feat: allow DemoSource URL to default to the location of the class

Author: javier-godoy

src/main/java/com/flowingcode/vaadin/addons/GithubLink.java

@@ -26,7 +26,7 @@
 import java.lang.annotation.Target;
 
 /**
- * This annotation is used for configuring the URL in the {@code GitHubCorner}
+ * This annotation is used for configuring the URL in the {@code GitHubCorner} and {@code DemoClass}
  *
  * @author Javier Godoy / Flowing Code
  */

src/main/java/com/flowingcode/vaadin/addons/demo/DemoSource.java

@@ -25,13 +25,20 @@
 import java.lang.annotation.Target;
 
 /**
- * This annotation is used for configuring the source code URL in a {@link TabbedDemo}
+ * This annotation is used for configuring the source code URL in a {@link TabbedDemo}. If no
+ * {@code value} is specified, and the demo view is annotated with {@link @GithubLink}, the source
+ * URL defaults to the location of the annotated class under {@code src/java/test} in the master
+ * branch of the repository.
  *
  * @author Javier Godoy / Flowing Code
  */
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.TYPE)
 public @interface DemoSource {
 
-  String value();
+  static final String GITHUB_SOURCE = "__GITHUB__";
+
+  /** A link to the source code, if different from the annotated class. */
+  String value() default GITHUB_SOURCE;
+
 }

src/main/java/com/flowingcode/vaadin/addons/demo/TabbedDemo.java

@@ -19,6 +19,7 @@
  */
 package com.flowingcode.vaadin.addons.demo;
 
+import com.flowingcode.vaadin.addons.GithubLink;
 import com.vaadin.flow.component.Component;
 import com.vaadin.flow.component.checkbox.Checkbox;
 import com.vaadin.flow.component.dependency.StyleSheet;
@@ -94,10 +95,19 @@ public TabbedDemo() {
    * @param demo the demo instance
    */
   public void addDemo(Component demo) {
-    String sourceCodeUrl =
-        Optional.ofNullable(demo.getClass().getAnnotation(DemoSource.class))
-            .map(DemoSource::value)
+    DemoSource demoSource = demo.getClass().getAnnotation(DemoSource.class);
+
+    String sourceCodeUrl = null;
+    if (demoSource != null) {
+      sourceCodeUrl = demoSource.value();
+      if (sourceCodeUrl.equals(DemoSource.GITHUB_SOURCE)) {
+        sourceCodeUrl = Optional.ofNullable(this.getClass().getAnnotation(GithubLink.class))
+            .map(githubLink -> githubLink.value() + "/blob/master/src/test/java/"
+                + demo.getClass().getName().replace('.', '/'))
             .orElse(null);
+      }
+    }
+
     String label =
         Optional.ofNullable(demo.getClass().getAnnotation(PageTitle.class))
             .map(PageTitle::value)

src/test/java/com/flowingcode/vaadin/addons/demo/Demo.java

@@ -19,12 +19,14 @@
  */
 package com.flowingcode.vaadin.addons.demo;
 
+import com.flowingcode.vaadin.addons.GithubLink;
 import com.vaadin.flow.component.orderedlayout.VerticalLayout;
 import com.vaadin.flow.component.textfield.TextField;
 import com.vaadin.flow.router.Route;
 
 /** Hello world! */
 @Route("")
+@GithubLink("https://github.com/FlowingCode/CommonsDemo")
 public class Demo extends TabbedDemo {
 
   public Demo() {
@@ -47,5 +49,6 @@ public Demo() {
     addDemo(vl3, "Demo Without Source Code");
 
     addDemo(new SampleDemo());
+    addDemo(new SampleDemoDefault());
   }
 }

src/test/java/com/flowingcode/vaadin/addons/demo/SampleDemo.java

@@ -24,8 +24,7 @@
 import com.vaadin.flow.router.PageTitle;
 
 @PageTitle("Demo 4")
-@DemoSource(
-"https://github.com/FlowingCode/CommonsDemo/blob/master/src/test/java/com/flowingcode/vaadin/addons/demo/SampleDemo.java")
+@DemoSource("https://github.com/FlowingCode/CommonsDemo/blob/master/src/test/java/com/flowingcode/vaadin/addons/demo/SampleDemo.java")
 public class SampleDemo extends Div {
 
   public SampleDemo() {

src/test/java/com/flowingcode/vaadin/addons/demo/SampleDemoDefault.java

@@ -0,0 +1,34 @@
+/*-
+ * #%L
+ * Commons Demo
+ * %%
+ * Copyright (C) 2020 - 2021 Flowing Code
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package com.flowingcode.vaadin.addons.demo;
+
+import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.component.html.Span;
+import com.vaadin.flow.router.PageTitle;
+
+@PageTitle("Demo 5")
+@DemoSource
+public class SampleDemoDefault extends Div {
+
+  public SampleDemoDefault() {
+    add(new Span("Demo component with defaulted @DemoSource annotation"));
+  }
+
+}