span>Next</span>");
            DOM.sinkEvents(down, Event.ONCLICK);
            DOM.insertChild(root, up, 0);
            DOM.appendChild(root, down);
            DOM.appendChild(root, status);
            DOM.setElementProperty(status, "className", CLASSNAME + "-status");
            DOM.sinkEvents(root, Event.ONMOUSEDOWN | Event.ONMOUSEWHEEL);
            addCloseHandler(this);
        }

        /**
         * Shows the popup where the user can see the filtered options
         * 
         * @param currentSuggestions
         *            The filtered suggestions
         * @param currentPage
         *            The current page number
         * @param totalSuggestions
         *            The total amount of suggestions
         */
        public void showSuggestions(
                Collection<FilterSelectSuggestion> currentSuggestions,
                int currentPage, int totalSuggestions) {

            // Add TT anchor point
            DOM.setElementProperty(getElement(), "id",
                    "VAADIN_COMBOBOX_OPTIONLIST");

            menu.setSuggestions(currentSuggestions);
            final int x = VFilterSelect.this.getAbsoluteLeft();
            topPosition = tb.getAbsoluteTop();
            topPosition += tb.getOffsetHeight();
            setPopupPosition(x, topPosition);

            int nullOffset = (nullSelectionAllowed && "".equals(lastFilter) ? 1
                    : 0);
            boolean firstPage = (currentPage == 0);
            final int first = currentPage * pageLength + 1
                    - (firstPage ? 0 : nullOffset);
            final int last = first + currentSuggestions.size() - 1
                    - (firstPage && "".equals(lastFilter) ? nullOffset : 0);
            final int matches = totalSuggestions - nullOffset;
            if (last > 0) {
                // nullsel not counted, as requested by user
                DOM.setInnerText(status, (matches == 0 ? 0 : first) + "-"
                        + last + "/" + matches);
            } else {
                DOM.setInnerText(status, "");
            }
            // We don't need to show arrows or statusbar if there is only one
            // page
            if (totalSuggestions <= pageLength || pageLength == 0) {
                setPagingEnabled(false);
            } else {
                setPagingEnabled(true);
            }
            setPrevButtonActive(first > 1);
            setNextButtonActive(last < matches);

            // clear previously fixed width
            menu.setWidth("");
            DOM.setStyleAttribute(DOM.getFirstChild(menu.getElement()),
                    "width", "");

            setPopupPositionAndShow(this);

        }

        /**
         * Should the next page button be visible to the user?
         * 
         * @param active
         */
        private void setNextButtonActive(boolean active) {
            if (active) {
                DOM.sinkEvents(down, Event.ONCLICK);
                DOM.setElementProperty(down, "className", CLASSNAME
                        + "-nextpage");
            } else {
                DOM.sinkEvents(down, 0);
                DOM.setElementProperty(down, "className", CLASSNAME
                        + "-nextpage-off");
            }
        }

        /**
         * Should the previous page button be visible to the user
         * 
         * @param active
         */
        private void setPrevButtonActive(boolean active) {
            if (active) {
                DOM.sinkEvents(up, Event.ONCLICK);
                DOM.setElementProperty(up, "className", CLASSNAME + "-prevpage");
            } else {
                DOM.sinkEvents(up, 0);
                DOM.setElementProperty(up, "className", CLASSNAME
                        + "-prevpage-off");
            }

        }

        /**
         * Selects the next item in the filtered selections
         */
        public void selectNextItem() {
            final MenuItem cur = menu.getSelectedItem();
            final int index = 1 + menu.getItems().indexOf(cur);
            if (menu.getItems().size() > index) {
                final MenuItem newSelectedItem = menu.getItems().get(index);
                menu.selectItem(newSelectedItem);
                tb.setText(newSelectedItem.getText());
                tb.setSelectionRange(lastFilter.length(), newSelectedItem
                        .getText().length() - lastFilter.length());

            } else if (hasNextPage()) {
                selectPopupItemWhenResponseIsReceived = Select.FIRST;
                filterOptions(currentPage + 1, lastFilter);
            }
        }

        /**
         * Selects the previous item in the filtered selections
         */
        public void selectPrevItem() {
            final MenuItem cur = menu.getSelectedItem();
            final int index = -1 + menu.getItems().indexOf(cur);
            if (index > -1) {
                final MenuItem newSelectedItem = menu.getItems().get(index);
                menu.selectItem(newSelectedItem);
                tb.setText(newSelectedItem.getText());
                tb.setSelectionRange(lastFilter.length(), newSelectedItem
                        .getText().length() - lastFilter.length());
            } else if (index == -1) {
                if (currentPage > 0) {
                    selectPopupItemWhenResponseIsReceived = Select.LAST;
                    filterOptions(currentPage - 1, lastFilter);
                }
            } else {
                final MenuItem newSelectedItem = menu.getItems().get(
                        menu.getItems().size() - 1);
                menu.selectItem(newSelectedItem);
                tb.setText(newSelectedItem.getText());
                tb.setSelectionRange(lastFilter.length(), newSelectedItem
                        .getText().length() - lastFilter.length());
            }
        }

        /*
         * Using a timer to scroll up or down the pages so when we receive lots
         * of consecutive mouse wheel events the pages does not flicker.
         */
        private LazyPageScroller lazyPageScroller = new LazyPageScroller();

        private class LazyPageScroller extends Timer {
            private int pagesToScroll = 0;

