/*
* Ext GWT 2.2.4 - Ext for GWT
* Copyright(c) 2007-2010, Ext JS, LLC.
* licensing@extjs.com
*
* http://extjs.com/license
*/
package com.extjs.gxt.ui.client.dnd;
import java.util.List;
import com.extjs.gxt.ui.client.core.El;
import com.extjs.gxt.ui.client.data.ModelData;
import com.extjs.gxt.ui.client.dnd.DND.Feedback;
import com.extjs.gxt.ui.client.event.DNDEvent;
import com.extjs.gxt.ui.client.util.Rectangle;
import com.extjs.gxt.ui.client.widget.grid.Grid;
import com.google.gwt.user.client.Element;
/**
* A <code>DropTarget</code> implementation for Grids. Supports both inserts and
* appends, specified using
* {@link #setOperation(com.extjs.gxt.ui.client.dnd.DND.Operation)}.
* <p />
* Supported drag data:
* <ul>
* <li>A single ModelData instance.</li>
* <li>A List of ModelData instances.</li>
* <li>A List of TreeStoreModel instances (children are ignored).
* </ul>
*/
public class GridDropTarget extends DropTarget {
protected ModelData activeItem;
protected Grid<ModelData> grid;
protected int insertIndex;
boolean before;
private boolean autoScroll = true;
private ScrollSupport scrollSupport;
/**
* Creates a new drop target instance.
*
* @param grid the target grid
*/
@SuppressWarnings({"unchecked", "rawtypes"})
public GridDropTarget(Grid grid) {
super(grid);
this.grid = grid;
}
/**
* Returns the target grid component.
*
* @return the grid
*/
public Grid<ModelData> getGrid() {
return grid;
}
/**
* Returns true if auto scroll is enabled (defaults to true).
*
* @return true if auto scroll enabled
*/
public boolean isAutoScroll() {
return autoScroll;
}
/**
* True to automatically scroll the tree when the user hovers over the top and
* bottom of the tree grid (defaults to true).
*
* @see ScrollSupport
*
* @param autoScroll true to enable auto scroll
*/
public void setAutoScroll(boolean autoScroll) {
this.autoScroll = autoScroll;
}
@Override
protected void onDragCancelled(DNDEvent event) {
super.onDragCancelled(event);
if (autoScroll) {
scrollSupport.stop();
}
}
@Override
protected void onDragDrop(DNDEvent e) {
super.onDragDrop(e);
Object data = e.getData();
List<ModelData> models = prepareDropData(data, true);
if (models.size() > 0) {
if (feedback == Feedback.APPEND) {
grid.getStore().add(models);
} else {
grid.getStore().insert(models, insertIndex);
}
}
insertIndex = -1;
activeItem = null;
if (autoScroll) {
scrollSupport.stop();
}
}
@Override
protected void onDragEnter(DNDEvent e) {
super.onDragEnter(e);
e.setCancelled(false);
e.getStatus().setStatus(true);
if (autoScroll) {
if (scrollSupport == null) {
scrollSupport = new ScrollSupport(grid.getView().getScroller());
} else if (scrollSupport.getScrollElement() == null) {
scrollSupport.setScrollElement(grid.getView().getScroller());
}
scrollSupport.start();
}
}
@Override
protected void onDragFail(DNDEvent event) {
super.onDragFail(event);
if (autoScroll) {
scrollSupport.stop();
}
}
@Override
protected void onDragLeave(DNDEvent e) {
super.onDragLeave(e);
if (autoScroll) {
scrollSupport.stop();
}
}
@Override
protected void onDragMove(DNDEvent event) {
if (!event.within(grid.getView().getBody().dom)) {
event.setCancelled(true);
event.getStatus().setStatus(false);
return;
}
event.setCancelled(false);
event.getStatus().setStatus(true);
}
@Override
protected void showFeedback(DNDEvent event) {
event.getStatus().setStatus(true);
if (feedback == Feedback.INSERT) {
Element row = grid.getView().findRow(event.getTarget()).cast();
if (row == null && grid.getStore().getCount() > 0) {
row = grid.getView().getRow(grid.getStore().getCount() - 1).cast();
}
if (row != null) {
int height = row.getOffsetHeight();
int mid = height / 2;
mid += row.getAbsoluteTop();
int y = event.getClientY();
before = y < mid;
int idx = grid.getView().findRowIndex(row);
activeItem = grid.getStore().getAt(idx);
insertIndex = adjustIndex(event, idx);
showInsert(event, row);
} else {
insertIndex = 0;
}
}
}
private int adjustIndex(DNDEvent event, int index) {
Object data = event.getData();
int i = index;
List<ModelData> models = prepareDropData(data, true);
for (ModelData m : models) {
int idx = grid.getStore().indexOf(m);
if (idx > -1 && (before ? idx < index : idx <= index)) {
i--;
}
}
return before ? i : i + 1;
}
private void showInsert(DNDEvent event, Element row) {
Insert insert = Insert.get();
insert.show(row);
Rectangle rect = El.fly(row).getBounds();
int y = !before ? (rect.y + rect.height - 4) : rect.y - 2;
insert.el().setBounds(rect.x, y, rect.width, 6);
}
}