1 files changed, 88 insertions, 0 deletions
diff --git a/vendor/oojs/oojs-ui/php/mixins/TabIndexedElement.php b/vendor/oojs/oojs-ui/php/mixins/TabIndexedElement.php
new file mode 100644
index 00000000..223b5371
--- /dev/null
+++ b/vendor/oojs/oojs-ui/php/mixins/TabIndexedElement.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace OOUI;
+
+/**
+ * Element supporting "sequential focus navigation" using the 'tabindex' attribute.
+ *
+ * @abstract
+ */
+class TabIndexedElement extends ElementMixin {
+	/**
+	 * Tab index value.
+	 *
+	 * @var number|null
+	 */
+	protected $tabIndex = null;
+
+	public static $targetPropertyName = 'tabIndexed';
+
+	/**
+	 * @param Element $element Element being mixed into
+	 * @param array $config Configuration options
+	 * @param number|null $config['tabIndex'] Tab index value. Use 0 to use default ordering, use -1 to
+	 *   prevent tab focusing, use null to suppress the `tabindex` attribute. (default: 0)
+	 */
+	public function __construct( Element $element, array $config = array() ) {
+		// Parent constructor
+		$target = isset( $config['tabIndexed'] ) ? $config['tabIndexed'] : $element;
+		parent::__construct( $element, $target, $config );
+
+		// Initialization
+		$this->setTabIndex( isset( $config['tabIndex'] ) ? $config['tabIndex'] : 0 );
+	}
+
+	/**
+	 * Set tab index value.
+	 *
+	 * @param number|null $tabIndex Tab index value or null for no tab index
+	 * @chainable
+	 */
+	public function setTabIndex( $tabIndex ) {
+		$tabIndex = is_numeric( $tabIndex ) ? $tabIndex : null;
+
+		if ( $this->tabIndex !== $tabIndex ) {
+			$this->tabIndex = $tabIndex;
+			$this->updateTabIndex();
+		}
+
+		return $this;
+	}
+
+	/**
+	 * Update the tabIndex attribute, in case of changes to tabIndex or disabled
+	 * state.
+	 *
+	 * @chainable
+	 */
+	public function updateTabIndex() {
+		$disabled = $this->element->isDisabled();
+		if ( $this->tabIndex !== null ) {
+			$this->target->setAttributes( array(
+				// Do not index over disabled elements
+				'tabindex' => $disabled ? -1 : $this->tabIndex,
+				// ChromeVox and NVDA do not seem to inherit this from parent elements
+				'aria-disabled' => ( $disabled ? 'true' : 'false' )
+			) );
+		} else {
+			$this->target->removeAttributes( array( 'tabindex', 'aria-disabled' ) );
+		}
+		return $this;
+	}
+
+	/**
+	 * Get tab index value.
+	 *
+	 * @return number|null Tab index value
+	 */
+	public function getTabIndex() {
+		return $this->tabIndex;
+	}
+
+	public function getConfig( &$config ) {
+		if ( $this->tabIndex !== 0 ) {
+			$config['tabIndex'] = $this->tabIndex;
+		}
+		return parent::getConfig( $config );
+	}
+}