private void UpdateVerticalScrollbar()
{
var count = LogSource?.GetProperty(Properties.LogEntryCount) ?? 0;
var totalHeight = count * _textSettings.LineHeight;
var usableHeight = PartTextCanvas.ActualHeight;
if (totalHeight > usableHeight)
{
_verticalScrollBar.Minimum = 0;
_verticalScrollBar.Maximum = Math.Ceiling((totalHeight - usableHeight) / _textSettings.LineHeight) *
_textSettings.LineHeight;
_verticalScrollBar.ViewportSize = usableHeight;
_verticalScrollBar.Visibility = Visibility.Visible;
}
else
{
_verticalScrollBar.Minimum = 0;
_verticalScrollBar.Maximum = 0;
_verticalScrollBar.ViewportSize = usableHeight;
_verticalScrollBar.Visibility = Visibility.Collapsed;
}
}
public LogSourceSection CalculateVisibleSection()
{
if (_logSource == null)
{
return(new LogSourceSection(0, 0));
}
double maxLinesInViewport = (ActualHeight - _yOffset) / _textSettings.LineHeight;
var maxCount = (int)Math.Ceiling(maxLinesInViewport);
var logLineCount = LogSource.GetProperty(Properties.LogEntryCount);
// Somebody may have specified that he wants to view line X, but if the source
// doesn't offer this line (yet), then we must show something else...
var actualCurrentLine = _currentLine >= logLineCount?Math.Max(0, logLineCount - maxCount) : _currentLine;
int linesLeft = logLineCount - actualCurrentLine;
int count = Math.Min(linesLeft, maxCount);
if (count < 0)
{
return(new LogSourceSection());
}
return(new LogSourceSection(actualCurrentLine, count));
}