private void TextDocument_TextSegmentAdded(object sender, AlterTextSegmentArgs e)
{
var textLine = e.TextSegment;
var hdc = this.GetHdc().DangerousGetHandle();
var newInformation = textLine.CalculateVisuals(this, hdc, this.GetTextRectangle(false, true).Width, this.LineHeight);
this.ReleaseHdc();
// Insert an empty one here that is later overwritten in "UpdateVisualInformationLine".
// This insertion is just a placeholder so that the code later knows that all values have changed from the default.
this._textSegmentVisualInformations.Insert(e.LineIndex, new TextSegmentVisualInfos());
this.UpdateVisualInformationLine(e.LineIndex, e.TextSegment, e.CharacterCountDifference, newInformation);
}
private void TextDocument_TextSegmentAlter(object sender, AlterTextSegmentArgs e)
{
var textLine = e.TextSegment;
if (this._textSegmentVisualInformations.Count - 1 < e.LineIndex)
{
// Add an empty one so that the check below returns that the previous line count was 0.
this._textSegmentVisualInformations.Add(new TextSegmentVisualInfos());
}
var hdc = this.GetHdc().DangerousGetHandle();
var information = textLine.CalculateVisuals(this, hdc, this.GetTextRectangle(false, true).Width, this.LineHeight);
this.ReleaseHdc();
this.UpdateVisualInformationLine(e.LineIndex, e.TextSegment, e.CharacterCountDifference, information);
}
private void TextDocument_TextSegmentRemoved(object sender, AlterTextSegmentArgs e)
{
var textLine = e.TextSegment;
// Remove the line count.
this._visualLineCount -= this.GetVisualInformation(e.LineIndex).GetLineCountVisual(e.TextColumnIndex);
this._layoutLinesOverflow.Remove(textLine); // Remove any potential width overflow the line had.
this._textSegmentVisualInformations.RemoveAt(e.LineIndex);
if (Focused == false)
{
// If it is not focused, it means that this is probably a virtual copy of the text control,
// and we need to make it keep the same selection start so it does not jump around.
if (e.TextSegment.Index <= this.SelectionStart)
{
this.SelectionStart += e.CharacterCountDifference;
}
}
}
