Add AbstractSelectionModel for Grid

Also adds shared state for grid's selection models.
This is mostly for making it possible later to modify the selection models,
without breaking backwards API compatibility and having to duplicate code.

Change-Id: If93720df282bf5ca3aff17a20b455d60b33f764c

9 files changed, 247 insertions, 106 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
new file mode 100644
index 0000000000..5f705cb237
--- /dev/null
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/AbstractSelectionModelConnector.java
@@ -0,0 +1,79 @@
+/*
+ * 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.widget.grid.selection.SelectionModel;
+import com.vaadin.client.widgets.Grid;
+import com.vaadin.shared.ui.grid.AbstractSelectionModelState;
+
+import elemental.json.JsonObject;
+
+/**
+ * Abstract base class for grid's selection models.
+ *
+ * @author Vaadin Ltd
+ *
+ * @since 8.0
+ */
+public abstract class AbstractSelectionModelConnector
+        extends AbstractExtensionConnector {
+
+    @Override
+    protected void extend(ServerConnector target) {
+        initSelectionModel();
+    }
+
+    /**
+     * Initializes the selection model and sets it to the grid.
+     * <p>
+     * This method is only invoked once by {@link #extend(ServerConnector)} in
+     * {@link AbstractSelectionModelConnector} when the grid is available via
+     * {@link #getGrid()} and the selection model should be taken into use.
+     */
+    protected abstract void initSelectionModel();
+
+    @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();
+    }
+
+    @Override
+    public AbstractSelectionModelState getState() {
+        return (AbstractSelectionModelState) super.getState();
+    }
+
+    /**
+     * Returns whether the given item selected in grid or not.
+     *
+     * @param item
+     *            the item to check
+     * @return {@code true} if selected {@code false} if not
+     */
+    protected boolean isSelected(JsonObject item) {
+        return SelectionModel.isItemSelected(item);
+    }
+}
diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/MultiSelectionModelConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/MultiSelectionModelConnector.java
index b24cb54e63..8ad86f1541 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/MultiSelectionModelConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/MultiSelectionModelConnector.java
@@ -18,11 +18,9 @@ package com.vaadin.client.connectors.grid;
 import java.util.Optional;
 
 import com.google.gwt.event.shared.HandlerRegistration;
-import com.vaadin.client.ServerConnector;
 import com.vaadin.client.annotations.OnStateChange;
 import com.vaadin.client.data.DataSource;
 import com.vaadin.client.data.DataSource.RowHandle;
-import com.vaadin.client.extensions.AbstractExtensionConnector;
 import com.vaadin.client.renderers.Renderer;
 import com.vaadin.client.widget.grid.events.SelectAllEvent;
 import com.vaadin.client.widget.grid.selection.MultiSelectionRenderer;
@@ -53,7 +51,8 @@ import elemental.json.JsonObject;
  *
  */
 @Connect(com.vaadin.ui.components.grid.MultiSelectionModelImpl.class)
-public class MultiSelectionModelConnector extends AbstractExtensionConnector {
+public class MultiSelectionModelConnector
+        extends AbstractSelectionModelConnector {
 
     private HandlerRegistration selectAllHandler;
     private HandlerRegistration dataAvailable;
@@ -110,7 +109,7 @@ public class MultiSelectionModelConnector extends AbstractExtensionConnector {
     }
 
     @Override
-    protected void extend(ServerConnector target) {
+    protected void initSelectionModel() {
         getGrid().setSelectionModel(new MultiSelectionModel());
         // capture current rows so that can show selection update immediately
         dataAvailable = getGrid().addDataAvailableHandler(
@@ -128,24 +127,10 @@ public class MultiSelectionModelConnector extends AbstractExtensionConnector {
     }
 
     @Override
-    public GridConnector getParent() {
-        return (GridConnector) super.getParent();
-    }
-
-    @Override
     public MultiSelectionModelState getState() {
         return (MultiSelectionModelState) super.getState();
     }
 
-    /**
-     * Shorthand for fetching the grid this selection model is bound to.
-     *
-     * @return the grid
-     */
-    protected Grid<JsonObject> getGrid() {
-        return getParent().getWidget();
-    }
-
     @OnStateChange({ "selectAllCheckBoxVisible", "allSelected" })
     void onSelectAllCheckboxStateUpdates() {
         // in case someone wants to override this, moved the actual updating to
@@ -232,15 +217,9 @@ public class MultiSelectionModelConnector extends AbstractExtensionConnector {
         }
     }
 
