com.extjs.gxt.ui.client.widget.form.ComboBox.java Source code

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/*
 * Sencha GXT 2.3.1 - Sencha for GWT
 * Copyright(c) 2007-2013, Sencha, Inc.
 * licensing@sencha.com
 * 
 * http://www.sencha.com/products/gxt/license/
 */
package com.extjs.gxt.ui.client.widget.form;

import com.extjs.gxt.ui.client.GXT;
import com.extjs.gxt.ui.client.Style.Scroll;
import com.extjs.gxt.ui.client.core.El;
import com.extjs.gxt.ui.client.core.XDOM;
import com.extjs.gxt.ui.client.data.*;
import com.extjs.gxt.ui.client.event.*;
import com.extjs.gxt.ui.client.store.ListStore;
import com.extjs.gxt.ui.client.store.StoreEvent;
import com.extjs.gxt.ui.client.store.StoreListener;
import com.extjs.gxt.ui.client.util.*;
import com.extjs.gxt.ui.client.widget.ComponentHelper;
import com.extjs.gxt.ui.client.widget.LayoutContainer;
import com.extjs.gxt.ui.client.widget.ListView;
import com.extjs.gxt.ui.client.widget.ModelPropertyRenderer;
import com.extjs.gxt.ui.client.widget.toolbar.PagingToolBar;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.InputElement;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.text.shared.SafeHtmlRenderer;
import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.RootPanel;

import java.util.ArrayList;
import java.util.List;

/**
 * A combobox component.
 * 
 * <p />
 * When not forcing a selection ({@link #setForceSelection(boolean)})
 * {@link #getValue()} can return null event if the user has typed text into the
 * field if that text cannot be tied to a model from from the combo's store. In
 * this case, you can use {@link #getRawValue()} to get the fields string value.
 *
 * <p />
 * A custom <code>PropertyEditor</code> can be used to "format" the value that
 * is displayed in the combo's text field. For example:
 * 
 * <pre>
 * combo.setPropertyEditor(new ListModelPropertyEditor&lt;State&gt;() {
 *   public String getStringValue(State value) {
 *     return value.getAbbr() + &quot; &quot; + value.getName();
 *   }
 * });
 * </pre>
 * 
 * A <code>ModelProcessor</code> can be used to "format" the values in the drop
 * down list:
 * 
 * <pre>
 * combo.getView().setModelProcessor(new ModelProcessor&lt;State&gt;() {
 *   public State prepareData(State model) {
 *     model.set(&quot;test&quot;, model.getAbbr() + &quot; &quot; + model.getName());
 *     return model;
 *   }
 * });
 * </pre>
 * 
 * <dl>
 * <dt><b>Events:</b></dt>
 * <dd><b>Expand</b> : FieldEvent(field)<br>
 * <div>Fires when the dropdown list is expanded.</div>
 * <ul>
 * <li>field : this</li>
 * </ul>
 * </dd>
 * 
 * <dd><b>Collapse</b> : FieldEvent(field)<br>
 * <div>Fires when the dropdown list is collapsed.</div>
 * <ul>
 * <li>field : this</li>
 * </ul>
 * </dd>
 * 
 * <dd><b>BeforeSelect</b> : FieldEvent(field)<br>
 * <div>Fires before a list item is selected. Listeners can cancel the action by
 * calling {@link BaseEvent#setCancelled(boolean)}.</div>
 * <ul>
 * <li>field : this</li>
 * </ul>
 * </dd>
 * <dd><b>Select</b> : FieldEvent(field)<br>
 * <div>Fires when a list item is selected.</div>
 * <ul>
 * <li>field : this</li>
 * </ul>
 * </dd>
 * 
 * <dd><b>BeforeQuery</b> : FieldEvent(field, value)<br>
 * <div>Fires before all queries are processed. Listeners can cancel the action
 * by calling {@link BaseEvent#setCancelled(boolean)}.</div>
 * <ul>
 * <li>field : this</li>
 * <li>value : query</li>
 * </ul>
 * </dd>
 * </dl>
 * <dl>
 * 
 * <dt>Inherited Events:</dt>
 * <dd>Field Focus</dd>
 * <dd>Field Blur</dd>
 * <dd>Field Change</dd>
 * <dd>Field Invalid</dd>
 * <dd>Field Valid</dd>
 * <dd>Field KeyPress</dd>
 * <dd>Field SpecialKey</dd>
 * <dd>TriggerField TriggerClick</dd>
 * </dl>
 * 
 * @param <D> the model data type
 */
@SuppressWarnings("deprecation")
public class ComboBox<D extends ModelData> extends TriggerField<D> implements SelectionProvider<D> {

    /**
     * ComboBox error messages.
     */
    public class ComboBoxMessages extends TextFieldMessages {

        private String loadingText = GXT.MESSAGES.loadMask_msg();
        private String valueNoutFoundText;

