/*******************************************************************************
 * 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 org.eclipse.ui.dialogs;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.jface.viewers.CheckboxTableViewer;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
import org.eclipse.ui.internal.ide.IIDEHelpContextIds;
import org.eclipse.ui.model.WorkbenchContentProvider;
import org.eclipse.ui.model.WorkbenchLabelProvider;

/**
 * Standard project reference page for a wizard that creates a 
 * project resource.
 * <p>
 * This page may be used by clients as-is; it may be also be
 * subclassed to suit.
 * </p>
 * <p>
 * Example usage:
 * <pre>
 * referencePage = new WizardNewProjectReferencePage("basicReferenceProjectPage");
 * referencePage.setTitle("Project");
 * referencePage.setDescription("Select referenced projects.");
 * </pre>
 * </p>
 */
public class WizardNewProjectReferencePage extends WizardPage {
    // widgets
    private CheckboxTableViewer referenceProjectsViewer;

    private static final String REFERENCED_PROJECTS_TITLE = IDEWorkbenchMessages.WizardNewProjectReferences_title;

    private static final int PROJECT_LIST_MULTIPLIER = 15;

    /**
     * Creates a new project reference wizard page.
     *
     * @param pageName the name of this page
     */
    public WizardNewProjectReferencePage(String pageName) {
        super(pageName);
    }

    /** (non-Javadoc)
     * Method declared on IDialogPage.
     */
    public void createControl(Composite parent) {

        Font font = parent.getFont();

        Composite composite = new Composite(parent, SWT.NONE);
        composite.setLayout(new GridLayout());
        composite.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
        composite.setFont(font);

        PlatformUI.getWorkbench().getHelpSystem().setHelp(composite,
                IIDEHelpContextIds.NEW_PROJECT_REFERENCE_WIZARD_PAGE);

        Label referenceLabel = new Label(composite, SWT.NONE);
        referenceLabel.setText(REFERENCED_PROJECTS_TITLE);
        referenceLabel.setFont(font);

        referenceProjectsViewer = CheckboxTableViewer.newCheckList(composite,
                SWT.BORDER);
        referenceProjectsViewer.getTable().setFont(composite.getFont());
        GridData data = new GridData();
        data.horizontalAlignment = GridData.FILL;
        data.grabExcessHorizontalSpace = true;

        data.heightHint = getDefaultFontHeight(referenceProjectsViewer
                .getTable(), PROJECT_LIST_MULTIPLIER);
        referenceProjectsViewer.getTable().setLayoutData(data);
        referenceProjectsViewer.setLabelProvider(WorkbenchLabelProvider
                .getDecoratingWorkbenchLabelProvider());
        referenceProjectsViewer.setContentProvider(getContentProvider());
        referenceProjectsViewer.setInput(ResourcesPlugin.getWorkspace());

        setControl(composite);
    }

    /**
     * Returns a content provider for the reference project
     * viewer. It will return all projects in the workspace.
     *
     * @return the content provider
     */
    protected IStructuredContentProvider getContentProvider() {
        return new WorkbenchContentProvider() {
            public Object[] getChildren(Object element) {
                if (!(element instanceof IWorkspace))
                    return new Object[0];
                IProject[] projects = ((IWorkspace) element).getRoot()
                        .getProjects();
                return projects == null ? new Object[0] : projects;
            }
        };
    }

    /**
     * Get the defualt widget height for the supplied control.
     * @return int
     * @param control - the control being queried about fonts
     * @param lines - the number of lines to be shown on the table.
     */
    private static int getDefaultFontHeight(Control control, int lines) {
        FontData[] viewerFontData = control.getFont().getFontData();
        int fontHeight = 10;

        //If we have no font data use our guess
        if (viewerFontData.length > 0)
            fontHeight = viewerFontData[0].getHeight();
        return lines * fontHeight;

    }

    /**
     * Returns the referenced projects selected by the user.
     *
     * @return the referenced projects
     */
    public IProject[] getReferencedProjects() {
        Object[] elements = referenceProjectsViewer.getCheckedElements();
        IProject[] projects = new IProject[elements.length];
        System.arraycopy(elements, 0, projects, 0, elements.length);
        return projects;
    }
}