问具有多选特性的GXT - ComoboBox

EN

    package com.ui.test.client;

    import java.util.List;

    import com.extjs.gxt.ui.client.data.ModelData;
    import com.extjs.gxt.ui.client.event.ComponentEvent;
    import com.extjs.gxt.ui.client.event.WindowEvent;
    import com.extjs.gxt.ui.client.event.WindowListener;
    import com.extjs.gxt.ui.client.store.ListStore;
    import com.extjs.gxt.ui.client.widget.CheckBoxListView;
    import com.extjs.gxt.ui.client.widget.Dialog;
    import com.extjs.gxt.ui.client.widget.form.TriggerField;
    import com.extjs.gxt.ui.client.widget.layout.FillLayout;
    import com.google.gwt.user.client.Element;

    public class MultiSelectComboBox extends TriggerField {

        private Dialog checkBoxListHolder;
        private CheckBoxListView listView;
        private ListStore store;

        private String delimiter = ",";
        private boolean readOnly;


        public MultiSelectComboBox() {
            store = new ListStore();
            listView = new CheckBoxListView();
        }




        @Override
        protected void onTriggerClick(ComponentEvent ce) {
            super.onTriggerClick(ce);
            if(readOnly) {
                return;
            }
            checkBoxListHolder.setSize(getWidth(), 200);
            listView.setWidth(getWidth());
            checkBoxListHolder.setPosition(getAbsoluteLeft(), 
                    getAbsoluteTop() + getHeight());
            if(checkBoxListHolder.isVisible()) {
                checkBoxListHolder.hide();
            }
            else {
                checkBoxListHolder.show();
            }
        }




        @Override
        protected void onRender(Element target, int index) {
            super.onRender(target, index);

            checkBoxListHolder = new Dialog();
            checkBoxListHolder.setClosable(false);
            checkBoxListHolder.setHeaderVisible(false);
            checkBoxListHolder.setFooter(false);
            checkBoxListHolder.setFrame(false);
            checkBoxListHolder.setResizable(false);
            checkBoxListHolder.setAutoHide(false);
            checkBoxListHolder.getButtonBar().setVisible(false);
            checkBoxListHolder.setLayout(new FillLayout());
            checkBoxListHolder.add(listView);
            listView.setStore(store);

            checkBoxListHolder.addWindowListener(new WindowListener(){

                @Override
                public void windowHide(WindowEvent we) {
                    setValue(parseCheckedValues(listView));
                }

            });

        }




        private String parseCheckedValues(CheckBoxListView checkBoxView) {
            StringBuffer buf = new StringBuffer();
            if(checkBoxView != null) {
                List selected = checkBoxView.getChecked();
                int index = 1, len = selected.size();
                for(D c : selected) {
                    buf.append(c.get(listView.getDisplayProperty()));
                    if(index  getListView() {
            return listView;
        }

        public void setListView(CheckBoxListView listView) {
            this.listView = listView;
        }

        public ListStore getStore() {
            return store;
        }

        public void setStore(ListStore store) {
            this.store = store;
        }

        public String getDelimiter() {
            return delimiter;
        }

        public void setDelimiter(String delimiter) {
            this.delimiter = delimiter;
        }

        public boolean isReadOnly() {
            return readOnly;
        }

        public void setReadOnly(boolean readOnly) {
            this.readOnly = readOnly;
        }


    }