        /**
         * Returns the loading text.
         * 
         * @return the loading text
         */
        public String getLoadingText() {
            return loadingText;
        }

        /**
         * Returns the value not found error text.
         * 
         * @return the error text
         */
        public String getValueNoutFoundText() {
            return valueNoutFoundText;
        }

        /**
         * Sets the loading text.
         * 
         * @param loadingText the loading text
         */
        public void setLoadingText(String loadingText) {
            this.loadingText = loadingText;
        }

        /**
         * When using a name/value combo, if the value passed to setValue is not
         * found in the store, valueNotFoundText will be displayed as the field text
         * if defined.
         * 
         * @param valueNoutFoundText
         */
        public void setValueNoutFoundText(String valueNoutFoundText) {
            this.valueNoutFoundText = valueNoutFoundText;
        }

    }

    /**
     * TriggerAction enum.
     */
    public enum TriggerAction {
        ALL, QUERY;
    }

    protected boolean autoComplete = false;
    protected boolean delayedCheck;
    protected String lastQuery;

    protected int pageSize;
    protected PagingToolBar pageTb;
    protected ListStore<D> store;
    private String allQuery = "";
    private BaseEventPreview eventPreview;
    private boolean expanded;
    private El footer;
    private boolean forceSelection;
    private InputElement hiddenInput;
    private String itemSelector;
    private String lastSelectionText;
    private boolean lazyRender = true, initialized;
    private LayoutContainer list;
    private String listAlign = "tl-bl?";
    private String listStyle = "x-combo-list";
    private ListView<D> listView;
    private int maxHeight = 300;
    private int minChars = 4;
    private int minListWidth = 70;
    private String mode = "remote";
    private int queryDelay = 500;
    private D selectedItem;
    private String selectedStyle = "x-combo-selected";
    private StoreListener<D> storeListener;
    private DelayedTask taTask, dqTask;
    private SafeHtmlRenderer<List<D>> renderer;
    private TriggerAction triggerAction = TriggerAction.QUERY;
    private boolean typeAhead;
    private int typeAheadDelay = 250;
    private boolean useQueryCache = true;

    private String valueField;

    /**
     * Creates a combo box.
     */
    public ComboBox() {
        messages = new ComboBoxMessages();
        listView = new ListView<D>();
        setPropertyEditor(new ListModelPropertyEditor<D>());
        monitorWindowResize = true;
        windowResizeDelay = 0;
        initComponent();
    }

    public void addSelectionChangedListener(SelectionChangedListener<D> listener) {
        addListener(Events.SelectionChange, listener);
    }

    @Override
    public void clear() {
        getStore().clearFilters();
        boolean f = forceSelection;
        forceSelection = false;
        super.clear();
        forceSelection = f;
    }

    /**
     * Clears any text/value currently set in the field.
     */
    public void clearSelections() {
        setRawValue("");
        lastSelectionText = "";
        applyEmptyText();
        value = null;
    }

    /**
     * Hides the dropdown list if it is currently expanded. Fires the
     * <i>Collapse</i> event on completion.
     */
    public void collapse() {
        if (!expanded) {
            return;
        }
        eventPreview.remove();
        expanded = false;
        list.hide();

        RootPanel.get().remove(list);
        if (GXT.isAriaEnabled() && hasFocus) {
            // inspect 32 is keeping focus on hidden list item in dropdown
            input.blur();
            input.focus();
        }
        fireEvent(Events.Collapse, new FieldEvent(this));
    }

    /**
     * Execute a query to filter the dropdown list. Fires the BeforeQuery event
     * prior to performing the query allowing the query action to be canceled if
     * needed.
     * 
     * @param q the query
     * @param forceAll true to force the query to execute even if there are
     *          currently fewer characters in the field than the minimum specified
     *          by the minChars config option. It also clears any filter
     *          previously saved in the current store
     */
    public void doQuery(String q, boolean forceAll) {
        if (q == null) {
            q = "";
        }

        FieldEvent fe = new FieldEvent(this);
        fe.setValue(q);
        if (!fireEvent(Events.BeforeQuery, fe)) {
            return;
        }

        if (forceAll || q.length() >= minChars) {
            if (!useQueryCache || !q.equals(lastQuery)) {
                lastQuery = q;
                if (mode.equals("local")) {
                    selectedItem = null;
                    store.filter(getDisplayField(), q);
                    onLoad(null);
                } else {
                    expand();
                    store.getLoader().load(getParams(q));
                }
            } else {
                selectedItem = null;
                onLoad(null);
            }
        }
    }

    /**
     * Expands the dropdown list if it is currently hidden. Fires the
     * <i>expand</i> event on completion.
     */
    public void expand() {
        if (expanded || !hasFocus) {
            return;
        }

        if (!initialized) {
            createList(false);
        } else {
            RootPanel.get().add(list);
        }

        list.show();
        list.layout();
        list.el().updateZIndex(0);
        restrict();

        eventPreview.add();
        expanded = true;
        fireEvent(Events.Expand, new FieldEvent(this));
    }

