source: stable/HeuristicLab.Problems.Instances.Views/3.3/ProblemInstanceProviderViewGeneric.cs @ 10020

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.ComponentModel;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using HeuristicLab.MainForm;
using HeuristicLab.MainForm.WindowsForms;
using HeuristicLab.PluginInfrastructure;

namespace HeuristicLab.Problems.Instances.Views {
  [View("ProblemInstanceProviderViewGeneric")]
  [Content(typeof(IProblemInstanceProvider<>), IsDefaultView = true)]
  public partial class ProblemInstanceProviderViewGeneric<T> : ProblemInstanceProviderView {

    public new IProblemInstanceProvider<T> Content {
      get { return (IProblemInstanceProvider<T>)base.Content; }
      set { base.Content = value; }
    }

    private IProblemInstanceConsumer<T> GenericConsumer { get { return Consumer as IProblemInstanceConsumer<T>; } }

    private IProblemInstanceConsumer consumer;
    public override IProblemInstanceConsumer Consumer {
      get { return consumer; }
      set {
        consumer = value;
        SetEnabledStateOfControls();
      }
    }

    public ProblemInstanceProviderViewGeneric() {
      InitializeComponent();
    }

    protected override void OnContentChanged() {
      base.OnContentChanged();
      if (Content == null) {
        instancesComboBox.DataSource = null;
      } else {
        instancesComboBox.DisplayMember = "Name";
        var dataDescriptors = Content.GetDataDescriptors().ToList();
        ShowInstanceLoad(dataDescriptors.Any());
        instancesComboBox.DataSource = dataDescriptors;
        instancesComboBox.SelectedIndex = -1;
      }
    }

    protected void ShowInstanceLoad(bool show) {
      if (show) {
        instanceLabel.Show();
        instancesComboBox.Show();
      } else {
        instanceLabel.Hide();
        instancesComboBox.Hide();
      }
    }

    protected override void SetEnabledStateOfControls() {
      base.SetEnabledStateOfControls();
      instancesComboBox.Enabled = !ReadOnly && !Locked && Content != null && GenericConsumer != null;
    }

    private void instancesComboBox_DataSourceChanged(object sender, EventArgs e) {
      var comboBox = (ComboBox)sender;
      if (comboBox.DataSource == null)
        comboBox.Items.Clear();
      toolTip.SetToolTip(comboBox, String.Empty);
    }

    private void instancesComboBox_SelectionChangeCommitted(object sender, System.EventArgs e) {
      toolTip.SetToolTip(instancesComboBox, String.Empty);
      if (instancesComboBox.SelectedIndex >= 0) {
        var descriptor = (IDataDescriptor)instancesComboBox.SelectedItem;

        IContentView activeView = (IContentView)MainFormManager.MainForm.ActiveView;
        var mainForm = (MainForm.WindowsForms.MainForm)MainFormManager.MainForm;
        // lock active view and show progress bar
        mainForm.AddOperationProgressToContent(activeView.Content, "Loading problem instance.");
        // continuation for removing the progess bar from the active view
        Action<Task> removeProgressFromContent = (_) => mainForm.RemoveOperationProgressFromContent(activeView.Content);

        // task structure:
        // loadFromProvider
        // |
        // +-> on fault -> show error dialog -> remove progress bar
        // |
        // `-> success  -> loadToProblem
        //                 |
        //                 +-> on fault -> show error dialog -> remove progress bar
        //                 |
        //                 `-> success -> set tool tip -> remove progress bar
        var loadFromProvider = new Task<T>(() => Content.LoadData(descriptor));

        // success
        var loadToProblem = loadFromProvider
          .ContinueWith(task => GenericConsumer.Load(task.Result), TaskContinuationOptions.OnlyOnRanToCompletion);
        // on error 
        loadFromProvider
          .ContinueWith(task => { ErrorHandling.ShowErrorDialog(String.Format("Could not load the problem instance {0}", descriptor.Name), task.Exception); }, TaskContinuationOptions.OnlyOnFaulted)
          .ContinueWith(removeProgressFromContent);

        // success
        loadToProblem
          .ContinueWith(task => toolTip.SetToolTip(instancesComboBox, descriptor.Description), TaskContinuationOptions.OnlyOnRanToCompletion)
          .ContinueWith(removeProgressFromContent);
        // on error
        loadToProblem.ContinueWith(task => { ErrorHandling.ShowErrorDialog(String.Format("This problem does not support loading the instance {0}", descriptor.Name), task.Exception); }, TaskContinuationOptions.OnlyOnFaulted)
        .ContinueWith(removeProgressFromContent);

        // start async loading task
        loadFromProvider.Start();
      }
    }
  }
}