Moves DragAndDropHandler from Grid to separate class

Includes the class in the widgets package build.

Change-Id: If72430d3005f7af0029070a72976853baac195a1

2 files changed, 242 insertions, 223 deletions

diff --git a/client/src/com/vaadin/client/ui/dd/DragAndDropHandler.java b/client/src/com/vaadin/client/ui/dd/DragAndDropHandler.java
new file mode 100644
index 0000000000..61fdd2850e
--- /dev/null
+++ b/client/src/com/vaadin/client/ui/dd/DragAndDropHandler.java
@@ -0,0 +1,241 @@
+/*
+ * Copyright 2000-2014 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.ui.dd;
+
+import com.google.gwt.dom.client.NativeEvent;
+import com.google.gwt.event.dom.client.KeyCodes;
+import com.google.gwt.event.shared.HandlerRegistration;
+import com.google.gwt.user.client.Event;
+import com.google.gwt.user.client.Event.NativePreviewEvent;
+import com.google.gwt.user.client.Event.NativePreviewHandler;
+import com.google.gwt.user.client.ui.RootPanel;
+import com.vaadin.client.WidgetUtil;
+import com.vaadin.client.widgets.Grid;
+
+/**
+ * A simple event handler for elements that can be drag and dropped. Properly
+ * handles drag start, cancel and end. For example, used in {@link Grid} column
+ * header reordering.
+ * <p>
+ * The showing of the dragged element, drag hints and reacting to drop/cancel is
+ * delegated to {@link DragAndDropCallback} implementation.
+ * 
+ * @since
+ * @author Vaadin Ltd
+ */
+public class DragAndDropHandler {
+
+    /**
+     * Callback interface for drag and drop.
+     */
+    public interface DragAndDropCallback {
+        /**
+         * Called when the drag has started. The drag can be canceled by
+         * returning {@code false}.
+         * 
+         * @param startEvent
+         *            the original event that started the drag
+         * @return {@code true} if the drag is OK to start, {@code false} to
+         *         cancel
+         */
+        boolean onDragStart(NativeEvent startEvent);
+
+        /**
+         * Called on drag.
+         * 
+         * @param event
+         *            the event related to the drag
+         */
+        void onDragUpdate(NativePreviewEvent event);
+
+        /**
+         * Called after the has ended on a drop or cancel.
+         */
+        void onDragEnd();
+
+        /**
+         * Called when the drag has ended on a drop.
+         */
+        void onDrop();
+
+        /**
+         * Called when the drag has been canceled.
+         */
+        void onDragCancel();
+    }
+
+    private HandlerRegistration dragStartNativePreviewHandlerRegistration;
+    private HandlerRegistration dragHandlerRegistration;
+
+    private boolean dragging;
+
+    private DragAndDropCallback callback;
+
+    private final NativePreviewHandler dragHandler = new NativePreviewHandler() {
+
+        @Override
+        public void onPreviewNativeEvent(NativePreviewEvent event) {
+            if (dragging) {
+                final int typeInt = event.getTypeInt();
+                switch (typeInt) {
+                case Event.ONKEYDOWN:
+                    int keyCode = event.getNativeEvent().getKeyCode();
+                    if (keyCode == KeyCodes.KEY_ESCAPE) {
+                        // end drag if ESC is hit
+                        cancelDrag(event);
+                    }
+                    break;
+                case Event.ONMOUSEMOVE:
+                case Event.ONTOUCHMOVE:
+                    callback.onDragUpdate(event);
+                    // prevent text selection on IE
+                    event.getNativeEvent().preventDefault();
+                    break;
+                case Event.ONTOUCHCANCEL:
+                    cancelDrag(event);
+                    break;
+                case Event.ONTOUCHEND:
+                    /* Avoid simulated event on drag end */
+                    event.getNativeEvent().preventDefault();
+                    //$FALL-THROUGH$
+                case Event.ONMOUSEUP:
+                    callback.onDragUpdate(event);
+                    callback.onDrop();
+                    stopDrag();
+                    event.cancel();
+                    break;
+                default:
+                    break;
+                }
+            } else {
+                stopDrag();
+            }
+        }
+
+    };
+
+    /**
+     * This method can be called to trigger drag and drop on any grid element
+     * that can be dragged and dropped.