    /**
     * Returns the all query.
     * 
     * @return the all query
     */
    public String getAllQuery() {
        return allQuery;
    }

    /**
     * Returns the display field.
     * 
     * @return the display field
     */
    public String getDisplayField() {
        return getPropertyEditor().getDisplayProperty();
    }

    /**
     * Returns true if the field's value is forced to one of the value in the
     * list.
     * 
     * @return the force selection state
     */
    public boolean getForceSelection() {
        return forceSelection;
    }

    /**
     * Returns the item selector.
     * 
     * @return the item selector
     */
    public String getItemSelector() {
        return itemSelector;
    }

    /**
     * Returns the list's list align value.
     * 
     * @return the list align value
     */
    public String getListAlign() {
        return listAlign;
    }

    /**
     * Returns the list style.
     * 
     * @return the list style
     */
    public String getListStyle() {
        return listStyle;
    }

    /**
     * Returns the combo's list view.
     * 
     * @return the view
     */
    public ListView<D> getListView() {
        return listView;
    }

    /**
     * Returns the loading text.
     * 
     * @return the loading text
     */
    public String getLoadingText() {
        return getMessages().getLoadingText();
    }

    /**
     * Returns the dropdown list's max height.
     * 
     * @return the max height
     */
    public int getMaxHeight() {
        return maxHeight;
    }

    @SuppressWarnings("unchecked")
    @Override
    public ComboBoxMessages getMessages() {
        return (ComboBoxMessages) messages;
    }

    /**
     * Returns the min characters used for autocompete and typeahead.
     * 
     * @return the minimum number of characters
     */
    public int getMinChars() {
        return minChars;
    }

    /**
     * Returns the dropdown list's min width.
     * 
     * @return the min width
     */
    public int getMinListWidth() {
        return minListWidth;
    }

    /**
     * Returns the page size.
     * 
     * @return the page size
     */
    public int getPageSize() {
        return pageSize;
    }

    /**
     * Returns the combo's paging tool bar.
     * 
     * @return the tool bar
     */
    public PagingToolBar getPagingToolBar() {
        return pageTb;
    }

    @Override
    public ListModelPropertyEditor<D> getPropertyEditor() {
        return (ListModelPropertyEditor<D>) propertyEditor;
    }

    /**
     * Returns the query delay.
     * 
     * @return the query delay
     */
    public int getQueryDelay() {
        return queryDelay;
    }

    /**
     * Returns the selected style.
     * 
     * @return the selected style
     */
    public String getSelectedStyle() {
        return selectedStyle;
    }

    public List<D> getSelection() {
        List<D> sel = new ArrayList<D>();
        D v = getValue();
        if (v != null) {
            sel.add(v);
        }
        return sel;
    }

    /**
     * Returns the combo's store.
     * 
     * @return the store
     */
    public ListStore<D> getStore() {
        return store;
    }

    /**
     * Returns the trigger action.
     * 
     * @return the trigger action
     */
    public TriggerAction getTriggerAction() {
        return triggerAction;
    }

    /**
     * Returns the type ahead delay in milliseconds.
     * 
     * @return the type ahead delay
     */
    public int getTypeAheadDelay() {
        return typeAheadDelay;
    }

    @Override
    public D getValue() {
        if (!initialized) {
            return value;
        }
        if (store != null) {
            getPropertyEditor().setList(store.getModels());
        }

        doForce();
        return super.getValue();
    }

    /**
     * Returns the value field name.
     * 
     * @return the value field name
     */
    public String getValueField() {
        return valueField;
    }

    /**
     * Returns the combo's list view.
     * 
     * @return the view
     */
    public ListView<D> getView() {
        return listView;
    }

    /**
     * Returns <code>true</code> if the panel is expanded.
     * 
     * @return the expand state
     */
    public boolean isExpanded() {
        return expanded;
    }

    /**
     * Returns true if lazy rendering is enabled.
     * 
     * @return true of lazy rendering
     */
    public boolean isLazyRender() {
        return lazyRender;
    }

    /**
     * Returns true if type ahead is enabled.
     * 
     * @return the type ahead state
     */
    public boolean isTypeAhead() {
        return typeAhead;
    }

    /**
     * Returns the state if the query cache is used or not.
     * 
     * @return the useQueryCache state
     */
    public boolean isUseQueryCache() {
        return useQueryCache;
    }

    public void removeSelectionListener(SelectionChangedListener<D> listener) {
        removeListener(Events.SelectionChange, listener);
    }

