rabbit.ui.internal.pages.UpdateJob.java Source code

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Here is the source code for rabbit.ui.internal.pages.UpdateJob.java

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/*
 * Copyright 2010 The Rabbit Eclipse Plug-in Project
 * 
 * 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 rabbit.ui.internal.pages;

import rabbit.data.access.IAccessor;
import rabbit.ui.Preference;

import static com.google.common.base.Preconditions.checkNotNull;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.ui.PlatformUI;
import org.joda.time.LocalDate;

import java.util.Collection;

/**
 * An internal update job for updating a page.
 */
public abstract class UpdateJob<T> extends Job {

    private final TreeViewer viewer;
    private final Preference pref;
    private final IAccessor<T> accessor;

    /**
     * Constructs a new job.
     * 
     * @param viewer The tree viewer to be updated.
     * @param pref The preference for getting the data.
     * @param accessor The data accessor for getting the data from.
     * @throws NullPointerException If any of the arguments are null.
     */
    public UpdateJob(TreeViewer viewer, Preference pref, IAccessor<T> accessor) {
        super("Updating Rabbit View...");
        this.viewer = checkNotNull(viewer);
        this.pref = checkNotNull(pref);
        this.accessor = checkNotNull(accessor);
    }

    @Override
    protected IStatus run(IProgressMonitor monitor) {
        if (monitor.isCanceled()) {
            return Status.CANCEL_STATUS;
        } else {
            monitor.beginTask("Updating page...", 2);
        }

        LocalDate start = LocalDate.fromCalendarFields(pref.getStartDate());
        LocalDate end = LocalDate.fromCalendarFields(pref.getEndDate());
        final Collection<T> data = accessor.getData(start, end);
        monitor.worked(1);

        if (monitor.isCanceled()) {
            return Status.CANCEL_STATUS;
        }

        PlatformUI.getWorkbench().getDisplay().syncExec(new Runnable() {
            @Override
            public void run() {
                viewer.getTree().setRedraw(false);
                TreePath[] expandedPaths = viewer.getExpandedTreePaths();
                viewer.setInput(getInput(data));
                viewer.setExpandedTreePaths(expandedPaths);
                viewer.getTree().setRedraw(true);
            }
        });
        monitor.worked(1);
        monitor.done();
        return Status.OK_STATUS;
    }

    /**
     * When data is received from the data accessor, this method is called to get
     * the input object for the viewer.
     * 
     * @param data The data received from the data accessor.
     * @return The input object for the viewer.
     */
    protected abstract Object getInput(Collection<T> data);
}