+     * 
+     * @param dragStartingEvent
+     *            the drag triggering event, usually a {@link Event#ONMOUSEDOWN}
+     *            or {@link Event#ONTOUCHSTART} event on the draggable element
+     * 
+     * @param callback
+     *            the callback that will handle actual drag and drop related
+     *            operations
+     */
+    public void onDragStartOnDraggableElement(
+            final NativeEvent dragStartingEvent,
+            final DragAndDropCallback callback) {
+        dragStartNativePreviewHandlerRegistration = Event
+                .addNativePreviewHandler(new NativePreviewHandler() {
+
+                    private int startX = WidgetUtil
+                            .getTouchOrMouseClientX(dragStartingEvent);
+                    private int startY = WidgetUtil
+                            .getTouchOrMouseClientY(dragStartingEvent);
+
+                    @Override
+                    public void onPreviewNativeEvent(NativePreviewEvent event) {
+                        final int typeInt = event.getTypeInt();
+                        if (typeInt == -1
+                                && event.getNativeEvent().getType()
+                                        .toLowerCase().contains("pointer")) {
+                            /*
+                             * Ignore PointerEvents since IE10 and IE11 send
+                             * also MouseEvents for backwards compatibility.
+                             */
+                            return;
+                        }
+                        switch (typeInt) {
+                        case Event.ONMOUSEOVER:
+                        case Event.ONMOUSEOUT:
+                            // we don't care
+                            break;
+                        case Event.ONKEYDOWN:
+                        case Event.ONKEYPRESS:
+                        case Event.ONKEYUP:
+                        case Event.ONBLUR:
+                        case Event.ONFOCUS:
+                            // don't cancel possible drag start
+                            break;
+                        case Event.ONMOUSEMOVE:
+                        case Event.ONTOUCHMOVE:
+                            int currentX = WidgetUtil
+                                    .getTouchOrMouseClientX(event
+                                            .getNativeEvent());
+                            int currentY = WidgetUtil
+                                    .getTouchOrMouseClientY(event
+                                            .getNativeEvent());
+                            if (Math.abs(startX - currentX) > 3
+                                    || Math.abs(startY - currentY) > 3) {
+                                removeNativePreviewHandlerRegistration();
+                                startDrag(dragStartingEvent, event, callback);
+                            }
+                            break;
+                        default:
+                            // on any other events, clean up this preview
+                            // listener
+                            removeNativePreviewHandlerRegistration();
+                            break;
+                        }
+                    }
+                });
+    }
+
+    private void startDrag(NativeEvent startEvent,
+            NativePreviewEvent triggerEvent, DragAndDropCallback callback) {
+        if (callback.onDragStart(startEvent)) {
+            dragging = true;
+            // just capture something to prevent text selection in IE
+            Event.setCapture(RootPanel.getBodyElement());
+            this.callback = callback;
+            dragHandlerRegistration = Event
+                    .addNativePreviewHandler(dragHandler);
+            callback.onDragUpdate(triggerEvent);
+        }
+    }
+
+    private void stopDrag() {
+        dragging = false;
+        if (dragHandlerRegistration != null) {
+            dragHandlerRegistration.removeHandler();
+            dragHandlerRegistration = null;
+        }
+        Event.releaseCapture(RootPanel.getBodyElement());
+        if (callback != null) {
+            callback.onDragEnd();
+            callback = null;
+        }
+    }
+
+    private void cancelDrag(NativePreviewEvent event) {
+        callback.onDragCancel();
+        callback.onDragEnd();
+        stopDrag();
+        event.cancel();
+        event.getNativeEvent().preventDefault();
+    }
+
+    private void removeNativePreviewHandlerRegistration() {
+        if (dragStartNativePreviewHandlerRegistration != null) {
+            dragStartNativePreviewHandlerRegistration.removeHandler();
+            dragStartNativePreviewHandlerRegistration = null;
+        }
+    }
+}
diff --git a/client/src/com/vaadin/client/widgets/Grid.java b/client/src/com/vaadin/client/widgets/Grid.java
index 9fcdd20296..dad6f0fcfc 100644
--- a/client/src/com/vaadin/client/widgets/Grid.java
