Create drag source and drop target extensions for tree grid (#9463)

Resolves #9372

4 files changed, 301 insertions, 0 deletions

diff --git a/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDragSource.java b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDragSource.java
new file mode 100644
index 0000000000..68d0c68b13
--- /dev/null
+++ b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDragSource.java
@@ -0,0 +1,54 @@
+/*
+ * 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.ui.treegrid.TreeGridDragSourceState;
+import com.vaadin.ui.TreeGrid;
+
+/**
+ * Makes a TreeGrid's rows draggable for HTML5 drag and drop functionality.
+ * <p>
+ * When dragging a selected row, all the visible selected rows are dragged. Note
+ * that ONLY visible rows are taken into account and the subtree belonging to a
+ * selected row is not dragged either.
+ *
+ * @param <T>
+ *            The TreeGrid bean type.
+ * @author Vaadin Ltd.
+ * @since 8.1
+ */
+public class TreeGridDragSource<T> extends GridDragSource<T> {
+
+    /**
+     * Extends a TreeGrid and makes it's rows draggable.
+     *
+     * @param target
+     *            TreeGrid to be extended.
+     */
+    public TreeGridDragSource(TreeGrid<T> target) {
+        super(target);
+    }
+
+    @Override
+    protected TreeGridDragSourceState getState() {
+        return (TreeGridDragSourceState) super.getState();
+    }
+
+    @Override
+    protected TreeGridDragSourceState getState(boolean markAsDirty) {
+        return (TreeGridDragSourceState) super.getState(markAsDirty);
+    }
+}
diff --git a/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropEvent.java b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropEvent.java
new file mode 100644
index 0000000000..015f6169d5
--- /dev/null
+++ b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropEvent.java
@@ -0,0 +1,99 @@
+/*
+ * 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 java.util.Map;
+import java.util.Optional;
+
+import com.vaadin.shared.MouseEventDetails;
+import com.vaadin.shared.ui.dnd.DropEffect;
+import com.vaadin.shared.ui.grid.DropLocation;
+import com.vaadin.ui.AbstractComponent;
+import com.vaadin.ui.TreeGrid;
+import com.vaadin.ui.dnd.DragSourceExtension;
+
+/**
+ * Drop event on an HTML5 drop target {@link TreeGrid} row.
+ *
+ * @param <T>
+ *         The TreeGrid bean type.
+ * @author Vaadin Ltd.
+ * @see TreeGridDropTarget#addTreeGridDropListener(TreeGridDropListener)
+ * @since 8.1
+ */
+public class TreeGridDropEvent<T> extends GridDropEvent<T> {
+
+    private Integer depth;
+    private Boolean collapsed;
+
+    /**
+     * Creates a TreeGrid row drop event.
+     *
+     * @param target
+     *         TreeGrid that received the drop.
+     * @param data
+     *         Map containing all types and corresponding data from the {@code
+     *         DataTransfer} object.
+     * @param dropEffect
+     *         the desired drop effect
+     * @param dragSourceExtension
+     *         Drag source extension of the component that initiated the drop
+     *         event.
+     * @param dropTargetRow
+     *         Target row that received the drop, or {@code null} if dropped on
+     *         empty grid
+     * @param dropLocation
+     *         Location of the drop within the target row.
+     * @param mouseEventDetails
+     *         Mouse event details object containing information about the drop
+     *         event
+     * @param depth
+     *         depth of the row in the hierarchy
+     * @param collapsed
+     *         whether the target row is collapsed
+     */
+    public TreeGridDropEvent(TreeGrid<T> target, Map<String, String> data,
+            DropEffect dropEffect,
+            DragSourceExtension<? extends AbstractComponent> dragSourceExtension,
+            T dropTargetRow, DropLocation dropLocation,
+            MouseEventDetails mouseEventDetails, Integer depth,
+            Boolean collapsed) {
+        super(target, data, dropEffect, dragSourceExtension, dropTargetRow,
+                dropLocation, mouseEventDetails);
+
+        this.depth = depth;
+        this.collapsed = collapsed;
+    }
+
+    /**
+     * Gets the depth of the drop target row in the hierarchy.
+     *
+     * @return the depth of the drop target row in the hierarchy
+     */
+    public Optional<Integer> getDropTargetRowDepth() {
+        return Optional.ofNullable(depth);
+    }
+
+    /**
+     * Tells whether the drop target row is collapsed.
+     *
+     * @return {@code true} if the drop target row is collapsed, {@code false}
