LibHoverPreferencePage.java

/*******************************************************************************
 * Copyright (c) 2011 Red Hat, Inc.
 * 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
 *
 * Contributors:
 *     Red Hat Incorporated - initial API and implementation
 *******************************************************************************/
package org.eclipse.linuxtools.internal.cdt.libhover.devhelp.preferences;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.util.Collection;

import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.IJobChangeEvent;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.core.runtime.jobs.JobChangeAdapter;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.preference.DirectoryFieldEditor;
import org.eclipse.jface.preference.FieldEditorPreferencePage;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.linuxtools.cdt.libhover.LibHoverInfo;
import org.eclipse.linuxtools.cdt.libhover.LibhoverPlugin;
import org.eclipse.linuxtools.internal.cdt.libhover.LibHover;
import org.eclipse.linuxtools.internal.cdt.libhover.LibHoverLibrary;
import org.eclipse.linuxtools.internal.cdt.libhover.devhelp.DevHelpPlugin;
import org.eclipse.linuxtools.internal.cdt.libhover.devhelp.ParseDevHelp;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPreferencePage;

/**
 * This class represents a preference page that
 * is contributed to the Preferences dialog. By
 * subclassing <samp>FieldEditorPreferencePage</samp>, we
 * can use the field support built into JFace that allows
 * us to create a page that is small and knows how to
 * save, restore and apply itself.
 * <p>
 * This page is used to modify preferences only. They
 * are stored in the preference store that belongs to
 * the main plug-in class. That way, preferences can
 * be accessed directly via the preference store.
 */

public class LibHoverPreferencePage extends FieldEditorPreferencePage implements
        IWorkbenchPreferencePage {

    private final static String DEVHELP_DIR = "Libhover.Devhelp.Directory"; //$NON-NLS-1$
    private final static String GENERATE = "Libhover.Devhelp.Generate.lbl"; //$NON-NLS-1$
    private final static String REGENERATE_MSG = "Libhover.Devhelp.Regenerate.msg"; //$NON-NLS-1$
    private final static String TITLE = "Libhover.Devhelp.Preference.title"; //$NON-NLS-1$

    private Button generateButton;

    public LibHoverPreferencePage() {
        super(GRID);
        setPreferenceStore(DevHelpPlugin.getDefault().getPreferenceStore());
    }

    private static class DevhelpStringFieldEditor extends DirectoryFieldEditor {
        public DevhelpStringFieldEditor(String name, String labelText,
                Composite parent) {
            super(name, labelText, parent);
            setFilterPath(new File(DevHelpPlugin.getDefault().getPreferenceStore().getString(name)));
        }

    }

    private synchronized void regenerate() {
        generateButton.setEnabled(false);
        Job k = new Job(LibHoverMessages.getString(REGENERATE_MSG)) {

            @Override
            protected IStatus run(IProgressMonitor monitor) {
                IPreferenceStore ps = DevHelpPlugin.getDefault().getPreferenceStore();
                ParseDevHelp.DevHelpParser p =
                    new ParseDevHelp.DevHelpParser(ps.getString(PreferenceConstants.DEVHELP_DIRECTORY));
                LibHoverInfo hover = p.parse(monitor);
                // Update the devhelp library info if it is on library list
                Collection<LibHoverLibrary> libs = LibHover.getLibraries();
                for (LibHoverLibrary l : libs) {
                    if (l.getName().equals("devhelp")) { //$NON-NLS-1$
                        l.setHoverinfo(hover);
                        break;
                    }
                }
                try {
                    // Now, output the LibHoverInfo for caching later
                    IPath location = LibhoverPlugin.getDefault().getStateLocation().append("C"); //$NON-NLS-1$
                    File ldir = new File(location.toOSString());
                    ldir.mkdir();
                    location = location.append("devhelp.libhover"); //$NON-NLS-1$
                    try (FileOutputStream f = new FileOutputStream(
                            location.toOSString());
                            ObjectOutputStream out = new ObjectOutputStream(f)) {
                        out.writeObject(hover);
                    }
                    monitor.done();
                } catch(IOException e) {
                    monitor.done();
                    return new Status(IStatus.ERROR, DevHelpPlugin.PLUGIN_ID, e.getLocalizedMessage(), e);
                }


                return Status.OK_STATUS;
            }

        };
        k.setUser(true);
        k.addJobChangeListener(new JobChangeAdapter() {
            @Override
            public void done(IJobChangeEvent event) {
                Display.getDefault().syncExec(() -> {
				    if (generateButton != null)
				        generateButton.setEnabled(true);
				});
            }
        });
        k.schedule();
    }

    @Override
    protected void contributeButtons(Composite parent) {
        ((GridLayout) parent.getLayout()).numColumns++;
        generateButton = new Button(parent, SWT.NONE);
        generateButton.setFont(parent.getFont());
        generateButton.setText(LibHoverMessages.getString(GENERATE));
        generateButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent evt) {
                regenerate();
            }
        });
        generateButton.addDisposeListener(event -> generateButton = null);
        GridData gd = new GridData();

        gd.horizontalAlignment = GridData.FILL;
        int widthHint = convertHorizontalDLUsToPixels(
                IDialogConstants.BUTTON_WIDTH);
        gd.widthHint = Math.max(widthHint, generateButton.computeSize(
                SWT.DEFAULT, SWT.DEFAULT, true).x);

        generateButton.setLayoutData(gd);
    }

    /**
     * Creates the field editors. Field editors are abstractions of
     * the common GUI blocks needed to manipulate various types
     * of preferences. Each field editor knows how to save and
     * restore itself.
     */
    @Override
    public void createFieldEditors() {
        addField(
                new LabelFieldEditor(
                        getFieldEditorParent(),
                        LibHoverMessages.getString(TITLE)));
        addField(
                new DevhelpStringFieldEditor(
                        PreferenceConstants.DEVHELP_DIRECTORY,
                        LibHoverMessages.getString(DEVHELP_DIR),
                        getFieldEditorParent()));


    }

    @Override
    public void init(IWorkbench workbench) {
    }

}