Classe TableLayoutSettings

// The following class implements a sliding-tile puzzle.// The GridStrip control is a custom ToolStrip that arranges// its ToolStripButton controls in a grid layout. There is // one empty cell, into which the user can slide an adjacent// tile with a drag-and-drop operation. Tiles that are eligible // for moving are highlighted.publicclass GridStrip : ToolStrip
{
    // The button that is the drag source.private ToolStripButton dragButton = null;

    // Settings for the ToolStrip control's TableLayoutPanel.// This provides access to the cell position of each// ToolStripButton.private TableLayoutSettings tableSettings = null;

    // The empty cell. ToolStripButton controls that are// adjacent to this button can be moved to this button's// cell position.private ToolStripButton emptyCellButton = null;

    // The dimensions of each tile. A tile is represented// by a ToolStripButton controls.private Size tileSize = new Size(128, 128);

    // The number of rows in the GridStrip control.privatereadonlyint rows = 5;

    // The number of columns in the GridStrip control.privatereadonlyint columns = 5;

    // The one-time initialzation behavior is enforced// with this field. For more information, see the // OnPaint method.privatebool firstTime = false;

    // This is a required by the Windows Forms designer.private System.ComponentModel.IContainer components;

    // The default constructor.  public GridStrip()
    {
        this.InitializeComponent();

        this.InitializeTableLayoutSettings();
    }

    // This property exposes the empty cell to the // GridStripRenderer class.internal ToolStripButton EmptyCell
    {
        get
        {
            returnthis.emptyCellButton;
        }
    }

    // This utility method initializes the TableLayoutPanel // which contains the ToolStripButton controls.privatevoid InitializeTableLayoutSettings()
    {
        // Specify the numbers of rows and columns in the GridStrip control.this.tableSettings = base.LayoutSettings as TableLayoutSettings;
        this.tableSettings.ColumnCount = this.rows;
        this.tableSettings.RowCount = this.columns;

        // Create a dummy bitmap with the dimensions of each tile.// The GridStrip control sizes itself based on these dimensions.
        Bitmap b = new Bitmap(tileSize.Width, tileSize.Height);

        // Populate the GridStrip control with ToolStripButton controls.for (int i = 0; i < this.tableSettings.ColumnCount; i++)
        {
            for (int j = 0; j < this.tableSettings.RowCount; j++)
            {
                // Create a new ToolStripButton control.
                ToolStripButton btn = new ToolStripButton();
                btn.DisplayStyle = ToolStripItemDisplayStyle.Image;
                btn.Image = b;
                btn.ImageAlign = ContentAlignment.MiddleCenter;
                btn.ImageScaling = ToolStripItemImageScaling.None;
                btn.Margin = Padding.Empty;
                btn.Padding = Padding.Empty;

                // Add the new ToolStripButton control to the GridStrip.this.Items.Add(btn);

                // Set the cell position of the ToolStripButton control.
                TableLayoutPanelCellPosition cellPos = new TableLayoutPanelCellPosition(i, j);
                this.tableSettings.SetCellPosition(btn, cellPos);

                // If this is the ToolStripButton control at cell (0,0),// assign it as the empty cell button.if( i == 0 && j == 0 )
                {
                    btn.Text = "Empty Cell";
                    btn.Image = b;
                    this.emptyCellButton = btn;
                }
            }
        }
    }

    // This method defines the Paint event behavior.// The GridStripRenderer requires that the GridStrip// be fully layed out when it is renders, so this// initialization code cannot be placed in the// GridStrip constructor. By the time the Paint// event is raised, the control layout has been // completed, so the GridStripRenderer can paint// correctly. This one-time initialization is// implemented with the firstTime field.protectedoverridevoid OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        if (!this.firstTime)
        {
            this.Renderer = new GridStripRenderer();

            // Comment this line to see the unscrambled image.this.ScrambleButtons();
            this.firstTime = true;
        }
    }

    // This utility method changes the ToolStripButton control // positions in the TableLayoutPanel. This scrambles the // buttons to initialize the puzzle.privatevoid ScrambleButtons()
    {
        int i = 0;
        int lastElement = this.Items.Count - 1;

        while ( (i != lastElement ) &&
                (lastElement - i > 1) )
        {
            TableLayoutPanelCellPosition pos1 = 
                this.tableSettings.GetCellPosition(this.Items[i]);

            TableLayoutPanelCellPosition pos2 = 
                this.tableSettings.GetCellPosition(this.Items[lastElement]);

            this.tableSettings.SetCellPosition(
                this.Items[i++], 
                pos2);

            this.tableSettings.SetCellPosition(
                this.Items[lastElement--], 
                pos1);
        }
    }

    // This method defines the MouseDown event behavior. // If the user has clicked on a valid drag source, // the drag operation starts.protectedoverridevoid OnMouseDown(MouseEventArgs mea)
    {
        base.OnMouseDown(mea);

