/////////////////////////////////////////////////////////////////////////////////////////////////////
// NON-PUBLIC PROCEDURES
/////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// Examines the cached elements, prunes ones that no longer have valid tags, and returns a match if found.
/// </summary>
/// <param name="tag">The target tag for which to search.</param>
/// <returns>A cached element, if found.</returns>
private AdornmentElement GetCachedElement(object tag)
{
AdornmentElement targetElement = null;
if (tag != null)
{
for (var index = cachedElements.Count - 1; index >= 0; index--)
{
var tagRef = cachedElements[index].Item1;
if (tagRef.IsAlive)
{
// If there is a tag match, use the cached element and remove the entry
if (tagRef.Target == tag)
{
targetElement = cachedElements[index].Item2;
cachedElements.RemoveAt(index);
}
}
else
{
// Remove the entry
cachedElements.RemoveAt(index);
}
}
}
return(targetElement);
}
/////////////////////////////////////////////////////////////////////////////////////////////////////
// PUBLIC PROCEDURES
/////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// Adds an adornment to the <see cref="AdornmentLayer"/>.
/// </summary>
/// <param name="viewLine">The current <see cref="ITextViewLine"/> being examined.</param>
/// <param name="tagRange">The <see cref="ITag"/> and the range it covers.</param>
protected override void AddAdornment(ITextViewLine viewLine, TagSnapshotRange <IntraLineViewportTag> tagRange)
{
// Determine the bounds
var bounds = this.GetAdornmentBounds(tagRange.Tag);
var charBounds = viewLine.GetCharacterBounds(tagRange.SnapshotRange.StartOffset);
bounds.Y = charBounds.Bottom;
// See if a cached version of the element for the tag is available
var element = this.GetCachedElement(tagRange.Tag);
if (element == null)
{
// Create the element
element = new AdornmentElement();
}
// Update the size
element.Width = bounds.Width;
element.Height = bounds.Height;
element.Tag = tagRange.Tag;
// Add the adornment
this.AdornmentLayer.AddAdornment(AdornmentChangeReason.Other, element, bounds.Location, tagRange.Tag.Key, OnAdornmentRemoved);
}