            @Override
            public void run() {
                if (pagesToScroll != 0) {
                    if (!waitingForFilteringResponse) {
                        /*
                         * Avoid scrolling while we are waiting for a response
                         * because otherwise the waiting flag will be reset in
                         * the first response and the second response will be
                         * ignored, causing an empty popup...
                         * 
                         * As long as the scrolling delay is suitable
                         * double/triple clicks will work by scrolling two or
                         * three pages at a time and this should not be a
                         * problem.
                         */
                        filterOptions(currentPage + pagesToScroll, lastFilter);
                    }
                    pagesToScroll = 0;
                }
            }

            public void scrollUp() {
                if (currentPage + pagesToScroll > 0) {
                    pagesToScroll--;
                    cancel();
                    schedule(200);
                }
            }

            public void scrollDown() {
                if (totalMatches > (currentPage + pagesToScroll + 1)
                        * pageLength) {
                    pagesToScroll++;
                    cancel();
                    schedule(200);
                }
            }
        }

        /*
         * (non-Javadoc)
         * 
         * @see
         * com.google.gwt.user.client.ui.Widget#onBrowserEvent(com.google.gwt
         * .user.client.Event)
         */

        @Override
        public void onBrowserEvent(Event event) {
            if (event.getTypeInt() == Event.ONCLICK) {
                final Element target = DOM.eventGetTarget(event);
                if (target == up || target == DOM.getChild(up, 0)) {
                    lazyPageScroller.scrollUp();
                } else if (target == down || target == DOM.getChild(down, 0)) {
                    lazyPageScroller.scrollDown();
                }
            } else if (event.getTypeInt() == Event.ONMOUSEWHEEL) {
                int velocity = event.getMouseWheelVelocityY();
                if (velocity > 0) {
                    lazyPageScroller.scrollDown();
                } else {
                    lazyPageScroller.scrollUp();
                }
            }

            /*
             * Prevent the keyboard focus from leaving the textfield by
             * preventing the default behaviour of the browser. Fixes #4285.
             */
            handleMouseDownEvent(event);
        }

        /**
         * Should paging be enabled. If paging is enabled then only a certain
         * amount of items are visible at a time and a scrollbar or buttons are
         * visible to change page. If paging is turned of then all options are
         * rendered into the popup menu.
         * 
         * @param paging
         *            Should the paging be turned on?
         */
        public void setPagingEnabled(boolean paging) {
            if (isPagingEnabled == paging) {
                return;
            }
            if (paging) {
                DOM.setStyleAttribute(down, "display", "");
                DOM.setStyleAttribute(up, "display", "");
                DOM.setStyleAttribute(status, "display", "");
            } else {
                DOM.setStyleAttribute(down, "display", "none");
                DOM.setStyleAttribute(up, "display", "none");
                DOM.setStyleAttribute(status, "display", "none");
            }
            isPagingEnabled = paging;
        }

        /*
         * (non-Javadoc)
         * 
         * @see
         * com.google.gwt.user.client.ui.PopupPanel$PositionCallback#setPosition
         * (int, int)
         */

        @Override
        public void setPosition(int offsetWidth, int offsetHeight) {

            int top = -1;
            int left = -1;

            // reset menu size and retrieve its "natural" size
            menu.setHeight("");
            if (currentPage > 0) {
                // fix height to avoid height change when getting to last page
                menu.fixHeightTo(pageLength);
            }
            offsetHeight = getOffsetHeight();

            final int desiredWidth = getMainWidth();
            int naturalMenuWidth = DOM.getElementPropertyInt(
                    DOM.getFirstChild(menu.getElement()), "offsetWidth");

            if (popupOuterPadding == -1) {
                popupOuterPadding = Util.measureHorizontalPaddingAndBorder(
                        getElement(), 2);
            }

            if (naturalMenuWidth < desiredWidth) {
                menu.setWidth((desiredWidth - popupOuterPadding) + "px");
                DOM.setStyleAttribute(DOM.getFirstChild(menu.getElement()),
                        "width", "100%");
                naturalMenuWidth = desiredWidth;
            }

            if (BrowserInfo.get().isIE()) {
                /*
                 * IE requires us to specify the width for the container
                 * element. Otherwise it will be 100% wide
                 */
                int rootWidth = naturalMenuWidth - popupOuterPadding;
                DOM.setStyleAttribute(getContainerElement(), "width", rootWidth
                        + "px");
            }

            if (offsetHeight + getPopupTop() > Window.getClientHeight()
                    + Window.getScrollTop()) {
                // popup on top of input instead
                top = getPopupTop() - offsetHeight
                        - VFilterSelect.this.getOffsetHeight();
                if (top < 0) {
                    top = 0;
                }
            } else {
                top = getPopupTop();
                /*
                 * Take popup top margin into account. getPopupTop() returns the
                 * top value including the margin but the value we give must not
                 * include the margin.
                 */
                int topMargin = (top - topPosition);
                top -= topMargin;
            }

            // fetch real width (mac FF bugs here due GWT popups overflow:auto )
            offsetWidth = DOM.getElementPropertyInt(
                    DOM.getFirstChild(menu.getElement()), "offsetWidth");
            if (offsetWidth + getPopupLeft() > Window.getClientWidth()
                    + Window.getScrollLeft()) {
                left = VFilterSelect.this.getAbsoluteLeft()
                        + VFilterSelect.this.getOffsetWidth()
                        + Window.getScrollLeft() - offsetWidth;
                if (left < 0) {
                    left = 0;
                }
            } else {
                left = getPopupLeft();
            }
            setPopupPosition(left, top);
        }

