/* * Smart GWT (GWT for SmartClient) * Copyright 2008 and beyond, Isomorphic Software, Inc. * * Smart GWT is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License version 3 * as published by the Free Software Foundation. Smart GWT is also * available under typical commercial license terms - see * http://smartclient.com/license * * This software is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ import com.google.gwt.event.dom.client.LoadEvent; import com.google.gwt.event.dom.client.LoadHandler; import com.google.gwt.user.client.ui.Image; import com.google.gwt.user.client.ui.RootLayoutPanel; import com.smartgwt.client.types.Cursor; import com.smartgwt.client.types.DragAppearance; import com.smartgwt.client.types.ImageStyle; import com.smartgwt.client.types.Overflow; import com.smartgwt.client.util.EventHandler; import com.smartgwt.client.widgets.Canvas; import com.smartgwt.client.widgets.Img; import com.smartgwt.client.widgets.events.DragMoveEvent; import com.smartgwt.client.widgets.events.DragMoveHandler; import com.smartgwt.client.widgets.events.DragStartEvent; import com.smartgwt.client.widgets.events.DragStartHandler; import com.google.gwt.core.client.EntryPoint; public class DragPanSample implements EntryPoint { public static class DragPanSampleImg extends Img { private static final String IMG_URL = Canvas.getImgURL("[APPIMG]other/cpu.jpg"); private static boolean loaded = false; private int startScrollLeft; private int startScrollTop; public DragPanSampleImg() { setWidth(200); setHeight(200); if (loaded) setSrc(IMG_URL); setLeft(50); setTop(50); setOverflow(Overflow.HIDDEN); setShowEdges(true); setPadding(20); setImageType(ImageStyle.NORMAL); setCanDrag(true); setCursor(Cursor.ALL_SCROLL); setDragAppearance(DragAppearance.NONE); addDragStartHandler(new DragStartHandler() { public void onDragStart(DragStartEvent event) { startScrollLeft = getScrollLeft(); startScrollTop = getScrollTop(); } }); addDragMoveHandler(new DragMoveHandler() { public void onDragMove(DragMoveEvent event) { int left = startScrollLeft - EventHandler.getX() + EventHandler.getMouseDownX(); int top = startScrollTop - EventHandler.getY() + EventHandler.getMouseDownY(); scrollTo(left,top); } }); if (!loaded) { final Image image = new Image(); image.addLoadHandler(new LoadHandler() { @Override public void onLoad(LoadEvent event) { loaded = true; setSrc(IMG_URL); } }); image.setVisible(false); // Need to attach the Image to the widget tree in order for the load handler // to fire. RootLayoutPanel.get().add(image); image.setUrl(IMG_URL); } } } @Override public void onModuleLoad() { new DragPanSampleImg().draw(); } }