DocumentTypeSelectionPage.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 John Krasnay 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:
 *     John Krasnay - initial API and implementation
 *******************************************************************************/
package net.sf.vex.editor;

import java.util.Arrays;
import java.util.Set;

import net.sf.vex.dom.Validator;
import net.sf.vex.editor.config.DocumentType;

import org.eclipse.jface.dialogs.IDialogSettings;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;

/**
 * Wizard page for selecting the document type and root element for the
 * new document.
 */
public class DocumentTypeSelectionPage extends WizardPage {

    private static final String SETTINGS_PUBLIC_ID = "publicId"; //$NON-NLS-1$
    private static final String SETTINGS_ROOT_ELEMENT_PREFIX = "root."; //$NON-NLS-1$
    
    /**
     * Class constructor.
     */
    public DocumentTypeSelectionPage() {
        super(Messages.getString("DocumentTypeSelectionPage.pageName")); //$NON-NLS-1$
        this.setPageComplete(false);
        
        IDialogSettings rootSettings = VexPlugin.getInstance().getDialogSettings();
        this.settings = rootSettings.getSection("newDocument"); //$NON-NLS-1$
        if (this.settings == null) {
            this.settings = rootSettings.addNewSection("newDocument"); //$NON-NLS-1$
        }
        
        this.doctypes = DocumentType.getDocumentTypesWithStyles();
        Arrays.sort(this.doctypes);
    }
    
    public void createControl(Composite parent) {
        
        Composite pane = new Composite(parent, SWT.NONE);
        GridLayout layout = new GridLayout();
        layout.numColumns = 2;
        pane.setLayout(layout);
        GridData gd;
        
        Label label = new Label(pane, SWT.NONE);
        label.setText(Messages.getString("DocumentTypeSelectionPage.doctype")); //$NON-NLS-1$
        
        this.typeCombo = new Combo(pane, SWT.DROP_DOWN | SWT.READ_ONLY);
        gd = new GridData();
        gd.grabExcessHorizontalSpace = true;
        gd.horizontalAlignment = GridData.FILL;
        this.typeCombo.setLayoutData(gd);
        this.typeCombo.addSelectionListener(typeComboSelectionListener);

        label = new Label(pane, SWT.NONE);
        label.setText(Messages.getString("DocumentTypeSelectionPage.rootElement")); //$NON-NLS-1$
        this.setControl(pane);
        
        this.elementCombo = new Combo(pane, SWT.DROP_DOWN | SWT.READ_ONLY);
        gd = new GridData();
        gd.grabExcessHorizontalSpace = true;
        gd.horizontalAlignment = GridData.FILL;
        this.elementCombo.setLayoutData(gd);
        this.elementCombo.addSelectionListener(elementComboSelectionListener);
        
        String publicId = this.settings.get(SETTINGS_PUBLIC_ID);
        int initSelection = -1;
        String[] typeNames = new String[this.doctypes.length];
        for (int i = 0; i < this.doctypes.length; i++) {
            typeNames[i] = this.doctypes[i].getName();
            if (this.doctypes[i].getPublicId().equals(publicId)) {
                initSelection = i;
            }
        }

        this.typeCombo.setItems(typeNames);
        
        if (initSelection != -1) {
            this.typeCombo.select(initSelection);
            // calling select() does not fire the selection listener, 
            // so we update it manually
            this.updateElementCombo();
        }

        this.setTitle(Messages.getString("DocumentTypeSelectionPage.title")); //$NON-NLS-1$
        this.setDescription(Messages.getString("DocumentTypeSelectionPage.desc")); //$NON-NLS-1$
    }

    /**
     * Returns the selected document type.
     */
    public DocumentType getDocumentType() {
        int i = this.typeCombo.getSelectionIndex();
        if (i == -1) {
            return null;
        } else {
            return this.doctypes[i];
        }
    }

    /**
     * Returns the selected name of the root element.
     */
    public String getRootElementName() {
        return this.elementCombo.getText();
    }
    
    /**
     * Called from the wizard's performFinal method to save the settings for
     * this page.
     */
    public void saveSettings() {
        DocumentType doctype = this.getDocumentType();
        if (doctype != null) {
            this.settings.put(SETTINGS_PUBLIC_ID, doctype.getPublicId());
            String key = SETTINGS_ROOT_ELEMENT_PREFIX + doctype.getPublicId();
            this.settings.put(key, this.getRootElementName());
        }
    }
    
    //============================================================== PRIVATE
    
    private IDialogSettings settings;
    private DocumentType[] doctypes;
    private Combo typeCombo;
    private Combo elementCombo;

    /**
     * Update the elementCombo to reflect elements in the currently selected
     * type.
     */
    private void updateElementCombo() {
        int index = this.typeCombo.getSelectionIndex();
        DocumentType dt = this.doctypes[index];
        this.elementCombo.removeAll();
        
        String[] roots = getDocumentType().getRootElements();
        String selectedRoot = null;
                       
        if (roots.length == 0) {
            Validator validator = dt.getValidator();
            if (validator != null) {
                Set set = validator.getValidRootElements();
                roots = (String[]) set.toArray(new String[set.size()]);
            }
        } else {
            selectedRoot = roots[0];
        }
            
               
        Arrays.sort(roots);
        this.elementCombo.setItems(roots);

        if (selectedRoot == null) {
            // Restore the last used root element
            String key = SETTINGS_ROOT_ELEMENT_PREFIX + dt.getPublicId();
            selectedRoot = this.settings.get(key);
        }
        
        this.setPageComplete(false);
        if (selectedRoot != null) {
            for (int i = 0; i < roots.length; i++) {
                if (roots[i].equals(selectedRoot)) {
                    this.elementCombo.select(i);
                    this.setPageComplete(true);
                    break;
                }
            }
        }
    }
    
    /**
     * Sets the root element combo box when the document type combo box is selected.
     */
    private SelectionListener typeComboSelectionListener = new SelectionListener() {
        public void widgetSelected(SelectionEvent e) {
            updateElementCombo();
        }
        public void widgetDefaultSelected(SelectionEvent e) {
        }
    };
    
    /**
     * When a root element is selected, mark the page as complete.
     */
    private SelectionListener elementComboSelectionListener = new SelectionListener() {
        public void widgetSelected(SelectionEvent e) {
            setPageComplete(true);
        }
        public void widgetDefaultSelected(SelectionEvent e) {
        }
    };

}