/*******************************************************************************
 * 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 java.util.ArrayList;

import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.help.WorkbenchHelp;
import org.eclipse.ui.internal.*;

/**
 * Displays information about the product.
 *
 * @private
 *		This class is internal to the workbench and must not be called outside the workbench
 */
public class AboutDialog extends ProductInfoDialog {
	private final static int MAX_IMAGE_WIDTH_FOR_TEXT = 250;
	private final static int FEATURES_ID = IDialogConstants.CLIENT_ID + 1;
	private final static int PLUGINS_ID = IDialogConstants.CLIENT_ID + 2;
	private final static int INFO_ID = IDialogConstants.CLIENT_ID + 3;

	private IWorkbenchWindow window;
	private Workbench workbench;
	private Image image; //image to display on dialog
	private AboutInfo aboutInfo;
	private ArrayList images = new ArrayList();
	private StyledText text;

	/**
	 * Create an instance of the AboutDialog
	 */
	public AboutDialog(IWorkbenchWindow window) {
		super(window.getShell());
		this.window = window;
		this.workbench = (Workbench) window.getWorkbench();
		aboutInfo = workbench.getConfigurationInfo().getAboutInfo();
	}
	
	/* (non-Javadoc)
	 * Method declared on Dialog.
	 */
	protected void buttonPressed(int buttonId) {
		switch (buttonId) {
			case FEATURES_ID :
				new AboutFeaturesDialog(getShell()).open();
				return;
			case PLUGINS_ID :
				new AboutPluginsDialog(getShell()).open();
				return;
			case INFO_ID :
				BusyIndicator.showWhile(getShell().getDisplay(), new Runnable() {
					public void run() {
						workbench.getConfigurationInfo().openSystemSummaryEditor(window);
					}
				});
				close();
				return;
		}
		
		super.buttonPressed(buttonId);
	}

	public boolean close() {
		//get rid of the image that was displayed on the left-hand side of the Welcome dialog
		if (image != null)
			image.dispose();
		for (int i = 0; i < images.size(); i++) {
			((Image) images.get(i)).dispose();
		}
		return super.close();
	}
	/* (non-Javadoc)
	 * Method declared on Window.
	 */
	protected void configureShell(Shell newShell) {
		super.configureShell(newShell);
		String name = aboutInfo.getProductName();
		if (name != null)
			newShell.setText(WorkbenchMessages.format("AboutDialog.shellTitle", new Object[] { name })); //$NON-NLS-1$
		WorkbenchHelp.setHelp(newShell, IHelpContextIds.ABOUT_DIALOG);
	}
	/**
	 * Add buttons to the dialog's button bar.
	 *
	 * Subclasses should override.
	 *
	 * @param parent the button bar composite
	 */
	protected void createButtonsForButtonBar(Composite parent) {
		parent.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

		createButton(parent, FEATURES_ID, WorkbenchMessages.getString("AboutDialog.featureInfo"), false); //$NON-NLS-1$
		createButton(parent, PLUGINS_ID, WorkbenchMessages.getString("AboutDialog.pluginInfo"), false); //$NON-NLS-1$
		createButton(parent, INFO_ID, WorkbenchMessages.getString("AboutDialog.systemInfo"), false); //$NON-NLS-1$

		Label l = new Label(parent, SWT.NONE);
		l.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		GridLayout layout = (GridLayout) parent.getLayout();
		layout.numColumns++;
		layout.makeColumnsEqualWidth = false;

		Button b = createButton(parent, IDialogConstants.OK_ID, IDialogConstants.OK_LABEL, true);
		b.setFocus();
	}
	/**
	 * Creates and returns the contents of the upper part 
	 * of the dialog (above the button bar).
	 *
	 * Subclasses should overide.
	 *
	 * @param the parent composite to contain the dialog area
	 * @return the dialog area control
	 */
	protected Control createDialogArea(Composite parent) {
		setHandCursor(new Cursor(parent.getDisplay(), SWT.CURSOR_HAND));
		setBusyCursor(new Cursor(parent.getDisplay(), SWT.CURSOR_WAIT));
		getShell().addDisposeListener(new DisposeListener() {
			public void widgetDisposed(DisposeEvent e) {
				if (getHandCursor() != null)
					getHandCursor().dispose();
				if (getBusyCursor() != null)
					getBusyCursor().dispose();
			}
		});

		ImageDescriptor imageDescriptor = aboutInfo.getAboutImage(); // may be null
		if (imageDescriptor != null)
			image = imageDescriptor.createImage();
		if (image == null || image.getBounds().width <= MAX_IMAGE_WIDTH_FOR_TEXT) {
			// show text
			String aboutText = aboutInfo.getAboutText();
			if (aboutText != null) {
				// get an about item
				setItem(scan(aboutText));
			}
		}