-    /**
-     * Returns whether the given item selected in grid or not.
-     *
-     * @param item
-     *            the item to check
-     * @return {@code true} if selected {@code false} if not
-     */
+    @Override
     protected boolean isSelected(JsonObject item) {
-        return getState().allSelected || SelectionModel.isItemSelected(item);
+        return getState().allSelected || super.isSelected(item);
     }
 
     /**
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 aba6d906b3..d18f372a2c 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
@@ -15,8 +15,6 @@
  */
 package com.vaadin.client.connectors.grid;
 
-import com.vaadin.client.ServerConnector;
-import com.vaadin.client.extensions.AbstractExtensionConnector;
 import com.vaadin.client.widget.grid.selection.ClickSelectHandler;
 import com.vaadin.client.widget.grid.selection.SelectionModel;
 import com.vaadin.shared.data.DataCommunicatorConstants;
@@ -33,38 +31,43 @@ import elemental.json.JsonObject;
  * @since 8.0
  */
 @Connect(com.vaadin.ui.components.grid.SingleSelectionModelImpl.class)
-public class SingleSelectionModelConnector extends AbstractExtensionConnector {
+public class SingleSelectionModelConnector
+        extends AbstractSelectionModelConnector {
 
-    private ClickSelectHandler clickSelectHandler;
+    private ClickSelectHandler<JsonObject> clickSelectHandler;
 
-    @Override
-    protected void extend(ServerConnector target) {
-        getParent().getWidget()
-                .setSelectionModel(new SelectionModel<JsonObject>() {
+    /**
+     * Single selection model for grid.
+     */
+    protected class SingleSelectionModel implements SelectionModel<JsonObject> {
 
-                    @Override
-                    public void select(JsonObject item) {
-                        getRpcProxy(SelectionServerRpc.class).select(
-                                item.getString(DataCommunicatorConstants.KEY));
-                    }
+        @Override
+        public void select(JsonObject item) {
+            getRpcProxy(SelectionServerRpc.class)
+                    .select(item.getString(DataCommunicatorConstants.KEY));
+        }
 
-                    @Override
-                    public void deselect(JsonObject item) {
-                        getRpcProxy(SelectionServerRpc.class).deselect(
-                                item.getString(DataCommunicatorConstants.KEY));
-                    }
+        @Override
+        public void deselect(JsonObject item) {
+            getRpcProxy(SelectionServerRpc.class)
+                    .deselect(item.getString(DataCommunicatorConstants.KEY));
+        }
 
-                    @Override
-                    public boolean isSelected(JsonObject item) {
-                        return SelectionModel.isItemSelected(item);
-                    }
+        @Override
+        public boolean isSelected(JsonObject item) {
+            return SingleSelectionModelConnector.this.isSelected(item);
+        }
 
-                    @Override
-                    public void deselectAll() {
-                        getRpcProxy(SelectionServerRpc.class).select(null);
-                    }
+        @Override
+        public void deselectAll() {
+            getRpcProxy(SelectionServerRpc.class).select(null);
+        }
+    }
+
+    @Override
+    protected void initSelectionModel() {
+        getGrid().setSelectionModel(new SingleSelectionModel());
 
-                });
         clickSelectHandler = new ClickSelectHandler<>(getParent().getWidget());
     }
 
@@ -76,9 +79,4 @@ public class SingleSelectionModelConnector extends AbstractExtensionConnector {
         }
     }
 
