Explicitly support and use @repeatable from Java 8

Author: Legioth

headertags-demo/src/main/java/org/vaadin/leif/headertags/demo/DemoUI.java

@@ -4,7 +4,6 @@
 
 import org.vaadin.leif.headertags.Link;
 import org.vaadin.leif.headertags.Meta;
-import org.vaadin.leif.headertags.MetaTags;
 import org.vaadin.leif.headertags.Viewport;
 import org.vaadin.leif.headertags.ViewportGenerator;
 
@@ -17,10 +16,9 @@
 // Sets a basic viewport meta header
 @Viewport("width=device-width, initial-scale=1")
 // Adds multiple tags of the same type
-@MetaTags({
-        // Replaces the Vaadin X-UA-Compatible header
-        @Meta(httpEquiv = "X-UA-Compatible", content = "hello"),
-        @Meta(name = "test", content = "test") })
+// Replaces the Vaadin X-UA-Compatible header
+@Meta(httpEquiv = "X-UA-Compatible", content = "hello")
+@Meta(name = "test", content = "test")
 // And showing how to create a link tag as well
 @Link(rel = "foobar", href = "about:blank")
 public class DemoUI extends UI {

headertags/src/main/java/org/vaadin/leif/headertags/HeadTag.java

@@ -2,6 +2,7 @@
 
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
@@ -34,8 +35,11 @@
  * <p>
  * Support for multiple annotations of the same type can also be used by
  * defining a collection annotation where value() returns an array of compatible
- * annotations. See {@link MetaTags} for an example of this usage.
- * 
+ * annotations. See {@link MetaTags} for an example of this usage. It's also
+ * recommended to add {@link Repeatable} to the main annotation to enable
+ * directly adding multiple similar annotation to a UI instead of using the
+ * collection annotation.
+ *
  * @see Meta
  * @see Viewport
  */
@@ -46,7 +50,7 @@
 public @interface HeadTag {
     /**
      * The tag name to use for for annotations annotated with this type.
-     * 
+     *
      * @return the HTML tag name
      */
     public String value();

headertags/src/main/java/org/vaadin/leif/headertags/Link.java

@@ -3,6 +3,7 @@
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Inherited;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
@@ -17,45 +18,46 @@
 @Target(ElementType.TYPE)
 @Documented
 @Inherited
+@Repeatable(LinkTags.class)
 public @interface Link {
     /**
      * The rel attribute value of the meta tag
-     * 
+     *
      * @return the rel attribute
      */
     public String rel();
 
     /**
      * The href attribute value of the meta tag
-     * 
+     *
      * @return the href attribute
      */
     public String href();
 
     /**
      * The media attribute value of the meta tag
-     * 
+     *
      * @return the media attribute
      */
     public String media() default HeadTag.NULL_VALUE;
 
     /**
      * The type attribute value of the meta tag
-     * 
+     *
      * @return the type attribute
      */
     public String type() default HeadTag.NULL_VALUE;
 
     /**
      * The sizes attribute value of the meta tag
-     * 
+     *
      * @return the sizes attribute
      */
     public String sizes() default HeadTag.NULL_VALUE;
 
     /**
      * The sizes attribute value of the meta tag
-     * 
+     *
      * @return the sizes attribute
      */
     public String title() default HeadTag.NULL_VALUE;

headertags/src/main/java/org/vaadin/leif/headertags/Meta.java

@@ -3,52 +3,52 @@
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Inherited;
+import java.lang.annotation.Repeatable;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
  * Defines an arbitrary <meta> tag for the host page of a UI class.
- * <p>
- * To add multiple tags, use {@link MetaTags}
  */
 @HeadTag("meta")
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.TYPE)
 @Documented
 @Inherited
+@Repeatable(MetaTags.class)
 public @interface Meta {
     /**
      * The name attribute value of the meta tag
-     * 
+     *
      * @return the name attribute
      */
     public String name() default HeadTag.NULL_VALUE;
 
     /**
      * The content attribute value of the meta tag
-     * 
+     *
      * @return the content attribute
      */
     public String content() default HeadTag.NULL_VALUE;
 
     /**
      * The http-equiv attribute value of the meta tag
-     * 
+     *
      * @return the http-equiv attribute
      */
     public String httpEquiv() default HeadTag.NULL_VALUE;
 
     /**
      * The charset attribute value of the meta tag
-     * 
+     *
      * @return the charset attribute
      */
     public String charset() default HeadTag.NULL_VALUE;
 
     /**
      * The itemprop attribute value of the meta tag
-     * 
+     *
      * @return the itemprop attribute
      */
     public String itemprop() default HeadTag.NULL_VALUE;