Add API for data destruction to DataGenerator interface (#19038)

This patch provides destroyData implementation for all default data
generators.

Change-Id: I1458080ee0203a27b52e604d3a30c9e5240c0383

3 files changed, 53 insertions, 15 deletions

diff --git a/server/src/com/vaadin/data/DataGenerator.java b/server/src/com/vaadin/data/DataGenerator.java
index a5333b8523..5e301d8151 100644
--- a/server/src/com/vaadin/data/DataGenerator.java
+++ b/server/src/com/vaadin/data/DataGenerator.java
@@ -18,7 +18,6 @@ package com.vaadin.data;
 import java.io.Serializable;
 
 import com.vaadin.ui.Grid.AbstractGridExtension;
-import com.vaadin.ui.Grid.AbstractRenderer;
 
 import elemental.json.JsonObject;
 
@@ -26,8 +25,8 @@ import elemental.json.JsonObject;
  * Interface for {@link AbstractGridExtension}s that allows adding data to row
  * objects being sent to client by the {@link RpcDataProviderExtension}.
  * <p>
- * {@link AbstractRenderer} implements this interface to provide encoded data to
- * client for {@link Renderer}s automatically.
+ * This class also provides a way to remove any unneeded data once the data
+ * object is no longer used on the client-side.
  * 
  * @since 7.6
  * @author Vaadin Ltd
@@ -46,4 +45,13 @@ public interface DataGenerator extends Serializable {
      */
     public void generateData(Object itemId, Item item, JsonObject rowData);
 
+    /**
+     * Informs the DataGenerator that an item id has been dropped and is no
+     * longer needed.
+     * 
+     * @param itemId
+     *            removed item id
+     */
+    public void destroyData(Object itemId);
+
 }
diff --git a/server/src/com/vaadin/data/RpcDataProviderExtension.java b/server/src/com/vaadin/data/RpcDataProviderExtension.java
index 78c87ab23d..45caf01587 100644
--- a/server/src/com/vaadin/data/RpcDataProviderExtension.java
+++ b/server/src/com/vaadin/data/RpcDataProviderExtension.java
@@ -98,7 +98,7 @@ public class RpcDataProviderExtension extends AbstractExtension {
 
             // Remove still active rows that were "dropped"
             droppedItems.removeAll(itemIds);
-            internalDropActiveItems(droppedItems);
+            internalDropItems(droppedItems);
             droppedItems.clear();
         }
 
@@ -115,15 +115,6 @@ public class RpcDataProviderExtension extends AbstractExtension {
             }
         }
 
-        private void internalDropActiveItems(Collection<Object> itemIds) {
-            for (Object itemId : droppedItems) {
-                assert activeItemMap.containsKey(itemId) : "Item ID should exist in the activeItemMap";
-
-                activeItemMap.remove(itemId).removeListener();
-                keyMapper.remove(itemId);
-            }
-        }
-
         /**
          * Gets a collection copy of currently active item ids.
          * 
@@ -147,6 +138,15 @@ public class RpcDataProviderExtension extends AbstractExtension {
             rowData.put(GridState.JSONKEY_ROWKEY, keyMapper.key(itemId));
         }
 
+        @Override
+        public void destroyData(Object itemId) {
+            keyMapper.remove(itemId);
+            GridValueChangeListener removed = activeItemMap.remove(itemId);
+
+            if (removed != null) {
+                removed.removeListener();
+            }
+        }
     }
 
     /**
@@ -372,6 +372,13 @@ public class RpcDataProviderExtension extends AbstractExtension {
                                 .getConnectorId() : ""));
             }
         }
+
+        @Override
+        public void destroyData(Object itemId) {
+            if (visibleDetails.contains(itemId)) {
+                destroyDetails(itemId);
+            }
+        }
     }
 
     private final Indexed container;
@@ -734,8 +741,7 @@ public class RpcDataProviderExtension extends AbstractExtension {
     public void setParent(ClientConnector parent) {
         if (parent == null) {
             // We're being detached, release various listeners
-            activeItemHandler.internalDropActiveItems(activeItemHandler
-                    .getActiveItemIds());
+            internalDropItems(activeItemHandler.getActiveItemIds());
 
             if (container instanceof ItemSetChangeNotifier) {
                 ((ItemSetChangeNotifier) container)
@@ -750,6 +756,20 @@ public class RpcDataProviderExtension extends AbstractExtension {
     }
 
     /**
+     * Informs all DataGenerators than an item id has been dropped.
+     * 
+     * @param droppedItemIds
+     *            collection of dropped item ids
+     */
+    private void internalDropItems(Collection<Object> droppedItemIds) {
+        for (Object itemId : droppedItemIds) {
+            for (DataGenerator generator : dataGenerators) {
+                generator.destroyData(itemId);
+            }
+        }
+    }
+
+    /**
      * Informs this data provider that given columns have been removed from
      * grid.
      * 
diff --git a/server/src/com/vaadin/ui/Grid.java b/server/src/com/vaadin/ui/Grid.java
index f0e7b664e0..cee045128f 100644
--- a/server/src/com/vaadin/ui/Grid.java
+++ b/server/src/com/vaadin/ui/Grid.java
@@ -1131,6 +1131,11 @@ public class Grid extends AbstractFocusable implements SelectionNotifier,
         }
 
         @Override
+        public void destroyData(Object itemId) {
+            // NO-OP
+        }
+
+        @Override
         protected Object getItemId(String rowKey) {
             return rowKey != null ? super.getItemId(rowKey) : null;
         }
@@ -1880,6 +1885,11 @@ public class Grid extends AbstractFocusable implements SelectionNotifier,
             data.put(columnKeys.key(cell.getPropertyId()), AbstractRenderer
                     .encodeValue(modelValue, renderer, converter, getLocale()));
         }
+
+        @Override
+        public void destroyData(Object itemId) {
+            // NO-OP
+        }
     }
 
     /**