        /**
         * Was the popup just closed?
         * 
         * @return true if popup was just closed
         */
        public boolean isJustClosed() {
            final long now = (new Date()).getTime();
            return (lastAutoClosed > 0 && (now - lastAutoClosed) < 200);
        }

        /*
         * (non-Javadoc)
         * 
         * @see
         * com.google.gwt.event.logical.shared.CloseHandler#onClose(com.google
         * .gwt.event.logical.shared.CloseEvent)
         */

        @Override
        public void onClose(CloseEvent<PopupPanel> event) {
            if (event.isAutoClosed()) {
                lastAutoClosed = (new Date()).getTime();
            }
        }

        /**
         * Updates style names in suggestion popup to help theme building.
         * 
         * @param uidl
         *            UIDL for the whole combo box
         * @param componentState
         *            shared state of the combo box
         */
        public void updateStyleNames(UIDL uidl, ComponentState componentState) {
            setStyleName(CLASSNAME + "-suggestpopup");
            if (ComponentStateUtil.hasStyles(componentState)) {
                for (String style : componentState.styles) {
                    if (!"".equals(style)) {
                        addStyleDependentName(style);
                    }
                }
            }
        }

    }

    /**
     * The menu where the suggestions are rendered
     */
    public class SuggestionMenu extends MenuBar implements SubPartAware,
            LoadHandler {

        /**
         * Tracks the item that is currently selected using the keyboard. This
         * is need only because mouseover changes the selection and we do not
         * want to use that selection when pressing enter to select the item.
         */
        private MenuItem keyboardSelectedItem;

        private VLazyExecutor delayedImageLoadExecutioner = new VLazyExecutor(
                100, new ScheduledCommand() {

                    @Override
                    public void execute() {
                        if (suggestionPopup.isVisible()
                                && suggestionPopup.isAttached()) {
                            setWidth("");
                            DOM.setStyleAttribute(
                                    DOM.getFirstChild(getElement()), "width",
                                    "");
                            suggestionPopup
                                    .setPopupPositionAndShow(suggestionPopup);
                        }

                    }
                });

        /**
         * Default constructor
         */
        SuggestionMenu() {
            super(true);
            setStyleName(CLASSNAME + "-suggestmenu");
            addDomHandler(this, LoadEvent.getType());
        }

        /**
         * Fixes menus height to use same space as full page would use. Needed
         * to avoid height changes when quickly "scrolling" to last page
         */
        public void fixHeightTo(int pagelenth) {
            if (currentSuggestions.size() > 0) {
                final int pixels = pagelenth * (getOffsetHeight() - 2)
                        / currentSuggestions.size();
                setHeight((pixels + 2) + "px");
            }
        }

        /**
         * Sets the suggestions rendered in the menu
         * 
         * @param suggestions
         *            The suggestions to be rendered in the menu
         */
        public void setSuggestions(
                Collection<FilterSelectSuggestion> suggestions) {
            // Reset keyboard selection when contents is updated to avoid
            // reusing old, invalid data
            setKeyboardSelectedItem(null);

            clearItems();
            final Iterator<FilterSelectSuggestion> it = suggestions.iterator();
            while (it.hasNext()) {
                final FilterSelectSuggestion s = it.next();
                final MenuItem mi = new MenuItem(s.getDisplayString(), true, s);

                Util.sinkOnloadForImages(mi.getElement());

                this.addItem(mi);
                if (s == currentSuggestion) {
                    selectItem(mi);
                }
            }
        }

        /**
         * Send the current selection to the server. Triggered when a selection
         * is made or on a blur event.
         */
        public void doSelectedItemAction() {
            // do not send a value change event if null was and stays selected
            final String enteredItemValue = tb.getText();
            if (nullSelectionAllowed && "".equals(enteredItemValue)
                    && selectedOptionKey != null
                    && !"".equals(selectedOptionKey)) {
                if (nullSelectItem) {
                    reset();
                    return;
                }
                // null is not visible on pages != 0, and not visible when
                // filtering: handle separately
                client.updateVariable(paintableId, "filter", "", false);
                client.updateVariable(paintableId, "page", 0, false);
                client.updateVariable(paintableId, "selected", new String[] {},
                        immediate);
                suggestionPopup.hide();
                return;
            }

            updateSelectionWhenReponseIsReceived = waitingForFilteringResponse;
            if (!waitingForFilteringResponse) {
                doPostFilterSelectedItemAction();
            }
        }

        /**
         * Triggered after a selection has been made
         */
        public void doPostFilterSelectedItemAction() {
            final MenuItem item = getSelectedItem();
            final String enteredItemValue = tb.getText();

            updateSelectionWhenReponseIsReceived = false;

            // check for exact match in menu
            int p = getItems().size();
            if (p > 0) {
                for (int i = 0; i < p; i++) {
                    final MenuItem potentialExactMatch = getItems().get(i);
                    if (potentialExactMatch.getText().equals(enteredItemValue)) {
                        selectItem(potentialExactMatch);
                        // do not send a value change event if null was and
                        // stays selected
                        if (!"".equals(enteredItemValue)
                                || (selectedOptionKey != null && !""
                                        .equals(selectedOptionKey))) {
                            doItemAction(potentialExactMatch, true);
                        }
                        suggestionPopup.hide();
                        return;
                    }
                }
            }
            if (allowNewItem) {

                if (!prompting && !enteredItemValue.equals(lastNewItemString)) {
                    /*
                     * Store last sent new item string to avoid double sends
                     */
                    lastNewItemString = enteredItemValue;
                    client.updateVariable(paintableId, "newitem",
                            enteredItemValue, immediate);
                }
            } else if (item != null
                    && !"".equals(lastFilter)
                    && (filteringmode == FilteringMode.CONTAINS ? item
                            .getText().toLowerCase()
                            .contains(lastFilter.toLowerCase()) : item
                            .getText().toLowerCase()
                            .startsWith(lastFilter.toLowerCase()))) {
                doItemAction(item, true);
            } else {
                // currentSuggestion has key="" for nullselection
                if (currentSuggestion != null
                        && !currentSuggestion.key.equals("")) {
                    // An item (not null) selected
                    String text = currentSuggestion.getReplacementString();
                    tb.setText(text);
                    selectedOptionKey = currentSuggestion.key;
                } else {
                    // Null selected
                    tb.setText("");
                    selectedOptionKey = null;
                }
            }
            suggestionPopup.hide();
        }

        private static final String SUBPART_PREFIX = "item";