    @Override
    public void reset() {
        getStore().clearFilters();
        boolean f = forceSelection;
        forceSelection = false;
        super.reset();
        forceSelection = f;
    }

    public void select(D sel) {
        if (listView != null && sel != null) {
            int index = store.indexOf(sel);
            selectedItem = sel;
            if (index < listView.getElements().size()) {
                listView.getSelectionModel().select(sel, false);
                fly(listView.getElement(index)).scrollIntoView(listView.getElement(), false);
            }
        }
    }

    /**
     * Select an item in the dropdown list by its numeric index in the list. This
     * function does NOT cause the select event to fire. The list must expanded
     * for this function to work, otherwise use #setValue.
     * 
     * @param index the index of the item to select
     */
    public void select(int index) {
        select(store.getAt(index));
    }

    /**
     * The text query to send to the server to return all records for the list
     * with no filtering (defaults to '').
     * 
     * @param allQuery the all query
     */
    public void setAllQuery(String allQuery) {
        this.allQuery = allQuery;
    }

    /**
     * The underlying data field name to bind to this ComboBox (defaults to
     * 'text').
     * 
     * @param displayField the display field
     */
    public void setDisplayField(String displayField) {
        getPropertyEditor().setDisplayProperty(displayField);
    }

    /**
     * Sets the panel's expand state.
     * 
     * @param expand <code>true<code> true to expand
     */
    public void setExpanded(boolean expand) {
        this.expanded = expand;
        if (isRendered()) {
            if (expand) {
                expand();
            } else {
                collapse();
            }
        }
    }

    /**
     * Sets whether the combo's value is restricted to one of the values in the
     * list, false to allow the user to set arbitrary text into the field
     * (defaults to false).
     * 
     * @param forceSelection true to force selection
     */
    public void setForceSelection(boolean forceSelection) {
        this.forceSelection = forceSelection;
    }

    /**
     * This setting is required if a custom XTemplate has been specified.
     * 
     * @param itemSelector the item selector
     */
    public void setItemSelector(String itemSelector) {
        this.itemSelector = itemSelector;
    }

    /**
     * True to lazily render the combo's drop down list (default to true,
     * pre-render).
     * 
     * @param lazyRender true to lazy render the drop down list
     */
    public void setLazyRender(boolean lazyRender) {
        this.lazyRender = lazyRender;
    }

    /**
     * Sets a valid anchor position value. See {@link El#alignTo} for details on
     * supported anchor positions (defaults to 'tl-bl?').
     * 
     * @param listAlign the new list align value
     */
    public void setListAlign(String listAlign) {
        this.listAlign = listAlign;
    }

    /**
     * Sets the style for the drop down list (defaults to 'x-combo-list');
     * 
     * @param listStyle the list style
     */
    public void setListStyle(String listStyle) {
        this.listStyle = listStyle;
    }

    /**
     * Sets the loading text.
     * 
     * @param loadingText the loading text
     */
    public void setLoadingText(String loadingText) {
        getMessages().setLoadingText(loadingText);
    }

    /**
     * Sets the maximum height in pixels of the dropdown list before scrollbars
     * are shown (defaults to 300).
     * 
     * @param maxHeight the max hieght
     */
    public void setMaxHeight(int maxHeight) {
        this.maxHeight = maxHeight;
    }

    /**
     * Sets the minimum number of characters the user must type before
     * autocomplete and typeahead active (defaults to 4 if remote, or 0 if local).
     * 
     * @param minChars
     */
    public void setMinChars(int minChars) {
        this.minChars = minChars;
    }

    /**
     * Sets the minimum width of the dropdown list in pixels (defaults to 70, will
     * be ignored if listWidth has a higher value).
     * 
     * @param minListWidth the min width
     */
    public void setMinListWidth(int minListWidth) {
        this.minListWidth = minListWidth;
    }

    /**
     * Sets the page size. Only applies when using a paging toolbar.
     * 
     * @param pageSize the page size
     */
    public void setPageSize(int pageSize) {
        assertPreRender();
        this.pageSize = pageSize;
        if (pageSize > 0) {
            if (pageTb != null) {
                pageTb.setPageSize(pageSize);
            } else {
                pageTb = createPagingToolBar(pageSize);
            }
        } else {
            pageTb = null;
        }
    }

    @Override
    public void setPropertyEditor(PropertyEditor<D> propertyEditor) {
        assert propertyEditor instanceof ListModelPropertyEditor<?> : "PropertyEditor must be a ListModelPropertyEditor instance";
        super.setPropertyEditor(propertyEditor);
    }

    /**
     * The length of time in milliseconds to delay between the start of typing and
     * sending the query to filter the dropdown list.
     * 
     * @param queryDelay the query delay
     */
    public void setQueryDelay(int queryDelay) {
        this.queryDelay = queryDelay;
    }

    @Override
    public void setRawValue(String text) {
        if (rendered) {
            if (text == null) {
                String msg = getMessages().getValueNoutFoundText();
                text = msg != null ? msg : "";
            }
            getInputEl().setValue(text);
        }
    }

