package com.vaadin.tests.dd;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.event.dom.client.MouseDownEvent;
import com.google.gwt.event.dom.client.MouseDownHandler;
import com.google.gwt.event.dom.client.MouseMoveEvent;
import com.google.gwt.event.dom.client.MouseMoveHandler;
import com.google.gwt.event.dom.client.MouseOutEvent;
import com.google.gwt.event.dom.client.MouseOutHandler;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.ui.dd.VDragAndDropManager;
import com.vaadin.client.ui.dd.VTransferable;
/**
* Example code to implement Component that has something to drag.
*/
public class VMyDragSource extends Composite implements MouseDownHandler,
MouseMoveHandler, MouseOutHandler {
private boolean mouseDown;
private MouseDownEvent mDownEvent;
@SuppressWarnings("unused")
public VMyDragSource() {
FlowPanel fp = new FlowPanel();
initWidget(fp);
HTML html = new HTML("DragThis");
fp.add(html);
html.addMouseDownHandler(this);
html.addMouseMoveHandler(this);
html.addMouseOutHandler(this);
}
/*
* Below a sophisticated drag start implementation. Drag event is started if
* mouse is moved 5 pixels with left mouse key down.
*/
@Override
public void onMouseDown(MouseDownEvent event) {
if (event.getNativeButton() == NativeEvent.BUTTON_LEFT) {
mouseDown = true;
mDownEvent = event;
}
}
@Override
public void onMouseMove(MouseMoveEvent event) {
if (mouseDown) {
int deltaX = Math.abs(mDownEvent.getClientX() - event.getClientX());
int deltaY = Math.abs(mDownEvent.getClientY() - event.getClientY());
if (deltaX > 5 || deltaY > 5) {
// Start the drag and drop operation
// create Transferable, that contains the payload
VTransferable transferable = new VTransferable();
transferable.setData("Text", "myPayload");
// Tell DragAndDropManager to start a drag and drop operation.
// Also let it handle all events (last parameter true). Could
// also do all event handling here too.
VDragAndDropManager.get().startDrag(transferable,
mDownEvent.getNativeEvent(), true);
mouseDown = false;
mDownEvent = null;
}
}
}
@Override
public void onMouseOut(MouseOutEvent event) {
mouseDown = false;
mDownEvent = null;
}
public Widget getWidgetForPaintable() {
return this;
}
}