        @Override
        public Element getSubPartElement(String subPart) {
            int index = Integer.parseInt(subPart.substring(SUBPART_PREFIX
                    .length()));

            MenuItem item = getItems().get(index);

            return item.getElement();
        }

        @Override
        public String getSubPartName(Element subElement) {
            if (!getElement().isOrHasChild(subElement)) {
                return null;
            }

            Element menuItemRoot = subElement;
            while (menuItemRoot != null
                    && !menuItemRoot.getTagName().equalsIgnoreCase("td")) {
                menuItemRoot = menuItemRoot.getParentElement().cast();
            }
            // "menuItemRoot" is now the root of the menu item

            final int itemCount = getItems().size();
            for (int i = 0; i < itemCount; i++) {
                if (getItems().get(i).getElement() == menuItemRoot) {
                    String name = SUBPART_PREFIX + i;
                    return name;
                }
            }
            return null;
        }

        @Override
        public void onLoad(LoadEvent event) {
            // Handle icon onload events to ensure shadow is resized
            // correctly
            delayedImageLoadExecutioner.trigger();

        }

        public void selectFirstItem() {
            MenuItem firstItem = getItems().get(0);
            selectItem(firstItem);
        }

        private MenuItem getKeyboardSelectedItem() {
            return keyboardSelectedItem;
        }

        protected void setKeyboardSelectedItem(MenuItem firstItem) {
            keyboardSelectedItem = firstItem;
        }

        public void selectLastItem() {
            List<MenuItem> items = getItems();
            MenuItem lastItem = items.get(items.size() - 1);
            selectItem(lastItem);
        }
    }

    @Deprecated
    public static final FilteringMode FILTERINGMODE_OFF = FilteringMode.OFF;
    @Deprecated
    public static final FilteringMode FILTERINGMODE_STARTSWITH = FilteringMode.STARTSWITH;
    @Deprecated
    public static final FilteringMode FILTERINGMODE_CONTAINS = FilteringMode.CONTAINS;

    private static final String CLASSNAME = "v-filterselect";
    private static final String STYLE_NO_INPUT = "no-input";

    protected int pageLength = 10;

    private boolean enableDebug = false;

    private final FlowPanel panel = new FlowPanel();

    /**
     * The text box where the filter is written
     */
    protected final TextBox tb = new TextBox() {

        // Overridden to avoid selecting text when text input is disabled
        @Override
        public void setSelectionRange(int pos, int length) {
            if (textInputEnabled) {
                super.setSelectionRange(pos, length);
            } else {
                super.setSelectionRange(getValue().length(), 0);
            }
        };
    };

    protected final SuggestionPopup suggestionPopup = new SuggestionPopup();

    /**
     * Used when measuring the width of the popup
     */
    private final HTML popupOpener = new HTML("") {

        /*
         * (non-Javadoc)
         * 
         * @see
         * com.google.gwt.user.client.ui.Widget#onBrowserEvent(com.google.gwt
         * .user.client.Event)
         */

        @Override
        public void onBrowserEvent(Event event) {
            super.onBrowserEvent(event);

            /*
             * Prevent the keyboard focus from leaving the textfield by
             * preventing the default behaviour of the browser. Fixes #4285.
             */
            handleMouseDownEvent(event);
        }
    };

    private final Image selectedItemIcon = new Image();

    protected ApplicationConnection client;

    protected String paintableId;

    protected int currentPage;

    /**
     * A collection of available suggestions (options) as received from the
     * server.
     */
    protected final List<FilterSelectSuggestion> currentSuggestions = new ArrayList<FilterSelectSuggestion>();

    protected boolean immediate;

    protected String selectedOptionKey;

    protected boolean waitingForFilteringResponse = false;
    protected boolean updateSelectionWhenReponseIsReceived = false;
    private boolean tabPressedWhenPopupOpen = false;
    protected boolean initDone = false;

    protected String lastFilter = "";

    protected enum Select {
        NONE, FIRST, LAST
    };

    protected Select selectPopupItemWhenResponseIsReceived = Select.NONE;

    /**
     * The current suggestion selected from the dropdown. This is one of the
     * values in currentSuggestions except when filtering, in this case
     * currentSuggestion might not be in currentSuggestions.
     */
    protected FilterSelectSuggestion currentSuggestion;

    protected int totalMatches;
    protected boolean allowNewItem;
    protected boolean nullSelectionAllowed;
    protected boolean nullSelectItem;
    protected boolean enabled;
    protected boolean readonly;

    protected FilteringMode filteringmode = FilteringMode.OFF;

    // shown in unfocused empty field, disappears on focus (e.g "Search here")
    private static final String CLASSNAME_PROMPT = "prompt";
    protected String inputPrompt = "";
    protected boolean prompting = false;

