/// <summary>
/// Returns the .NET color that matches an element's background color.
/// </summary>
/// <param name="element"></param>
/// <param name="detectImage">
/// Takes background-image into account when looking for background color.
/// This is positionally sensitive so if you're not sure if your elements
/// are in the "correct" positions relative to each other (such as in
/// Web Layout view) you may want to set this to false.
/// </param>
/// <param name="pageUrl">The URL that should be used to escape relative background image paths. Can be null.</param>
/// <param name="defaultColor"></param>
/// <returns></returns>
public static Color GetBackgroundColor(IHTMLElement element, bool detectImage, string pageUrl, Color defaultColor)
{
Rectangle childBounds = new Rectangle(HTMLElementHelper.CalculateOffset(element), new Size(element.offsetWidth, element.offsetHeight));
while (element != null)
{
IHTMLCurrentStyle style = ((IHTMLElement2)element).currentStyle;
string colorStr = style.backgroundColor as string;
if (!string.IsNullOrEmpty(colorStr) && colorStr != "transparent")
{
if (colorStr == "inherit")
{
detectImage = false;
}
else
{
return(GetColorFromHexColor(ParseColorToHex(colorStr), defaultColor));
}
}
string imageUrl = style.backgroundImage;
if (detectImage &&
!string.IsNullOrEmpty(imageUrl) &&
imageUrl != "none" &&
(style.backgroundRepeat == "repeat" || style.backgroundRepeat == "repeat-y"))
{
StyleUrl styleUrl = new CssParser(imageUrl.Trim()).Next() as StyleUrl;
Trace.Assert(styleUrl != null, "Style URL could not be parsed");
if (styleUrl != null)
{
// If there's a background image URL...
string url = styleUrl.LiteralText;
using (Stream imageStream = GetStreamForUrl(url, pageUrl, element))
{
if (imageStream != null)
{
// ...and we were able to open/download it...
using (Image image = Image.FromStream(imageStream))
{
if (image is Bitmap)
{
// ...and it's a Bitmap, then use it to get the color.
Rectangle containerBounds = new Rectangle(HTMLElementHelper.CalculateOffset(element), new Size(element.offsetWidth, element.offsetHeight));
Color color = GetColorFromBackgroundImage((Bitmap)image,
childBounds,
containerBounds,
style);
// We can't use semi-transparent backgrounds, keep looking
if (color.A == 255)
{
return(color);
}
}
}
}
}
}
}
element = element.parentElement;
}
return(defaultColor);
}