    /**
     * Sets the CSS style name to apply to the selected item in the dropdown list
     * (defaults to 'x-combo-selected').
     * 
     * @param selectedStyle the selected style
     */
    public void setSelectedStyle(String selectedStyle) {
        this.selectedStyle = selectedStyle;
    }

    public void setSelection(List<D> selection) {
        if (selection.size() > 0) {
            setValue(selection.get(0));
        } else {
            setValue(null);
        }
    }

    /**
     * Sets the renderer to be used for the content of each combo list item.
     *
     * @param itemRenderer the renderer used only for the content of each item in the list
     */
    public void setItemRenderer(SafeHtmlRenderer<D> itemRenderer) {
        assertPreRender();
        renderer = new ComboBoxListRenderer<>(listStyle, itemRenderer);
    }

    /**
     * Sets the combo's store.
     * 
     * @param store the store
     */
    public void setStore(ListStore<D> store) {
        if (rendered) {
            bindStore(store);
        } else {
            this.store = store;
        }
    }

    public SafeHtmlRenderer<List<D>> getRenderer() {
        return renderer;
    }

    public void setRenderer(SafeHtmlRenderer<List<D>> renderer) {
        this.renderer = renderer;
    }

    /**
     * The action to execute when the trigger field is activated. Use
     * {@link TriggerAction#ALL} to run the query specified by the allQuery config
     * option (defaults to {@link TriggerAction#QUERY}).
     * 
     * @param triggerAction the trigger action
     */
    public void setTriggerAction(TriggerAction triggerAction) {
        this.triggerAction = triggerAction;
    }

    /**
     * True to populate and autoselect the remainder of the text being typed after
     * a configurable delay ({@link #typeAheadDelay}) if it matches a known value
     * (defaults to false)
     * 
     * @param typeAhead
     */
    public void setTypeAhead(boolean typeAhead) {
        this.typeAhead = typeAhead;
        if (rendered) {
            if (typeAhead && taTask == null) {
                taTask = new DelayedTask(new Listener<BaseEvent>() {
                    public void handleEvent(BaseEvent be) {
                        onTypeAhead();
                    }
                });
            } else if (!typeAhead && taTask != null) {
                taTask.cancel();
                taTask = null;
            }
        }
    }

    /**
     * The length of time in milliseconds to wait until the typeahead text is
     * displayed if typeAhead = true (defaults to 250).
     * 
     * @param typeAheadDelay the type ahead delay
     */
    public void setTypeAheadDelay(int typeAheadDelay) {
        this.typeAheadDelay = typeAheadDelay;
    }

    /**
     * Set this to false to disable the last query cache (defaults to true).
     * 
     * When set to false the store gets queried on each expand for the data that
     * should get displayed in the list. If you use a loader, than each time the
     * ComboBox gets expanded, the server gets asked for the data.
     * 
     * You want to do this for example, if you filter the content of this ComboBox
     * against some selection in another field.
     * 
     * @param useQueryCache the useQueryCache to set
     */
    public void setUseQueryCache(boolean useQueryCache) {
        this.useQueryCache = useQueryCache;
    }

    @Override
    public void setValue(D value) {
        D oldValue = this.value;
        super.setValue(value);
        updateHiddenValue();
        this.lastSelectionText = getRawValue();
        if (!Util.equalWithNull(oldValue, value)) {
            SelectionChangedEvent<D> se = new SelectionChangedEvent<D>(this, getSelection());
            fireEvent(Events.SelectionChange, se);
        }
    }

    /**
     * Sets the model field used to retrieve the "value" from the model. If
     * specified, a hidden form field will contain the value. The hidden form
     * field name will be the combo's field name plus "-hidden".
     * 
     * @param valueField the value field name
     */
    public void setValueField(String valueField) {
        this.valueField = valueField;
    }

    /**
     * Sets the combo's view.
     * 
     * @param view the view
     */
    public void setView(ListView<D> view) {
        this.listView = view;
    }

    protected void collapseIf(PreviewEvent pe) {
        if (!list.el().isOrHasChild(pe.getTarget()) && !el().isOrHasChild(pe.getTarget())) {
            collapse();
        }
    }

    protected PagingToolBar createPagingToolBar(int pageSize) {
        return new PagingToolBar(pageSize);
    }

    protected void doForce() {
        if (forceSelection) {
            boolean f = forceSelection;
            forceSelection = false;
            String rv = getRawValue();
            if (getAllowBlank() && (rv == null || rv.equals(""))) {
                forceSelection = f;
                return;
            }

            if (!initialized) {
                createList(true);
            }

            if (getValue() == null) {
                if (lastSelectionText != null && !"".equals(lastSelectionText)) {
                    setRawValue(lastSelectionText);
                    if (mode.equals("local")) {
                        // we need to filter the store here, so that the store only contains
                        // the items needed.
                        // we adjust the lastQuery, so doLoad does not use an old value
                        lastQuery = lastSelectionText;
                        store.filter(getDisplayField(), getRawValue());
                    }
                } else {
                    applyEmptyText();
                }
            }
            forceSelection = f;
        }
    }

