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

Resolves #9372

4 files changed, 213 insertions, 5 deletions

diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/GridDropTargetConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/GridDropTargetConnector.java
index 5b409e3174..9954134821 100644
--- a/client/src/main/java/com/vaadin/client/connectors/grid/GridDropTargetConnector.java
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/GridDropTargetConnector.java
@@ -124,7 +124,14 @@ public class GridDropTargetConnector extends DropTargetExtensionConnector {
                 rowKey, dropLocation, mouseEventDetails);
     }
 
-    private JsonObject getRowData(TableRowElement row) {
+    /**
+     * Get the row data as json object for the given row.
+     *
+     * @param row
+     *         table row element
+     * @return row data as json object for the given row
+     */
+    protected JsonObject getRowData(TableRowElement row) {
         int rowIndex = ((Escalator.AbstractRowContainer) getGridBody())
                 .getLogicalRowIndex(row);
         return gridConnector.getDataSource().getRow(rowIndex);
@@ -132,8 +139,13 @@ public class GridDropTargetConnector extends DropTargetExtensionConnector {
 
     /**
      * Returns the location of the event within the row.
+     *
+     * @param target
+     *         drop target element
+     * @param event
+     *         drop event
      */
-    private DropLocation getDropLocation(Element target, NativeEvent event) {
+    protected DropLocation getDropLocation(Element target, NativeEvent event) {
         if (TableRowElement.is(target)) {
             if (getState().dropMode == DropMode.BETWEEN) {
                 if (getRelativeY(target,
@@ -241,7 +253,14 @@ public class GridDropTargetConnector extends DropTargetExtensionConnector {
         element.removeClassName(styleDragEmpty);
     }
 
-    private Element getTargetElement(Element source) {
+    /**
+     * Gets the target element for a dragover or drop event.
+     *
+     * @param source
+     *         the event target of the event
+     * @return the element that should be handled as the target of the event
+     */
+    protected Element getTargetElement(Element source) {
         final Element tableWrapper = getDropTargetElement();
         final BodyRowContainer gridBody = getGridBody();
         final int rowCount = gridBody.getRowCount();
diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/TreeGridDragSourceConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/TreeGridDragSourceConnector.java
new file mode 100644
index 0000000000..c2450bb9db
--- /dev/null
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/TreeGridDragSourceConnector.java
@@ -0,0 +1,37 @@
+/*
+ * 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.shared.ui.Connect;
+import com.vaadin.shared.ui.treegrid.TreeGridDragSourceState;
+import com.vaadin.ui.components.grid.TreeGridDragSource;
+
+/**
+ * Adds HTML5 drag and drop functionality to a TreeGrid's rows. This is the
+ * client side counterpart of {@link TreeGridDragSource}.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
+ */
+@Connect(TreeGridDragSource.class)
+public class TreeGridDragSourceConnector extends GridDragSourceConnector {
+
+    @Override
+    public TreeGridDragSourceState getState() {
+        return (TreeGridDragSourceState) super.getState();
+    }
+
+}
diff --git a/client/src/main/java/com/vaadin/client/connectors/grid/TreeGridDropTargetConnector.java b/client/src/main/java/com/vaadin/client/connectors/grid/TreeGridDropTargetConnector.java
new file mode 100644
index 0000000000..fd13426514
--- /dev/null
+++ b/client/src/main/java/com/vaadin/client/connectors/grid/TreeGridDropTargetConnector.java
@@ -0,0 +1,86 @@
+/*
+ * 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 java.util.List;
+import java.util.Map;
+
+import com.google.gwt.dom.client.Element;
+import com.google.gwt.dom.client.NativeEvent;
+import com.google.gwt.dom.client.TableRowElement;
+import com.vaadin.client.MouseEventDetailsBuilder;
+import com.vaadin.shared.MouseEventDetails;
+import com.vaadin.shared.data.HierarchicalDataCommunicatorConstants;
+import com.vaadin.shared.ui.Connect;
+import com.vaadin.shared.ui.grid.DropLocation;
+import com.vaadin.shared.ui.grid.GridState;
+import com.vaadin.shared.ui.treegrid.TreeGridDropTargetRpc;
+import com.vaadin.shared.ui.treegrid.TreeGridDropTargetState;
+import com.vaadin.ui.components.grid.TreeGridDropTarget;
+
+import elemental.json.JsonObject;
+
+/**
+ * Makes TreeGrid an HTML5 drop target. This is the client side counterpart of
+ * {@link TreeGridDropTarget}.
+ *
+ * @author Vaadin Ltd
+ * @since 8.1
+ */
+@Connect(TreeGridDropTarget.class)
+public class TreeGridDropTargetConnector extends GridDropTargetConnector {
+
+    @Override
+    protected void sendDropEventToServer(List<String> types,
+            Map<String, String> data, String dropEffect,
+            NativeEvent dropEvent) {
+        String rowKey = null;
+        DropLocation dropLocation = null;
+        Integer rowDepth = null;
+        Boolean rowCollapsed = null;
+
+        Element targetElement = getTargetElement(
+                (Element) dropEvent.getEventTarget().cast());
+        // the target element is either the tablewrapper or one of the body rows
+        if (TableRowElement.is(targetElement)) {
+            JsonObject rowData = getRowData(targetElement.cast());
+            rowKey = rowData.getString(GridState.JSONKEY_ROWKEY);
+            dropLocation = getDropLocation(targetElement, dropEvent);
+
+            // Collect hierarchy information
+            JsonObject hierarchyDescription = rowData.getObject(
+                    HierarchicalDataCommunicatorConstants.ROW_HIERARCHY_DESCRIPTION);
+            rowDepth = (int) hierarchyDescription
+                    .getNumber(HierarchicalDataCommunicatorConstants.ROW_DEPTH);
+            rowCollapsed = hierarchyDescription.getBoolean(
+                    HierarchicalDataCommunicatorConstants.ROW_COLLAPSED);
+        } else {
+            dropLocation = DropLocation.EMPTY;
+        }
+
+        MouseEventDetails mouseEventDetails = MouseEventDetailsBuilder
+                .buildMouseEventDetails(dropEvent, targetElement);
+
+        getRpcProxy(TreeGridDropTargetRpc.class).drop(types, data, dropEffect,
+                rowKey, rowDepth, rowCollapsed, dropLocation,
+                mouseEventDetails);
+    }
+
+    @Override
+    public TreeGridDropTargetState getState() {
+        return (TreeGridDropTargetState) super.getState();
+    }
+}
diff --git a/client/src/main/java/com/vaadin/client/widget/treegrid/TreeGrid.java b/client/src/main/java/com/vaadin/client/widget/treegrid/TreeGrid.java
index fb66bebb7d..328d594fe1 100644
--- a/client/src/main/java/com/vaadin/client/widget/treegrid/TreeGrid.java
+++ b/client/src/main/java/com/vaadin/client/widget/treegrid/TreeGrid.java
@@ -16,10 +16,14 @@
 package com.vaadin.client.widget.treegrid;
 
