//=====================================================================
/// <summary>
/// This is used to clone the column
/// </summary>
/// <returns>A clone of the column</returns>
public override object Clone()
{
RatingColumn clone = (RatingColumn)base.Clone();
clone.ImageList = images;
clone.MaximumRating = maxRating;
return(clone);
}
/// <summary>
/// This is overridden to update the cell value with a new rating value when it is clicked
/// </summary>
/// <param name="e">The event arguments</param>
protected override void OnContentClick(DataGridViewCellEventArgs e)
{
RatingColumn owner = base.OwningColumn as RatingColumn;
int rating;
object newValue = this.NewValue;
if (keyRating != -1)
{
rating = keyRating;
}
else
if (this.MouseRating != -1)
{
rating = this.MouseRating + 1;
}
else
{
rating = -1;
}
if (!base.ReadOnly && base.DataGridView != null && owner != null && rating != -1 &&
rating <= owner.MaximumRating)
{
// Let the user map the rating to a cell value
MapRatingEventArgs mapArgs = new MapRatingEventArgs(e.ColumnIndex, e.RowIndex, rating, rating);
owner.OnMapRatingToValue(mapArgs);
// If the value changed, use that. If the value didn't change, use the new index value but
// convert it to the matching type.
if (mapArgs.Value == null || !mapArgs.Value.Equals(rating))
{
this.NewValue = mapArgs.Value;
}
else
if (newValue is int)
{
this.NewValue = rating;
}
else
if (newValue is short)
{
this.NewValue = (short)rating;
}
else
{
this.NewValue = mapArgs.Value;
}
base.DataGridView.NotifyCurrentCellDirty(true);
base.DataGridView.InvalidateCell(this);
}
}
/// <summary>
/// Change the mouse cursor back to the default when leaving the cell
/// </summary>
/// <param name="rowIndex">The row index of the cell</param>
protected override void OnMouseLeave(int rowIndex)
{
RatingColumn owner = base.OwningColumn as RatingColumn;
if (!base.ReadOnly && owner != null && base.DataGridView.Cursor != owner.OriginalCursor)
{
base.DataGridView.Cursor = owner.OriginalCursor;
}
this.MouseRating = -1;
base.OnMouseLeave(rowIndex);
base.DataGridView.InvalidateCell(base.ColumnIndex, rowIndex);
}
/// <summary>
/// Gets the image to display in the cell
/// </summary>
/// <param name="value">The value to be use in determining the image</param>
/// <param name="rowIndex">The index of the cell's parent row</param>
/// <returns>The image that should be displayed in the cell</returns>
protected override object GetCellImage(object value, int rowIndex)
{
RatingColumn owner = base.OwningColumn as RatingColumn;
// If this is a shared cell, we don't want to draw hot images as they may end up in several places.
// As such, only draw them if the mouse is in the cell being drawn.
Point mouseCell = DataGridViewHelper.MouseEnteredCellAddress(base.DataGridView);
if (owner != null)
{
return(owner.DrawImage(value, rowIndex,
(mouseCell.X == owner.Index && mouseCell.Y == rowIndex) ? this.MouseRating : -1));
}
return(null);
}
/// <summary>
/// Change the mouse pointer to a hand when the mouse moves over one of the images
/// </summary>
/// <param name="e">The event arguments</param>
protected override void OnMouseMove(DataGridViewCellMouseEventArgs e)
{
RatingColumn owner = base.OwningColumn as RatingColumn;
Rectangle content = base.GetContentBounds(e.RowIndex);
Cursor newCursor = null;
int index, width, lastMouseRating = this.MouseRating;
base.OnMouseMove(e);
this.MouseRating = -1;
// Figure out if the mouse is actually over an image
if (owner != null && !base.ReadOnly)
{
newCursor = owner.OriginalCursor;
if (content.Contains(e.Location))
{
width = owner.ImageListInternal.ImageSize.Width;
index = (e.Location.X - content.X) / width;
if (e.Location.X - content.X - (index * width) < width)
{
newCursor = Cursors.Hand;
this.MouseRating = index;
}
}
// Update the cursor if necessary and redraw the cell
if (base.DataGridView != null)
{
if (newCursor != null && base.DataGridView.Cursor != newCursor)
{
base.DataGridView.Cursor = newCursor;
}
if (this.MouseRating != lastMouseRating)
{
base.DataGridView.InvalidateCell(e.ColumnIndex, e.RowIndex);
}
}
}
}
/// <summary>
/// Calculates the preferred size, in pixels, of the cell
/// </summary>
/// <param name="graphics">The graphics context for the cell</param>
/// <param name="cellStyle">The cell style</param>
/// <param name="rowIndex">The index of the cell's parent row</param>
/// <param name="constraintSize">The cell's maximum allowable size</param>
/// <returns>The preferred cell size in pixels</returns>
protected override Size GetPreferredSize(Graphics graphics, DataGridViewCellStyle cellStyle,
int rowIndex, Size constraintSize)
{
Size size;
int widthOffset, heightOffset, freeDimension;
if (base.DataGridView == null || base.OwningColumn == null)
{
return(new Size(-1, -1));
}
if (cellStyle == null)
{
throw new ArgumentNullException("cellStyle");
}
if (constraintSize.Width == 0)
{
if (constraintSize.Height == 0)
{
freeDimension = 0; // Both free
}
else
{
freeDimension = 2; // Width is free
}
}
else
{
freeDimension = 1; // Height is free
}
DataGridViewAdvancedBorderStyle borderStylePlaceholder = new DataGridViewAdvancedBorderStyle();
DataGridViewAdvancedBorderStyle advancedBorderStyle = base.AdjustCellBorderStyle(
base.DataGridView.AdvancedCellBorderStyle, borderStylePlaceholder, false, false, false, false);
Rectangle borderWidths = base.BorderWidths(advancedBorderStyle);
widthOffset = (borderWidths.Left + borderWidths.Width) + cellStyle.Padding.Horizontal;
heightOffset = (borderWidths.Top + borderWidths.Height) + cellStyle.Padding.Vertical;
RatingColumn owner = base.OwningColumn as RatingColumn;
size = new Size(owner.ImageListInternal.ImageSize.Width * owner.MaximumRating,
owner.ImageListInternal.ImageSize.Height);
switch (freeDimension)
{
case 1:
size.Width = 0;
break;
case 2:
size.Height = 0;
break;
}
if (freeDimension != 1)
{
size.Width += widthOffset;
if (base.DataGridView.ShowCellErrors)
{
size.Width = Math.Max(size.Width, widthOffset + 16);
}
}
if (freeDimension != 2)
{
size.Height += heightOffset;
if (base.DataGridView.ShowCellErrors)
{
size.Height = Math.Max(size.Height, heightOffset + 16);
}
}
return(size);
}
