org.cloudcoder.app.client.view.CoursesListView.java Source code

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Here is the source code for org.cloudcoder.app.client.view.CoursesListView.java

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// CloudCoder - a web-based pedagogical programming environment
// Copyright (C) 2011-2014, Jaime Spacco <jspacco@knox.edu>
// Copyright (C) 2011-2014, David H. Hovemeyer <david.hovemeyer@gmail.com>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package org.cloudcoder.app.client.view;

import java.util.Arrays;

import org.cloudcoder.app.client.model.Session;
import org.cloudcoder.app.client.model.StatusMessage;
import org.cloudcoder.app.client.page.SessionObserver;
import org.cloudcoder.app.client.rpc.RPC;
import org.cloudcoder.app.shared.model.Course;
import org.cloudcoder.app.shared.model.CourseAndCourseRegistration;
import org.cloudcoder.app.shared.model.CourseListSelection;
import org.cloudcoder.app.shared.model.CourseSelection;
import org.cloudcoder.app.shared.util.Publisher;
import org.cloudcoder.app.shared.util.Subscriber;
import org.cloudcoder.app.shared.util.SubscriptionRegistrar;
import com.google.gwt.core.client.GWT;
import com.google.gwt.user.cellview.client.DataGrid;
import com.google.gwt.user.cellview.client.TextColumn;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.ResizeComposite;
import com.google.gwt.view.client.SelectionChangeEvent;
import com.google.gwt.view.client.SelectionChangeEvent.Handler;
import com.google.gwt.view.client.SingleSelectionModel;

/**
 * @author jankvr
 *
 */
public class CoursesListView extends ResizeComposite implements Subscriber, SessionObserver, IRedisplayable {

    private DataGrid<CourseAndCourseRegistration> grid;
    private Session session;
    private CourseAndCourseRegistration selected;

    public CoursesListView() {

        grid = new DataGrid<CourseAndCourseRegistration>();
        grid.addColumn(new TextColumn<CourseAndCourseRegistration>() {

            @Override
            public String getValue(CourseAndCourseRegistration course) {
                return course.getCourse().getNameAndTitle();
            }

        }, "Course Name");

        grid.addColumn(new TextColumn<CourseAndCourseRegistration>() {

            @Override
            public String getValue(CourseAndCourseRegistration course) {
                return course.getCourse().getTermAndYear().toString();
            }
        }, "Term and year");

        initWidget(grid);
    }

    public CourseAndCourseRegistration getSelectedCourse() {
        return selected;
    }

    @Override
    public void redisplay() {
        CourseAndCourseRegistration[] courseList = session.get(CourseAndCourseRegistration[].class);
        if (courseList != null) {
            GWT.log("CourseListView redisplaying " + courseList.length + " courses");
            displayCourses(courseList);
        }

    }

    protected void displayCourses(CourseAndCourseRegistration[] result) {
        grid.setRowCount(result.length);
        grid.setRowData(Arrays.asList(result));
        grid.setVisibleRange(0, result.length);
    }

    @Override
    public void activate(final Session session, SubscriptionRegistrar subscriptionRegistrar) {
        this.session = session;
        this.session.subscribe(Session.Event.ADDED_OBJECT, this, subscriptionRegistrar);

        final SingleSelectionModel<CourseAndCourseRegistration> selectionModel = new SingleSelectionModel<CourseAndCourseRegistration>();
        selectionModel.addSelectionChangeHandler(new Handler() {

            @Override
            public void onSelectionChange(SelectionChangeEvent event) {
                selected = selectionModel.getSelectedObject();
                session.add(new CourseListSelection(selected));
            }

        });

        grid.setSelectionModel(selectionModel);

        loadCourses();
    }

    @Override
    public void eventOccurred(Object key, Publisher publisher, Object hint) {
        if (key == Session.Event.ADDED_OBJECT && hint instanceof CourseSelection) {
            //page.getSession().add(StatusMessage.information("changed to " + selected.getNameAndTitle()));
            loadCourses();
        }

    }

    public void setEnabled(boolean b) {

    }

    public void loadCourses() {
        RPC.getCoursesAndProblemsService
                .getCourseAndCourseRegistrations(new AsyncCallback<CourseAndCourseRegistration[]>() {

                    @Override
                    public void onFailure(Throwable caught) {
                        session.add(StatusMessage.error("Could not load courses"));
                    }

                    @Override
                    public void onSuccess(CourseAndCourseRegistration[] result) {
                        session.add(result);
                        displayCourses(result);
                    }

                });
    }
}