-    @Override
-    public GridConnector getParent() {
-        return (GridConnector) super.getParent();
-    }
-
 }
diff --git a/server/src/main/java/com/vaadin/ui/components/grid/AbstractSelectionModel.java b/server/src/main/java/com/vaadin/ui/components/grid/AbstractSelectionModel.java
new file mode 100644
index 0000000000..dc8ee18f3a
--- /dev/null
+++ b/server/src/main/java/com/vaadin/ui/components/grid/AbstractSelectionModel.java
@@ -0,0 +1,62 @@
+/*
+ * 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.ui.components.grid;
+
+import com.vaadin.shared.data.DataCommunicatorConstants;
+import com.vaadin.shared.ui.grid.AbstractSelectionModelState;
+import com.vaadin.ui.Grid.AbstractGridExtension;
+import com.vaadin.ui.Grid.GridSelectionModel;
+
+import elemental.json.JsonObject;
+
+/**
+ * Abstract selection model for grid.
+ *
+ * @author Vaadin Ltd
+ *
+ * @since 8.0
+ *
+ * @param <T>
+ *            the type of the items in grid.
+ */
+public abstract class AbstractSelectionModel<T> extends AbstractGridExtension<T>
+        implements GridSelectionModel<T> {
+
+    @Override
+    public void generateData(T item, JsonObject jsonObject) {
+        if (isSelected(item)) {
+            jsonObject.put(DataCommunicatorConstants.SELECTED, true);
+        }
+    }
+
+    @Override
+    protected AbstractSelectionModelState getState() {
+        return (AbstractSelectionModelState) super.getState();
+    }
+
+    @Override
+    protected AbstractSelectionModelState getState(boolean markAsDirty) {
+        return (AbstractSelectionModelState) super.getState(markAsDirty);
+    }
+
+    @Override
+    public void remove() {
+        deselectAll();
+
+        super.remove();
+    }
+
+}
diff --git a/server/src/main/java/com/vaadin/ui/components/grid/MultiSelectionModelImpl.java b/server/src/main/java/com/vaadin/ui/components/grid/MultiSelectionModelImpl.java
index 70a056f34c..465115d831 100644
--- a/server/src/main/java/com/vaadin/ui/components/grid/MultiSelectionModelImpl.java
+++ b/server/src/main/java/com/vaadin/ui/components/grid/MultiSelectionModelImpl.java
@@ -30,17 +30,13 @@ import com.vaadin.event.selection.MultiSelectionListener;
 import com.vaadin.server.data.DataProvider;
 import com.vaadin.server.data.Query;
 import com.vaadin.shared.Registration;
-import com.vaadin.shared.data.DataCommunicatorConstants;
 import com.vaadin.shared.data.selection.GridMultiSelectServerRpc;
 import com.vaadin.shared.ui.grid.MultiSelectionModelState;
 import com.vaadin.ui.Grid;
-import com.vaadin.ui.Grid.AbstractGridExtension;
 import com.vaadin.ui.Grid.MultiSelectionModel;
 import com.vaadin.ui.MultiSelect;
 import com.vaadin.util.ReflectTools;
 
-import elemental.json.JsonObject;
-
 /**
  * Multiselection model for grid.
  * <p>
@@ -56,7 +52,7 @@ import elemental.json.JsonObject;
  * @param <T>
  *            the type of the selected item in grid.
  */
-public class MultiSelectionModelImpl<T> extends AbstractGridExtension<T>
+public class MultiSelectionModelImpl<T> extends AbstractSelectionModel<T>
         implements MultiSelectionModel<T> {
 
     /**
@@ -257,13 +253,6 @@ public class MultiSelectionModelImpl<T> extends AbstractGridExtension<T>
         }
     }
 
-    @Override
-    public void remove() {
-        updateSelection(Collections.emptySet(), getSelectedItems(), false);
-
-        super.remove();
-    }
-
     /**
      * Adds a selection listener that will be called when the selection is
      * changed either by the user or programmatically.
@@ -280,15 +269,6 @@ public class MultiSelectionModelImpl<T> extends AbstractGridExtension<T>
     }
 
     @Override
-    public void generateData(T item, JsonObject jsonObject) {
-        // in case of all items selected, don't write individual items as
-        // seleted
-        if (isSelected(item)) {
-            jsonObject.put(DataCommunicatorConstants.SELECTED, true);
-        }
-    }
-
-    @Override
     public Set<T> getSelectedItems() {
         return Collections.unmodifiableSet(new LinkedHashSet<>(selection));
     }
diff --git a/server/src/main/java/com/vaadin/ui/components/grid/SingleSelectionModelImpl.java b/server/src/main/java/com/vaadin/ui/components/grid/SingleSelectionModelImpl.java
index e68487f358..283b8edc50 100644
--- a/server/src/main/java/com/vaadin/ui/components/grid/SingleSelectionModelImpl.java
+++ b/server/src/main/java/com/vaadin/ui/components/grid/SingleSelectionModelImpl.java
@@ -26,17 +26,14 @@ import java.util.Set;
 import com.vaadin.event.selection.SingleSelectionEvent;
 import com.vaadin.event.selection.SingleSelectionListener;
 import com.vaadin.shared.Registration;
-import com.vaadin.shared.data.DataCommunicatorConstants;
 import com.vaadin.shared.data.selection.SelectionServerRpc;
+import com.vaadin.shared.ui.grid.SingleSelectionModelState;
 import com.vaadin.ui.Component;
 import com.vaadin.ui.Grid;
-import com.vaadin.ui.Grid.AbstractGridExtension;
 import com.vaadin.ui.Grid.SingleSelectionModel;
 import com.vaadin.ui.SingleSelect;
 import com.vaadin.util.ReflectTools;
 
