Add "deselect allowed" feature to the Grid. (#8227)

* Add "deselect allowed" feature to the Grid.

Fixes #8149

3 files changed, 76 insertions, 19 deletions

diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/AbstractSelectionModelConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/AbstractSelectionModelConnector.java
index 114bc313d6..2210317c7c 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/AbstractSelectionModelConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/AbstractSelectionModelConnector.java
@@ -19,6 +19,7 @@ import com.vaadin.client.ServerConnector;
 import com.vaadin.client.annotations.OnStateChange;
 import com.vaadin.client.extensions.AbstractExtensionConnector;
 import com.vaadin.client.widget.grid.selection.SelectionModel;
+import com.vaadin.client.widget.grid.selection.SpaceSelectHandler;
 import com.vaadin.client.widgets.Grid;
 import com.vaadin.shared.ui.grid.AbstractSelectionModelState;
 
@@ -34,9 +35,24 @@ import elemental.json.JsonObject;
 public abstract class AbstractSelectionModelConnector
         extends AbstractExtensionConnector {
 
+    private SpaceSelectHandler<JsonObject> spaceSelectHandler;
+
     @Override
     protected void extend(ServerConnector target) {
         initSelectionModel();
+
+        // Default selection style is space key.
+        spaceSelectHandler = new SpaceSelectHandler<>(getGrid());
+    }
+
+    @Override
+    public void onUnregister() {
+        super.onUnregister();
+
+        if (spaceSelectHandler != null) {
+            spaceSelectHandler.removeHandler();
+            spaceSelectHandler = null;
+        }
     }
 
     /**
@@ -62,6 +78,15 @@ public abstract class AbstractSelectionModelConnector
         return getParent().getWidget();
     }
 
+    /**
+     * Gets space selection handler registered for the Grid.
+     * 
+     * @return space selection handler
+     */
+    protected SpaceSelectHandler<JsonObject> getSpaceSelectionHandler() {
+        return spaceSelectHandler;
+    }
+
     @OnStateChange("selectionAllowed")
     private void onSelectionAllowedChange() {
         getGrid().getSelectionModel()
diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/GridConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/GridConnector.java
index 828c795777..2e48e3a64a 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/GridConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/GridConnector.java
@@ -47,8 +47,6 @@ import com.vaadin.client.widget.grid.events.BodyClickHandler;
 import com.vaadin.client.widget.grid.events.BodyDoubleClickHandler;
 import com.vaadin.client.widget.grid.events.GridClickEvent;
 import com.vaadin.client.widget.grid.events.GridDoubleClickEvent;
-import com.vaadin.client.widget.grid.selection.ClickSelectHandler;
-import com.vaadin.client.widget.grid.selection.SpaceSelectHandler;
 import com.vaadin.client.widget.grid.sort.SortEvent;
 import com.vaadin.client.widget.grid.sort.SortOrder;
 import com.vaadin.client.widgets.Grid;
@@ -111,8 +109,6 @@ public class GridConnector extends AbstractListingConnector
 
     /* Child component list for HasComponentsConnector */
     private List<ComponentConnector> childComponents;
-    private SpaceSelectHandler<JsonObject> spaceSelectHandler;
-    private ClickSelectHandler<JsonObject> clickSelectHandler;
     private ItemClickHandler itemClickHandler = new ItemClickHandler();
 
     /**
@@ -147,8 +143,6 @@ public class GridConnector extends AbstractListingConnector
     protected void init() {
         super.init();
 
-        // Default selection style is space key.
-        spaceSelectHandler = new SpaceSelectHandler<>(getWidget());
         getWidget().addSortHandler(this::handleSortEvent);
         getWidget().setRowStyleGenerator(rowRef -> {
             JsonObject json = rowRef.getRow();
@@ -344,12 +338,6 @@ public class GridConnector extends AbstractListingConnector
         super.onUnregister();
 
         columnToIdMap.clear();
-        removeClickHandler();
-
-        if (spaceSelectHandler != null) {
-            spaceSelectHandler.removeHandler();
-            spaceSelectHandler = null;
-        }
     }
 
     @Override
@@ -415,13 +403,6 @@ public class GridConnector extends AbstractListingConnector
         return (GridState) super.getState();
     }
 
-    private void removeClickHandler() {
-        if (clickSelectHandler != null) {
-            clickSelectHandler.removeHandler();
-            clickSelectHandler = null;
-        }
-    }
-
     @Override
     public boolean hasTooltip() {
         // Always check for generated descriptions.
diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/SingleSelectionModelConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/SingleSelectionModelConnector.java
index 9b1d7cc27a..560ccb2d85 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/SingleSelectionModelConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/SingleSelectionModelConnector.java
@@ -15,12 +15,14 @@
  */
 package com.vaadin.client.connectors.grid;
 
+import com.vaadin.client.annotations.OnStateChange;
 import com.vaadin.client.widget.grid.events.GridSelectionAllowedEvent;
 import com.vaadin.client.widget.grid.selection.ClickSelectHandler;
 import com.vaadin.client.widget.grid.selection.SelectionModel;
 import com.vaadin.shared.data.DataCommunicatorConstants;
 import com.vaadin.shared.data.selection.SelectionServerRpc;
 import com.vaadin.shared.ui.Connect;
+import com.vaadin.shared.ui.grid.SingleSelectionModelState;
 
 import elemental.json.JsonObject;
 
@@ -44,6 +46,8 @@ public class SingleSelectionModelConnector
 
         private boolean isSelectionAllowed = true;
 
+        private boolean deselectAllowed = true;
+
         @Override
         public void select(JsonObject item) {
             getRpcProxy(SelectionServerRpc.class)
@@ -77,6 +81,39 @@ public class SingleSelectionModelConnector
         public boolean isSelectionAllowed() {
             return isSelectionAllowed;
         }
+
+        /**
+         * Sets whether it's allowed to deselect the selected row through the
+         * UI. Deselection is allowed by default.
+         *
+         * @param deselectAllowed
+         *            <code>true</code> if the selected row can be deselected
+         *            without selecting another row instead; otherwise
+         *            <code>false</code>.
+         */
+        public void setDeselectAllowed(boolean deselectAllowed) {
+            this.deselectAllowed = deselectAllowed;
+            updateHandlerDeselectAllowed();
+        }
+
+        /**
+         * Gets whether it's allowed to deselect the selected row through the
+         * UI.
+         *
+         * @return <code>true</code> if deselection is allowed; otherwise
+         *         <code>false</code>
+         */
+        public boolean isDeselectAllowed() {
+            return deselectAllowed;
+        }
+
+        private void updateHandlerDeselectAllowed() {
+            if (clickSelectHandler != null) {
+                clickSelectHandler.setDeselectAllowed(deselectAllowed);
+            }
+            getSpaceSelectionHandler().setDeselectAllowed(deselectAllowed);
+        }
+
     }
 
     @Override
@@ -94,4 +131,18 @@ public class SingleSelectionModelConnector
         }
     }
 
+    @Override
+    public SingleSelectionModelState getState() {
+        return (SingleSelectionModelState) super.getState();
+    }
+
+    @OnStateChange("deselectAllowed")
+    private void updateDeselectAllowed() {
+        getSelectionModel().setDeselectAllowed(getState().deselectAllowed);
+    }
+
+    private SingleSelectionModel getSelectionModel() {
+        return (SingleSelectionModel) getGrid().getSelectionModel();
+    }
+
 }