ShellCommandErrorDialog.java

/*
 * Copyright 2008-2012 Amazon Technologies, Inc. 
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at:
 * 
 *    http://aws.amazon.com/apache2.0
 *
 * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES 
 * OR CONDITIONS OF ANY KIND, either express or implied. See the 
 * License for the specific language governing permissions and 
 * limitations under the License. 
 */

package com.amazonaws.eclipse.ec2.ui;

import java.util.LinkedList;
import java.util.List;

import org.eclipse.jface.dialogs.MessageDialog;
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.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Link;
import org.eclipse.swt.widgets.Text;

import com.amazonaws.eclipse.core.ui.WebLinkListener;
import com.amazonaws.eclipse.ec2.ShellCommandException;
import com.amazonaws.eclipse.ec2.ShellCommandResults;

/**
 * Dialog for showing the details of a failed attempt at executing a command,
 * including support for possible retries, and directing users to more help.
 */
public class ShellCommandErrorDialog extends MessageDialog {

	private final ShellCommandException sce;
	private Text outputText;
	private Text errorOutputText;
	private List<Button> attemptRadioButtons = new LinkedList<Button>();

	/**
	 * Creates a new ShellCommandErrorDialog, ready to be opened and display
	 * information the specified ShellCommandException.
	 * 
	 * @param sce
	 *            The ShellCommandException to display.
	 */
	public ShellCommandErrorDialog(ShellCommandException sce) {
		super(Display.getDefault().getShells()[0],
				"Error Executing Command",
				null,
				sce.getMessage(),
				MessageDialog.ERROR,
				new String[] {"Ok"},
				1);
		
		this.sce = sce;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.dialogs.MessageDialog#createCustomArea(org.eclipse.swt.widgets.Composite)
	 */
	@Override
	protected Control createCustomArea(Composite parent) {
		Composite composite = new Composite(parent, SWT.NONE);
		composite.setLayoutData(new GridData(GridData.FILL_BOTH));
		composite.setLayout(new GridLayout(1, false));		
	
		if (sce.getNumberOfAttempts() > 1) {
			createAttemptSelectionArea(composite);
			attemptRadioButtons.get(0).setSelection(true);
		}
		createCommandOutputArea(composite);
		createHelpLinkArea(composite);
		
		update();

		return composite;
	}

	/*
	 * Private Interface
	 */

	/**
	 * Creates a new UI section displaying a link where users can go for more
	 * help.
	 * 
	 * @param composite
	 *            The parent composite for this new section.
	 */
	private void createHelpLinkArea(Composite composite) {
		Link link = new Link(composite, SWT.WRAP);
		link.setText("Need help?  " +
				"<a href=\"http://aws.amazon.com/eclipse/\">http://aws.amazon.com/eclipse/</a>");
		WebLinkListener webLinkListener = new WebLinkListener();
		link.addListener(SWT.Selection, webLinkListener);
	}

	/**
	 * Creates a new UI section displaying the details of the selected attempt
	 * to execute a command.
	 * 
	 * @param composite
	 *            The parent composite for this new section.
	 */
	private void createCommandOutputArea(Composite composite) {
		Composite outputComposite = new Composite(composite, SWT.NONE);
		outputComposite.setLayout(new GridLayout(1, false));
		outputComposite.setLayoutData(new GridData(GridData.FILL_BOTH));
		
		Group outputGroup = new Group(outputComposite, SWT.None);
		outputGroup.setLayoutData(new GridData(GridData.FILL_BOTH));
		outputGroup.setLayout(new GridLayout(2, false));
		outputGroup.setText("Command Output:");
		
		newLabel(outputGroup, "Output:");
		outputText = newText(outputGroup, "");
		
		newLabel(outputGroup, "Errors:");
		errorOutputText = newText(outputGroup, "");
	}

	/**
	 * Creates a new UI section displaying a list of attempts that a user can
	 * select to see more information.
	 * 
	 * @param composite
	 *            The parent composite for this new section.
	 */
	private void createAttemptSelectionArea(Composite composite) {
		Composite attemptsComposite = new Composite(composite, SWT.NONE);
		attemptsComposite.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		attemptsComposite.setLayout(new GridLayout(1, true));
		
		Group attemptsGroup = new Group(attemptsComposite, SWT.None);
		attemptsGroup.setLayoutData(new GridData(GridData.FILL_BOTH));
		attemptsGroup.setLayout(new GridLayout(1, false));

		Label l = new Label(attemptsGroup, SWT.WRAP);
		l.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
		l.setText("Select an attempt to see the output from it:");
		
		SelectionListener listener = new SelectionListener() {
			public void widgetDefaultSelected(SelectionEvent e) {
			}
			
			public void widgetSelected(SelectionEvent e) {
				update();
			}				
		};

		attemptRadioButtons = new LinkedList<Button>();
		for (ShellCommandResults results : sce.getShellCommandResults()) {
			Button button = new Button(attemptsGroup, SWT.RADIO);
			button.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
			attemptRadioButtons.add(button);

			button.addSelectionListener(listener);
			
			button.setText("Attempt " + attemptRadioButtons.size() 
					+ "  (exit code: " + results.exitCode + ")");
			button.setData(results);
		}
	}

	/**
	 * Returns the ShellCommandResults associated with the selected command
	 * execution attempt.
	 * 
	 * @return The ShellCommandResults associated with the selected attempt.
	 */
	private ShellCommandResults getSelectedAttempt() {
		for (Button button : attemptRadioButtons) {
			if (button.getSelection()) {
				return (ShellCommandResults)button.getData();
			}
		}

		return sce.getShellCommandResults().get(0);
	}

	/**
	 * Updates the command output section so that the correct output is
	 * displayed based on what command execution attempt is selected.
	 */
	private void update() {
		ShellCommandResults results = getSelectedAttempt();

		outputText.setText(results.output);
		errorOutputText.setText(results.errorOutput);
	}
	
	/**
	 * Utility method for creating a Text widget.
	 */
	private Text newText(Composite composite, String s) {
		Text text = new Text(composite, SWT.READ_ONLY | SWT.BORDER | SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL);
		text.setText(s);
		
		GridData data = new GridData(GridData.FILL_BOTH);
		data.minimumHeight = 80;
		data.heightHint = 100;
		data.minimumWidth  = 100;
		data.widthHint = 250;
		text.setLayoutData(data);
		
		return text;
	}
	
	/**
	 * Utility method for creating a Label widget.
	 */
	private Label newLabel(Composite outputComposite, String text) {
		Label label = new Label(outputComposite, SWT.NONE);
		label.setText(text);
		
		GridData data = new GridData();
		data.verticalAlignment = SWT.TOP;
		label.setLayoutData(data);
		
		return label;
	}
	
}