/// <summary>
/// Gets a style-specific attribute value.
/// </summary>
/// <typeparam name="T">The type of the attribute value.</typeparam>
/// <param name="style">The style.</param>
/// <param name="name">The name of the attribute.</param>
/// <param name="result">The attribute value.</param>
/// <returns>
/// <see langword="true"/> if the renderer can provide a value for the attribute; otherwise,
/// <see langword="false"/> if the renderer does not know the style or the attribute.
/// </returns>
/// <remarks>
/// This method calls <see cref="OnParseAttribute{T}"/> to convert a
/// <see cref="ThemeAttribute"/> to a value of type <typeparamref name="T"/>.
/// </remarks>
public bool GetAttribute<T>(string style, string name, out T result)
{
result = default(T);
if (style == null)
return false;
if (string.IsNullOrEmpty(name))
return false;
// Get style.
ThemeStyle themeStyle;
bool found = Theme.Styles.TryGet(style, out themeStyle);
if (!found)
return false;
// Search for attribute including style inheritance.
ThemeAttribute attribute = null;
while (attribute == null && themeStyle != null)
{
if (!themeStyle.Attributes.TryGet(name, out attribute))
{
// Try ancestor.
themeStyle = themeStyle.Inherits;
}
}
if (attribute == null)
return false;
return OnParseAttribute(attribute, out result);
}
protected bool OnParseAttribute<T>(ThemeAttribute attribute, out T result)
{
result = default(T);
if (result is Vector2F)
{
result = (T)(object)ThemeHelper.ParseVector2F(attribute.Value);
}
else if (result is Vector3)
{
result = (T)(object)ThemeHelper.ParseVector3(attribute.Value);
}
else if (result is Vector4)
{
result = (T)(object)ThemeHelper.ParseVector4(attribute.Value);
}
else if (typeof(T) == typeof(string) || typeof(T) == typeof(object))
{
result = (T)(object)attribute.Value;
}
else if (result is Color)
{
result = (T)(object)ThemeHelper.ParseColor(attribute.Value, Color.Black);
}
else if (typeof(T).IsAssignableFrom(typeof(Rectangle)))
#else
else if (typeof(T).GetTypeInfo().IsAssignableFrom(typeof(Rectangle).GetTypeInfo()))
{
result = (T)(object)ThemeHelper.ParseRectangle(attribute.Value);
}
else if (typeof(T).IsAssignableFrom(typeof(Texture2D)))
#else
else if (typeof(T).GetTypeInfo().IsAssignableFrom(typeof(Texture2D).GetTypeInfo()))
{
result = (T)(object)GetTexture(attribute.Value);
}
else
{
try
{
result = ObjectHelper.Parse<T>(attribute.Value);
}
catch
{
return false;
}
}
return true;
}