/// <summary>
/// Draws the HistoryViewItem, rendering it to the Canvas.
/// </summary>
/// <param name="next">The next chronological HistoryViewItem.</param>
/// <param name="currentEvent">The current event in the machine's history.</param>
public void Draw(HistoryViewItem next, HistoryEvent currentEvent)
{
for (int t = 0; t < Events.Count; t++)
{
Draw(Events[t], t, next, currentEvent);
}
}
/// <summary>
/// Draws a given history event at the given position.
/// </summary>
/// <param name="historyEvent">The history event to draw.</param>
/// <param name="x">The position at which to draw the event.</param>
/// <param name="next">The next chronological HistoryViewItem.</param>
/// <param name="currentEvent">The current event in the machine's history.</param>
private void Draw(HistoryEvent historyEvent, int x, HistoryViewItem next, HistoryEvent currentEvent)
{
if (historyEvent == null)
{
return;
}
// Calculate the "centre" of the cell at position x.
double cx = x + 0.5;
double cy = 0.5;
// If the history event isn't "ours", then draw it as a "passthrough" line.
bool passthrough = (HistoryEvent != historyEvent);
if (historyEvent.Parent != null)
{
// Draw a line from our parent.
DrawLine(cx, 1, cx, cy, Brushes.DarkBlue);
}
BookmarkHistoryEvent bookmarkHistoryEvent = historyEvent as BookmarkHistoryEvent;
if (bookmarkHistoryEvent != null && bookmarkHistoryEvent.Bookmark != null && !passthrough)
{
// User bookmarks are drawn as a red dot, system bookmarks as dark red.
DrawDot(cx, bookmarkHistoryEvent.Bookmark.System ? Brushes.DarkRed : Brushes.Crimson, historyEvent != currentEvent);
}
if (passthrough)
{
// A "passthrough" event is drawn as a straight line.
int childNextX = next.EventIndex(historyEvent);
if (childNextX != -1)
{
DrawLine(cx, cy, childNextX + 0.5, 0, Brushes.DarkBlue);
}
}
else if (next != null && historyEvent.Children.Count >= 1)
{
// For history events with children, draw a line from the centre of the cell to each child
for (int c = 0; c < historyEvent.Children.Count; c++)
{
int childNextX = next.EventAncestorIndex(historyEvent.Children[c]);
if (childNextX != -1)
{
DrawLine(cx, cy, childNextX + 0.5, 0, Brushes.DarkBlue);
}
}
}
else
{
// History events with no children are drawn as a terminating dot.
DrawDot(cx, (bookmarkHistoryEvent != null) ? (bookmarkHistoryEvent.Bookmark.System ? Brushes.DarkRed : Brushes.Crimson) : Brushes.DarkBlue, historyEvent != currentEvent);
}
}