        ToolStripButton btn = this.GetItemAt(mea.Location) as ToolStripButton;

        if (btn != null)
        {
            if (this.IsValidDragSource(btn))
            {
                this.dragButton = btn;
            }
        }
    }

    // This method defines the MouseMove event behavior. protectedoverridevoid OnMouseMove(MouseEventArgs mea)
    {
        base.OnMouseMove(mea);

        // Is a drag operation pending?if (this.dragButton != null)
        {
            // A drag operation is pending. Call DoDragDrop to // determine the disposition of the operation.
            DragDropEffects dropEffect = this.DoDragDrop(
                new DataObject(this.dragButton), 
                DragDropEffects.Move);
        }
    }

    // This method defines the DragOver event behavior. protectedoverridevoid OnDragOver(DragEventArgs dea)
    {
        base.OnDragOver(dea);

        // Get the ToolStripButton control // at the given mouse position.
        Point p = new Point(dea.X, dea.Y);
        ToolStripButton item = this.GetItemAt(
            this.PointToClient(p)) as ToolStripButton;

        // If the ToolStripButton control is the empty cell,// indicate that the move operation is valid.if( item == this.emptyCellButton )
        {
            // Set the drag operation to indicate a valid move.
            dea.Effect = DragDropEffects.Move;
        }
    }

    // This method defines the DragDrop event behavior. protectedoverridevoid OnDragDrop(DragEventArgs dea)
    {
        base.OnDragDrop(dea);

        // Did a valid move operation occur?if (dea.Effect == DragDropEffects.Move)
        {
            // The move operation is valid. Adjust the state// of the GridStrip control's TableLayoutPanel,// by swapping the positions of the source button// and the empty cell button.// Get the cell of the control to move.
            TableLayoutPanelCellPosition sourcePos = 
                tableSettings.GetCellPosition(this.dragButton);

            // Get the cell of the emptyCellButton.
            TableLayoutPanelCellPosition dropPos = 
                tableSettings.GetCellPosition(this.emptyCellButton);

            // Move the control to the empty cell.
            tableSettings.SetCellPosition(this.dragButton, dropPos);

            // Set the position of the empty cell to // that of the previously occupied cell.
            tableSettings.SetCellPosition(this.emptyCellButton, sourcePos);

            // Reset the drag operation.this.dragButton = null;
        }
    }

    // This method defines the DragLeave event behavior. // If the mouse leaves the client area of the GridStrip// control, the drag operation is canceled.protectedoverridevoid OnDragLeave(EventArgs e)
    {
        base.OnDragLeave(e);

        // Reset the drag operation.this.dragButton = null;
    }

    // This method defines the ueryContinueDrag event behavior. // If the mouse leaves the client area of the GridStrip// control, the drag operation is canceled.protectedoverridevoid OnQueryContinueDrag(QueryContinueDragEventArgs qcdevent)
    {
        base.OnQueryContinueDrag(qcdevent);

        // Get the current mouse position, in screen coordinates.
        Point mousePos = this.PointToClient(Control.MousePosition);

        // If the mouse position is outside the GridStrip control's// client area, cancel the drag operation. Be sure to// transform the mouse's screen coordinates to client coordinates. if (!this.ClientRectangle.Contains(mousePos))
        {
            qcdevent.Action = DragAction.Cancel;
        }
    }

    // This utility method determines if a button// is positioned relative to the empty cell // such that it can be dragged into the empty cell.privatebool IsValidDragSource(ToolStripButton b)
    {
        TableLayoutPanelCellPosition sourcePos = 
            tableSettings.GetCellPosition(b);

        TableLayoutPanelCellPosition emptyPos = 
            tableSettings.GetCellPosition(this.emptyCellButton);

        return (IsValidDragSource(sourcePos, emptyPos));
    }

    // This utility method determines if a cell position// is adjacent to the empty cell.internalstaticbool IsValidDragSource(
        TableLayoutPanelCellPosition sourcePos, 
        TableLayoutPanelCellPosition emptyPos)
    {
        bool returnValue = false;

        // A cell is considered to be a valid drag source if it// is adjacent to the empty cell. Cells that are positioned// on a diagonal are not valid.if (((sourcePos.Column == emptyPos.Column - 1) && (sourcePos.Row == emptyPos.Row)) ||
            ((sourcePos.Column == emptyPos.Column + 1) && (sourcePos.Row == emptyPos.Row)) ||
            ((sourcePos.Column == emptyPos.Column) && (sourcePos.Row == emptyPos.Row - 1)) ||
            ((sourcePos.Column == emptyPos.Column) && (sourcePos.Row == emptyPos.Row + 1)))
        {
            returnValue = true;
        }

        return returnValue;
    }