-import elemental.json.JsonObject;
-
 /**
  * Single selection model for grid.
  *
@@ -46,7 +43,7 @@ import elemental.json.JsonObject;
  * @param <T>
  *            the type of the selected item in grid.
  */
-public class SingleSelectionModelImpl<T> extends AbstractGridExtension<T>
+public class SingleSelectionModelImpl<T> extends AbstractSelectionModel<T>
         implements SingleSelectionModel<T> {
 
     private static final Method SELECTION_CHANGE_METHOD = ReflectTools
@@ -81,6 +78,16 @@ public class SingleSelectionModelImpl<T> extends AbstractGridExtension<T>
         });
     }
 
+    @Override
+    protected SingleSelectionModelState getState() {
+        return (SingleSelectionModelState) super.getState();
+    }
+
+    @Override
+    protected SingleSelectionModelState getState(boolean markAsDirty) {
+        return (SingleSelectionModelState) super.getState(markAsDirty);
+    }
+
     /**
      * Adds a selection listener to this select. The listener is called when the
      * value of this select is changed either by the user or programmatically.
@@ -224,23 +231,6 @@ public class SingleSelectionModelImpl<T> extends AbstractGridExtension<T>
         }
     }
 
-    @Override
-    public void generateData(T item, JsonObject jsonObject) {
-        if (isSelected(item)) {
-            jsonObject.put(DataCommunicatorConstants.SELECTED, true);
-        }
-    }
-
-    @Override
-    public void remove() {
-        // when selection model changes, firing an event for selection change
-        // event fired before removing so that parent is still intact (in case
-        // needed)
-        setSelectedFromServer(null);
-
-        super.remove();
-    }
-
     /**
      * Gets a wrapper for using this grid as a single select in a binder.
      *
diff --git a/shared/src/main/java/com/vaadin/shared/ui/grid/AbstractSelectionModelState.java b/shared/src/main/java/com/vaadin/shared/ui/grid/AbstractSelectionModelState.java
new file mode 100644
index 0000000000..9cd29341b1
--- /dev/null
+++ b/shared/src/main/java/com/vaadin/shared/ui/grid/AbstractSelectionModelState.java
@@ -0,0 +1,28 @@
+/*
+ * 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.shared.ui.grid;
+
+import com.vaadin.shared.communication.SharedState;
+
+/**
+ * Shared state for grid's abstract selection model.
+ *
+ * @author Vaadin Ltd
+ *
+ * @since 8.0
+ */
+public class AbstractSelectionModelState extends SharedState {
+}
diff --git a/shared/src/main/java/com/vaadin/shared/ui/grid/MultiSelectionModelState.java b/shared/src/main/java/com/vaadin/shared/ui/grid/MultiSelectionModelState.java
index 5d2a1c6094..0f7ccdc102 100644
--- a/shared/src/main/java/com/vaadin/shared/ui/grid/MultiSelectionModelState.java
+++ b/shared/src/main/java/com/vaadin/shared/ui/grid/MultiSelectionModelState.java
@@ -15,15 +15,14 @@
  */
 package com.vaadin.shared.ui.grid;
 
-import com.vaadin.shared.communication.SharedState;
-
 /**
- * SharedState object for MultiSelectionModel.
+ * SharedState object for MultiSelectionModelImpl.
  *
- * @since 8.0
  * @author Vaadin Ltd
+ *
+ * @since 8.0
  */
-public class MultiSelectionModelState extends SharedState {
+public class MultiSelectionModelState extends AbstractSelectionModelState {
 
     /** Is the select all checkbox visible. */
     public boolean selectAllCheckBoxVisible;
diff --git a/shared/src/main/java/com/vaadin/shared/ui/grid/SingleSelectionModelState.java b/shared/src/main/java/com/vaadin/shared/ui/grid/SingleSelectionModelState.java
new file mode 100644
index 0000000000..2ad1a30a3d
--- /dev/null
+++ b/shared/src/main/java/com/vaadin/shared/ui/grid/SingleSelectionModelState.java
@@ -0,0 +1,26 @@
+/*
+ * 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.shared.ui.grid;
+
+/**
+ * Shared state for grid's single selection model.
+ *
+ * @author Vaadin Ltd
+ *
+ * @since 8.0
+ */
+public class SingleSelectionModelState extends AbstractSelectionModelState {
+}