How to add button in TinyMCE TEENY mode?

Question

I managed to add a button to TinyMCE with this code:

add_action ('admin_init', 'my_tinymce_button');
function my_tinymce_button() {
     if ( current_user_can( 'edit_posts' ) && current_user_can( 'edit_pages' ) ) {
          add_filter( 'mce_buttons', 'my_register_tinymce_button' );
          add_filter( 'mce_external_plugins', 'my_add_tinymce_button' );
     }
}

//This callback registers our plug-in
function my_add_tinymce_button( $plugin_array ) {
     $plugin_array['year_button_plugin'] = plugin_dir_url(__FILE__) . "index.js";
     return $plugin_array;
}

//This callback adds our button to the toolbar
function my_register_tinymce_button($buttons) {
    //register buttons with their id.
    array_push($buttons, "green");
    return $buttons;
}

But, this does not work in the editor's teeny mode. Any suggestions?

Answer 1

I solved it this way:

/**
 * Plugin Name: customp
 * Description: some
 * Version: 1.0.0
 * License:           GPL-2.0+ 
 * Text Domain:       customp
 * Domain Path:       /languages
 */

add_action('admin_head', '_20161201_admin_head');


function _20161201_admin_head() {
    global $typenow;
    // check user permissions
    if ( !current_user_can('edit_posts') && !current_user_can('edit_pages') ) {
    return;
    }
    // verify the post type
    if( ! in_array( $typenow, array( 'post', 'page' ) ) )
        return;
    // check if WYSIWYG is enabled
    if ( get_user_option('rich_editing') == 'true') {       
        add_filter("mce_external_plugins", "_20161201_add_script");
        add_filter('mce_buttons', '_20161201_register');
    }
}

function _20161201_register($buttons) {
   array_push($buttons, "20161201");
   return $buttons;
}

function _20161201_add_script($plugin_array) {
    $plugin_array['20161201'] = plugins_url( 'js/20161201-rich.js', __FILE__ ); 
    return $plugin_array;
}

add_action('admin_print_scripts', '_20161201_admin_print_scripts');
function _20161201_admin_print_scripts() {
  wp_enqueue_script( '20161201quicktags',   plugin_dir_url(__FILE__) . 'js/20161201-html.js',   array('quicktags')
  );
}

And js/20161201-rich.js

(function() {
    tinymce.PluginManager.add('20161201', function( editor, url ) {
        editor.addButton( '20161201', {
            text: 'Hello World',
            title: 'My test button',
            icon: false,
            onclick: function() {
                editor.insertContent('Hello World!');
            }
        });
    });
})();

And js/20161201-html.js is

edButtons[edButtons.length] = new edButton( 'hello', 'hello world', '<hello>', '</hello>', '' );