Fix validation in non-buffered Grid editor (#12281)

Handle possible race condition by disabling the editor's widget while awaiting validation from the server.

Fixes #12270

4 files changed, 91 insertions, 8 deletions

diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/EditorConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/EditorConnector.java
index 515bb17915..297a360f8b 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/EditorConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/EditorConnector.java
@@ -29,7 +29,6 @@ import com.vaadin.client.extensions.AbstractExtensionConnector;
 import com.vaadin.client.widget.grid.EditorHandler;
 import com.vaadin.client.widgets.Grid;
 import com.vaadin.client.widgets.Grid.Column;
-import com.vaadin.shared.Range;
 import com.vaadin.shared.data.DataCommunicatorConstants;
 import com.vaadin.shared.ui.Connect;
 import com.vaadin.shared.ui.grid.editor.EditorClientRpc;
@@ -104,6 +103,12 @@ public class EditorConnector extends AbstractExtensionConnector {
                     getParent().getWidget().getEditor()
                             .setEditorError(errorMessage, errorColumns);
                 }
+
+                @Override
+                public void confirmValidity(boolean isValid) {
+                    getParent().getWidget().getEditor().getEventHandler()
+                            .confirmValidity(isValid);
+                }
             });
         }
 
@@ -131,6 +136,11 @@ public class EditorConnector extends AbstractExtensionConnector {
         }
 
         @Override
+        public void checkValidity() {
+            rpc.checkValidity();
+        }
+
+        @Override
         public Widget getWidget(Column<?, JsonObject> column) {
             String connId = getState().columnFields
                     .get(getParent().getColumnId(column));
diff --git a/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java b/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java
index 4580f16105..a76760af6e 100644
--- a/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java
+++ b/client/src/main/java/com/vaadin/client/widget/grid/DefaultEditorEventHandler.java
@@ -15,6 +15,10 @@
  */
 package com.vaadin.client.widget.grid;
 
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
 import com.google.gwt.core.client.Duration;
 import com.google.gwt.dom.client.BrowserEvents;
 import com.google.gwt.dom.client.Element;
@@ -30,8 +34,6 @@ import com.vaadin.client.widgets.Grid;
 import com.vaadin.client.widgets.Grid.Editor;
 import com.vaadin.client.widgets.Grid.EditorDomEvent;
 
-import java.util.List;
-
 /**
  * The default handler for Grid editor events. Offers several overridable
  * protected methods for easier customization.
@@ -51,6 +53,7 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
     private int lastTouchEventX = -1;
     private int lastTouchEventY = -1;
     private int lastTouchEventRow = -1;
+    private PendingEdit pendingEdit;
 
     /**
      * Returns whether the given event is a touch event that should open the
@@ -223,7 +226,16 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
                     }
                 }
 
-                editRow(event, rowIndex + delta.rowDelta, colIndex);
+                int newRowIndex = rowIndex + delta.rowDelta;
+                if (newRowIndex != event.getRowIndex()) {
+                    triggerValueChangeEvent(event);
+                    // disable until validity check is done
+                    setWidgetEnabled(event.getEditorWidget(), false);
+                    event.getEditor().getHandler().checkValidity();
+                    pendingEdit = new PendingEdit(event, newRowIndex, colIndex);
+                } else {
+                    editRow(event, newRowIndex, colIndex);
+                }
             }
 
             return changed;
@@ -401,10 +413,6 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
         // Limit colIndex between 0 and colCount - 1
         colIndex = Math.max(0, Math.min(colCount - 1, colIndex));
 
-        if (rowIndex != event.getRowIndex()) {
-            triggerValueChangeEvent(event);
-        }
-
         event.getEditor().editRow(rowIndex, colIndex);
     }
 
@@ -451,4 +459,53 @@ public class DefaultEditorEventHandler<T> implements Editor.EventHandler<T> {
 
         return handled || swallowEvent;
     }
+
+    @Override
+    public void confirmValidity(boolean isValid) {
+        if (pendingEdit == null) {
+            getLogger().log(Level.SEVERE,
+                    "An editor's validation confirmation was received, but"
+                            + " no pending edit object was found ");
+            return;
+        }
+        setWidgetEnabled(pendingEdit.pendingEvent.getEditorWidget(), true);
+        if (isValid) {
+            editRow(pendingEdit.pendingEvent, pendingEdit.pendingRowIndex,
+                    pendingEdit.pendingColIndex);
+        } else {
+            pendingEdit.pendingEvent.getEditorWidget().getElement().focus();
+        }
+
+        pendingEdit = null;
+    }
+
+    private void setWidgetEnabled(Widget widget, boolean widgetEnabled) {
+        final ComponentConnector connector = Util.findConnectorFor(widget);
+        // only enable widget if it hasn't been disabled programmatically
+        if (connector.getState().enabled) {
+            connector.setWidgetEnabled(widgetEnabled);
+        }
+    }
+
+    private static final Logger getLogger() {
+        return Logger.getLogger(DefaultEditorEventHandler.class.getName());
+    }
+
+    private final class PendingEdit {
+        private EditorDomEvent<T> pendingEvent;
+        private int pendingRowIndex;
+        private int pendingColIndex;
+
+        private PendingEdit(EditorDomEvent<T> pendingEvent, int pendingRowIndex,
+                int pendingColIndex) {
+            if (pendingEvent == null) {
+                throw new IllegalArgumentException(
+                        "The pending event cannot be null");
+            }
+            this.pendingEvent = pendingEvent;
+            this.pendingRowIndex = pendingRowIndex;
+            this.pendingColIndex = pendingColIndex;
+        }
+
+    }
 }
diff --git a/client/src/main/java/com/vaadin/client/widget/grid/EditorHandler.java b/client/src/main/java/com/vaadin/client/widget/grid/EditorHandler.java
index f603ebb5ea..958af5061b 100644
--- a/client/src/main/java/com/vaadin/client/widget/grid/EditorHandler.java
+++ b/client/src/main/java/com/vaadin/client/widget/grid/EditorHandler.java
@@ -189,4 +189,11 @@ public interface EditorHandler<T> {
      *         editable
      */
     public Widget getWidget(Grid.Column<?, T> column);
+
+    /**
+     * Called by the editor's event handler when editing is shifting to a new
+     * row in order to check the validity of the binder's value.
+     *
+     */
+    public void checkValidity();
 }
diff --git a/client/src/main/java/com/vaadin/client/widgets/Grid.java b/client/src/main/java/com/vaadin/client/widgets/Grid.java
index c5fe79d260..6e0b9aaf59 100755
--- a/client/src/main/java/com/vaadin/client/widgets/Grid.java
+++ b/client/src/main/java/com/vaadin/client/widgets/Grid.java
@@ -1416,6 +1416,15 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
              *         done, false otherwise
              */
             boolean handleEvent(EditorDomEvent<T> event);
+
+            /**
+             * Confirms the valid status of the binder so as to determine
+             * whether to allow pending navigation action.
+             *
+             * @param isValid
+             *            {@code true} if the binder value is valid
+             */
+            void confirmValidity(boolean isValid);
         }
 
         protected enum State {