// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

package com.symbian.smt.gui.smtwidgets;

import java.lang.reflect.InvocationTargetException;

import org.eclipse.core.runtime.IProgressMonitor;

import org.eclipse.jface.dialogs.Dialog;

import org.eclipse.jface.dialogs.IDialogConstants;

import org.eclipse.jface.dialogs.IInputValidator;

import org.eclipse.jface.dialogs.MessageDialog;

import org.eclipse.jface.dialogs.ProgressMonitorDialog;

import org.eclipse.jface.operation.IRunnableWithProgress;

import org.eclipse.jface.resource.StringConverter;

import org.eclipse.swt.SWT;

import org.eclipse.swt.events.ModifyEvent;

import org.eclipse.swt.events.ModifyListener;

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.Button;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Control;

import org.eclipse.swt.widgets.FileDialog;

import org.eclipse.swt.widgets.Label;

import org.eclipse.swt.widgets.Shell;

import org.eclipse.swt.widgets.Text;

import org.eclipse.ui.PlatformUI;

/**

 * This dialog is adapted from Eclipse's InputDialog in order to accept the name

 * (local or URL) of an XML file. Validation of the XML also occurs.

 * 

 * @author barbararosi-schwartz

 * 

 */

public class XmlFileSelectionDialog extends Dialog {

	private static final String BROWSE_BUTTON = "Browse..."; //$NON-NLS-1$

	private static final String EMPTY_STRING = ""; //$NON-NLS-1$

	/**

	 * Browse button widget.

	 */

	private Button browseButton;

	/**

	 * Cancel button widget.

	 */

	private Button cancelButton;

	/**

	 * Error message string.

	 */

	private String errorMessage;

	/**

	 * Error message label widget.

	 */

	private Text errorMessageText;

	/**

	 * The file extensions to filter on.

	 */

	private String[] extensionFilter;

	/**

	 * The message to display, or <code>null</code> if none.

	 */

	private String message;

	/**

	 * Ok button widget.

	 */

	private Button okButton;

	/**

	 * Input text widget.

	 */

	private Text inputText;

	/**

	 * The title of the dialog.

	 */

	private String title;

	/**

	 * The input m_validator, or <code>null</code> if none.

	 */

	private IXmlFileInputValidator validator;

	/**

	 * The input value; the empty string by default.

	 */

	private String inputValue = EMPTY_STRING;

	/**

	 * Creates an input dialog with OK and Cancel buttons. Note that the dialog

	 * will have no visual representation (no widgets) until it is told to open.

	 * <p>

	 * Note that the <code>open</code> method blocks for input dialogs.

	 * </p>

	 * 

	 * @param parentShell

	 *            the parent shell, or <code>null</code> to create a top-level

	 *            shell

	 * @param dialogTitle

	 *            the dialog title, or <code>null</code> if none

	 * @param dialogMessage

	 *            the dialog message, or <code>null</code> if none

	 * @param initialValue

	 *            the initial input value, or <code>null</code> if none

	 *            (equivalent to the empty string)

	 * @param extensionFilter

	 *            the file extensions to filter on.

	 * @param validator

	 *            an input validator, or <code>null</code> if none

	 */

	public XmlFileSelectionDialog(Shell parentShell, String dialogTitle,

			String dialogMessage, String initialValue,

			String[] extensionFilter, IXmlFileInputValidator validator) {

		super(parentShell);

		this.title = dialogTitle;

		message = dialogMessage;

		this.extensionFilter = extensionFilter;

		if (initialValue == null) {

			inputValue = EMPTY_STRING;

		} else {

			inputValue = initialValue;

		}

		this.validator = validator;

	}

	/*

	 * Method declared on Dialog.

