source: contact-form-7/tags/5.9.6/admin/includes/welcome-panel.php

<?php

abstract class WPCF7_WelcomePanelColumn {

        abstract protected function icon();
        abstract protected function title();
        abstract protected function content();

        public function print_content() {
                $icon = sprintf(
                        '<span class="dashicons dashicons-%s" aria-hidden="true"></span>',
                        esc_attr( $this->icon() )
                );

                $title = sprintf(
                        '<h3>%1$s %2$s</h3>',
                        $icon,
                        $this->title()
                );

                $content = $this->content();

                if ( is_array( $content ) ) {
                        $content = implode( "\n\n", $content );
                }

                $content = wp_kses_post( $content );
                $content = wptexturize( $content );
                $content = convert_chars( $content );
                $content = wpautop( $content );

                echo "\n";
                echo '<div class="welcome-panel-column">';
                echo $title;
                echo $content;
                echo '</div>';
        }
}


class WPCF7_WelcomePanelColumn_AntiSpam extends WPCF7_WelcomePanelColumn {

        protected function icon() {
                return 'shield';
        }

        protected function title() {
                return esc_html(
                        __( "Getting spammed? You have protection.", 'contact-form-7' )
                );
        }

        protected function content() {
                return array(
                        esc_html( __( "Spammers target everything; your contact forms are not an exception. Before you get spammed, protect your contact forms with the powerful anti-spam features Contact Form 7 provides.", 'contact-form-7' ) ),
                        sprintf(
                                /* translators: links labeled 1: 'Akismet', 2: 'reCAPTCHA', 3: 'disallowed list' */
                                esc_html( __( 'Contact Form 7 supports spam-filtering with %1$s. Intelligent %2$s blocks annoying spambots. Plus, using %3$s, you can block messages containing specified keywords or those sent from specified IP addresses.', 'contact-form-7' ) ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/spam-filtering-with-akismet/', 'contact-form-7' ),
                                        __( 'Akismet', 'contact-form-7' )
                                ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/recaptcha/', 'contact-form-7' ),
                                        __( 'reCAPTCHA', 'contact-form-7' )
                                ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/comment-blacklist/', 'contact-form-7' ),
                                        __( 'disallowed list', 'contact-form-7' )
                                )
                        ),
                );
        }
}


class WPCF7_WelcomePanelColumn_Donation extends WPCF7_WelcomePanelColumn {

        protected function icon() {
                return 'megaphone';
        }

        protected function title() {
                return esc_html(
                        __( "Contact Form 7 needs your support.", 'contact-form-7' )
                );
        }

        protected function content() {
                return array(
                        esc_html( __( "It is hard to continue development and support for this plugin without contributions from users like you.", 'contact-form-7' ) ),
                        sprintf(
                                /* translators: %s: link labeled 'making a donation' */
                                esc_html( __( 'If you enjoy using Contact Form 7 and find it useful, please consider %s.', 'contact-form-7' ) ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/donate/', 'contact-form-7' ),
                                        __( 'making a donation', 'contact-form-7' )
                                )
                        ),
                        esc_html( __( "Your donation will help encourage and support the plugin&#8217;s continued development and better user support.", 'contact-form-7' ) ),
                );
        }
}


class WPCF7_WelcomePanelColumn_Flamingo extends WPCF7_WelcomePanelColumn {

        protected function icon() {
                return 'editor-help';
        }

        protected function title() {
                return esc_html(
                        __( "Before you cry over spilt mail&#8230;", 'contact-form-7' )
                );
        }

        protected function content() {
                return array(
                        esc_html( __( "Contact Form 7 does not store submitted messages anywhere. Therefore, you may lose important messages forever if your mail server has issues or you make a mistake in mail configuration.", 'contact-form-7' ) ),
                        sprintf(
                                /* translators: %s: link labeled 'Flamingo' */
                                esc_html( __( 'Install a message storage plugin before this happens to you. %s saves all messages through contact forms into the database. Flamingo is a free WordPress plugin created by the same author as Contact Form 7.', 'contact-form-7' ) ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/save-submitted-messages-with-flamingo/', 'contact-form-7' ),
                                        __( 'Flamingo', 'contact-form-7' )
                                )
                        ),
                );
        }
}


class WPCF7_WelcomePanelColumn_Integration extends WPCF7_WelcomePanelColumn {

        protected function icon() {
                return 'superhero-alt';
        }

        protected function title() {
                return esc_html(
                        __( "You have strong allies to back you up.", 'contact-form-7' )
                );
        }

        protected function content() {
                return array(
                        sprintf(
                                /* translators: 1: link labeled 'Brevo' */
                                esc_html( __( 'Your contact forms will become more powerful and versatile by integrating them with external APIs. With CRM and email marketing services, you can build your own contact lists (%1$s).', 'contact-form-7' ) ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/sendinblue-integration/', 'contact-form-7' ),
                                        __( 'Brevo', 'contact-form-7' )
                                )
                        ),
                        sprintf(
                                /* translators: 1: link labeled 'reCAPTCHA', 2: link labeled 'Stripe' */
                                esc_html( __( 'With help from cloud-based machine learning, anti-spam services will protect your forms (%1$s). Even payment services are natively supported (%2$s).', 'contact-form-7' ) ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/recaptcha/', 'contact-form-7' ),
                                        __( 'reCAPTCHA', 'contact-form-7' )
                                ),
                                wpcf7_link(
                                        __( 'https://contactform7.com/stripe-integration/', 'contact-form-7' ),
                                        __( 'Stripe', 'contact-form-7' )
                                )
                        ),
                );
        }
}


function wpcf7_welcome_panel() {
        $columns = array();