    // Set true when popupopened has been clicked. Cleared on each UIDL-update.
    // This handles the special case where are not filtering yet and the
    // selected value has changed on the server-side. See #2119
    protected boolean popupOpenerClicked;
    protected int suggestionPopupMinWidth = 0;
    private int popupWidth = -1;
    /*
     * Stores the last new item string to avoid double submissions. Cleared on
     * uidl updates
     */
    protected String lastNewItemString;
    protected boolean focused = false;

    /**
     * If set to false, the component should not allow entering text to the
     * field even for filtering.
     */
    private boolean textInputEnabled = true;

    /**
     * Default constructor
     */
    public VFilterSelect() {
        selectedItemIcon.setStyleName("v-icon");
        selectedItemIcon.addLoadHandler(new LoadHandler() {

            @Override
            public void onLoad(LoadEvent event) {
                if (BrowserInfo.get().isIE8()) {
                    // IE8 needs some help to discover it should reposition the
                    // text field
                    forceReflow();
                }
                updateRootWidth();
                updateSelectedIconPosition();
            }
        });

        popupOpener.sinkEvents(Event.ONMOUSEDOWN);
        panel.add(tb);
        panel.add(popupOpener);
        initWidget(panel);
        setStyleName(CLASSNAME);
        tb.addKeyDownHandler(this);
        tb.addKeyUpHandler(this);
        tb.setStyleName(CLASSNAME + "-input");
        tb.addFocusHandler(this);
        tb.addBlurHandler(this);
        tb.addClickHandler(this);
        popupOpener.setStyleName(CLASSNAME + "-button");
        popupOpener.addClickHandler(this);
    }

    /**
     * Does the Select have more pages?
     * 
     * @return true if a next page exists, else false if the current page is the
     *         last page
     */
    public boolean hasNextPage() {
        if (totalMatches > (currentPage + 1) * pageLength) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Filters the options at a certain page. Uses the text box input as a
     * filter
     * 
     * @param page
     *            The page which items are to be filtered
     */
    public void filterOptions(int page) {
        filterOptions(page, tb.getText());
    }

    /**
     * Filters the options at certain page using the given filter
     * 
     * @param page
     *            The page to filter
     * @param filter
     *            The filter to apply to the components
     */
    public void filterOptions(int page, String filter) {
        filterOptions(page, filter, true);
    }

    /**
     * Filters the options at certain page using the given filter
     * 
     * @param page
     *            The page to filter
     * @param filter
     *            The filter to apply to the options
     * @param immediate
     *            Whether to send the options request immediately
     */
    private void filterOptions(int page, String filter, boolean immediate) {
        if (filter.equals(lastFilter) && currentPage == page) {
            if (!suggestionPopup.isAttached()) {
                suggestionPopup.showSuggestions(currentSuggestions,
                        currentPage, totalMatches);
            }
            return;
        }
        if (!filter.equals(lastFilter)) {
            // we are on subsequent page and text has changed -> reset page
            if ("".equals(filter)) {
                // let server decide
                page = -1;
            } else {
                page = 0;
            }
        }

        waitingForFilteringResponse = true;
        client.updateVariable(paintableId, "filter", filter, false);
        client.updateVariable(paintableId, "page", page, immediate);
        lastFilter = filter;
        currentPage = page;
    }

    protected void updateReadOnly() {
        tb.setReadOnly(readonly || !textInputEnabled);
    }

    protected void setTextInputEnabled(boolean textInputEnabled) {
        // Always update styles as they might have been overwritten
        if (textInputEnabled) {
            removeStyleDependentName(STYLE_NO_INPUT);
        } else {
            addStyleDependentName(STYLE_NO_INPUT);
        }

        if (this.textInputEnabled == textInputEnabled) {
            return;
        }

        this.textInputEnabled = textInputEnabled;
        updateReadOnly();
    }

    /**
     * Sets the text in the text box.
     * 
     * @param text
     *            the text to set in the text box
     */
    protected void setTextboxText(final String text) {
        tb.setText(text);
    }

    /**
     * Turns prompting on. When prompting is turned on a command prompt is shown
     * in the text box if nothing has been entered.
     */
    protected void setPromptingOn() {
        if (!prompting) {
            prompting = true;
            addStyleDependentName(CLASSNAME_PROMPT);
        }
        setTextboxText(inputPrompt);
    }

    /**
     * Turns prompting off. When prompting is turned on a command prompt is
     * shown in the text box if nothing has been entered.
     * 
     * @param text
     *            The text the text box should contain.
     */
    protected void setPromptingOff(String text) {
        setTextboxText(text);
        if (prompting) {
            prompting = false;
            removeStyleDependentName(CLASSNAME_PROMPT);
        }
    }

    /**
     * Triggered when a suggestion is selected
     * 
     * @param suggestion
     *            The suggestion that just got selected.
     */
    public void onSuggestionSelected(FilterSelectSuggestion suggestion) {
        updateSelectionWhenReponseIsReceived = false;

        currentSuggestion = suggestion;
        String newKey;
        if (suggestion.key.equals("")) {
            // "nullselection"
            newKey = "";
        } else {
            // normal selection
            newKey = String.valueOf(suggestion.getOptionKey());
        }

        String text = suggestion.getReplacementString();
        if ("".equals(newKey) && !focused) {
            setPromptingOn();
        } else {
            setPromptingOff(text);
        }
        setSelectedItemIcon(suggestion.getIconUri());
        if (!(newKey.equals(selectedOptionKey) || ("".equals(newKey) && selectedOptionKey == null))) {
            selectedOptionKey = newKey;
            client.updateVariable(paintableId, "selected",
                    new String[] { selectedOptionKey }, immediate);
            // currentPage = -1; // forget the page
        }
        suggestionPopup.hide();
    }

