Merge pull request #3435 from apache/3973-backport.layout.switch

CAUSEWAY-3973: [v2] Backport Layout Switching Fixes

Author: andi-huber

adoc/changelog.adoc

@@ -3,7 +3,8 @@
 🐞 Bug Fixes
 
 - [Commons] Internal OneShot Util may deadlock https://issues.apache.org/jira/browse/CAUSEWAY-3972[CAUSEWAY-3972] (potentially preventing App from startup)
-
+- Switching between Layout Variants may result in Members staying hidden 
+https://issues.apache.org/jira/browse/CAUSEWAY-3971[CAUSEWAY-3971], https://issues.apache.org/jira/browse/CAUSEWAY-3973[CAUSEWAY-3973]
 
 = Feb 2016
 

api/applib/src/main/java/module-info.java

@@ -37,7 +37,7 @@
     exports org.apache.causeway.applib.jaxb;
     exports org.apache.causeway.applib.layout.component;
     exports org.apache.causeway.applib.layout.grid.bootstrap;
-    exports org.apache.causeway.applib.layout.grid;
+    exports org.apache.causeway.applib.layout.resource;
     exports org.apache.causeway.applib.layout.links;
     exports org.apache.causeway.applib.layout.menubars.bootstrap;
     exports org.apache.causeway.applib.layout.menubars;
@@ -151,7 +151,6 @@
     opens org.apache.causeway.applib.annotation;
     opens org.apache.causeway.applib.layout.component;
     opens org.apache.causeway.applib.layout.grid.bootstrap;
-    opens org.apache.causeway.applib.layout.grid;
     opens org.apache.causeway.applib.layout.links;
     opens org.apache.causeway.applib.layout.menubars.bootstrap;
     opens org.apache.causeway.applib.layout.menubars;

api/applib/src/main/java/org/apache/causeway/applib/layout/grid/Grid.java

@@ -20,6 +20,12 @@
 
 import java.io.Serializable;
 
+import org.apache.causeway.applib.layout.component.ActionLayoutData;
+import org.apache.causeway.applib.layout.component.CollectionLayoutData;
+import org.apache.causeway.applib.layout.component.DomainObjectLayoutData;
+import org.apache.causeway.applib.layout.component.FieldSet;
+import org.apache.causeway.applib.layout.component.PropertyLayoutData;
+
 /**
  * @since 1.x {@index}
  */
@@ -31,8 +37,26 @@ public interface BSElement extends WithinGrid, Serializable {
      * custom styling.
      */
     String getCssClass();
-
     void setCssClass(final String cssClass);
 
+    public interface BSElementVisitor {
+        default void enter(final BSGrid bsGrid) {}
+        default void exit(final BSGrid bsGrid) {}
+        default void enter(final BSRow bsRow) {}
+        default void exit(final BSRow bsRow) {}
+        default void enter(final BSCol bsCol) {}
+        default void exit(final BSCol bsCol) {}
+        default void visit(final BSClearFix bsClearFix) {}
+        default void enter(final BSTabGroup bsTabGroup) {}
+        default void exit(final BSTabGroup bsTabGroup) {}
+        default void enter(final BSTab bsTab) {}
+        default void exit(final BSTab bsTab) {}
+
+        default void visit(final DomainObjectLayoutData domainObjectLayoutData) {}
+        default void visit(final ActionLayoutData actionLayoutData) {}
+        default void visit(final PropertyLayoutData propertyLayoutData) {}
+        default void visit(final CollectionLayoutData collectionLayoutData) {}
+        default void visit(final FieldSet fieldSet) {}
+    }
 
 }