+++ b/client/src/com/vaadin/client/widgets/Grid.java
@@ -67,7 +67,6 @@ import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.HasEnabled;
 import com.google.gwt.user.client.ui.HasWidgets;
 import com.google.gwt.user.client.ui.ResizeComposite;
-import com.google.gwt.user.client.ui.RootPanel;
 import com.google.gwt.user.client.ui.ToggleButton;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.BrowserInfo;
@@ -79,6 +78,7 @@ import com.vaadin.client.renderers.ComplexRenderer;
 import com.vaadin.client.renderers.Renderer;
 import com.vaadin.client.renderers.WidgetRenderer;
 import com.vaadin.client.ui.SubPartAware;
+import com.vaadin.client.ui.dd.DragAndDropHandler;
 import com.vaadin.client.widget.escalator.Cell;
 import com.vaadin.client.widget.escalator.ColumnConfiguration;
 import com.vaadin.client.widget.escalator.EscalatorUpdater;
@@ -211,228 +211,6 @@ public class Grid<T> extends ResizeComposite implements
     }
 
     /**
-     * A simple event handler for elements that can be drag and dropped. Loosely
-     * based on {@link com.vaadin.client.ui.dd.VDragAndDropManager}, but without
-     * any Vaadin related stuff. Properly handles drag start, cancel and end.
-     * For example, used in {@link Grid} column header reordering.
-     * <p>
-     * The showing of the dragged element, drag hints and reacting to
-     * drop/cancel is delegated to {@link DragAndDropCallback} implementation.
-     * 
-     * @author Vaadin Ltd
-     */
-    private static class DragAndDropHandler {
-
-        /**
-         * Callback interface for drag and drop.
-         */
-        public interface DragAndDropCallback {
-            /**
-             * Called when the drag has started. The drag can be canceled by
-             * returning {@code false}.
-             * 
-             * @param startEvent
-             *            the original event that started the drag
-             * @return {@code true} if the drag is OK to start, {@code false} to
-             *         cancel
-             */
-            boolean onDragStart(NativeEvent startEvent);
-
-            /**
-             * Called on drag.
-             * 
-             * @param event
-             *            the event related to the drag
-             */
-            void onDragUpdate(NativePreviewEvent event);
-
-            /**
-             * Called after the has ended on a drop or cancel.
-             */
-            void onDragEnd();
-
-            /**
-             * Called when the drag has ended on a drop.
-             */
-            void onDrop();
-
-            /**
-             * Called when the drag has been canceled.
-             */
-            void onDragCancel();
-        }
-
-        private HandlerRegistration dragStartNativePreviewHandlerRegistration;
-        private HandlerRegistration dragHandlerRegistration;
-
-        private boolean dragging;
-
-        private DragAndDropCallback callback;
-
-        private final NativePreviewHandler dragHandler = new NativePreviewHandler() {
-
-            @Override
-            public void onPreviewNativeEvent(NativePreviewEvent event) {
-                if (dragging) {
-                    final int typeInt = event.getTypeInt();
-                    switch (typeInt) {
-                    case Event.ONKEYDOWN:
-                        int keyCode = event.getNativeEvent().getKeyCode();
-                        if (keyCode == KeyCodes.KEY_ESCAPE) {
-                            // end drag if ESC is hit
-                            cancelDrag(event);
-                        }
-                        break;
-                    case Event.ONMOUSEMOVE:
-                    case Event.ONTOUCHMOVE:
-                        callback.onDragUpdate(event);
-                        // prevent text selection on IE
-                        event.getNativeEvent().preventDefault();
-                        break;
-                    case Event.ONTOUCHCANCEL:
-                        cancelDrag(event);
-                        break;
-                    case Event.ONTOUCHEND:
-                        /* Avoid simulated event on drag end */
-                        event.getNativeEvent().preventDefault();
-                        //$FALL-THROUGH$
-                    case Event.ONMOUSEUP:
-                        callback.onDragUpdate(event);
-                        callback.onDrop();
-                        stopDrag();
-                        event.cancel();
-                        break;
-                    default:
-                        break;
-                    }
-                } else {
-                    stopDrag();
-                }
-            }
-
-        };
-
-        private static Logger getLogger() {
-            return Logger.getLogger(DragAndDropHandler.class.getName());
-        }
-
-        /**
-         * This method can be called to trigger drag and drop on any grid
-         * element that can be dragged and dropped.