    protected D findModel(String property, String value) {
        if (value == null)
            return null;
        for (D model : store.getModels()) {
            if (value.equals(getPropertyEditor().getStringValue(model))) {
                return model;
            }
        }
        return null;
    }

    protected void fireKey(FieldEvent fe) {
        if (fe.isNavKeyPress() && !isExpanded() && !delayedCheck) {
            fireEvent(Events.SpecialKey, fe);
        }
    }

    protected Element getAlignElement() {
        return getElement();
    }

    @Override
    protected El getFocusEl() {
        return input;
    }

    protected PagingLoadConfig getParams(String query) {
        PagingLoadConfig config = null;
        if (store.getLoader() instanceof BaseLoader<?> && ((BaseLoader<?>) store.getLoader()).isReuseLoadConfig()) {
            config = (PagingLoadConfig) ((BaseLoader<?>) store.getLoader()).getLastConfig();
        } else {
            config = new BasePagingLoadConfig();
        }
        config.setLimit(pageSize);
        config.setOffset(0);
        config.set("query", query);
        return config;
    }

    protected boolean hasFocus() {
        return hasFocus || expanded;
    }

    @SuppressWarnings("rawtypes")
    protected void initComponent() {
        storeListener = new StoreListener<D>() {

            @Override
            public void storeBeforeDataChanged(StoreEvent<D> se) {
                onBeforeLoad(se);
            }

            @Override
            public void storeDataChanged(StoreEvent<D> se) {
                onLoad(se);
            }

            @Override
            public void storeUpdate(StoreEvent<D> se) {
                onUpdate(se);
            }

        };

        eventPreview = new BaseEventPreview() {
            @Override
            protected boolean onPreview(PreviewEvent pe) {
                switch (pe.getType().getEventCode()) {
                case Event.ONSCROLL:
                case Event.ONMOUSEWHEEL:
                case Event.ONMOUSEDOWN:
                    collapseIf(pe);
                    break;
                }

                if (pe.getType() == KeyNav.getKeyEvent() && expanded && pe.getKeyCode() == KeyCodes.KEY_ENTER
                        && (pageTb == null || !pageTb.getElement().isOrHasChild(pe.getTarget()))) {
                    pe.stopEvent();
                    onViewClick(pe, false);
                }
                return true;
            }
        };
        eventPreview.setAutoHide(false);

        new KeyNav(this) {

            @Override
            public void onDown(ComponentEvent ce) {
                if (!isReadOnly()) {
                    ce.cancelBubble();
                    if (!isExpanded()) {
                        onTriggerClick(ce);
                    } else {
                        selectNext();
                    }
                }
            }

            @Override
            public void onEnter(ComponentEvent ce) {
                if (expanded) {
                    if (pageTb != null && ce.within(pageTb.getElement())) {
                        return;
                    }

                    ce.cancelBubble();
                    onViewClick(ce, false);
                    delayedCheck = true;
                    unsetDelayCheck();
                }
            }

            @Override
            public void onEsc(ComponentEvent ce) {
                if (expanded) {
                    ce.cancelBubble();
                    collapse();
                }
            }

            @Override
            public void onTab(ComponentEvent ce) {
                if (expanded) {
                    onViewClick(ce, false);
                }
            }

            @Override
            public void onUp(ComponentEvent ce) {
                if (expanded) {
                    ce.cancelBubble();
                    selectPrev();
                }
            }

        };
    }

    @SuppressWarnings("rawtypes")
    protected void initList() {
        if (listView == null) {
            listView = new ListView<D>();
        }

        String style = listStyle;
        listView.setStyleAttribute("overflowX", "hidden");
        listView.addStyleName(style + "-inner");
        listView.setStyleAttribute("padding", "0px");
        listView.setItemSelector(itemSelector != null ? itemSelector : "." + style + "-item");
        listView.setSelectOnOver(true);
        listView.setBorders(false);
        listView.setLoadingText(SafeGxt.fromNullableString(getMessages().getLoadingText()));
        listView.getSelectionModel().addListener(Events.SelectionChange, new Listener<SelectionChangedEvent<D>>() {
            public void handleEvent(SelectionChangedEvent<D> se) {
                selectedItem = listView.getSelectionModel().getSelectedItem();
                if (GXT.isAriaEnabled()) {
                    Element e = listView.getElement(listView.getStore().indexOf(selectedItem));
                    ComboBox.this.setAriaState("aria-activedescendant", e.getId());
                }
            }
        });

        listView.addListener(Events.Select, new Listener<ListViewEvent<D>>() {
            public void handleEvent(ListViewEvent<D> le) {
                onViewClick(le, true);
            }
        });
        if (renderer == null) {
            renderer = new ComboBoxListRenderer<>(listStyle, new ModelPropertyRenderer<D>(getDisplayField()));
        }

        if (pageTb != null) {
            pageTb.bind((PagingLoader) store.getLoader());
        }

        list = new LayoutContainer() {
            @Override
            protected void doAttachChildren() {
                super.doAttachChildren();
                ComponentHelper.doAttach(ComboBox.this.pageTb);