	 */

	protected void buttonPressed(int buttonId) {

		if (buttonId == IDialogConstants.OK_ID) {

			inputValue = inputText.getText();

		} else {

			inputValue = null;

		}

		super.buttonPressed(buttonId);

	}

	/*

	 * 

	 * 

	 * @see

	 * org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets

	 * .Shell)

	 */

	protected void configureShell(Shell shell) {

		super.configureShell(shell);

		if (title != null) {

			shell.setText(title);

		}

	}

	/*

	 * 

	 * 

	 * @see

	 * org.eclipse.jface.dialogs.Dialog#createButtonsForButtonBar(org.eclipse

	 * .swt.widgets.Composite)

	 */

	protected void createButtonsForButtonBar(Composite parent) {

		// create OK and Cancel buttons by default

		okButton = createButton(parent, IDialogConstants.OK_ID,

				IDialogConstants.OK_LABEL, true);

		cancelButton = createButton(parent, IDialogConstants.CANCEL_ID,

				IDialogConstants.CANCEL_LABEL, false);

		// do this here because setting the m_text will set enablement on the ok

		// button

		inputText.setFocus();

		if (inputValue != null) {

			inputText.setText(inputValue);

			inputText.selectAll();

		}

	}

	/*

	 * Method declared on Dialog.

	 */

	protected Control createDialogArea(Composite parent) {

		// create composite

		Composite composite = (Composite) super.createDialogArea(parent);

		GridLayout layout = (GridLayout) composite.getLayout();

		layout.numColumns = 2;

		// create message

		if (message != null) {

			Label label = new Label(composite, SWT.WRAP);

			label.setText(message);

			GridData data = new GridData(GridData.HORIZONTAL_ALIGN_FILL,

					GridData.VERTICAL_ALIGN_CENTER, true, true, 2, 1);

			data.widthHint = convertHorizontalDLUsToPixels(IDialogConstants.MINIMUM_MESSAGE_AREA_WIDTH);

			label.setLayoutData(data);

			label.setFont(parent.getFont());

		}

		inputText = new Text(composite, getInputTextStyle());

		inputText.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL

				| GridData.HORIZONTAL_ALIGN_FILL));

		inputText.addModifyListener(new ModifyListener() {

			public void modifyText(ModifyEvent e) {

				validateInput();

			}

		});

		browseButton = new Button(composite, SWT.PUSH);

		browseButton.setText(BROWSE_BUTTON);

		browseButton.addSelectionListener(new SelectionListener() {

			public void widgetDefaultSelected(SelectionEvent event) {

			}

			public void widgetSelected(SelectionEvent event) {

				FileDialog fd = new FileDialog(

						PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell(), 

						SWT.OPEN | SWT.APPLICATION_MODAL);

				fd.setText("Select the desired resource file name");

				if (extensionFilter != null) {

					fd.setFilterExtensions(extensionFilter);

				}

				String selected = fd.open();

				if (selected != null) {

					inputText.setText(selected);

				}

			}

		});

		GridData gd = new GridData(GridData.GRAB_HORIZONTAL

				| GridData.HORIZONTAL_ALIGN_FILL | GridData.GRAB_VERTICAL

				| GridData.VERTICAL_ALIGN_FILL);

		gd.horizontalSpan = 2;

		gd.minimumHeight = 40;

		errorMessageText = new Text(composite, SWT.MULTI | SWT.READ_ONLY

				| SWT.WRAP);

		errorMessageText.setLayoutData(gd);

		errorMessageText.setBackground(errorMessageText.getDisplay()

				.getSystemColor(SWT.COLOR_WIDGET_BACKGROUND));

		// Set the error message text

		setErrorMessage(errorMessage);

		applyDialogFont(composite);

		return composite;

	}

	/**

	 * @return the cancelButton

	 */

	public Button getCancelButton() {

		return cancelButton;

	}

	/**

	 * Returns the style bits that should be used for the input text field.

	 * Defaults to a single line entry. Subclasses may override.

	 * 

	 * @return the integer style bits that should be used when creating the

	 *         input text

	 */

	protected int getInputTextStyle() {

		return SWT.SINGLE | SWT.BORDER;

	}

	/**

	 * Returns the ok button.