-         * 
-         * @param dragStartingEvent
-         *            the drag triggering event, usually a
-         *            {@link Event#ONMOUSEDOWN} or {@link Event#ONTOUCHSTART}
-         *            event on the draggable element
-         * 
-         * @param callback
-         *            the callback that will handle actual drag and drop related
-         *            operations
-         */
-        public void onDragStartOnDraggableElement(
-                final NativeEvent dragStartingEvent,
-                final DragAndDropCallback callback) {
-            dragStartNativePreviewHandlerRegistration = Event
-                    .addNativePreviewHandler(new NativePreviewHandler() {
-
-                        private int startX = WidgetUtil
-                                .getTouchOrMouseClientX(dragStartingEvent);
-                        private int startY = WidgetUtil
-                                .getTouchOrMouseClientY(dragStartingEvent);
-
-                        @Override
-                        public void onPreviewNativeEvent(
-                                NativePreviewEvent event) {
-                            final int typeInt = event.getTypeInt();
-                            if (typeInt == -1
-                                    && event.getNativeEvent().getType()
-                                            .toLowerCase().contains("pointer")) {
-                                /*
-                                 * Ignore PointerEvents since IE10 and IE11 send
-                                 * also MouseEvents for backwards compatibility.
-                                 */
-                                return;
-                            }
-                            switch (typeInt) {
-                            case Event.ONMOUSEOVER:
-                            case Event.ONMOUSEOUT:
-                                // we don't care
-                                break;
-                            case Event.ONKEYDOWN:
-                            case Event.ONKEYPRESS:
-                            case Event.ONKEYUP:
-                            case Event.ONBLUR:
-                            case Event.ONFOCUS:
-                                // don't cancel possible drag start
-                                break;
-                            case Event.ONMOUSEMOVE:
-                            case Event.ONTOUCHMOVE:
-                                int currentX = WidgetUtil
-                                        .getTouchOrMouseClientX(event
-                                                .getNativeEvent());
-                                int currentY = WidgetUtil
-                                        .getTouchOrMouseClientY(event
-                                                .getNativeEvent());
-                                if (Math.abs(startX - currentX) > 3
-                                        || Math.abs(startY - currentY) > 3) {
-                                    removeNativePreviewHandlerRegistration();
-                                    startDrag(dragStartingEvent, event,
-                                            callback);
-                                }
-                                break;
-                            default:
-                                // on any other events, clean up this preview
-                                // listener
-                                removeNativePreviewHandlerRegistration();
-                                break;
-                            }
-                        }
-                    });
-        }
-
-        private void startDrag(NativeEvent startEvent,
-                NativePreviewEvent triggerEvent, DragAndDropCallback callback) {
-            if (callback.onDragStart(startEvent)) {
-                dragging = true;
-                // just capture something to prevent text selection in IE
-                Event.setCapture(RootPanel.getBodyElement());
-                this.callback = callback;
-                dragHandlerRegistration = Event
-                        .addNativePreviewHandler(dragHandler);
-                callback.onDragUpdate(triggerEvent);
-            }
-        }
-
-        private void stopDrag() {
-            dragging = false;
-            if (dragHandlerRegistration != null) {
-                dragHandlerRegistration.removeHandler();
-                dragHandlerRegistration = null;
-            }
-            Event.releaseCapture(RootPanel.getBodyElement());
-            if (callback != null) {
-                callback.onDragEnd();
-                callback = null;
-            }
-        }
-
-        private void cancelDrag(NativePreviewEvent event) {
-            callback.onDragCancel();
-            callback.onDragEnd();
-            stopDrag();
-            event.cancel();
-            event.getNativeEvent().preventDefault();
-        }
-
-        private void removeNativePreviewHandlerRegistration() {
-            if (dragStartNativePreviewHandlerRegistration != null) {
-                dragStartNativePreviewHandlerRegistration.removeHandler();
-                dragStartNativePreviewHandlerRegistration = null;
-            }
-        }
-    }
-
-    /**
      * Abstract base class for Grid header and footer sections.
      * 
      * @param <ROWTYPE>