            }

            @Override
            protected void doDetachChildren() {
                super.doDetachChildren();
                ComponentHelper.doDetach(ComboBox.this.pageTb);
            }

            @Override
            protected void onRender(Element parent, int index) {
                super.onRender(parent, index);
                eventPreview.getIgnoreList().add(getElement());

                el().makePositionable(true);

                setAriaRole("presentation");

                if (pageTb != null) {
                    footer = list.el().createChild("<div class='" + listStyle + "-ft'></div>");
                    pageTb.setBorders(false);
                    pageTb.render(footer.dom);
                }
            }
        };
        list.setScrollMode(Scroll.NONE);
        list.setShim(true);
        list.setShadow(true);
        list.setBorders(true);
        list.setStyleName(style);
        list.hide();
        list.addStyleName("x-ignore");

        assert store != null : "ComboBox needs a store";

        list.add(listView);

        listView.setRenderer(renderer);
        listView.setSelectStyle(selectedStyle);

        bindStore(store);

        if (!lazyRender) {
            createList(true);
        }
    }

    protected void onBeforeLoad(StoreEvent<D> se) {
        if (!hasFocus()) {
            return;
        }
        if (expanded) {
            restrict();
        }
    }

    @Override
    protected void onDetach() {
        collapse();
        super.onDetach();
        if (eventPreview != null) {
            eventPreview.remove();
        }
    }

    protected void onEmptyResults() {
        collapse();
    }

    @Override
    protected void onKeyDown(FieldEvent fe) {
        if (fe.getKeyCode() == KeyCodes.KEY_TAB) {
            if (expanded) {
                onViewClick(fe, false);
            }
        }
        super.onKeyDown(fe);
    }

    @Override
    protected void onKeyUp(FieldEvent fe) {
        super.onKeyUp(fe);
        if (!isReadOnly() && isEditable()
                && (!fe.isSpecialKey() || fe.getKeyCode() == KeyCodes.KEY_BACKSPACE || fe.getKeyCode() == 46)) {
            // last key
            dqTask.delay(queryDelay);
        }
    }

    protected void onLoad(StoreEvent<D> se) {
        if (!isAttached() || !hasFocus()) {
            return;
        }
        if (store.getCount() > 0) {
            if (expanded) {
                restrict();
            } else {
                expand();
            }

            if (lastQuery != null && lastQuery.equals(allQuery)) {
                if (isEditable()) {
                    selectAll();
                }
            } else {
                if (typeAhead) {
                    taTask.delay(typeAheadDelay);
                }
            }
            if (!selectByValue(getRawValue())) {
                select(0);
            }
        } else {
            onEmptyResults();
        }
    }

    protected void onRender(Element parent, int index) {
        super.onRender(parent, index);
        initList();

        if (!autoComplete) {
            getInputEl().dom.setAttribute("autocomplete", "off");
        }

        if (mode.equals("local")) {
            minChars = 0;
        }

        dqTask = new DelayedTask(new Listener<BaseEvent>() {
            public void handleEvent(BaseEvent be) {
                initQuery();
            }
        });

        if (valueField != null) {
            hiddenInput = Document.get().createHiddenInputElement().cast();
            hiddenInput.setName(getName() + "-hidden");
            getElement().appendChild(hiddenInput);
        }

        if (typeAhead) {
            taTask = new DelayedTask(new Listener<BaseEvent>() {
                public void handleEvent(BaseEvent be) {
                    onTypeAhead();
                }
            });
        }
        eventPreview.getIgnoreList().add(getElement());

        setAriaState("aria-owns", listView.getId());
        setAriaRole("combobox");
    }

    protected void onSelect(D model, int index) {
        FieldEvent fe = new FieldEvent(this);
        if (fireEvent(Events.BeforeSelect, fe)) {
            setValue(model);
            collapse();
            fireEvent(Events.Select, fe);
        }
    }

    protected void onTriggerClick(ComponentEvent ce) {
        super.onTriggerClick(ce);
        if (expanded) {
            collapse();
        } else {
            onFocus(null);
            if (triggerAction == TriggerAction.ALL) {
                doQuery(allQuery, true);
            } else {
                doQuery(getRawValue(), true);
            }

