/// <summary>
/// Paint a preview of the <see cref="Image" /> specified by
/// the image index provided by the <see cref="PaintValueEventArgs" />
/// </summary>
/// <param name="pe">The PaintValue event args</param>
public override void PaintValue(PaintValueEventArgs pe)
{
int imageIndex = -1;
// value is the image index
if (pe.Value != null)
{
try
{
imageIndex = (int)Convert.ToUInt16(pe.Value.ToString());
}
catch { }
}
// no instance, or the instance represents an undefined image
if ((pe.Context.Instance == null) || (imageIndex < 0))
{
return;
}
// get the image set
ImageSet imageSet = GetImageSet(pe.Context.Instance);
// make sure everything is valid
if ((imageSet == null) || (imageSet.Count == 0) || (imageIndex >= imageSet.Count))
{
return;
}
// Draw the preview image
pe.Graphics.DrawImage(imageSet.Images[imageIndex], pe.Bounds);
}
/// <summary>
/// Handle a conversion
/// </summary>
/// <param name="context">designer context</param>
/// <param name="culture">globalization info</param>
/// <param name="value">The value to be converted</param>
/// <param name="destinationType">Target type</param>
/// <returns>An instance of the <c>destinationType</c></returns>
/// <remarks>This code specifically handles conversion to a <see cref="InstanceDescriptor" /> so that
/// the <see cref="ImageSet" /> can be created using a constructor of the form:
/// <code>
/// new ImageSet(<see cref="System.Drawing.Size" />,<see cref="Color" />) ;
/// </code><para>
/// Note, the <see cref="InstanceDescriptor" /> is told that the instance may need further
/// initialization beyond the values provided to the constructor
/// </para></remarks>
public override object ConvertTo(
ITypeDescriptorContext context,
System.Globalization.CultureInfo culture,
object value,
Type destinationType
)
{
if ((destinationType == typeof(InstanceDescriptor)) && (value is ImageSet))
{
ImageSet imageSet = value as ImageSet;
ConstructorInfo ctorInfo = typeof(ImageSet).GetConstructor(new Type[] { typeof(Size), typeof(Color) });
if (ctorInfo != null)
{
return(new InstanceDescriptor(ctorInfo, new object[] { imageSet.Size, imageSet.TransparentColor }, false));
}
}
return(base.ConvertTo(context, culture, value, destinationType));
}
/// <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);
}
