com.google.gwt.gears.sample.managedresourcestoredemo.client.ManagedResourceStoreDemo.java Source code

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Here is the source code for com.google.gwt.gears.sample.managedresourcestoredemo.client.ManagedResourceStoreDemo.java

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/*
 * Copyright 2008 Google Inc.
 *
 * 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.google.gwt.gears.sample.managedresourcestoredemo.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.gears.client.Factory;
import com.google.gwt.gears.client.GearsException;
import com.google.gwt.gears.client.localserver.LocalServer;
import com.google.gwt.gears.client.localserver.ManagedResourceStore;
import com.google.gwt.gears.offline.client.Offline;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;

/**
 * Sample application demonstrating how to use the {@link ManagedResourceStore}
 * class provided by the {@link Offline} support.
 */
public class ManagedResourceStoreDemo implements EntryPoint {

    private final Button createManagedResourceStoreButton = new Button("Go Offline");

    private final Button removeManagedResourceStoreButton = new Button("Remove Store");

    private final Label statusLabel = new Label();

    public void onModuleLoad() {
        HorizontalPanel hpanel = new HorizontalPanel();
        hpanel.setSpacing(10);
        RootPanel.get("demo").add(hpanel);

        hpanel.add(createManagedResourceStoreButton);

        // See if we're already running from a ManagedResourceStore
        try {
            LocalServer server = Factory.getInstance().createLocalServer();

            // This check to see if the host page can be served locally
            if (server.canServeLocally(Window.Location.getPath())) {
                createManagedResourceStoreButton.setText("Refresh Manifest");

                // Give the user an opportunity to delete the MRS
                hpanel.add(removeManagedResourceStoreButton);
            }
        } catch (GearsException e) {
            // Gears probably isn't available (e.g. hosted mode)
        }

        createManagedResourceStoreButton.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                statusLabel.setText("Starting update");
                createManagedResourceStore();
            }
        });

        removeManagedResourceStoreButton.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                try {
                    LocalServer server = Factory.getInstance().createLocalServer();
                    ManagedResourceStore store = Offline.getManagedResourceStore();
                    server.removeManagedStore(store.getName());
                    statusLabel.setText("Removed ManagedResourceStore.  Press Refresh to see Online version.");
                    createManagedResourceStoreButton.setEnabled(false);
                    removeManagedResourceStoreButton.setEnabled(false);
                } catch (GearsException e) {
                    statusLabel.setText(e.getMessage());
                }
            }
        });

        hpanel.add(statusLabel);
    }

    private void createManagedResourceStore() {
        try {
            final ManagedResourceStore managedResourceStore = Offline.getManagedResourceStore();

            new Timer() {
                final String oldVersion = managedResourceStore.getCurrentVersion();

                @Override
                public void run() {
                    switch (managedResourceStore.getUpdateStatus()) {
                    case ManagedResourceStore.UPDATE_OK:
                        if (managedResourceStore.getCurrentVersion().equals(oldVersion)) {
                            statusLabel.setText("No update was available.");
                        } else {
                            statusLabel.setText("Update to " + managedResourceStore.getCurrentVersion()
                                    + " was completed.  Please refresh the page to see the changes.");
                            createManagedResourceStoreButton.setEnabled(false);
                        }
                        break;
                    case ManagedResourceStore.UPDATE_CHECKING:
                    case ManagedResourceStore.UPDATE_DOWNLOADING:
                        statusLabel.setText("Transferring data");
                        schedule(500);
                        break;
                    case ManagedResourceStore.UPDATE_FAILED:
                        statusLabel.setText(managedResourceStore.getLastErrorMessage());
                        break;
                    }
                }
            }.schedule(500);

        } catch (GearsException e) {
            statusLabel.setText("");
            Window.alert(e.getMessage());
        }
    }
}