public string GetSearchString()
{
var searchString = Document.Selection.Text.Trim();
if (searchString.Contains(RichEditBoxDefaultLineEnding.ToString()))
{
return(string.Empty);
}
var document = GetText();
if (string.IsNullOrEmpty(searchString) && Document.Selection.StartPosition < document.Length)
{
var startIndex = Document.Selection.StartPosition;
var endIndex = startIndex;
for (; startIndex >= 0; startIndex--)
{
if (!char.IsLetterOrDigit(document[startIndex]))
{
break;
}
}
for (; endIndex < document.Length; endIndex++)
{
if (!char.IsLetterOrDigit(document[endIndex]))
{
break;
}
}
if (startIndex != endIndex)
{
return(document.Substring(startIndex + 1, endIndex - startIndex - 1));
}
}
return(searchString);
}
/// <summary>
/// Add indentation based on current selection
/// </summary>
/// <param name="indent">
/// indent == -1 meaning '/t' should be used, otherwise it equals to number of spaces
/// </param>
private void AddIndentation(int indent)
{
GetTextSelectionPosition(out var start, out var end);
GetLineColumnSelection(out var startLine,
out var endLine,
out var startColumn,
out var endColumn,
out _,
out _);
var document = GetText();
var lines = GetDocumentLinesCache();
var tabStr = indent == -1 ? "\t" : new string(' ', indent);
// Handle single line selection scenario where part of the line is selected
if (startLine == endLine)
{
Document.Selection.TypeText(tabStr);
Document.Selection.StartPosition = Document.Selection.EndPosition;
return;
}
var startLineInitialIndex = start - startColumn + 1;
var endLineFinalIndex = end - endColumn + lines[endLine - 1].Length + 1;
if (endLineFinalIndex > document.Length)
{
endLineFinalIndex = document.Length;
}
var indentAmount = indent == -1 ? 1 : indent;
start += indentAmount;
var indentedStringBuilder = new StringBuilder();
for (var i = startLine - 1; i < endLine; i++)
{
indentedStringBuilder.Append(string.Concat(tabStr, lines[i],
(i < endLine - 1 || (endLine == lines.Length - 2 && string.IsNullOrEmpty(lines[endLine])))
? RichEditBoxDefaultLineEnding.ToString()
: string.Empty));
end += indentAmount;
}
if (string.Equals(document.Substring(startLineInitialIndex, endLineFinalIndex - startLineInitialIndex),
indentedStringBuilder.ToString()))
{
return;
}
if (Document.Selection.Text.EndsWith(RichEditBoxDefaultLineEnding) && endLineFinalIndex < document.Length)
{
indentedStringBuilder.Append(RichEditBoxDefaultLineEnding);
if (string.Equals(document.Substring(startLineInitialIndex, endLineFinalIndex - startLineInitialIndex),
indentedStringBuilder.ToString()))
{
return;
}
}
Document.Selection.GetRect(Windows.UI.Text.PointOptions.Transform, out Windows.Foundation.Rect rect,
out var _);
GetScrollViewerPosition(out var horizontalOffset, out var verticalOffset);
var wasSelectionInView = IsSelectionRectInView(rect, horizontalOffset, verticalOffset);
var newContent = document.Remove(startLineInitialIndex, endLineFinalIndex - startLineInitialIndex)
.Insert(startLineInitialIndex, indentedStringBuilder.ToString());
Document.SetText(TextSetOptions.None, newContent);
Document.Selection.SetRange(start, end);
// After SetText() and SetRange(), RichEdit will scroll selection into view and change scroll viewer's position even if it was already in the viewport
// It is better to keep its original scroll position after changing the indent in this case
if (wasSelectionInView)
{
_contentScrollViewer.ChangeView(
horizontalOffset,
verticalOffset,
zoomFactor: null,