 import com.google.gwt.dom.client.Element;
+import com.google.gwt.dom.client.TableRowElement;
 import com.google.gwt.event.shared.HandlerRegistration;
+import com.vaadin.client.widget.escalator.EscalatorUpdater;
+import com.vaadin.client.widget.escalator.Row;
 import com.vaadin.client.widget.grid.events.BodyClickHandler;
 import com.vaadin.client.widget.treegrid.events.TreeGridClickEvent;
 import com.vaadin.client.widgets.Grid;
+import com.vaadin.shared.data.HierarchicalDataCommunicatorConstants;
 
 import elemental.json.JsonObject;
 
@@ -27,14 +31,63 @@ import elemental.json.JsonObject;
  * An extension of the Grid widget, which supports displaying of hierarchical
  * data.
  *
- * @see Grid
- *
  * @author Vaadin Ltd
+ * @see Grid
  * @since 8.1
  */
 public class TreeGrid extends Grid<JsonObject> {
 
     /**
+     * Style name prefix for the row's depth in the hierarchy
+     */
+    private String depthStyleNamePrefix;
+
+    /**
+     * Body updater that adds additional style to each row containing depth
+     * information inside the hierarchy.
+     */
+    protected class BodyUpdater extends Grid.BodyUpdater {
+        @Override
+        public void update(Row row, Iterable cellsToUpdate) {
+            super.update(row, cellsToUpdate);
+
+            int rowIndex = row.getRow();
+            TableRowElement rowElement = row.getElement();
+
+            JsonObject rowData = getDataSource().getRow(rowIndex);
+            if (rowData != null) {
+                int depth = (int) rowData.getObject(
+                        HierarchicalDataCommunicatorConstants.ROW_HIERARCHY_DESCRIPTION)
+                        .getNumber(
+                                HierarchicalDataCommunicatorConstants.ROW_DEPTH);
+
+                // Add or replace style name containing depth information
+                String styleToBeReplaced = getFullClassName(
+                        depthStyleNamePrefix, rowElement.getClassName());
+                if (styleToBeReplaced == null) {
+                    rowElement.addClassName(depthStyleNamePrefix + depth);
+                } else {
+                    rowElement.replaceClassName(styleToBeReplaced,
+                            depthStyleNamePrefix + depth);
+                }
+            }
+        }
+
+        private String getFullClassName(String prefix, String classNameList) {
+            int start = classNameList.indexOf(prefix);
+            int end = start + prefix.length();
+            if (start > -1) {
+                while (end < classNameList.length()
+                        && classNameList.charAt(end) != ' ') {
+                    end++;
+                }
+                return classNameList.substring(start, end);
+            }
+            return null;
+        }
+    }
+
+    /**
      * Method for accessing the private {@link Grid#focusCell(int, int)} method
      * from this package
      */
@@ -50,8 +103,21 @@ public class TreeGrid extends Grid<JsonObject> {
         return this.@com.vaadin.client.widgets.Grid::isElementInChildWidget(*)(e);
     }-*/;
 
+
     @Override
     public HandlerRegistration addBodyClickHandler(BodyClickHandler handler) {
         return addHandler(handler, TreeGridClickEvent.TYPE);
     }
+
+    @Override
+    protected EscalatorUpdater createBodyUpdater() {
+        return new BodyUpdater();
+    }
+
+    @Override
+    public void setStylePrimaryName(String style) {
+        super.setStylePrimaryName(style);
+
+        depthStyleNamePrefix = getStylePrimaryName() + "-row-depth-";
+    }
 }