Add admin bar debug indicator.

Author: hellofromtonya

assets/css/admin-bar.html

@@ -0,0 +1,32 @@
+<style type="text/css">
+	#wpadminbar {
+		background-color: %s !important;
+	}
+
+	#wp-admin-bar-environment-notice {
+		display: none;
+	}
+
+	#wpadminbar .ab-item,
+	#wpadminbar a.ab-item,
+	#wpadminbar > #wp-toolbar span.ab-label,
+	#wpadminbar > #wp-toolbar span.noticon,
+	.adminbar--environment-notice {
+		color: #fff;
+	}
+
+	@media only screen and ( min-width: 800px ) {
+		#wp-admin-bar-environment-notice {
+			display: block;
+		}
+
+		#wp-admin-bar-environment-notice .ab-item {
+			background-color: %s !important;
+		}
+
+		#wp-admin-bar-environment-notice:hover .ab-item {
+			background-color: %s !important;
+			color: #fff;
+		}
+	}
+</style>

config/admin-bar.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * Admin Bar Runtime Configuration Parameters.
+ *
+ * @package     KnowTheCode\DebugToolkit
+ * @since       1.0.0
+ * @author      hellofromTonya
+ * @link        https://github.com/KnowTheCode/debug-toolkit
+ * @license     GNU-2.0+
+ */
+
+namespace KnowTheCode\DebugToolkit;
+
+return [
+	'message'      => 'DEBUG ACTIVE',
+	'color_scheme' => 'coffee',
+	'colors'       => [
+		'admin_bar_background_color' => '#627f00',
+		'message_background_color'   => '#cb4b14',
+		'message_hover_color'        => '#1b202d',
+	],
+];

debug-toolkit.php

@@ -51,4 +51,17 @@ function _get_plugin_root_dir() {
 	return __DIR__;
 }
 
+/**
+ * Load the Admin Bar.
+ *
+ * @since 1.0.0
+ */
+function load_admin_bar() {
+	require_once __DIR__ . '/src/class-admin-bar.php';
+	$config = require __DIR__ . '/config/admin-bar.php';
+
+	( new Admin_Bar( $config ) )->init();
+}
+
 require_once __DIR__ . '/vendor/autoload.php';
+load_admin_bar();

src/class-admin-bar.php

@@ -0,0 +1,104 @@
+<?php
+/**
+ * Admin functions to change the look of the admin bar when this plugin
+ * is activated, i.e. to differentiate that we are in development mode.
+ *
+ * @package     KnowTheCode\DebugToolkit
+ * @since       1.0.0
+ * @author      hellofromTonya
+ * @link        https://github.com/KnowTheCode/debug-toolkit
+ * @license     GNU-2.0+
+ */
+
+namespace KnowTheCode\DebugToolkit;
+
+/**
+ * Class Admin_Bar
+ * @package KnowTheCode\DebugToolkit
+ */
+class Admin_Bar {
+
+	/**
+	 * Configuration parameters.
+	 *
+	 * @var array
+	 */
+	protected $config;
+
+	/**
+	 * Admin_Bar constructor.
+	 *
+	 * @param array $config Configuration parameters.
+	 */
+	public function __construct( array $config ) {
+		$this->config = $config;
+	}
+
+	/**
+	 * Initializes by registering each hook's callback to the object.
+	 *
+	 * @since 1.0.0
+	 */
+	public function init() {
+		add_filter( 'get_user_option_admin_color', [ $this, 'set_local_development_admin_color_scheme' ], 5 );
+		add_action( 'admin_bar_menu', [ $this, 'add_admin_bar_notice' ], 9999 );
+		add_action( 'admin_head', [ $this, 'render_admin_bar_css' ], 9999 );
+		add_action( 'wp_head', [ $this, 'render_admin_bar_css' ], 9999 );
+	}
+
+	/**
+	 * Force different admin color scheme when this plugin is active.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return string
+	 */
+	public function set_local_development_admin_color_scheme() {
+		return $this->config['color_scheme'];
+	}
+
+	/**
+	 * Add an admin bar notice to alert user that they are in local development
+	 * and this plugin is activated.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return void
+	 */
+	public function add_admin_bar_notice() {
+		if ( ! is_admin_bar_showing() ) {
+			return;
+		}
+		global $wp_admin_bar;
+
+		$admin_notice = [
+			'parent' => 'top-secondary',
+			'id'     => 'environment-notice',
+			'title'  => sprintf( '<span class="adminbar--environment-notice">%s</span>', $this->config['message'] ),
+		];
+
+		$wp_admin_bar->add_menu( $admin_notice );
+	}
+
+
+	/**
+	 * Render the admin bar CSS.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return void
+	 */
+	public function render_admin_bar_css() {
+		if ( ! is_admin_bar_showing() ) {
+			return;
+		}
+
+		ob_start();
+
+		include _get_plugin_root_dir() . '/assets/css/admin-bar.html';
+
+		$css_pattern = ob_get_clean();
+
+		vprintf( $css_pattern, $this->config['colors'] );
+	}
+}