/// <summary>
/// When editing an image index value, let the user choose an image from
/// a popup that displays all the images in the associated <see cref="ImageSet" />
/// </summary>
/// <param name="context">designer context</param>
/// <param name="provider">designer service provider</param>
/// <param name="value">image index item</param>
/// <returns>An image index (selected from the popup) or -1 if the user canceled the
/// selection</returns>
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
wfes = (IWindowsFormsEditorService)
provider.GetService(typeof(IWindowsFormsEditorService));
if ((wfes == null) || (context == null))
{
return(null);
}
// Get the image set
ImageSet imageSet = GetImageSet(context.Instance);
// anything to show?
if ((imageSet == null) || (imageSet.Count == 0))
{
return(-1);
}
// Create an image panel that is close to square
Size dims = ImagePanel.CalculateBestDimensions(imageSet.Count, ImagePanel.PanelSizeHints.MinimizeBoth);
imagePanel = new ImagePanel((Bitmap)imageSet.Preview, imageSet.Count, dims.Height, dims.Width);
// set the current image index value as the default selection
imagePanel.DefaultImage = (int)value;
// no grid
imagePanel.GridColor = Color.Empty;
// listen for an image to be selected
imagePanel.ImageSelected += new EventHandler(imagePanel_ImageSelected);
// show the popup as a drop-down
wfes.DropDownControl(imagePanel);
// return the selection (or the original value if none selected)
return((selectedIndex != -1) ? selectedIndex : (int)value);
}