+     * otherwise
+     */
+    public Optional<Boolean> isDropTargetRowCollapsed() {
+        return Optional.ofNullable(collapsed);
+    }
+}
diff --git a/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropListener.java b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropListener.java
new file mode 100644
index 0000000000..d413a7b42b
--- /dev/null
+++ b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropListener.java
@@ -0,0 +1,44 @@
+/*
+ * 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 java.lang.reflect.Method;
+
+import com.vaadin.event.ConnectorEventListener;
+
+/**
+ * Drop listener for HTML5 drop on a TreeGrid row.
+ *
+ * @param <T>
+ *            The Grid bean type.
+ * @author Vaadin Ltd.
+ * @see TreeGridDropTarget#addTreeGridDropListener(TreeGridDropListener)
+ * @since 8.1
+ */
+@FunctionalInterface
+public interface TreeGridDropListener<T> extends ConnectorEventListener {
+
+    static final Method DROP_METHOD = TreeGridDropListener.class
+            .getDeclaredMethods()[0];
+
+    /**
+     * Called when drop event is fired on a Grid row.
+     *
+     * @param event
+     *            Server side drop event.
+     */
+    void drop(TreeGridDropEvent<T> event);
+}
diff --git a/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropTarget.java b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropTarget.java
new file mode 100644
index 0000000000..1d440b5fec
--- /dev/null
+++ b/server/src/main/java/com/vaadin/ui/components/grid/TreeGridDropTarget.java
@@ -0,0 +1,104 @@
+/*
+ * 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 java.util.LinkedHashMap;
+import java.util.Map;
+
+import com.vaadin.shared.Registration;
+import com.vaadin.shared.ui.dnd.DropEffect;
+import com.vaadin.shared.ui.grid.DropMode;
+import com.vaadin.shared.ui.treegrid.TreeGridDropTargetRpc;
+import com.vaadin.shared.ui.treegrid.TreeGridDropTargetState;
+import com.vaadin.ui.TreeGrid;
+
+/**
+ * Makes the rows of a TreeGrid HTML5 drop targets. This is the server side
+ * counterpart of GridDropTargetExtensionConnector.
+ *
+ * @param <T>
+ *         Type of the TreeGrid bean.
+ * @author Vaadin Ltd
+ * @since 8.1
+ */
+public class TreeGridDropTarget<T> extends GridDropTarget<T> {
+
+    /**
+     * Extends a TreeGrid and makes it's rows drop targets for HTML5 drag and
+     * drop.
+     *
+     * @param target
+     *         TreeGrid to be extended.
+     * @param dropMode
+     *         Drop mode that describes the allowed drop locations within the
+     *         TreeGrid's row.
+     */
+    public TreeGridDropTarget(TreeGrid<T> target, DropMode dropMode) {
+        super(target, dropMode);
+    }
+
+    /**
+     * Attaches drop listener for the current drop target. {@link
+     * TreeGridDropListener#drop(TreeGridDropEvent)} is called when drop event
+     * happens on the client side.
+     *
+     * @param listener
+     *         Listener to handle drop event.
+     * @return Handle to be used to remove this listener.
+     */
+    public Registration addTreeGridDropListener(
+            TreeGridDropListener<T> listener) {
+        return addListener(TreeGridDropEvent.class, listener,
+                TreeGridDropListener.DROP_METHOD);
+    }
+
+    @Override
+    protected void registerDropTargetRpc() {
+        registerRpc((TreeGridDropTargetRpc) (types, data, dropEffect, rowKey,
+                depth, collapsed, dropLocation, mouseEventDetails) -> {
+
+            // Create a linked map that preserves the order of types
+            Map<String, String> dataPreserveOrder = new LinkedHashMap<>();
+            types.forEach(type -> dataPreserveOrder.put(type, data.get(type)));
+
+            T dropTargetRow = getParent().getDataCommunicator().getKeyMapper()
+                    .get(rowKey);
+
+            TreeGridDropEvent<T> event = new TreeGridDropEvent<>(getParent(),
+                    dataPreserveOrder,
+                    DropEffect.valueOf(dropEffect.toUpperCase()),
+                    getUI().getActiveDragSource(), dropTargetRow, dropLocation,
+                    mouseEventDetails, depth, collapsed);
+
+            fireEvent(event);
+        });
+    }
+
+    @Override
+    public TreeGrid<T> getParent() {
+        return (TreeGrid<T>) super.getParent();
+    }
+
+    @Override
+    protected TreeGridDropTargetState getState() {
+        return (TreeGridDropTargetState) super.getState();
+    }
+
+    @Override
+    protected TreeGridDropTargetState getState(boolean markAsDirty) {
+        return (TreeGridDropTargetState) super.getState(markAsDirty);
+    }
+}