		// page group
		Composite outer = (Composite) super.createDialogArea(parent);
		outer.setSize(outer.computeSize(SWT.DEFAULT, SWT.DEFAULT));
		GridLayout layout = new GridLayout();
		outer.setLayout(layout);
		outer.setLayoutData(new GridData(GridData.FILL_BOTH));

		// the image & text	
		Composite topContainer = new Composite(outer, SWT.NONE);
		layout = new GridLayout();
		layout.numColumns = (image == null || getItem() == null ? 1 : 2);
		layout.marginWidth = 0;
		topContainer.setLayout(layout);
		GridData data = new GridData();
		data.horizontalAlignment = GridData.FILL;
		data.grabExcessHorizontalSpace = true;
		topContainer.setLayoutData(data);

		//image on left side of dialog
		if (image != null) {
			Label imageLabel = new Label(topContainer, SWT.NONE);
			data = new GridData();
			data.horizontalAlignment = GridData.FILL;
			data.verticalAlignment = GridData.BEGINNING;
			data.grabExcessHorizontalSpace = false;
			imageLabel.setLayoutData(data);
			imageLabel.setImage(image);
		}

		if (getItem() != null) {
			// text on the right
			text = new StyledText(topContainer, SWT.MULTI | SWT.READ_ONLY);
			text.setCaret(null);
			text.setFont(parent.getFont());
			data = new GridData();
			data.horizontalAlignment = GridData.FILL;
			data.verticalAlignment = GridData.BEGINNING;
			data.grabExcessHorizontalSpace = true;
			text.setText(getItem().getText());
			text.setLayoutData(data);
			text.setCursor(null);
			text.setBackground(topContainer.getBackground());
			setLinkRanges(text, getItem().getLinkRanges());
			addListeners(text);
		}

		// horizontal bar
		Label bar = new Label(outer, SWT.HORIZONTAL | SWT.SEPARATOR);
		data = new GridData();
		data.horizontalAlignment = GridData.FILL;
		bar.setLayoutData(data);

		// feature images
		Composite featureContainer = new Composite(outer, SWT.NONE);
		RowLayout rowLayout = new RowLayout();
		rowLayout.wrap = true;
		featureContainer.setLayout(rowLayout);
		data = new GridData();
		data.horizontalAlignment = GridData.FILL;
		featureContainer.setLayoutData(data);

		final AboutInfo[] infoArray = getFeaturesInfo();
		for (int i = 0; i < infoArray.length; i++) {
			ImageDescriptor desc = infoArray[i].getFeatureImage();
			Image image = null;
			if (desc != null) {
				Button button = new Button(featureContainer, SWT.FLAT | SWT.PUSH);
				button.setData(infoArray[i]);
				image = desc.createImage();
				images.add(image);
				button.setImage(image);
				String name = infoArray[i].getProviderName();
				if (name == null)
					name = ""; //$NON-NLS-1$
				button.setToolTipText(name);
				button.addSelectionListener(new SelectionAdapter() {
					public void widgetSelected(SelectionEvent event) {
						AboutFeaturesDialog d = new AboutFeaturesDialog(getShell());
						d.setInitialSelection((AboutInfo) event.widget.getData());
						d.open();
					}
				});
			}
		}

		// spacer
		bar = new Label(outer, SWT.NONE);
		data = new GridData();
		data.horizontalAlignment = GridData.FILL;
		bar.setLayoutData(data);

		return outer;
	}

	/**
	 * Returns the feature infos.
	 * They are grouped by provider and image.
	 */
	private AboutInfo[] getFeaturesInfo() {
		AboutInfo[] rawArray = workbench.getConfigurationInfo().getFeaturesInfo();
		// quickly exclude any that do not have a provider name and image
		ArrayList infoList = new ArrayList();
		for (int i = 0; i < rawArray.length; i++) {
			if (rawArray[i].getProviderName() != null && rawArray[i].getFeatureImageName() != null)
				infoList.add(rawArray[i]);
		}
		AboutInfo[] infoArray = (AboutInfo[]) infoList.toArray(new AboutInfo[infoList.size()]);

		// now exclude those with duplicate images
		infoList = new ArrayList();
		for (int i = 0; i < infoArray.length; i++) {
			// check for identical provider
			boolean add = true;
			for (int j = 0; j < infoList.size(); j++) {
				AboutInfo current = (AboutInfo) infoList.get(j);
				if (current.getProviderName().equals(infoArray[i].getProviderName())) {
					// check for identical image
					if (current.getFeatureImageName().equals(infoArray[i].getFeatureImageName())) {
						// same name
						// we have to check if the CRC's are identical
						Long crc1 = current.getFeatureImageCRC();
						Long crc2 = infoArray[i].getFeatureImageCRC();
						if (crc1 == null ? false : crc1.equals(crc2)) {
							// duplicate
							add = false;
							break;
						}
					}
				}
			}
			if (add)
				infoList.add(infoArray[i]);
		}
		infoList.remove(aboutInfo);
		return (AboutInfo[]) infoList.toArray(new AboutInfo[infoList.size()]);
	}

}