private ModTag HitTest(IEnumerable <string> tags, Graphics g, CellEventArgs e)
{
if (tags == null || e.SubItem == null)
{
return(null);
}
var bounds = e.SubItem.Bounds;
var offset = new Point(bounds.X + TagRenderInfo.rX,
bounds.Y + TagRenderInfo.rY);
var tagList = AvailableTags.Where(t => tags.Select(s => s.ToLower()).Contains(t.Key)).Select(kvp => kvp.Value);
foreach (var tag in tagList)
{
var tagSize = g.MeasureString(tag.Label, e.SubItem.Font).ToSize();
var renderInfo = new TagRenderInfo(offset, bounds, tagSize, Color.Black);
if (renderInfo.HitBox.Contains(e.Location))
{
return(tag);
}
offset.X += renderInfo.HitBox.Width + TagRenderInfo.rX;
// stop drawing outside of the column bounds
if (offset.X > bounds.Right)
{
break;
}
}
return(null);
}
/// <summary>
/// Arranges the tags to form the distinctive tag cloud layout.
/// </summary>
public void Arrange()
{
RectangleF totalBounds = RectangleF.Empty;
Random rnd = IsDeterministic ? new Random(0) : new Random();
_renderItems.Clear();
CycleCount = 0;
// sort tags by frequency (highest first)
var orderedItems = Items.OrderByDescending(x => x.Frequency);
int maxFrequency = orderedItems.Select(x => x.Frequency).DefaultIfEmpty(0).First();
int minFrequency = orderedItems.Select(x => x.Frequency).DefaultIfEmpty(0).Last();
foreach (TagItem tag in orderedItems)
{
RectangleF bestBounds = RectangleF.Empty;
int bestDist = 0;
// calculate font size to use
float scale = (maxFrequency != minFrequency)
? ((float)(tag.Frequency - minFrequency) / (float)(maxFrequency - minFrequency))
: 0;
float fontSize = BASE_FONT_SIZE + (BASE_FONT_SIZE * (FontSizeGradient * scale));
// measure text and calculate bounds
SizeF sz;
using (Font font = new Font(FontFamily, fontSize, FontStyle)) {
sz = TextRenderer.MeasureText(tag.Text, font, Size.Empty, TEXT_FORMAT_FLAGS);
}
SizeF offset = new SizeF(-(sz.Width / 2f), -(sz.Height / 2f));
RectangleF tagBounds = new RectangleF(offset.ToPointF(), sz);
// initialise rendering info with what we know so far
TagRenderInfo info = new TagRenderInfo()
{
Item = tag, FontSize = fontSize
};
// try a random subset of the angles between 0 and 360 degrees
foreach (int angle in Enumerable.Range(0, 360).Shuffle(rnd).Take(90))
{
int tagDist = 0;
while (true)
{
// measure outward from the origin
PointF p = PointF.Empty.GetRadialPoint(angle, tagDist);
tagBounds.Location = PointF.Add(p, offset);
// check whether tag would overlap (collide) with previously-placed tags
bool collision = false;
foreach (var other in _renderItems)
{
CycleCount++;
if (other.Bounds.IntersectsWith(tagBounds))
{
collision = true;
break;
}
}
// once there are no collisions this location becomes a candidate angle
if (!collision)
{
break;
}
// ...otherwise, increase distance from origin and try again
tagDist += 5;
// if we've already exceeded the most optimal distance, we can stop here
if ((bestDist != 0) && (tagDist > bestDist))
{
break;
}
}
// determine whether this candidate angle produces the most optimal solution
RectangleF tryBounds = RectangleF.Union(totalBounds, tagBounds);
float tryArea = (tryBounds.Width * tryBounds.Height);
float bestArea = (bestBounds.Width * bestBounds.Height);
float tryAspectDiff = Math.Abs((tryBounds.Width / tryBounds.Height) - PreferredAspectRatio);
float bestAspectDiff = Math.Abs((bestBounds.Width / bestBounds.Height) - PreferredAspectRatio);
bool isBest = (bestBounds.IsEmpty || (tryArea < bestArea)) &&
(bestBounds.IsEmpty || (tryAspectDiff < bestAspectDiff)) &&
((bestDist == 0) || (tagDist <= bestDist));
if (isBest)
{
// this becomes the new most optimal solution (until/if a better one is found)
bestBounds = tryBounds;
bestDist = tagDist;
info.Bounds = tagBounds;
// if the total bounds did not increase at all, skip over the remaining angles
if (bestBounds == totalBounds)
{
break;
}
}
}
// commit the current tag
_renderItems.AddLast(info);
totalBounds = bestBounds;
}
Bounds = totalBounds;
}
