BoundDataGridView.cs :  » Persistence-Frameworks » Ubik » StoresAndStockPricing » Controls » C# / CSharp Open Source

using System;
using System.Collections.Generic;
using System.Text;
using Ubik.Engine.Client;
using System.ComponentModel;
using System.Windows.Forms;

namespace StoresAndStockPricing.Controls{
  public class BoundDataGridView : DataGridView
  {
    private IBoundDataGridViewSource _bindingSource;
    private Transaction _transaction;
    private bool _valueChanged = false;
    private bool _columnsLoaded = false;
    private ListChangedEventHandler _listChangedHander;

    public BoundDataGridView()
    {
      _listChangedHander = new ListChangedEventHandler(BoundDataGridView_ListChanged);
      InitializeComponent();
    }

    /// <summary>
    /// MUST use this rather than DataSource... I need to work out more about rebinding columns otherwise.
    /// </summary>
    public IBoundDataGridViewSource BindingSource
    {
      get
      {
        return _bindingSource;
      }
      set
      {
        if (_bindingSource != null)
        {
          ((System.ComponentModel.IBindingList)_bindingSource).ListChanged -= _listChangedHander;
        }

        _bindingSource = value;

        if (_bindingSource != null)
        {
          ((IBindingList)_bindingSource).ListChanged += _listChangedHander;
        }

        DataSource = (IBindingList)_bindingSource;
      }
    }

    void BoundDataGridView_ListChanged(object sender, System.ComponentModel.ListChangedEventArgs e)
    {
      if (!_columnsLoaded)
      {
        // Have to force the view to re-bind, not sure why...
        // There is probably a better way to do this.
        DataSource = null;
        DataSource = (IBindingList)_bindingSource;
        _columnsLoaded = Columns.Count > 0;
      }
    }

    private void InitializeComponent()
    {
      ((System.ComponentModel.ISupportInitialize)(this)).BeginInit();
      this.SuspendLayout();
      // 
      // BoundDataGridView
      // 
      this.CellBeginEdit += new System.Windows.Forms.DataGridViewCellCancelEventHandler(this.BoundDataGridView_OnCellBeginEdit);
      this.CellEndEdit += new System.Windows.Forms.DataGridViewCellEventHandler(this.BoundDataGridView_OnCellEndEdit);
      this.CellValueChanged += new System.Windows.Forms.DataGridViewCellEventHandler(this.BoundDataGridView_OnCellValueChanged);
      this.DataError += new DataGridViewDataErrorEventHandler(BoundDataGridView_DataError);
      ((System.ComponentModel.ISupportInitialize)(this)).EndInit();
      this.ResumeLayout(false);
    }

    private void BoundDataGridView_DataError(object sender, DataGridViewDataErrorEventArgs e)
    {
      EndTransaction(false);
      e.ThrowException = true;
    }

    private void BoundDataGridView_OnCellBeginEdit(object sender, System.Windows.Forms.DataGridViewCellCancelEventArgs e)
    {
      if (_transaction == null && _bindingSource != null)
        _transaction = _bindingSource.Session.BeginTransaction();
    }

    private void BoundDataGridView_OnCellValueChanged(object sender, System.Windows.Forms.DataGridViewCellEventArgs e)
    {
      _valueChanged = true;
    }

    private void BoundDataGridView_OnCellEndEdit(object sender, System.Windows.Forms.DataGridViewCellEventArgs e)
    {
      EndTransaction(true);
    }

    private void EndTransaction(bool commit)
    {
      if (_transaction == null)
        throw new InvalidOperationException();

      if (!_valueChanged || !commit)
      {
        Transaction aborted = _transaction;
        _transaction = null;
        aborted.Abort();
      }
      else
      {
        _transaction.Commit();
        _transaction = null;
        _valueChanged = false;
      }
    }

    public T GetSelectedItem<T>() where T : Individual
    {
      if (SelectedRows.Count == 1)
        return ((BoundDataGridViewRow<T>)SelectedRows[0].DataBoundItem).Value;
      else
        throw new InvalidOperationException(BoundDataGridViewResources.MultipleItemsSelected);
    }

    public IEnumerable<T> GetSelectedItems<T>() where T : Individual
    {
      foreach (DataGridViewRow row in SelectedRows)
      {
        yield return ((BoundDataGridViewRow<T>)row.DataBoundItem).Value;
      }
    }

    public void SelectItem<T>(T item) where T : Individual
    {
      ClearSelection();

      foreach (DataGridViewRow row in Rows)
      {
        if (((BoundDataGridViewRow<T>)row.DataBoundItem).Value == item)
        {
          row.Selected = true;
          return;
        }
      }
    }
  }
}