I'm trying to create an extended control, which will display tips for writing. And everything is good, but the last step was faced with a problem.
Typing more then one word causes selection like "\r\n".
For example, type "Lorem" - it's ok. But type "Lorem " (with space) - broken.
01.public class ImprovedRichTextBox : RadRichTextBox
02.{
03. private static readonly DependencyProperty IsSuggestionConsistentProperty =
04. DependencyProperty.Register(
05. "IsSuggestionConsistent",
06. typeof (bool),
07. typeof (ImprovedRichTextBox),
08. new PropertyMetadata(default(bool))
09. );
10.
11. public bool IsSuggestionConsistent
12. {
13. get { return (bool)GetValue(IsSuggestionConsistentProperty); }
14. set { SetValue(IsSuggestionConsistentProperty, value); }
15. }
16.
17. private DocumentPosition _startPosition;
18. private DocumentPosition _previousPosition;
19.
20. // My custom added functionality
21. protected override void OnDocumentContentChanged()
22. {
23. base.OnDocumentContentChanged();
24.
25. var position = new DocumentPosition(Document.CaretPosition);
26.
27. var back = new DocumentPosition(position);
28.
29. if (!back.MoveToPrevious())
30. {
31. IsSuggestionConsistent = false;
32. return;
33. }
34.
35. if (IsSuggestionConsistent)
36. {
37. var i = _previousPosition.CompareTo(back);
38.
39. var end = new DocumentPosition(position);
40. end.MoveToLastPositionInDocument();
41.
42. if (i != 0 && (end.CompareTo(position) != 0 || end.CompareTo(_previousPosition) != 0))
43. {
44. IsSuggestionConsistent = false;
45. }
46. }
47.
48. _previousPosition = new DocumentPosition(position);
49.
50. if (!IsSuggestionConsistent)
51. {
52. _startPosition = new DocumentPosition(back);
53. IsSuggestionConsistent = true;
54. }
55.
56. var selection = Document.Selection;
57.
58. // KEY feature: begin
59. var selectionStart = _startPosition;
60.
61. // KEY feature: actual end of typing phrase
62. var selectionEnd = position;
63.
64. //
65. // The problem area is here:
66. //
67.
68. selection.SetSelectionStart(selectionStart);
69. selection.AddSelectionEnd(selectionEnd);
70.
71. // Everything is good while typing a word like "Lorem"
72. //
73. // But it will break if you put a space... Actually, it should be "Lorem ipsum", but catches only "\r\n"
74.
75. Debug.WriteLine("|" + selection.GetSelectedText() + "|");
76. selection.Clear();
77. }
78.}