    /**
     * Sets the icon URI of the selected item. The icon is shown on the left
     * side of the item caption text. Set the URI to null to remove the icon.
     * 
     * @param iconUri
     *            The URI of the icon
     */
    protected void setSelectedItemIcon(String iconUri) {
        if (iconUri == null || iconUri.length() == 0) {
            if (selectedItemIcon.isAttached()) {
                panel.remove(selectedItemIcon);
                if (BrowserInfo.get().isIE8()) {
                    // IE8 needs some help to discover it should reposition the
                    // text field
                    forceReflow();
                }
                updateRootWidth();
            }
        } else {
            panel.insert(selectedItemIcon, 0);
            selectedItemIcon.setUrl(iconUri);
            updateRootWidth();
            updateSelectedIconPosition();
        }
    }

    private void forceReflow() {
        Util.setStyleTemporarily(tb.getElement(), "zoom", "1");
    }

    /**
     * Positions the icon vertically in the middle. Should be called after the
     * icon has loaded
     */
    private void updateSelectedIconPosition() {
        // Position icon vertically to middle
        int availableHeight = 0;
        availableHeight = getOffsetHeight();

        int iconHeight = Util.getRequiredHeight(selectedItemIcon);
        int marginTop = (availableHeight - iconHeight) / 2;
        DOM.setStyleAttribute(selectedItemIcon.getElement(), "marginTop",
                marginTop + "px");
    }

    private static Set<Integer> navigationKeyCodes = new HashSet<Integer>();
    static {
        navigationKeyCodes.add(KeyCodes.KEY_DOWN);
        navigationKeyCodes.add(KeyCodes.KEY_UP);
        navigationKeyCodes.add(KeyCodes.KEY_PAGEDOWN);
        navigationKeyCodes.add(KeyCodes.KEY_PAGEUP);
        navigationKeyCodes.add(KeyCodes.KEY_ENTER);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.event.dom.client.KeyDownHandler#onKeyDown(com.google.gwt
     * .event.dom.client.KeyDownEvent)
     */

    @Override
    public void onKeyDown(KeyDownEvent event) {
        if (enabled && !readonly) {
            int keyCode = event.getNativeKeyCode();

            debug("key down: " + keyCode);
            if (waitingForFilteringResponse
                    && navigationKeyCodes.contains(keyCode)) {
                /*
                 * Keyboard navigation events should not be handled while we are
                 * waiting for a response. This avoids flickering, disappearing
                 * items, wrongly interpreted responses and more.
                 */
                debug("Ignoring " + keyCode
                        + " because we are waiting for a filtering response");
                DOM.eventPreventDefault(DOM.eventGetCurrentEvent());
                event.stopPropagation();
                return;
            }

            if (suggestionPopup.isAttached()) {
                debug("Keycode " + keyCode + " target is popup");
                popupKeyDown(event);
            } else {
                debug("Keycode " + keyCode + " target is text field");
                inputFieldKeyDown(event);
            }
        }
    }

    private void debug(String string) {
        if (enableDebug) {
            VConsole.error(string);
        }
    }

    /**
     * Triggered when a key is pressed in the text box
     * 
     * @param event
     *            The KeyDownEvent
     */
    private void inputFieldKeyDown(KeyDownEvent event) {
        switch (event.getNativeKeyCode()) {
        case KeyCodes.KEY_DOWN:
        case KeyCodes.KEY_UP:
        case KeyCodes.KEY_PAGEDOWN:
        case KeyCodes.KEY_PAGEUP:
            // open popup as from gadget
            filterOptions(-1, "");
            lastFilter = "";
            tb.selectAll();
            break;
        case KeyCodes.KEY_ENTER:
            /*
             * This only handles the case when new items is allowed, a text is
             * entered, the popup opener button is clicked to close the popup
             * and enter is then pressed (see #7560).
             */
            if (!allowNewItem) {
                return;
            }

            if (currentSuggestion != null
                    && tb.getText().equals(
                            currentSuggestion.getReplacementString())) {
                // Retain behavior from #6686 by returning without stopping
                // propagation if there's nothing to do
                return;
            }
            suggestionPopup.menu.doSelectedItemAction();

