/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/

package org.eclipse.ui.internal.dialogs;

import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Font;
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.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.TableItem;
import org.eclipse.ui.internal.WorkbenchMessages;

/**
 * @since 3.0
 */
class PreferenceImportExportSettingsSelectionPage extends AbstractPreferenceImportExportPage {
	
	/**
	 * The message to display when there are no errors on this page.
	 */
	private static final String EXPORT_MESSAGE = WorkbenchMessages.getString("ImportExportPages.exportSettingsSelect"); //$NON-NLS-1$
	/**
	 * The message to display when there are no errors on this page.
	 */
	private static final String IMPORT_MESSAGE = WorkbenchMessages.getString("ImportExportPages.importSettingsSelect"); //$NON-NLS-1$
	/**
	 * The name of this page -- used to find the page later.
	 */
	private static final String NAME = "org.eclipse.ui.preferences.importExportSettingsSelectionPage"; //$NON-NLS-1$
	
	/**
	 * The table containing the list of settings to choose from.
	 */
	private Table settingsTable;
	
	/**
	 * Constructs a new instance of a settings selection page with the given
	 * mode.
	 * @param exportWizard Whether the preference selection if for an export
	 * operation.
	 */
	PreferenceImportExportSettingsSelectionPage(boolean exportWizard) {
		super(NAME, exportWizard);
	}
	
	/**
	 * This page can always finish.  If no items are selected, it simply means
	 * that nothing will be exported.
	 * @return <code>true</code>.
	 */
	boolean canFinish() {
		return true;
	}
	
	/**
	 * This page is always the last page, and so you cannot flip to the next 
	 * page.
	 * @return <code>false</code>.
	 */
	public boolean canFlipToNextPage() {
		return false;
	}
	
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.dialogs.IDialogPage#createControl(org.eclipse.swt.widgets.Composite)
	 */
	public void createControl(Composite parent) {
	    Font parentFont = parent.getFont();
		final Composite page = new Composite(parent, SWT.NONE);
		GridLayout layout = new GridLayout(2, false);
		page.setLayout(layout);
		initializeDialogUnits(page);

		// Set-up the title, subtitle and icon.
		if (export) {
			setTitle(EXPORT_TITLE);
			setMessage(EXPORT_MESSAGE);
			setImageDescriptor(getImageDescriptor("wizban/export_wiz.gif")); //$NON-NLS-1$
		} else {
			setTitle(IMPORT_TITLE);
			setMessage(IMPORT_MESSAGE);
			setImageDescriptor(getImageDescriptor("wizban/import_wiz.gif")); //$NON-NLS-1$
		}

		GridData layoutData;

		// Set-up the table and its columns.
		settingsTable = new Table(page, SWT.CHECK | SWT.BORDER);
		settingsTable.setFont(parentFont);
		layoutData = new GridData(GridData.FILL_BOTH);
		layoutData.verticalSpan = 3;
		settingsTable.setLayoutData(layoutData);
		settingsTable.setLinesVisible(true);
		settingsTable.setHeaderVisible(true);
        final TableColumn columnChecked = new TableColumn(settingsTable, SWT.LEFT, 0);
        final TableColumn columnName = new TableColumn(settingsTable, SWT.LEFT, 1);
        final TableColumn columnValue = new TableColumn(settingsTable, SWT.LEFT, 2);
		for (int i = 0; i < 50; i++) {
        	TableItem item = new TableItem(settingsTable, SWT.NULL);
        	item.setText(new String[] { "", "org.eclipse.sample.preference", "Sample value (ignore)" });  //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$
        	item.setChecked(true);
		}
        
        columnName.setText(WorkbenchMessages.getString("ImportExportPages.name")); //$NON-NLS-1$
        columnValue.setText(WorkbenchMessages.getString("ImportExportPages.value")); //$NON-NLS-1$
        columnChecked.pack();
        columnName.pack();
        columnValue.pack();

        // Set-up the select all button.
		final Button selectAllButton = new Button(page, SWT.PUSH);
		selectAllButton.setFont(parentFont);
		layoutData = new GridData();
		selectAllButton.setText(WorkbenchMessages.getString("ImportExportPages.selectAll")); //$NON-NLS-1$
		layoutData.heightHint = convertVerticalDLUsToPixels(IDialogConstants.BUTTON_HEIGHT);
		layoutData.widthHint = computePushButtonWidthHint(selectAllButton);
		layoutData.verticalAlignment = GridData.BEGINNING;
		selectAllButton.setLayoutData(layoutData);
		selectAllButton.addSelectionListener(new SelectionAdapter() {
			public final void widgetSelected(SelectionEvent event) {
				setCheckAll(true);
			}
		});

		// Set-up the deselect all button.
		final Button deselectAllButton = new Button(page, SWT.PUSH);
		deselectAllButton.setFont(parentFont);
		layoutData = new GridData();
		deselectAllButton.setText(WorkbenchMessages.getString("ImportExportPages.deselectAll")); //$NON-NLS-1$
		layoutData.heightHint = convertVerticalDLUsToPixels(IDialogConstants.BUTTON_HEIGHT);
		layoutData.widthHint = computePushButtonWidthHint(deselectAllButton);
		layoutData.verticalAlignment = GridData.BEGINNING;
		deselectAllButton.setLayoutData(layoutData);
		deselectAllButton.addSelectionListener(new SelectionAdapter() {
			public final void widgetSelected(SelectionEvent event) {
				setCheckAll(false);
			}
		});

		// Set-up the invert selection button.
		final Button invertSelectionButton = new Button(page, SWT.PUSH);
		invertSelectionButton.setFont(parentFont);
		layoutData = new GridData();
		invertSelectionButton.setText(WorkbenchMessages.getString("ImportExportPages.invertSelection")); //$NON-NLS-1$
		layoutData.heightHint = convertVerticalDLUsToPixels(IDialogConstants.BUTTON_HEIGHT);
		layoutData.widthHint = computePushButtonWidthHint(invertSelectionButton);
		layoutData.verticalAlignment = GridData.BEGINNING;
		invertSelectionButton.setLayoutData(layoutData);
		invertSelectionButton.addSelectionListener(new SelectionAdapter() {
			public final void widgetSelected(SelectionEvent event) {
				invertSelection();
			}
		});

		// Remember the composite as the top-level control.
		setControl(page);
		
		// Restore all the controls to their previous values.
		init();
	}
	
	/**
	 * Initializes all of the controls to their previous values.  This page
	 * doesn't really remember anything right now, so this just checks all of
	 * the table items.
	 */
	private void init() {
		setCheckAll(true);
	}
	
	/**
	 * Inverts the current selection (checked state) of all the settings.
	 */
	private void invertSelection() {
		final TableItem[] items = settingsTable.getItems();
		for (int i = 0; i < items.length; i++) {
			TableItem item = items[i];
			item.setChecked(!item.getChecked());
		}
	}
	
	/**
	 * This sets the checked state on all the settings to the given value.  This
	 * can be used as either a select all or a deselect all. 
	 * @param checked The state to set.
	 */
	private void setCheckAll(final boolean checked) {
		TableItem[] items = settingsTable.getItems();
		for (int i = 0; i < items.length; i++) {
			items[i].setChecked(checked);
		}
	}
	
	boolean validate() {
		return true;
	}
}