disableAnimation: true);
}
}
/// <summary>
/// Remove indentation based on current selection
/// </summary>
/// <param name="indent">
/// indent == -1 meaning '/t' should be used, otherwise it equals to number of spaces
/// </param>
private void RemoveIndentation(int indent)
{
GetTextSelectionPosition(out var start, out var end);
GetLineColumnSelection(out var startLine,
out var endLine,
out var startColumn,
out var endColumn,
out _,
out _);
var document = GetText();
var lines = GetDocumentLinesCache();
var startLineInitialIndex = start - startColumn + 1;
var endLineFinalIndex = end - endColumn + lines[endLine - 1].Length + 1;
if (endLineFinalIndex > document.Length)
{
endLineFinalIndex = document.Length;
}
if (startLineInitialIndex == endLineFinalIndex)
{
return;
}
var indentedStringBuilder = new StringBuilder();
for (var i = startLine - 1; i < endLine; i++)
{
var lineTrailingString = (i < endLine - 1 || (endLine == lines.Length - 2 && string.IsNullOrEmpty(lines[endLine])))
? RichEditBoxDefaultLineEnding.ToString()
: string.Empty;
if (lines[i].StartsWith('\t'))
{
indentedStringBuilder.Append(lines[i].Remove(0, 1) + lineTrailingString);
end--;
}
else
{
var spaceCount = 0;
var indentAmount = indent == -1 ? 4 : indent;
for (var charIndex = 0;
charIndex < lines[i].Length && lines[i][charIndex] == ' ';
charIndex++)
{
spaceCount++;
}
if (spaceCount == 0)
{
indentedStringBuilder.Append(lines[i] + lineTrailingString);
continue;
}
var insufficientSpace = spaceCount % indentAmount;
if (insufficientSpace > 0)
{
indentedStringBuilder.Append(lines[i].Remove(0, insufficientSpace) +
lineTrailingString);
end -= insufficientSpace;
}
else
{
indentedStringBuilder.Append(lines[i].Remove(0, indentAmount) +
lineTrailingString);
end -= indentAmount;
}
}
if (i == startLine - 1)
{
if (startLine == endLine)
{
start -= lines[i].Length - indentedStringBuilder.Length;
}
else
{
start -= lines[i].Length - indentedStringBuilder.Length + 1;
}
if (start < startLineInitialIndex)
{
if (end == start)
{
end = startLineInitialIndex;
}
start = startLineInitialIndex;
}
}
}
if (string.Equals(document.Substring(startLineInitialIndex, endLineFinalIndex - startLineInitialIndex),
indentedStringBuilder.ToString()))
{
return;
}
if (Document.Selection.Text.EndsWith(RichEditBoxDefaultLineEnding) && endLineFinalIndex < document.Length)
{
indentedStringBuilder.Append(RichEditBoxDefaultLineEnding);
if (string.Equals(document.Substring(startLineInitialIndex, endLineFinalIndex - startLineInitialIndex),
indentedStringBuilder.ToString()))
{
return;
}
}
Document.Selection.GetRect(Windows.UI.Text.PointOptions.Transform, out Windows.Foundation.Rect rect,
out var _);
GetScrollViewerPosition(out var horizontalOffset, out var verticalOffset);
var wasSelectionInView = IsSelectionRectInView(rect, horizontalOffset, verticalOffset);
var newContent = document.Remove(startLineInitialIndex, endLineFinalIndex - startLineInitialIndex)
.Insert(startLineInitialIndex, indentedStringBuilder.ToString());
Document.SetText(TextSetOptions.None, newContent);
Document.Selection.SetRange(start, end);
// After SetText() and SetRange(), RichEdit will scroll selection into view and change scroll viewer's position even if it was already in the viewport
// It is better to keep its original scroll position after changing the indent in this case
if (wasSelectionInView)
{
_contentScrollViewer.ChangeView(
horizontalOffset,
verticalOffset,
zoomFactor: null,
disableAnimation: true);
}
}