            event.stopPropagation();
            break;
        }

    }

    /**
     * Triggered when a key was pressed in the suggestion popup.
     * 
     * @param event
     *            The KeyDownEvent of the key
     */
    private void popupKeyDown(KeyDownEvent event) {
        // Propagation of handled events is stopped so other handlers such as
        // shortcut key handlers do not also handle the same events.
        switch (event.getNativeKeyCode()) {
        case KeyCodes.KEY_DOWN:
            suggestionPopup.selectNextItem();
            suggestionPopup.menu.setKeyboardSelectedItem(suggestionPopup.menu
                    .getSelectedItem());
            DOM.eventPreventDefault(DOM.eventGetCurrentEvent());
            event.stopPropagation();
            break;
        case KeyCodes.KEY_UP:
            suggestionPopup.selectPrevItem();
            suggestionPopup.menu.setKeyboardSelectedItem(suggestionPopup.menu
                    .getSelectedItem());
            DOM.eventPreventDefault(DOM.eventGetCurrentEvent());
            event.stopPropagation();
            break;
        case KeyCodes.KEY_PAGEDOWN:
            if (hasNextPage()) {
                filterOptions(currentPage + 1, lastFilter);
            }
            event.stopPropagation();
            break;
        case KeyCodes.KEY_PAGEUP:
            if (currentPage > 0) {
                filterOptions(currentPage - 1, lastFilter);
            }
            event.stopPropagation();
            break;
        case KeyCodes.KEY_TAB:
            tabPressedWhenPopupOpen = true;
            filterOptions(currentPage);
            // onBlur() takes care of the rest
            break;
        case KeyCodes.KEY_ESCAPE:
            reset();
            event.stopPropagation();
            break;
        case KeyCodes.KEY_ENTER:
            if (suggestionPopup.menu.getKeyboardSelectedItem() == null) {
                /*
                 * Nothing selected using up/down. Happens e.g. when entering a
                 * text (causes popup to open) and then pressing enter.
                 */
                if (!allowNewItem) {
                    /*
                     * New items are not allowed: If there is only one
                     * suggestion, select that. Otherwise do nothing.
                     */
                    if (currentSuggestions.size() == 1) {
                        onSuggestionSelected(currentSuggestions.get(0));
                    }
                } else {
                    // Handle addition of new items.
                    suggestionPopup.menu.doSelectedItemAction();
                }
            } else {
                /*
                 * Get the suggestion that was navigated to using up/down.
                 */
                currentSuggestion = ((FilterSelectSuggestion) suggestionPopup.menu
                        .getKeyboardSelectedItem().getCommand());
                onSuggestionSelected(currentSuggestion);
            }

            event.stopPropagation();
            break;
        }

    }

    /**
     * Triggered when a key was depressed
     * 
     * @param event
     *            The KeyUpEvent of the key depressed
     */

    @Override
    public void onKeyUp(KeyUpEvent event) {
        if (enabled && !readonly) {
            switch (event.getNativeKeyCode()) {
            case KeyCodes.KEY_ENTER:
            case KeyCodes.KEY_TAB:
            case KeyCodes.KEY_SHIFT:
            case KeyCodes.KEY_CTRL:
            case KeyCodes.KEY_ALT:
            case KeyCodes.KEY_DOWN:
            case KeyCodes.KEY_UP:
            case KeyCodes.KEY_PAGEDOWN:
            case KeyCodes.KEY_PAGEUP:
            case KeyCodes.KEY_ESCAPE:
                ; // NOP
                break;
            default:
                if (textInputEnabled) {
                    filterOptions(currentPage);
                }
                break;
            }
        }
    }

    /**
     * Resets the Select to its initial state
     */
    private void reset() {
        if (currentSuggestion != null) {
            String text = currentSuggestion.getReplacementString();
            setPromptingOff(text);
            selectedOptionKey = currentSuggestion.key;
        } else {
            if (focused) {
                setPromptingOff("");
            } else {
                setPromptingOn();
            }
            selectedOptionKey = null;
        }
        lastFilter = "";
        suggestionPopup.hide();
    }

    /**
     * Listener for popupopener
     */

    @Override
    public void onClick(ClickEvent event) {
        if (textInputEnabled
                && event.getNativeEvent().getEventTarget().cast() == tb
                        .getElement()) {
            // Don't process clicks on the text field if text input is enabled
            return;
        }
        if (enabled && !readonly) {
            // ask suggestionPopup if it was just closed, we are using GWT
            // Popup's auto close feature
            if (!suggestionPopup.isJustClosed()) {
                // If a focus event is not going to be sent, send the options
                // request immediately; otherwise queue in the same burst as the
                // focus event. Fixes #8321.
                boolean immediate = focused
                        || !client.hasEventListeners(this, EventId.FOCUS);
                filterOptions(-1, "", immediate);
                popupOpenerClicked = true;
                lastFilter = "";
            }
            DOM.eventPreventDefault(DOM.eventGetCurrentEvent());
            focus();
            tb.selectAll();
        }
    }

    /**
     * Calculate minimum width for FilterSelect textarea
     */
    protected native int minWidth(String captions)
    /*-{
        if(!captions || captions.length <= 0)
                return 0;
        captions = captions.split("|");
        var d = $wnd.document.createElement("div");
        var html = "";
        for(var i=0; i < captions.length; i++) {
                html += "<div>" + captions[i] + "</div>";
                // TODO apply same CSS classname as in suggestionmenu
        }
        d.style.position = "absolute";
        d.style.top = "0";
        d.style.left = "0";
        d.style.visibility = "hidden";
        d.innerHTML = html;
        $wnd.document.body.appendChild(d);
        var w = d.offsetWidth;
        $wnd.document.body.removeChild(d);
        return w;
    }-*/;

    /**
     * A flag which prevents a focus event from taking place
     */
    boolean iePreventNextFocus = false;

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.event.dom.client.FocusHandler#onFocus(com.google.gwt.event
     * .dom.client.FocusEvent)
     */

    @Override
    public void onFocus(FocusEvent event) {

        /*
         * When we disable a blur event in ie we need to refocus the textfield.
         * This will cause a focus event we do not want to process, so in that
         * case we just ignore it.
         */
        if (BrowserInfo.get().isIE() && iePreventNextFocus) {
            iePreventNextFocus = false;
            return;
        }

        focused = true;
        if (prompting && !readonly) {
            setPromptingOff("");
        }
        addStyleDependentName("focus");

        if (client.hasEventListeners(this, EventId.FOCUS)) {
            client.updateVariable(paintableId, EventId.FOCUS, "", true);
        }
    }

    /**
     * A flag which cancels the blur event and sets the focus back to the
     * textfield if the Browser is IE
     */
    boolean preventNextBlurEventInIE = false;