	 * 

	 * @return the ok button

	 */

	public Button getOkButton() {

		return okButton;

	}

	/**

	 * Returns the text area.

	 * 

	 * @return the text area

	 */

	public Text getText() {

		return inputText;

	}

	/**

	 * Returns the validator.

	 * 

	 * @return the validator

	 */

	protected IInputValidator getValidator() {

		return validator;

	}

	/**

	 * Returns the string typed into this input dialog.

	 * 

	 * @return the input string

	 */

	public String getValue() {

		return inputValue;

	}

	/*

	 * (non-Javadoc)

	 * 

	 * @see org.eclipse.jface.dialogs.Dialog#okPressed()

	 */

	@Override

	protected void okPressed() {

		IRunnableWithProgress op = new IRunnableWithProgress() {

			String input = getValue();

			String result;

			// Validation of the XML content does not happen here as an invalid XML

			// file

			// is deemed acceptable. It occurs as part of the update that takes

			// place

			// in the ManageResources class, which is also responsible for arranging

			// for error markers to be placed on any invalid resource file or sys

			// def file.

			public void run(IProgressMonitor monitor) throws InvocationTargetException {

				monitor.beginTask("Reading " + input, 2);

				try {

					input = getValue();

					if (validator.isUrl(input)) {

						result = validator.isUrlResourceReadable(input);

					} else { // If file path is local

						result = validator.isFileReadable(input);

					}

				} catch (InvalidPathException e) {

					result = e.getMessage();

				}

				monitor.worked(1);

				monitor.setTaskName("Checking validation");

				setValidationError(result);

				monitor.worked(1);

				monitor.done();

			}

		};

		try {

			new ProgressMonitorDialog(getShell()).run(true, false, op);

		} catch (InterruptedException e) {

			return;

		} catch (InvocationTargetException e) {

			Throwable realException = e.getTargetException();

			MessageDialog.openError(getShell(), "Error", realException.getMessage());

			return;

		}

		finally {

			if (validationError != null) {

				setErrorMessage(validationError);

				setValidationError(null);

				return;

			}

		}

		super.okPressed();

	}

	private String validationError;

	private void setValidationError(String error) {

		validationError = error;

	}

	/**

	 * Sets or clears the error message. If not <code>null</code>, the OK button

	 * is disabled.

	 * 

	 * @param errorMessage

	 *            the error message, or <code>null</code> to clear

	 * @since 3.0

	 */

	public void setErrorMessage(String errorMessage) {

		this.errorMessage = errorMessage;

		if (errorMessageText != null && !errorMessageText.isDisposed()) {

			errorMessageText

					.setText(errorMessage == null ? "\n" : errorMessage); //$NON-NLS-1$

			// Disable the error message text control if there is no error, or

			// no error text (empty or whitespace only). Hide it also to avoid

			// color change.

			boolean hasError = errorMessage != null

					&& (StringConverter.removeWhiteSpaces(errorMessage))

							.length() > 0;

			errorMessageText.setEnabled(hasError);

			errorMessageText.setVisible(hasError);

			errorMessageText.getParent().update();

			// Access the ok button by id, in case clients have overridden

			// button creation.

			Control button = getButton(IDialogConstants.OK_ID);

			if (button != null) {

				button.setEnabled(errorMessage == null);

			}

		}

	}

	/**

	 * Validates the input.

	 * <p>

	 * The default implementation of this framework method delegates the request

	 * to the supplied input validator object; if it finds the input invalid,

	 * the error message is displayed in the dialog's message line. This

	 * hook method is called whenever the text changes in the input field.

	 * </p>

	 */

	protected void validateInput() {

		String errorMessage = null;

		if (validator != null) {

			errorMessage = validator.isValid(inputText.getText());

		}

		// It is important not to treat "" (blank error) the same as null

		// (no error)

		setErrorMessage(errorMessage);

	}

}