static TextViewPosition GetUpDownCaretPosition(TextView textView, TextViewPosition caretPosition, CaretMovementType direction, VisualLine visualLine, TextLine textLine, bool enableVirtualSpace, ref double xPos)
{
// moving up/down happens using the desired visual X position
if (double.IsNaN(xPos))
{
xPos = visualLine.GetTextLineVisualXPosition(textLine, caretPosition.VisualColumn);
}
// now find the TextLine+VisualLine where the caret will end up in
VisualLine targetVisualLine = visualLine;
TextLine targetLine;
int textLineIndex = visualLine.TextLines.IndexOf(textLine);
switch (direction)
{
case CaretMovementType.LineUp: {
// Move up: move to the previous TextLine in the same visual line
// or move to the last TextLine of the previous visual line
int prevLineNumber = visualLine.FirstDocumentLine.LineNumber - 1;
if (textLineIndex > 0)
{
targetLine = visualLine.TextLines[textLineIndex - 1];
}
else if (prevLineNumber >= 1)
{
DocumentLine prevLine = textView.Document.GetLineByNumber(prevLineNumber);
targetVisualLine = textView.GetOrConstructVisualLine(prevLine);
targetLine = targetVisualLine.TextLines[targetVisualLine.TextLines.Count - 1];
}
else
{
targetLine = null;
}
break;
}
case CaretMovementType.LineDown: {
// Move down: move to the next TextLine in the same visual line
// or move to the first TextLine of the next visual line
int nextLineNumber = visualLine.LastDocumentLine.LineNumber + 1;
if (textLineIndex < visualLine.TextLines.Count - 1)
{
targetLine = visualLine.TextLines[textLineIndex + 1];
}
else if (nextLineNumber <= textView.Document.LineCount)
{
DocumentLine nextLine = textView.Document.GetLineByNumber(nextLineNumber);
targetVisualLine = textView.GetOrConstructVisualLine(nextLine);
targetLine = targetVisualLine.TextLines[0];
}
else
{
targetLine = null;
}
break;
}
case CaretMovementType.PageUp:
case CaretMovementType.PageDown: {
// Page up/down: find the target line using its visual position
double yPos = visualLine.GetTextLineVisualYPosition(textLine, VisualYPosition.LineMiddle);
if (direction == CaretMovementType.PageUp)
{
yPos -= textView.RenderSize.Height;
}
else
{
yPos += textView.RenderSize.Height;
}
DocumentLine newLine = textView.GetDocumentLineByVisualTop(yPos);
targetVisualLine = textView.GetOrConstructVisualLine(newLine);
targetLine = targetVisualLine.GetTextLineByVisualYPosition(yPos);
break;
}
default:
throw new NotSupportedException(direction.ToString());
}
if (targetLine != null)
{
double yPos = targetVisualLine.GetTextLineVisualYPosition(targetLine, VisualYPosition.LineMiddle);
int newVisualColumn = targetVisualLine.GetVisualColumn(new Point(xPos, yPos), enableVirtualSpace);
// prevent wrapping to the next line; TODO: could 'IsAtEnd' help here?
int targetLineStartCol = targetVisualLine.GetTextLineVisualStartColumn(targetLine);
if (newVisualColumn >= targetLineStartCol + targetLine.Length)
{
if (newVisualColumn <= targetVisualLine.VisualLength)
{
newVisualColumn = targetLineStartCol + targetLine.Length - 1;
}
}
return(targetVisualLine.GetTextViewPosition(newVisualColumn));
}
else
{
return(caretPosition);
}
}
static void MoveCaretUpDown(TextArea textArea, CaretMovementType direction, VisualLine visualLine, TextLine textLine, int caretVisualColumn)
{
// moving up/down happens using the desired visual X position
double xPos = textArea.Caret.DesiredXPos;
if (double.IsNaN(xPos))
{
xPos = visualLine.GetTextLineVisualXPosition(textLine, caretVisualColumn);
}
// now find the TextLine+VisualLine where the caret will end up in
VisualLine targetVisualLine = visualLine;
TextLine targetLine;
int textLineIndex = visualLine.TextLines.IndexOf(textLine);
switch (direction)
{
case CaretMovementType.LineUp:
{
// Move up: move to the previous TextLine in the same visual line
// or move to the last TextLine of the previous visual line
int prevLineNumber = visualLine.FirstDocumentLine.LineNumber - 1;
if (textLineIndex > 0)
{
targetLine = visualLine.TextLines[textLineIndex - 1];
}
else if (prevLineNumber >= 1)
{
DocumentLine prevLine = textArea.Document.GetLineByNumber(prevLineNumber);
targetVisualLine = textArea.TextView.GetOrConstructVisualLine(prevLine);
targetLine = targetVisualLine.TextLines[targetVisualLine.TextLines.Count - 1];
}
else
{
targetLine = null;
}
break;
}
case CaretMovementType.LineDown:
{
// Move down: move to the next TextLine in the same visual line
// or move to the first TextLine of the next visual line
int nextLineNumber = visualLine.LastDocumentLine.LineNumber + 1;
if (textLineIndex < visualLine.TextLines.Count - 1)
{
targetLine = visualLine.TextLines[textLineIndex + 1];
}
else if (nextLineNumber <= textArea.Document.LineCount)
{
DocumentLine nextLine = textArea.Document.GetLineByNumber(nextLineNumber);
targetVisualLine = textArea.TextView.GetOrConstructVisualLine(nextLine);
targetLine = targetVisualLine.TextLines[0];
}
else
{
targetLine = null;
}
break;
}
case CaretMovementType.PageUp:
case CaretMovementType.PageDown:
{
// Page up/down: find the target line using its visual position
double yPos = visualLine.GetTextLineVisualYPosition(textLine, VisualYPosition.LineMiddle);
if (direction == CaretMovementType.PageUp)
{
yPos -= textArea.TextView.RenderSize.Height;
}
else
{
yPos += textArea.TextView.RenderSize.Height;
}
DocumentLine newLine = textArea.TextView.GetDocumentLineByVisualTop(yPos);
targetVisualLine = textArea.TextView.GetOrConstructVisualLine(newLine);
targetLine = targetVisualLine.GetTextLineByVisualYPosition(yPos);
break;
}
default:
throw new NotSupportedException(direction.ToString());
}
if (targetLine != null)
{
double yPos = targetVisualLine.GetTextLineVisualYPosition(targetLine, VisualYPosition.LineMiddle);
int newVisualColumn = targetVisualLine.GetVisualColumn(new Point(xPos, yPos), textArea.Selection.EnableVirtualSpace);
SetCaretPosition(textArea, targetVisualLine, targetLine, newVisualColumn, false);
textArea.Caret.DesiredXPos = xPos;
}
}