how to change source mode theme

hi,i got a problem several days,firstly,i added the codemirror plugins,it works well,but i wanna make a option to change the theme and codesytle(css/javascript/sql/...) in the source mode,so i added two customized drop-down lists in the toolbar,i found the customized drop-down code here,but i have no idea how to modify the this code to implement this function. Any help would be greately appreciated!

CKEDITOR.plugins.add('token',
{
    requires : ['richcombo'],
    init : function( editor )
    {
        var config = editor.config,
    lang = editor.lang.format;
    var tags = []; 
    tags[0]=["[contact_name]", "Name", "Name"];
    tags[1]=["[contact_email]", "email", "email"];
    tags[2]=["[contact_user_name]", "User name", "User name"];

        // add the menu to the editor
        editor.ui.addRichCombo('token',
        {
            label:         'token',
            title:         'token',
            voiceLabel: 'token',
            className:     'cke_format',
            multiSelect:false,
            panel:
            {
                css: [ editor.config.contentsCss, CKEDITOR.skin.getPath('editor') ],
                voiceLabel: editor.lang.panelVoiceLabel
            },
            modes:
            {
                wysiwyg: 0,
        source: 1
            },
            init: function()
            {
                this.startGroup( "codetheme" );
                
                for (var this_tag in tags)
                {
           this.add(tags[this_tag][0], tags[this_tag][1], tags[this_tag][2]);
        }
                
            },

            onClick: function( value )
            {
                editor.focus();
                editor.fire( 'saveSnapshot' );
                editor.insertHtml(value);
                editor.fire( 'saveSnapshot' );
            }
        });
    }
});