/**
* Copyright (c) 2014 by Brainwy Software Ltda. All Rights Reserved.
* Licensed under the terms of the Eclipse Public License (EPL).
* Please see the license.txt included with this distribution for details.
* Any modifications to this file must keep this entire header intact.
*/
package org.python.pydev.tree;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.DragSourceListener;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetAdapter;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.python.pydev.plugin.PydevPlugin;
import org.python.pydev.shared_core.callbacks.ICallback;
public class EnabledTreeDragReorder {
public static final String DRAG_IMAGE_DATA_KEY = "DRAG_IMAGE";
public static class DragData {
public final String text;
public final String image;
public DragData(String text, String image) {
this.text = text;
this.image = image;
}
public void update(TreeItem item) {
item.setText(text);
if (image != null) {
item.setImage(PydevPlugin.getImageCache().get(image));
item.setData(DRAG_IMAGE_DATA_KEY, image);
}
}
}
/**
* Based on SWT Snippet91.
*/
public static void enableDrag(final Tree tree, final boolean acceptDropInTree,
final ICallback<Object, Object> onDNDFinished) {
Transfer[] types = new Transfer[] { TreeItemDragDataTransfer.getInstance() };
int operations = DND.DROP_MOVE;// | DND.DROP_COPY | DND.DROP_LINK; //Note: disable copy and link.
final DragSource source = new DragSource(tree, operations);
source.setTransfer(types);
final TreeItem[] dragSourceItem = new TreeItem[1];
source.addDragListener(new DragSourceListener() {
@Override
public void dragStart(DragSourceEvent event) {
TreeItem[] selection = tree.getSelection();
if (selection.length > 0 && selection[0].getItemCount() == 0) {
event.doit = true;
dragSourceItem[0] = selection[0];
} else {
event.doit = false;
}
};
@Override
public void dragSetData(DragSourceEvent event) {
TreeItem treeItem = dragSourceItem[0];
if (treeItem != null) {
event.data = new DragData(treeItem.getText(), (String) treeItem.getData(DRAG_IMAGE_DATA_KEY));
}
}
@Override
public void dragFinished(DragSourceEvent event) {
if (event.detail == DND.DROP_MOVE && dragSourceItem[0] != null) {
dragSourceItem[0].dispose();
onDNDFinished.call(null);
}
dragSourceItem[0] = null;
}
});
DropTarget target = new DropTarget(tree, operations);
target.setTransfer(types);
target.addDropListener(new DropTargetAdapter() {
@Override
public void dropAccept(DropTargetEvent event) {
TreeItem item = (TreeItem) event.item;
if (item != null) {
TreeItem parent = item.getParentItem();
if (!acceptDropInTree) {
if (parent == null) {
if (dragSourceItem[0] != null) {
dragSourceItem[0] = null; //Don't dispose of it!
}
}
}
}
}
@Override
public void dragOver(DropTargetEvent event) {
event.feedback = DND.FEEDBACK_EXPAND | DND.FEEDBACK_SCROLL;
event.detail = DND.DROP_NONE; //This is what prevents a drop when it can't happen.
if (event.item != null) {
TreeItem item = (TreeItem) event.item;
if (item.getParentItem() == null && !acceptDropInTree) {
event.feedback = DND.FEEDBACK_NONE;
return;
}
event.detail = DND.DROP_MOVE; //Enable the drop to happen as we have a valid item.
Point pt = tree.getDisplay().map(null, tree, event.x, event.y);
Rectangle bounds = item.getBounds();
if (pt.y < bounds.y + bounds.height / 3) {
event.feedback |= DND.FEEDBACK_INSERT_BEFORE;
} else if (pt.y > bounds.y + 2 * bounds.height / 3) {
event.feedback |= DND.FEEDBACK_INSERT_AFTER;
} else {
event.feedback |= DND.FEEDBACK_SELECT;
}
}
}
@Override
public void drop(DropTargetEvent event) {
System.out.println("dropDone");
if (event.data == null) {
event.detail = DND.DROP_NONE;
return;
}
DragData data = (DragData) event.data;
if (event.item == null) {
TreeItem item = new TreeItem(tree, SWT.NONE);
data.update(item);
} else {
TreeItem item = (TreeItem) event.item;
TreeItem parent = item.getParentItem();
Point pt = tree.getDisplay().map(null, tree, event.x, event.y);
Rectangle bounds = item.getBounds();
if (parent != null) {
TreeItem[] items = parent.getItems();
int index = 0;
for (int i = 0; i < items.length; i++) {
if (items[i] == item) {
index = i;
break;
}
}
if (pt.y < bounds.y + bounds.height / 3) {
TreeItem newItem = new TreeItem(parent, SWT.NONE,
index);
data.update(newItem);
} else if (pt.y > bounds.y + 2 * bounds.height / 3) {
TreeItem newItem = new TreeItem(parent, SWT.NONE,
index + 1);
data.update(newItem);
} else {
TreeItem newItem = new TreeItem(item, SWT.NONE);
data.update(newItem);
}
} else {
if (!acceptDropInTree) {
return;
}
TreeItem[] items = tree.getItems();
int index = 0;
for (int i = 0; i < items.length; i++) {
if (items[i] == item) {
index = i;
break;
}
}
if (pt.y < bounds.y + bounds.height / 3) {
TreeItem newItem = new TreeItem(tree, SWT.NONE,
index);
data.update(newItem);
} else if (pt.y > bounds.y + 2 * bounds.height / 3) {
TreeItem newItem = new TreeItem(tree, SWT.NONE,
index + 1);
data.update(newItem);
} else {
TreeItem newItem = new TreeItem(item, SWT.NONE);
data.update(newItem);
}
}
}
}
});
}
}