source: branches/eraser6/Eraser/SettingsPanel.cs @ 307

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using Eraser.Manager;
using Eraser.Manager.Plugin;
using Microsoft.Win32;

namespace Eraser
{
    public partial class SettingsPanel : Eraser.BasePanel
    {
        public SettingsPanel()
        {
            InitializeComponent();
            Dock = DockStyle.None;

            //For new plugins, register the callback.
            Host.Instance.PluginLoad += new Host.OnPluginLoadEventHandler(OnNewPluginLoaded);

            //Load the values
            LoadPluginDependantValues();
            LoadSettings();
        }

        private void OnNewPluginLoaded(PluginInstance instance)
        {
            ListViewItem item = pluginsManager.Items.Add(instance.Plugin.Name);
            item.SubItems.Add(instance.Plugin.Author);
            item.SubItems.Add(instance.Assembly.GetName().Version.ToString());
            item.SubItems.Add(instance.Path);
            item.Tag = instance;
        }

        private void LoadPluginDependantValues()
        {
            //Load the list of plugins
            Host instance = Host.Instance;
            List<PluginInstance>.Enumerator i = instance.Plugins.GetEnumerator();
            while (i.MoveNext())
                OnNewPluginLoaded(i.Current);

            //Refresh the list of languages
            Dictionary<Guid, Language> languages = LanguageManager.GetAll();
            foreach (Language lang in languages.Values)
                uiLanguage.Items.Add(lang);

            //Refresh the list of erasure methods
            Dictionary<Guid, ErasureMethod> methods = ErasureMethodManager.GetAll();
            foreach (ErasureMethod method in methods.Values)
            {
                eraseFilesMethod.Items.Add(method);
                if (method is UnusedSpaceErasureMethod)
                    eraseUnusedMethod.Items.Add(method);
            }

            //Refresh the list of PRNGs
            Dictionary<Guid, PRNG> prngs = PRNGManager.GetAll();
            foreach (PRNG prng in prngs.Values)
                erasePRNG.Items.Add(prng);
        }

        private void LoadSettings()
        {
            foreach (Object lang in uiLanguage.Items)
                if (((Language)lang).GUID == ManagerLibrary.Instance.Settings.UILanguage)
                {
                    uiLanguage.SelectedItem = lang;
                    break;
                }

            foreach (Object method in eraseFilesMethod.Items)
                if (((ErasureMethod)method).GUID == ManagerLibrary.Instance.Settings.DefaultFileErasureMethod)
                {
                    eraseFilesMethod.SelectedItem = method;
                    break;
                }
             
            foreach (Object method in eraseUnusedMethod.Items)
                if (((ErasureMethod)method).GUID == ManagerLibrary.Instance.Settings.DefaultUnusedSpaceErasureMethod)
                {
                    eraseUnusedMethod.SelectedItem = method;
                    break;
                }

            foreach (Object prng in erasePRNG.Items)
                if (((PRNG)prng).GUID == ManagerLibrary.Instance.Settings.ActivePRNG)
                {
                    erasePRNG.SelectedItem = prng;
                    break;
                }

            lockedAllow.Checked =
                ManagerLibrary.Instance.Settings.EraseLockedFilesOnRestart;
            lockedConfirm.Checked =
                ManagerLibrary.Instance.Settings.ConfirmEraseOnRestart;
            schedulerMissedImmediate.Checked =
                ManagerLibrary.Instance.Settings.ExecuteMissedTasksImmediately;
            schedulerMissedIgnore.Checked =
                !ManagerLibrary.Instance.Settings.ExecuteMissedTasksImmediately;
            plausibleDeniability.Checked =
                ManagerLibrary.Instance.Settings.PlausibleDeniability;

