/// <summary>
/// Splits the element.
/// </summary>
/// <param name="splitStartOffset">Position inside this element at which it should be broken</param>
/// <param name="elements">The collection of line elements</param>
/// <param name="elementIndex">The index at which this element is in the elements list.</param>
public void Split(int splitStartOffset, IList<VisualLineElement> elements, int elementIndex)
{
if (splitStartOffset <= Offset || splitStartOffset >= Offset + Length)
throw new ArgumentOutOfRangeException("splitStartOffset", splitStartOffset, "Value must be between " + (Offset + 1) + " and " + (Offset + Length - 1));
if (elements == null)
throw new ArgumentNullException("elements");
if (elements[elementIndex] != this)
throw new ArgumentException("Invalid elementIndex - couldn't find this element at the index");
int part1Length = splitStartOffset - Offset;
int part2Length = Length - part1Length;
Length = part1Length;
UpdateText();
var splitPart = new VisualLineElement((VisualLine) Parent, splitStartOffset, part2Length);
elements.Insert(elementIndex + 1, splitPart);
}
/// <summary>
/// Applies a highlighting color to a visual line element.
/// </summary>
protected virtual void ApplyColorToElement(VisualLineElement element, HighlightingColor color)
{
element.TextRunProperties = color.Apply(element.TextRunProperties);
}
void PerformVisualElementConstruction(VisualLineElementGenerator[] generators)
{
TextDocument document = TextLayer.Document;
int offset = DocumentLine.Offset;
int currentLineEnd = offset + DocumentLine.Length;
int askInterestOffset = 0; // 0 or 1
while (offset + askInterestOffset <= currentLineEnd)
{
int textLineEndOffset = currentLineEnd;
foreach (VisualLineElementGenerator g in generators)
{
g.cachedInterest = g.GetFirstInterestedOffset(offset + askInterestOffset);
if (g.cachedInterest != -1)
{
if (g.cachedInterest < offset)
{
throw new ArgumentOutOfRangeException(g.GetType().Name + ".GetFirstInterestedOffset",
g.cachedInterest,
"GetFirstInterestedOffset must not return an offset less than startOffset. Return -1 to signal no interest.");
}
if (g.cachedInterest < textLineEndOffset)
{
textLineEndOffset = g.cachedInterest;
}
}
}
Debug.Assert(textLineEndOffset >= offset);
if (textLineEndOffset > offset)
{
int textElementLength = textLineEndOffset - offset;
var element = new VisualLineElement(this, offset, textElementLength);
elements.Add(element);
offset = textLineEndOffset;
}
// If no elements constructed / only zero-length elements constructed:
// do not asking the generators again for the same location (would cause endless loop)
askInterestOffset = 1;
foreach (VisualLineElementGenerator g in generators)
{
if (g.cachedInterest == offset)
{
VisualLineElement element = g.ConstructElement(offset);
if (element != null)
{
elements.Add(element);
if (element.Text.Length > 0)
{
// a non-zero-length element was constructed
askInterestOffset = 0;
offset += element.Text.Length;
if (offset > currentLineEnd)
{
DocumentLine newEndLine = document.GetLineByOffset(offset);
currentLineEnd = newEndLine.Offset + newEndLine.Length;
if (currentLineEnd < offset)
{
throw new InvalidOperationException(
"The VisualLineElementGenerator " + g.GetType().Name +
" produced an element which ends within the line delimiter");
}
}
break;
}
}
}
}
}
}
void PerformVisualElementConstruction(VisualLineElementGenerator[] generators)
{
TextDocument document = TextLayer.Document;
int offset = DocumentLine.Offset;
int currentLineEnd = offset + DocumentLine.Length;
int askInterestOffset = 0; // 0 or 1
while (offset + askInterestOffset <= currentLineEnd) {
int textLineEndOffset = currentLineEnd;
foreach (VisualLineElementGenerator g in generators) {
g.cachedInterest = g.GetFirstInterestedOffset(offset + askInterestOffset);
if (g.cachedInterest != -1) {
if (g.cachedInterest < offset)
throw new ArgumentOutOfRangeException(g.GetType().Name + ".GetFirstInterestedOffset",
g.cachedInterest,
"GetFirstInterestedOffset must not return an offset less than startOffset. Return -1 to signal no interest.");
if (g.cachedInterest < textLineEndOffset)
textLineEndOffset = g.cachedInterest;
}
}
Debug.Assert(textLineEndOffset >= offset);
if (textLineEndOffset > offset) {
int textElementLength = textLineEndOffset - offset;
var element = new VisualLineElement(this, offset, textElementLength);
elements.Add(element);
offset = textLineEndOffset;
}
// If no elements constructed / only zero-length elements constructed:
// do not asking the generators again for the same location (would cause endless loop)
askInterestOffset = 1;
foreach (VisualLineElementGenerator g in generators) {
if (g.cachedInterest == offset) {
VisualLineElement element = g.ConstructElement(offset);
if (element != null) {
elements.Add(element);
if (element.Text.Length > 0) {
// a non-zero-length element was constructed
askInterestOffset = 0;
offset += element.Text.Length;
if (offset > currentLineEnd) {
DocumentLine newEndLine = document.GetLineByOffset(offset);
currentLineEnd = newEndLine.Offset + newEndLine.Length;
if (currentLineEnd < offset) {
throw new InvalidOperationException(
"The VisualLineElementGenerator " + g.GetType().Name +
" produced an element which ends within the line delimiter");
}
}
break;
}
}
}
}
}
}