        $flamingo_is_active = defined( 'FLAMINGO_VERSION' );

        $sendinblue_is_active = false;

        if ( class_exists( 'WPCF7_Sendinblue' )
        and $sendinblue = WPCF7_Sendinblue::get_instance() ) {
                $sendinblue_is_active = $sendinblue->is_active();
        }

        if ( $flamingo_is_active and $sendinblue_is_active ) {
                $columns[] = new WPCF7_WelcomePanelColumn_AntiSpam();
                $columns[] = new WPCF7_WelcomePanelColumn_Donation();
        } elseif ( $flamingo_is_active ) {
                $columns[] = new WPCF7_WelcomePanelColumn_Integration();
                $columns[] = new WPCF7_WelcomePanelColumn_AntiSpam();
        } elseif ( $sendinblue_is_active ) {
                $columns[] = new WPCF7_WelcomePanelColumn_Flamingo();
                $columns[] = new WPCF7_WelcomePanelColumn_AntiSpam();
        } else {
                $columns[] = new WPCF7_WelcomePanelColumn_Flamingo();
                $columns[] = new WPCF7_WelcomePanelColumn_Integration();
        }

        $classes = 'wpcf7-welcome-panel';

        $vers = (array) get_user_meta( get_current_user_id(),
                'wpcf7_hide_welcome_panel_on', true
        );

        if ( wpcf7_version_grep( wpcf7_version( 'only_major=1' ), $vers ) ) {
                $classes .= ' hidden';
        }

?>
<div id="wpcf7-welcome-panel" class="<?php echo esc_attr( $classes ); ?>">
        <?php wp_nonce_field( 'wpcf7-welcome-panel-nonce', 'welcomepanelnonce', false ); ?>
        <a class="welcome-panel-close" href="<?php echo esc_url( menu_page_url( 'wpcf7', false ) ); ?>"><?php echo esc_html( __( 'Dismiss', 'contact-form-7' ) ); ?></a>

        <div class="welcome-panel-content">
                <div class="welcome-panel-column-container">
<?php

        foreach ( $columns as $column ) {
                $column->print_content();
        }

?>
                </div>
        </div>
</div>
<?php
}


add_action(
        'wp_ajax_wpcf7-update-welcome-panel',
        'wpcf7_admin_ajax_welcome_panel',
        10, 0
);

function wpcf7_admin_ajax_welcome_panel() {
        check_ajax_referer( 'wpcf7-welcome-panel-nonce', 'welcomepanelnonce' );

        $vers = get_user_meta( get_current_user_id(),
                'wpcf7_hide_welcome_panel_on', true
        );

        if ( empty( $vers ) or ! is_array( $vers ) ) {
                $vers = array();
        }

        if ( empty( $_POST['visible'] ) ) {
                $vers[] = wpcf7_version( 'only_major=1' );
        } else {
                $vers = array_diff( $vers, array( wpcf7_version( 'only_major=1' ) ) );
        }

        $vers = array_unique( $vers );

        update_user_meta( get_current_user_id(),
                'wpcf7_hide_welcome_panel_on', $vers
        );

        wp_die( 1 );
}


add_filter(
        'screen_settings',
        'wpcf7_welcome_panel_screen_settings',
        10, 2
);

function wpcf7_welcome_panel_screen_settings( $screen_settings, $screen ) {

        if ( 'toplevel_page_wpcf7' !== $screen->id ) {
                return $screen_settings;
        }

        $vers = (array) get_user_meta( get_current_user_id(),
                'wpcf7_hide_welcome_panel_on', true
        );

        $checkbox_id = 'wpcf7-welcome-panel-show';
        $checked = ! in_array( wpcf7_version( 'only_major=1' ), $vers );

        $checkbox = sprintf(
                '<input %s />',
                wpcf7_format_atts( array(
                        'id' => $checkbox_id,
                        'type' => 'checkbox',
                        'checked' => $checked,
                ) )
        );

        $screen_settings .= sprintf( '
<fieldset class="wpcf7-welcome-panel-options">
<legend>%1$s</legend>
<label for="%2$s">%3$s %4$s</label>
</fieldset>',
                esc_html( __( 'Welcome panel', 'contact-form-7' ) ),
                esc_attr( $checkbox_id ),
                $checkbox,
                esc_html( __( 'Show welcome panel', 'contact-form-7' ) )
        );

        return $screen_settings;
}