            //Select an intelligent default if the settings are invalid.
            string defaults = string.Empty;
            if (uiLanguage.SelectedIndex == -1)
            {
                defaults += "\tUser interface language\n";
            }
            if (eraseFilesMethod.SelectedIndex == -1)
            {
                if (eraseFilesMethod.Items.Count > 0)
                {
                    eraseFilesMethod.SelectedIndex = 0;
                    ManagerLibrary.Instance.Settings.DefaultFileErasureMethod =
                        ((ErasureMethod)eraseFilesMethod.SelectedItem).GUID;
                }
                defaults += "\tDefault file erasure method\n";
            }
            if (eraseUnusedMethod.SelectedIndex == -1)
            {
                if (eraseUnusedMethod.Items.Count > 0)
                {
                    eraseUnusedMethod.SelectedIndex = 0;
                    ManagerLibrary.Instance.Settings.DefaultUnusedSpaceErasureMethod =
                        ((ErasureMethod)eraseUnusedMethod.SelectedItem).GUID;
                }
                defaults += "\tDefault unused space erasure method\n";
            }
            if (erasePRNG.SelectedIndex == -1)
            {
                if (erasePRNG.Items.Count > 0)
                {
                    erasePRNG.SelectedIndex = 0;
                    ManagerLibrary.Instance.Settings.ActivePRNG =
                        ((PRNG)erasePRNG.SelectedItem).GUID;
                }
                defaults += "\tRandomness data source\n";
            }

            //Remind the user.
            if (defaults.Length != 0)
            {
                MessageBox.Show(string.Format("The following settings held invalid values:\n\n" +
                    "{0}\nThese settings have now been set to naive defaults.\n\n" +
                    "Please check that the new settings suit your required level of security.",
                    defaults), "Eraser", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                saveSettings_Click(null, null);
            }
        }

        private void lockedAllow_CheckedChanged(object sender, EventArgs e)
        {
            lockedConfirm.Enabled = lockedAllow.Checked;
        }

        private void pluginsMenu_Opening(object sender, CancelEventArgs e)
        {
            if (pluginsManager.SelectedItems.Count == 1)
            {
                PluginInstance instance = (PluginInstance)pluginsManager.SelectedItems[0].Tag;
                e.Cancel = !instance.Plugin.Configurable;
            }
            else
                e.Cancel = true;
        }

        private void settingsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (pluginsManager.SelectedItems.Count != 1)
                return;
            
            PluginInstance instance = (PluginInstance)pluginsManager.SelectedItems[0].Tag;
            instance.Plugin.DisplaySettings(this);
        }

        private void saveSettings_Click(object sender, EventArgs e)
        {
            //Error checks first.
            errorProvider.Clear();
            if (uiLanguage.SelectedIndex == -1)
            {
                errorProvider.SetError(uiLanguage, "An invalid language was selected.");
                return;
            }
            else if (eraseFilesMethod.SelectedIndex == -1)
            {
                errorProvider.SetError(eraseFilesMethod, "An invalid file erasure method " +
                    "was selected.");
                return;
            }
            else if (eraseUnusedMethod.SelectedIndex == -1)
            {
                errorProvider.SetError(eraseUnusedMethod, "An invalid unused disk space " +
                    "erasure method was selected.");
                return;
            }
            else if (erasePRNG.SelectedIndex == -1)
            {
                errorProvider.SetError(erasePRNG, "An invalid randomness data " +
                    "source was selected.");
                return;
            }

            ManagerLibrary.Instance.Settings.UILanguage =
                ((Language)uiLanguage.SelectedItem).GUID;
            ManagerLibrary.Instance.Settings.DefaultFileErasureMethod =
                ((ErasureMethod)eraseFilesMethod.SelectedItem).GUID;
            ManagerLibrary.Instance.Settings.DefaultUnusedSpaceErasureMethod =
                ((ErasureMethod)eraseUnusedMethod.SelectedItem).GUID;

            PRNG newPRNG = (PRNG)erasePRNG.SelectedItem;
            if (newPRNG.GUID != ManagerLibrary.Instance.Settings.ActivePRNG)
            {
                MessageBox.Show("The new randomness data source will only be used when " +
                    "the next task is run.\nCurrently running tasks will use the old source.",
                    "Eraser", MessageBoxButtons.OK, MessageBoxIcon.Information);
                ManagerLibrary.Instance.Settings.ActivePRNG = newPRNG.GUID;
            }
            ManagerLibrary.Instance.Settings.EraseLockedFilesOnRestart =
                lockedAllow.Checked;
            ManagerLibrary.Instance.Settings.ConfirmEraseOnRestart =
                lockedConfirm.Checked;
            ManagerLibrary.Instance.Settings.ExecuteMissedTasksImmediately =
                schedulerMissedImmediate.Checked;
            ManagerLibrary.Instance.Settings.PlausibleDeniability =
                plausibleDeniability.Checked;
        }
    }
}