descent.internal.ui.preferences.ClasspathVariablesPreferencePage.java Source code

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Here is the source code for descent.internal.ui.preferences.ClasspathVariablesPreferencePage.java

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/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package descent.internal.ui.preferences;

import org.eclipse.core.runtime.IPath;

import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.preference.PreferencePage;

import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPreferencePage;
import org.eclipse.ui.PlatformUI;

import descent.core.JavaCore;

import descent.internal.ui.IJavaHelpContextIds;
import descent.internal.ui.JavaPlugin;
import descent.internal.ui.wizards.buildpaths.VariableBlock;

public class ClasspathVariablesPreferencePage extends PreferencePage implements IWorkbenchPreferencePage {

    public static final String ID = "descent.ui.preferences.ClasspathVariablesPreferencePage"; //$NON-NLS-1$

    private VariableBlock fVariableBlock;
    private String fStoredSettings;

    /**
     * Constructor for ClasspathVariablesPreferencePage
     */
    public ClasspathVariablesPreferencePage() {
        setPreferenceStore(JavaPlugin.getDefault().getPreferenceStore());
        fVariableBlock = new VariableBlock(true, null);
        fStoredSettings = null;

        // title only used when page is shown programatically
        setTitle(PreferencesMessages.ClasspathVariablesPreferencePage_title);
        setDescription(PreferencesMessages.ClasspathVariablesPreferencePage_description);
        noDefaultAndApplyButton();
    }

    /*
     * (non-Javadoc)
     * @see org.eclipse.jface.dialogs.IDialogPage#createControl(org.eclipse.swt.widgets.Composite)
     */
    public void createControl(Composite parent) {
        super.createControl(parent);
        PlatformUI.getWorkbench().getHelpSystem().setHelp(getControl(),
                IJavaHelpContextIds.CP_VARIABLES_PREFERENCE_PAGE);
    }

    /*
     * @see PreferencePage#createContents(org.eclipse.swt.widgets.Composite)
     */
    protected Control createContents(Composite parent) {
        Control result = fVariableBlock.createContents(parent);
        Dialog.applyDialogFont(result);
        return result;
    }

    /*
     * @see IWorkbenchPreferencePage#init(org.eclipse.ui.IWorkbench)
     */
    public void init(IWorkbench workbench) {
    }

    /*
     * @see PreferencePage#performDefaults()
     */
    protected void performDefaults() {
        fVariableBlock.performDefaults();
        super.performDefaults();
    }

    /*
     * @see PreferencePage#performOk()
     */
    public boolean performOk() {
        JavaPlugin.getDefault().savePluginPreferences();
        return fVariableBlock.performOk();
    }

    /* (non-Javadoc)
     * @see org.eclipse.jface.dialogs.IDialogPage#setVisible(boolean)
     */
    public void setVisible(boolean visible) {
        // check if the stored settings have changed
        if (visible) {
            if (fStoredSettings != null && !fStoredSettings.equals(getCurrentSettings())) {
                fVariableBlock.refresh(null);
            }
        } else {
            if (fVariableBlock.hasChanges()) {
                String title = PreferencesMessages.ClasspathVariablesPreferencePage_savechanges_title;
                String message = PreferencesMessages.ClasspathVariablesPreferencePage_savechanges_message;
                if (MessageDialog.openQuestion(getShell(), title, message)) {
                    performOk();
                }
                fVariableBlock.setChanges(false); // forget
            }
            fStoredSettings = getCurrentSettings();
        }
        super.setVisible(visible);
    }

    private String getCurrentSettings() {
        StringBuffer buf = new StringBuffer();
        String[] names = JavaCore.getClasspathVariableNames();
        for (int i = 0; i < names.length; i++) {
            String curr = names[i];
            buf.append(curr).append('\0');
            IPath val = JavaCore.getClasspathVariable(curr);
            if (val != null) {
                buf.append(val.toString());
            }
            buf.append('\0');
        }
        return buf.toString();
    }

}