Provide a default appearance for fields that do not contain one. 

Workaround: set border and background manually:

var provider = new PdfFormatProvider();
var document = provider.Import(File.ReadAllBytes(@"..\..\..\Systemvariablen.pdf"));

foreach (var item in document.AcroForm.FormFields)
{ 
    var widget = item.Widgets.First() as VariableContentWidget;
     
    if (widget != null)
    { 
        widget.AppearanceCharacteristics.Background = new RgbColor(255, 0, 0);
        widget.AppearanceCharacteristics.BorderColor = new RgbColor(0, 0, 255);
        widget.Border = new AnnotationBorder(2, AnnotationBorderStyle.Solid, null);
      
        widget.RecalculateContent(); 
    }
}

pdfViewer.Document = document;

Introduce support for PolyLine Annotation

FixedDocumentSinglePagePresenter uses simple rendering mechanism using UIElements, which currently has some limitations:
- Layers are not supported, thus annotations and forms are not rendered (even read-only)
- UIElements could be affected (clipped) when UseLayoutRounding property set at parent level, when DPI is different that 96 DPI. 

Workaround: If content is clipped, ensure that UseLayoutRounding is set to false as presenter level:
<telerikUI:FixedDocumentSinglePagePresenter UseLayoutRounding="False" />

Currently, the Find() method searches from the beginning of the document to its end. Enable the customer to specify a particular range of pages the method should search through.

Before starting to decode big image, try to estimate the needed memory and check if such memory is available using the MemoryFailPoint class. The behavior in case of failure in printing scenarios should be considered carefully.
The user should be able to turn the behavior on and off.

Introduce support for Polygon Annotation

Introduce support for Circle Annotation

Introduce support for Square Annotation

Introduce support for Line Annotation.

Currently, we use System.Windows.Controls.TextBox for editing both TextBox and CombTextBox field types. We should implement CombTextBox editor which would allow having spaces between characters during the editing process.

This is reproducible when the matched result resides on different page.

Workaround: You may subscribe to the RadFixedDocument.CaretPosition.PositionChanged event and implement the scroll logic. Subscribe to PdfViewer's DocumentChanged event first if the document is not loaded.
        private void CaretPosition_PositionChanged(object sender, EventArgs e)
        {
            Telerik.Windows.Documents.Fixed.Model.RadFixedPage currentPage = this.pdfViewer.Document.CaretPosition.Page;
            int pageIndex = this.pdfViewer.Document.Pages.IndexOf(currentPage);
            this.pdfViewer.GoToPage(pageIndex + 1);
        }

When text is exported from PDF document using the TextFormatProvider (it's also used internally for the Copy operation), it is automatically split to lines using the vertical position of the words on the page, and small tolerance. 

Currently the tolerance is hard-coded to 0.1 pixels, which is not suitable for documents which contains scanned and OCR-ed text, and there the text lines could be slightly inclined. The result is that words on one slightly inclined line are recognized as if they are on separate lines.

This allows specifying a soft mask in the external graphics state.