PdfExport: InvalidOperationException: 'Nullable object must have a value.'

Null reference exception when adding shapes and using the AddShapeTextBoxCommand.

This results in prompt to save the changes when closing the file.

The fix is available in our latest LIB(v. 2014.3.1222).

"Based on style" combobox is not filled with all linked and paragraph styles in the following cases:
- "Modify style" dialog doesn't display the possible "based on" styles in the combobox when editing linked styles. 
- "Create new style from formatting" dialog doesn't display the possible "based on" styles in the combo box during creation of new linked style.

Steps to reproduce:

Variant 1:
- Click Home -> Styles -> Change Styles in the ribbon UI.
- Expand the the drop down of Heading 1 button and click 'Modify'
Expected: 'Style based on' combobox contains all paragraph and linked styles.
Actual: 'Style based on' combobox is empty.
-------------------
Variant 2:
- Click Home -> Styles -> Change Styles in the ribbon UI.
- Click 'New' button.
- Choose 'Style type:' Linked in the combobox.
Expected: 'Style based on' combobox contains all paragraph and linked styles.
Actual: 'Style based on' combobox is empty.

When a text doesn't specify font explicitly with \fN tag, and default character properties (\defchp) are not specified, or are specified but without font set, the font of the text is visualized with the default font - Verdana. Instead, the default font for the document should be used - defined with \deffN tag.

In certain rare occasions, double-clicking a table cell may throw:

inline does not belong to this document.
at Telerik.Windows.Documents.Model.RadDocument.GetContainingAnnotationRanges[TRangeStart](Inline inline, Predicate`1 filter, Boolean inclusive)
at Telerik.Windows.Documents.Selection.MouseSelectionHandler.HandleCheckBox(InlineLayoutBox layoutBox)
at Telerik.Windows.Documents.Selection.MouseSelectionHandler.RegisterDocumentSingleMouseDown(Boolean ctrlPressed, Boolean shiftPressed, Point position, UIElement originalSource)

. . .

The RTF specifications states that the header of the document should start with "\rtfN" where N is the version of the RTF. Currently, the RtfFormatProvider do not save the version, but only "\rtf". Most software handles this case, but in some cases the document cannot be read.

Extension method GetValueOrNull is exists in two assemblies. 

When document fragment containing consecutive spans with same style is inserted with RadRichTextBox.InsertFragment method, and the document is with specific structure (which is not exactly known), NullReferenceException in HierarchicalIndex.GetBoxByHierarchicalIndex could be thrown when text is typed in specific places in the document.

Workaround: Ensure that such spans are merged before creating the fragment:

var document = xamlProvider.Import(xaml);
document.MergeSpansWithSameStyles();
var fragment = new DocumentFragment(document);
rtb.InsertFragment(fragment);

---------------------------------------

Sample call stack:

System.NullReferenceException
 at Telerik.Windows.Documents.HierarchicalIndex.GetBoxByHierarchicalIndex(DocumentLayoutBox documentBox, HierarchicalIndex hierarchicalIndex)
 at Telerik.Windows.Documents.DocumentPosition.RestorePositionFromBoxIndex(Nullable`1 raiseEvent)
 at Telerik.Windows.Documents.Model.RadDocumentEditor.InsertTextInternal(String text, Span currentSpanStyle, Boolean explicitAcceptsReturn)
 at Telerik.Windows.Documents.Model.RadDocumentEditor.InsertFromUI(String text, Span currentSpanStyle, Boolean acceptsReturn)
 at Telerik.Windows.Controls.RadRichTextBox.Telerik.Windows.Documents.UI.ITextInputCommandsHandler.InsertText(String text)
 at Telerik.Windows.Documents.UI.CaretTextInputHandler.InsertText(String text)
 at Telerik.Windows.Documents.UI.CaretTextInputHandler.HandleTextInsertedWithoutIme(RadDocument document, String text)
 at Telerik.Windows.Documents.UI.CaretTextInputHandler.CaretUI_TextInserted(Object sender, TextInsertedEventArgs e)
 at Telerik.Windows.Documents.UI.Caret.OnTextInserted(Object sender, TextInsertedEventArgs e)
 at Telerik.Windows.Documents.UI.Caret.OnTextChanged()
 at Telerik.Windows.Documents.UI.Caret.Caret_TextChanged(Object sender, TextChangedEventArgs e)

...

Fix available in LIB Version 2018.2.813.

With multiple lines of text in the same paragraph, clicking on the last possible position on any line (except the last one), the caret moves to the first position on the next line.

RadRichTextBox: Creating a new document fragment from imported document adds empty paragraph at the end.

When the Windows 11 theme is applied, opening the drop-down menu of either the ShapesColorPicker or ShapesOutlinePicker results in an InvalidOperationException.

When the LevelText of the list style is empty, PdfFormatProvider throws an IndexOutOfRangeException while trying to draw the bullet.

Workaround: Ensure that the LevelText of the ListItemStyle is not an empty string:

foreach (ListStyle listStyle in this.radRichTextBox.Document.ListManager.GetAllListStyles())
{
    foreach (ListLevelStyle level in listStyle.Levels)
    {
        if (string.IsNullOrEmpty(level.LevelText))
        {
            level.LevelText = " ";
        }
    }
}

Possible workaround is to change the document of RadRichTextBox.

The invalid document can't be measured and IndexOutOfRangeException/NullReferenceException will be thrown.

When a paragraph is styled in HTML format  with line-height it should be with AtLeast line spacing type instead of Exact. 

The same thing happens when the line-height is specified as normal: style="line-height: normal;". 

When trying to import a document containing bookmark and BookmarkRangeEnd is after the last paragraph, a StackOverflowException is thrown in IntervalNode while trying to rebuild the document cache. (RadDocumentChildrenCache.RebuildTree()).

The same could be observed if the bookmark end is last in the header/footer, between table cells in the RadDocument body, or when all paragraphs after the bookmark range end are hidden (with vanish property).

Workaround: Detect the problematic annotations and remove them:
foreach (var rangeStart in document.EnumerateChildrenOfType<AnnotationRangeStart>())
{
    if (rangeStart.End == null || rangeStart.End.Parent == null || rangeStart.End.Parent.Parent == null)
    {
        //MessageBox.Show("This indicates a problem.");
        rangeStart.Parent.Children.Remove(rangeStart);
    }
}

Note: Until 2017 R2 SP1 release StackOverflowException is thrown, after this release an ArgumentException should be thrown.

The TableStylesGallery keeps a reference to the document, which doesn't allow the GC to collect it. The issue is reproducible when the document is loaded in RadRichTextBox in the constructor of the window or in its Loaded event.

When TextOptions.TextFormattingMode="Display" is set on RadRichTextBox, incorrect Measuring causes TextBlocks to not visualize correctly.