SourceGrid.GridVirtual.ProcessSpecialGridKey C# (CSharp) Method

        public virtual void ProcessSpecialGridKey(KeyEventArgs e)
        {
            if (e.Handled)
                return;

            bool enableArrows,enableTab,enablePageDownUp;
            enableArrows = enableTab = enablePageDownUp = false;

            if ( (SpecialKeys & GridSpecialKeys.Arrows) == GridSpecialKeys.Arrows)
                enableArrows = true;
            if ( (SpecialKeys & GridSpecialKeys.PageDownUp) == GridSpecialKeys.PageDownUp)
                enablePageDownUp = true;
            if ( (SpecialKeys & GridSpecialKeys.Tab) == GridSpecialKeys.Tab)
                enableTab = true;

            bool enableEscape = false;
            if ( (SpecialKeys & GridSpecialKeys.Escape) == GridSpecialKeys.Escape)
                enableEscape = true;
            bool enableEnter = false;
            if ( (SpecialKeys & GridSpecialKeys.Enter) == GridSpecialKeys.Enter)
                enableEnter = true;

            #region Processing keys
            //Escape
            if (e.KeyCode == Keys.Escape && enableEscape)
            {
                CellContext focusCellContext = new CellContext(this, Selection.ActivePosition);
                if (focusCellContext.Cell != null && focusCellContext.IsEditing())
                {
                    if (focusCellContext.EndEdit(true))
                        e.Handled = true;
                }
            }

            //Enter
            if (e.KeyCode == Keys.Enter && enableEnter)
            {
                CellContext focusCellContext = new CellContext(this, Selection.ActivePosition);
                if (focusCellContext.Cell != null && focusCellContext.IsEditing())
                {
                    focusCellContext.EndEdit(false);

                    e.Handled = true;
                }
            }

            //Tab
            if (e.KeyCode == Keys.Tab && enableTab)
            {
                CellContext focusCellContext = new CellContext(this, Selection.ActivePosition);
                if (focusCellContext.Cell != null && focusCellContext.IsEditing())
                {
                    //se l'editing non riesce considero il tasto processato
                    // altrimenti no, in questo modo il tab ha effetto anche per lo spostamento
                    if (focusCellContext.EndEdit(false) == false)
                    {
                        e.Handled = true;
                        return;
                    }
                }
            }
            #endregion

            #region Navigate keys: arrows, tab and PgDown/Up
            if (e.KeyCode == Keys.Down && enableArrows)
            {
                Selection.MoveActiveCell(1, 0);
                e.Handled = true;
            }
            else if (e.KeyCode == Keys.Up && enableArrows)
            {
                Selection.MoveActiveCell(-1, 0);
                e.Handled = true;
            }
            else if (e.KeyCode == Keys.Right && enableArrows)
            {
                Selection.MoveActiveCell(0, 1);
                e.Handled = true;
            }
            else if (e.KeyCode == Keys.Left && enableArrows)
            {
                Selection.MoveActiveCell(0, -1);
                e.Handled = true;
            }
            else if (e.KeyCode == Keys.Tab && enableTab)
            {
                //If the tab failed I automatically select the next control in the form (SelectNextControl)

                if (e.Modifiers == Keys.Shift) // backward
                {
                    if (Selection.MoveActiveCell(0, -1, -1, int.MaxValue) == false)
                        FindForm().SelectNextControl(this, false, true, true, true);
                    e.Handled = true;
                }
                else //forward
                {
                    if (Selection.MoveActiveCell(0, 1, 1, int.MinValue) == false)
                        FindForm().SelectNextControl(this, true, true, true, true);
                    e.Handled = true;
                }
            }
            else if ( (e.KeyCode == Keys.PageUp || e.KeyCode == Keys.PageDown)
                   && enablePageDownUp)
            {
                Point focusPoint = PositionToRectangle(Selection.ActivePosition).Location;
                focusPoint.Offset(1, 1); //in modo da entrare nella cella

                if (e.KeyCode == Keys.PageDown)
                    CustomScrollPageDown();
                else if (e.KeyCode == Keys.PageUp)
                    CustomScrollPageUp();

                Position newPosition = PositionAtPoint(focusPoint);
                if (Selection.CanReceiveFocus(newPosition))
                    Selection.Focus(newPosition, true);

                e.Handled = true;
            }
            #endregion

            #region Clipboard
            bool pasteEnabled = (ClipboardMode & ClipboardMode.Paste) == ClipboardMode.Paste;
            bool copyEnabled = (ClipboardMode & ClipboardMode.Copy) == ClipboardMode.Copy;
            bool cutEnabled = (ClipboardMode & ClipboardMode.Cut) == ClipboardMode.Cut;
            bool deleteEnabled = (ClipboardMode & ClipboardMode.Delete) == ClipboardMode.Delete;

            RangeRegion selRegion = Selection.GetSelectionRegion();

            //Paste
            if (e.Control && e.KeyCode == Keys.V && pasteEnabled && selRegion.IsEmpty() == false)
            {
                RangeData rngData = RangeData.ClipboardGetData();

                if (rngData != null)
                {
                    Range rng = selRegion.GetRanges()[0];

                    Range destinationRange = rngData.FindDestinationRange(this, rng.Start);

                    rngData.WriteData(this, destinationRange);
                    e.Handled = true;

                    Selection.ResetSelection(true);
                    Selection.SelectRange(destinationRange, true);
                }
            }
            //Copy
            else if (e.Control && e.KeyCode == Keys.C && copyEnabled && selRegion.IsEmpty() == false)
            {
                Range rng = selRegion.GetRanges()[0];

                RangeData data = new RangeData();
                data.LoadData(this, rng, rng.Start, CutMode.None);
                RangeData.ClipboardSetData(data);

                e.Handled = true;
            }
            //Cut
            else if (e.Control && e.KeyCode == Keys.X && cutEnabled && selRegion.IsEmpty() == false)
            {
                Range rng = selRegion.GetRanges()[0];

                RangeData data = new RangeData();
                data.LoadData(this, rng, rng.Start, CutMode.CutImmediately);
                RangeData.ClipboardSetData(data);

                e.Handled = true;
            }
            //Delete
            else if (e.KeyCode == Keys.Delete && deleteEnabled)
            {
                ClearValues(selRegion);

                e.Handled = true;
            }
            #endregion
        }