com.mycompany.client.MyApplication2.java Source code

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Here is the source code for com.mycompany.client.MyApplication2.java

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/*
 * Copyright 2009 Fred Sauer
 * 
 * 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.mycompany.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Random;
import com.google.gwt.user.client.ui.AbsolutePanel;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;

import com.allen_sauer.gwt.dnd.client.PickupDragController;
import com.allen_sauer.gwt.dnd.client.drop.AbsolutePositionDropController;
import com.allen_sauer.gwt.dnd.client.drop.DropController;
import com.allen_sauer.gwt.dnd.client.util.DOMUtil;

/**
 * Illustrative example.
 */
public class MyApplication2 implements EntryPoint {

    /**
     * Main entry point method.
     */
    @Override
    public void onModuleLoad() {
        // set uncaught exception handler
        GWT.setUncaughtExceptionHandler(new GWT.UncaughtExceptionHandler() {

            @Override
            public void onUncaughtException(Throwable throwable) {
                String text = "Uncaught exception: ";
                while (throwable != null) {
                    StackTraceElement[] stackTraceElements = throwable.getStackTrace();
                    text += throwable.toString() + "\n";
                    for (StackTraceElement element : stackTraceElements) {
                        text += "    at " + element + "\n";
                    }
                    throwable = throwable.getCause();
                    if (throwable != null) {
                        text += "Caused by: ";
                    }
                }
                DialogBox dialogBox = new DialogBox(true);
                DOM.setStyleAttribute(dialogBox.getElement(), "backgroundColor", "#ABCDEF");
                System.err.print(text);
                text = text.replaceAll(" ", " ");
                dialogBox.setHTML("<pre>" + text + "</pre>");
                dialogBox.center();
            }
        });

        // use a deferred command so that the handler catches onModuleLoad2() exceptions
        Scheduler.get().scheduleDeferred(new ScheduledCommand() {
            @Override
            public void execute() {
                onModuleLoad2();
            }
        });
    }

    /**
     * Deferred initialization method, called from {@link #onModuleLoad()}.
     */
    private void onModuleLoad2() {
        // Create a boundary panel to constrain all drag operations
        AbsolutePanel boundaryPanel = new AbsolutePanel();
        boundaryPanel.setPixelSize(400, 300);
        boundaryPanel.addStyleName("getting-started-blue");

        // Create a drop target on which we can drop labels
        AbsolutePanel targetPanel = new AbsolutePanel();
        targetPanel.setPixelSize(300, 200);
        targetPanel.addStyleName("getting-started-blue");

        // Add both panels to the root panel
        RootPanel.get().add(boundaryPanel);
        boundaryPanel.add(targetPanel, 40, 40);

        // Create a DragController for each logical area where a set of draggable
        // widgets and drop targets will be allowed to interact with one another.
        PickupDragController dragController = new PickupDragController(boundaryPanel, true);

        // Positioner is always constrained to the boundary panel
        // Use 'true' to also constrain the draggable or drag proxy to the boundary panel
        dragController.setBehaviorConstrainedToBoundaryPanel(false);

        // Allow multiple widgets to be selected at once using CTRL-click
        dragController.setBehaviorMultipleSelection(true);

        // create a DropController for each drop target on which draggable widgets
        // can be dropped
        DropController dropController = new AbsolutePositionDropController(targetPanel);

        // Don't forget to register each DropController with a DragController
        dragController.registerDropController(dropController);

        // create a few randomly placed draggable labels
        for (int i = 1; i <= 5; i++) {
            // create a label and give it style
            Label label = new Label("Label #" + i, false);
            label.addStyleName("getting-started-label");

            // add it to the DOM so that offset width/height becomes available
            targetPanel.add(label, 0, 0);

            // determine random label location within target panel
            int left = Random.nextInt(DOMUtil.getClientWidth(targetPanel.getElement()) - label.getOffsetWidth());
            int top = Random.nextInt(DOMUtil.getClientHeight(targetPanel.getElement()) - label.getOffsetHeight());

            // move the label
            targetPanel.setWidgetPosition(label, left, top);

            // make the label draggable
            dragController.makeDraggable(label);
        }
    }
}