com.google.gdt.eclipse.suite.ProjectMigrator.java Source code

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Here is the source code for com.google.gdt.eclipse.suite.ProjectMigrator.java

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/*******************************************************************************
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * 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.gdt.eclipse.suite;

import com.google.appengine.eclipse.core.nature.GaeNature;
import com.google.gdt.eclipse.core.natures.NatureUtils;
import com.google.gdt.eclipse.suite.launch.processors.DefaultWorkingDirectoryMigrator;
import com.google.gdt.eclipse.suite.launch.processors.LaunchConfigAffectingChangesListener;
import com.google.gdt.eclipse.suite.preferences.GdtPreferences;
import com.google.gwt.eclipse.core.nature.GWTNature;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceChangeEvent;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.ResourcesPlugin;

/**
 * Runs migration logic on projects.
 */
public class ProjectMigrator {

    public static final int CURRENT_VERSION = 4;

    /**
     * Scans projects in workspace for those that have not been migrated to the
     * latest version.
     */
    public void migrate() {
        boolean closedProjectsInWorkspace = false;

        // Attempt to migrate all projects
        IWorkspace workspace = ResourcesPlugin.getWorkspace();
        for (IProject project : workspace.getRoot().getProjects()) {
            if (project.isOpen()) {
                safelyMigrateIfVersionChanged(project);
            } else {
                closedProjectsInWorkspace = true;
            }
        }

        // Add listeners for all closed projects, so we can rebuild them, too,
        // when they're opened (but only if they are Google projects).
        if (closedProjectsInWorkspace) {
            workspace.addResourceChangeListener(new IResourceChangeListener() {
                public void resourceChanged(IResourceChangeEvent event) {
                    IResourceDelta delta = event.getDelta();
                    if (delta != null) {
                        // Find any project-level changes
                        IResourceDelta[] projectDeltas = delta.getAffectedChildren(IResourceDelta.CHANGED,
                                IResource.PROJECT);

                        // The master delta may include more than one project delta
                        for (IResourceDelta projectDelta : projectDeltas) {
                            // Find any deltas for projects being opened/closed
                            if ((projectDelta.getFlags() & IResourceDelta.OPEN) > 0) {
                                IProject project = (IProject) projectDelta.getResource();
                                if (project.isOpen()) {
                                    safelyMigrateIfVersionChanged(project);
                                }
                            }
                        }
                    }
                }
            });
        }
    }

    /**
     * The actual migration logic. Ensure the template is followed exactly --
     * specifically that {@link ProjectMigrator#CURRENT_VERSION} has been bumped,
     * and that it will equal the projectVersion at the end of this method. Also
     * make sure you use "if" and not "else if".
     * 
     * @param project
     * @param projectVersion
     */
    private void migrateProject(IProject project, int projectVersion) {

        if (projectVersion == 0) {
            projectVersion = 1;

            /* Dummy migration logic to serve as a template/example */
            project.toString();
        }

        if (projectVersion == 1) {
            projectVersion = 2;

            /*
             * Moves to the GPE's new style of launch configs where arguments reflect
             * the actual parameters passed to the launch
             */
            LaunchConfigAffectingChangesListener.INSTANCE.updateLaunchConfigurations(project);
        }

        if (projectVersion == 2) {
            projectVersion = 3;

            /*
             * Set the launch config's working directory to default (which will always
             * resolve to the WAR directory) if it currently equals the WAR directory.
             */
            new DefaultWorkingDirectoryMigrator().migrate(project);
        }

        if (projectVersion == 3) {
            projectVersion = 4;

            /*
             * GPE now realizes GWTShell from newer SDKs supports the -remoteUI
             * argument. Update the launch configs so those that use GWTShell will
             * switch to the Dev Mode view inside Eclipse.
             */
            LaunchConfigAffectingChangesListener.INSTANCE.updateLaunchConfigurations(project);
        }

        if (projectVersion != CURRENT_VERSION) {
            GdtPlugin.getLogger().logError("Project migrator did not migrate project to the latest version");
        }

        // Write back project version
        GdtPreferences.setProjectMigratorVersion(project, projectVersion);
    }

    /**
     * Migrates the given project if there is some migration that needs to be
     * done. This method ensures no exceptions escape.
     */
    private void safelyMigrateIfVersionChanged(IProject project) {
        try {
            if (NatureUtils.hasNature(project, GWTNature.NATURE_ID)
                    || NatureUtils.hasNature(project, GaeNature.NATURE_ID)) {
                int projectVersion = GdtPreferences.getProjectMigratorVersion(project);
                if (projectVersion != CURRENT_VERSION) {
                    migrateProject(project, projectVersion);
                }
            }
        } catch (Throwable e) {
            GdtPlugin.getLogger().logError(e, "Skipping project migrator for project " + project.getName());
        }
    }

}