Add MultiSelect support for Grid

Still missing following things coming in next patches:
- select all checkbox
- firing an event when data provider is changed in grid
- read only selection models for grid

Part 1 for vaadin/framework8-issues#232

Change-Id: Ib2c7c81a838f43cb7c521a56d50139c91961f54a

client/src/main/java/com/vaadin/client/connectors/grid/MultiSelectionModelConnector.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2000-2016 Vaadin Ltd.
+ *
+ * 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.
+ */
+package com.vaadin.client.connectors.grid;
+
+import com.vaadin.client.ServerConnector;
+import com.vaadin.client.extensions.AbstractExtensionConnector;
+import com.vaadin.client.renderers.Renderer;
+import com.vaadin.client.widget.grid.selection.MultiSelectionRenderer;
+import com.vaadin.client.widget.grid.selection.SelectionModel;
+import com.vaadin.client.widget.grid.selection.SelectionModelWithSelectionColumn;
+import com.vaadin.client.widgets.Grid;
+import com.vaadin.shared.data.DataCommunicatorConstants;
+import com.vaadin.shared.data.selection.GridMultiSelectServerRpc;
+import com.vaadin.shared.ui.Connect;
+
+import elemental.json.JsonObject;
+
+/**
+ * Connector for server side multiselection model implementation.
+ *
+ * @author Vaadin Ltd
+ *
+ * @since 8.0
+ *
+ */
+@Connect(com.vaadin.ui.components.grid.MultiSelectionModelImpl.class)
+public class MultiSelectionModelConnector extends AbstractExtensionConnector {
+
+    /**
+     * Client side multiselection model implementation.
+     */
+    protected class MultiSelectionModel implements SelectionModel<JsonObject>,
+            SelectionModelWithSelectionColumn {
+
+        @Override
+        public Renderer<Boolean> getRenderer() {
+            // this method is only called once when the selection model is set
+            // to grid
+            return new MultiSelectionRenderer<>(getGrid());
+        }
+
+        @Override
+        public void select(JsonObject item) {
+            getRpcProxy(GridMultiSelectServerRpc.class)
+                    .select(item.getString(DataCommunicatorConstants.KEY));
+        }
+
+        @Override
+        public void deselect(JsonObject item) {
+            // handled by diffstate
+            getRpcProxy(GridMultiSelectServerRpc.class)
+                    .deselect(item.getString(DataCommunicatorConstants.KEY));
+        }
+
+        @Override
+        public void deselectAll() {
+            // TODO Will be added in a separate patch
+            throw new UnsupportedOperationException(
+                    "Deselect all not supported.");
+        }
+
+        @Override
+        public boolean isSelected(JsonObject item) {
+            return SelectionModel.isItemSelected(item);
+        }
+
+    }
+
+    @Override
+    protected void extend(ServerConnector target) {
+        getGrid().setSelectionModel(new MultiSelectionModel());
+    }
+
+    @Override
+    public GridConnector getParent() {
+        return (GridConnector) super.getParent();
+    }
+
+    /**
+     * Shorthand for fetching the grid this selection model is bound to.
+     *
+     * @return the grid
+     */
+    protected Grid<JsonObject> getGrid() {
+        return getParent().getWidget();
+    }
+
+}

client/src/main/java/com/vaadin/client/connectors/grid/SingleSelectionModelConnector.java

@@ -15,11 +15,9 @@
  */
 package com.vaadin.client.connectors.grid;
 
-import java.util.Set;
-
 import com.vaadin.client.ServerConnector;
-import com.vaadin.client.data.SelectionModel;
 import com.vaadin.client.extensions.AbstractExtensionConnector;
+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;
@@ -33,7 +31,7 @@
  *
  * @since 8.0
  */
-@Connect(com.vaadin.ui.components.grid.SingleSelectionModel.class)
+@Connect(com.vaadin.ui.components.grid.SingleSelectionModelImpl.class)
 public class SingleSelectionModelConnector extends AbstractExtensionConnector {
 
     @Override
@@ -54,14 +52,13 @@ public void deselect(JsonObject item) {
                     }
 
                     @Override
-                    public Set<JsonObject> getSelectedItems() {
-                        throw new UnsupportedOperationException(
-                                "Selected item not known on the client side");
+                    public boolean isSelected(JsonObject item) {
+                        return SelectionModel.isItemSelected(item);
                     }
 
                     @Override
-                    public boolean isSelected(JsonObject item) {
-                        return SelectionModel.isItemSelected(item);
+                    public void deselectAll() {
+                        getRpcProxy(SelectionServerRpc.class).select(null);
                     }
 
                 });

client/src/main/java/com/vaadin/client/widget/grid/events/SelectAllEvent.java

@@ -16,7 +16,7 @@
 package com.vaadin.client.widget.grid.events;
 
 import com.google.gwt.event.shared.GwtEvent;
-import com.vaadin.client.data.SelectionModel;
+import com.vaadin.client.widget.grid.selection.SelectionModel;
 
 /**
  * A select all event, fired by the Grid when it needs all rows in data source

client/src/main/java/com/vaadin/client/widget/grid/selection/SelectionEvent.java

@@ -136,15 +136,6 @@ public Collection<T> getRemoved() {
         return Collections.unmodifiableCollection(removed);
     }
 
-    /**
-     * Gets currently selected rows.
-     *
-     * @return a non-null collection containing all currently selected rows.
-     */
-    public Collection<T> getSelected() {
-        return grid.getSelectedRows();
-    }
-
     /**
      * Gets a type identifier for this event.
      *

client/src/main/java/com/vaadin/client/data/SelectionModel.java → client/src/main/java/com/vaadin/client/widget/grid/selection/SelectionModel.java

@@ -13,9 +13,7 @@
  * License for the specific language governing permissions and limitations under
  * the License.
  */
-package com.vaadin.client.data;
-
-import java.util.Set;
+package com.vaadin.client.widget.grid.selection;
 
 import com.vaadin.shared.data.DataCommunicatorConstants;
 
@@ -51,14 +49,6 @@ public interface SelectionModel<T> {
      */
     void deselect(T item);
 
-    /**
-     * Returns a set of the currently selected items. It is safe to invoke other
-     * {@code SelectionModel} methods while iterating over the set.
-     *
-     * @return the items in the current selection, not null
-     */
-    Set<T> getSelectedItems();
-
     /**
      * Returns whether the given item is currently selected.
      *
@@ -71,9 +61,7 @@ public interface SelectionModel<T> {
     /**
      * Deselects all currently selected items.
      */
-    default void deselectAll() {
-        getSelectedItems().forEach(this::deselect);
-    }
+    void deselectAll();
 
     /**
      * Gets the selected state from a given grid row json object. This is a