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.event.dom.client.BlurHandler#onBlur(com.google.gwt.event
     * .dom.client.BlurEvent)
     */

    @Override
    public void onBlur(BlurEvent event) {

        if (BrowserInfo.get().isIE() && preventNextBlurEventInIE) {
            /*
             * Clicking in the suggestion popup or on the popup button in IE
             * causes a blur event to be sent for the field. In other browsers
             * this is prevented by canceling/preventing default behavior for
             * the focus event, in IE we handle it here by refocusing the text
             * field and ignoring the resulting focus event for the textfield
             * (in onFocus).
             */
            preventNextBlurEventInIE = false;

            Element focusedElement = Util.getIEFocusedElement();
            if (getElement().isOrHasChild(focusedElement)
                    || suggestionPopup.getElement()
                            .isOrHasChild(focusedElement)) {

                // IF the suggestion popup or another part of the VFilterSelect
                // was focused, move the focus back to the textfield and prevent
                // the triggered focus event (in onFocus).
                iePreventNextFocus = true;
                tb.setFocus(true);
                return;
            }
        }

        focused = false;
        if (!readonly) {
            // much of the TAB handling takes place here
            if (tabPressedWhenPopupOpen) {
                tabPressedWhenPopupOpen = false;
                suggestionPopup.menu.doSelectedItemAction();
                suggestionPopup.hide();
            } else if (!suggestionPopup.isAttached()
                    || suggestionPopup.isJustClosed()) {
                suggestionPopup.menu.doSelectedItemAction();
            }
            if (selectedOptionKey == null) {
                setPromptingOn();
            } else if (currentSuggestion != null) {
                setPromptingOff(currentSuggestion.caption);
            }
        }
        removeStyleDependentName("focus");

        if (client.hasEventListeners(this, EventId.BLUR)) {
            client.updateVariable(paintableId, EventId.BLUR, "", true);
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see com.vaadin.client.Focusable#focus()
     */

    @Override
    public void focus() {
        focused = true;
        if (prompting && !readonly) {
            setPromptingOff("");
        }
        tb.setFocus(true);
    }

    /**
     * Calculates the width of the select if the select has undefined width.
     * Should be called when the width changes or when the icon changes.
     */
    protected void updateRootWidth() {
        ComponentConnector paintable = ConnectorMap.get(client).getConnector(
                this);
        if (paintable.isUndefinedWidth()) {

            /*
             * When the select has a undefined with we need to check that we are
             * only setting the text box width relative to the first page width
             * of the items. If this is not done the text box width will change
             * when the popup is used to view longer items than the text box is
             * wide.
             */
            int w = Util.getRequiredWidth(this);
            if ((!initDone || currentPage + 1 < 0)
                    && suggestionPopupMinWidth > w) {
                /*
                 * We want to compensate for the paddings just to preserve the
                 * exact size as in Vaadin 6.x, but we get here before
                 * MeasuredSize has been initialized.
                 * Util.measureHorizontalPaddingAndBorder does not work with
                 * border-box, so we must do this the hard way.
                 */
                Style style = getElement().getStyle();
                String originalPadding = style.getPadding();
                String originalBorder = style.getBorderWidth();
                style.setPaddingLeft(0, Unit.PX);
                style.setBorderWidth(0, Unit.PX);
                int offset = w - Util.getRequiredWidth(this);
                style.setProperty("padding", originalPadding);
                style.setProperty("borderWidth", originalBorder);

                setWidth(suggestionPopupMinWidth + offset + "px");
            }

            /*
             * Lock the textbox width to its current value if it's not already
             * locked
             */
            if (!tb.getElement().getStyle().getWidth().endsWith("px")) {
                tb.setWidth((tb.getOffsetWidth() - selectedItemIcon
                        .getOffsetWidth()) + "px");
            }
        }
    }

    /**
     * Get the width of the select in pixels where the text area and icon has
     * been included.
     * 
     * @return The width in pixels
     */
    private int getMainWidth() {
        return getOffsetWidth();
    }

    @Override
    public void setWidth(String width) {
        super.setWidth(width);
        if (width.length() != 0) {
            tb.setWidth("100%");
        }
    }

    /**
     * Handles special behavior of the mouse down event
     * 
     * @param event
     */
    private void handleMouseDownEvent(Event event) {
        /*
         * Prevent the keyboard focus from leaving the textfield by preventing
         * the default behaviour of the browser. Fixes #4285.
         */
        if (event.getTypeInt() == Event.ONMOUSEDOWN) {
            event.preventDefault();
            event.stopPropagation();

            /*
             * In IE the above wont work, the blur event will still trigger. So,
             * we set a flag here to prevent the next blur event from happening.
             * This is not needed if do not already have focus, in that case
             * there will not be any blur event and we should not cancel the
             * next blur.
             */
            if (BrowserInfo.get().isIE() && focused) {
                preventNextBlurEventInIE = true;
            }
        }
    }

    @Override
    protected void onDetach() {
        super.onDetach();
        suggestionPopup.hide();
    }

    @Override
    public Element getSubPartElement(String subPart) {
        if ("textbox".equals(subPart)) {
            return tb.getElement();
        } else if ("button".equals(subPart)) {
            return popupOpener.getElement();
        }
        return null;
    }

    @Override
    public String getSubPartName(Element subElement) {
        if (tb.getElement().isOrHasChild(subElement)) {
            return "textbox";
        } else if (popupOpener.getElement().isOrHasChild(subElement)) {
            return "button";
        }
        return null;
    }
}