        }
        getInputEl().focus();
    }

    protected void onTypeAhead() {
        if (store.getCount() > 0) {
            D m = store.getAt(0);
            String newValue = propertyEditor.getStringValue(m);
            int len = newValue.length();
            int selStart = getRawValue().length();
            if (selStart != len) {
                setRawValue(newValue);
                select(selStart, newValue.length());
            }
        }
    }

    protected void onUpdate(StoreEvent<D> se) {
        // handle the case when the selected model's display property is updated
        if (!getRawValue().equals("") && getValue() == null && forceSelection) {
            setValue(null);
            store.clearFilters();
            setValue(se.getModel());
        }
    }

    protected void onViewClick(DomEvent de, boolean focus) {
        int idx = -1;
        // when testing in selenium the items will not be selected as the mouse
        // is not moved during the test
        Element elem = listView.findElement(de.getTarget());
        if (elem != null) {
            idx = listView.indexOf(elem);
        } else {
            D sel = listView.getSelectionModel().getSelectedItem();
            if (sel != null) {
                idx = store.indexOf(sel);
            }
        }
        if (idx != -1) {
            D sel = store.getAt(idx);
            onSelect(sel, idx);
        }

        if (focus) {
            DeferredCommand.addCommand(new Command() {
                public void execute() {
                    focus();
                }
            });
        }
    }

    protected void onWindowResize(int width, int height) {
        collapse();
    }

    protected void restrict() {
        list.el().setVisibility(false);
        listView.setHeight("auto");
        list.setHeight("auto");
        int w = Math.max(getWidth(), minListWidth);

        int fh = footer != null ? footer.getHeight() : 0;
        int fw = list.el().getFrameWidth("tb") + fh;

        int h = listView.getHeight() + fw;

        int mH = Math.min(maxHeight, Window.getClientHeight() - 10);
        h = Math.min(h, mH);
        list.setSize(w, h);
        list.el().alignTo(getAlignElement(), listAlign, null);

        h -= fw;

        int width = w - list.el().getFrameWidth("lr");
        listView.syncSize();
        listView.setSize(width, h);

        if (pageTb != null) {
            pageTb.setWidth(width);
        }

        int y = list.el().getY();
        int b = y + h + fw;
        int vh = XDOM.getViewportSize().height + XDOM.getBodyScrollTop();
        if (b > vh) {
            y = y - (b - vh) - 5;
            list.el().setTop(y);
        }
        list.el().setVisibility(true);
    }

    protected boolean selectByValue(String value) {
        D r = findModel(getDisplayField(), value);
        if (r != null) {
            select(r);
            return true;
        }
        return false;
    }

    @Override
    protected void triggerBlur(ComponentEvent ce) {
        doForce();
        dqTask.cancel();
        collapse();
        super.triggerBlur(ce);
    }

    protected void unsetDelayCheck() {
        DeferredCommand.addCommand(new Command() {
            public void execute() {
                delayedCheck = false;
            }
        });
    }

    @Override
    protected boolean validateBlur(DomEvent e, Element target) {
        return list == null || (list != null && !list.isVisible() && !list.getElement().isOrHasChild(target));
    }

    @Override
    protected boolean validateValue(String value) {
        if (forceSelection) {
            boolean f = forceSelection;
            forceSelection = false;
            if (getValue() == null) {
                forceSelection = f;
                String rv = getRawValue();
                if (getAllowBlank() && (rv == null || rv.equals(""))) {
                    return true;
                }
                markInvalid(getMessages().getBlankText());
                return false;
            }
            forceSelection = f;
        }
        return super.validateValue(value);
    }

    private void bindStore(ListStore<D> store) {
        if (this.store != null) {
            this.store.removeStoreListener(storeListener);
            this.store = null;
            if (listView != null) {
                listView.setStore(null);
            }
        }
        if (store != null) {
            this.store = store;
            mode = store.getLoader() == null ? "local" : "remote";
            if (listView != null) {
                listView.setStore(store);
            }
            store.addStoreListener(storeListener);
        }
    }

    private void createList(boolean remove) {
        RootPanel.get().add(list);
        initialized = true;
        if (remove) {
            RootPanel.get().remove(list);
        }
    }

    private void initQuery() {
        doQuery(getRawValue(), false);
    }

    protected void selectNext() {
        int count = store.getCount();
        if (count > 0) {
            int selectedIndex = store.indexOf(selectedItem);
            if (selectedIndex == -1) {
                select(0);
            } else if (selectedIndex < count - 1) {
                select(selectedIndex + 1);
            }
        }
    }

    protected void selectPrev() {
        int count = store.getCount();
        if (count > 0) {
            int selectedIndex = store.indexOf(selectedItem);
            if (selectedIndex == -1) {
                select(0);
            } else if (selectedIndex != 0) {
                select(selectedIndex - 1);
            }
        }
    }

    private void updateHiddenValue() {
        if (hiddenInput != null) {
            String v = "";
            D val = getValue();
            if (val != null && val.get(valueField) != null) {
                v = ((Object) val.get(valueField)).toString();
            }
            hiddenInput.setValue(v);
        }
    }

}