The Problem On opening a PDF document in the Preview app, PDF widget annotations appear pixelated/rasterized. This problem exists with button, text, and choice widget subtypes. The pixelation becomes more apparent when zoomed in. Expected Results PDF widgets should appear sharp and smooth, without pixelation. In previous versions of the Preview app, widgets appear vector-based as expected. Impact on User Experience PDF widgets appear pixelated and inconsistent with text content in the same PDF document. Widgets do not look like elements of an interactive form but, instead, resemble low-quality embedded images. Affected Apps/OSs: Preview 11.0 (1147), as well as other apps that use PDFKit, on macOS Golden Gate 27.0 (26A428). A similar problem appears to affect PDFKit on iOS 27.0 and iPadOS 27.0 as well. Feedback/bug report: FB24843022

The Problem When a user toggles radio buttons or checkboxes in a PDF using Preview, the widgets disappear following subsequent interactions after the file is saved and reopened. This renders the form fields unusable. Steps to Reproduce the Problem Open a PDF with radio buttons or checkboxes in Preview. Toggle a radio button or checkbox. Save and close the file. Re-open the PDF in Preview. Toggle the same button again. The button (and any others with the same field name) will disappear. Expected Results Toggling a radio button or checkbox should update the field value without causing the button (or related buttons) to disappear. This behavior is consistent with previous versions of PDFKit. What is Happening In Preview, interacting with radio buttons and checkboxes correctly updates their appearance as expected. Saving the PDF, however, causes the appearance dictionary to reference a new N entry that is a single appearance stream unassociated with any state. The annotation's AS entry is not updated. The original N entry remains but is no longer referenced. Subsequent interactions fail to update the visual presentation because the appearance stream is missing. Impact on User Experience Radio buttons and checkboxes may disappear and become unusable when toggled. PDF documents become irreparably altered after a button is toggled and the file is saved. PDF file size significantly increases when the file is saved. Users may believe they have successfully completed a form, only for the data to become inaccessible or invisible to recipients. Forms may need to be completely restarted or recreated from scratch if the original becomes unusable. The corrupted PDF structure might cause the file to render incorrectly or crash in third-party PDF viewers. Affected Apps/OSs Tested with Preview 11.0 (1147), as well as other apps that use PDFKit, on macOS Golden Gate 27.0 (26A428). This problem also affects PDFKit on iOS 27.0 and iPadOS 27.0. Feedback/bug report: FB24866826 Related Sample Output Original PDF File Checkbox widget annotation (6 0 obj), its appearance dictionary (17 0 obj), and normal appearance dictionary (18 0 obj). Button is not checked. 6 0 obj << /Border [ 0 0 0 ] /Rect [ 90 390 110 410 ] /T (button1) /F 4 /Subtype /Widget /DA (/.AppleSystemUIFont 13 Tf 0 g) /MK 16 0 R /C [ 0 ] /AP 17 0 R /V /Off /M (D:20260919225320Z00'00') /AS /Off /FT /Btn /Type /Annot /Ff 0 >> endobj 17 0 obj << /N 18 0 R >> endobj 18 0 obj << /Yes 20 0 R /Off 22 0 R >> endobj PDF File after Save Checkbox widget annotation object (6 0 obj), its new appearance dictionary object (8 0 obj), a new normal appearance stream object (20 0 obj), and the original appearance stream dictionary (now 21 0 obj). File saved after user checked button. 6 0 obj << /Ff 0 /Type /Annot /AS /Off /AP 8 0 R /MK 9 0 R /C [ 0 ] /FT /Btn /M (D:20260919225320Z00'00') /DA (/.AppleSystemUIFont 13 Tf 0 g) /Subtype /Widget /F 4 /Border [ 0 0 0 ] /Rect [ 90 390 110 410 ] /T (button1) /V (Yes) >> endobj 8 0 obj << /N 20 0 R >> endobj 20 0 obj << /Filter /FlateDecode /Resources << /ColorSpace << /CS1 [ /ICCBased 29 0 R ] /CS2 [ /ICCBased 30 0 R ] >> >> /BBox [ 0 0 20 20 ] /Type /XObject /Subtype /Form /Length 123 >> stream x UéA ¬0 Ô}≈|†≈nà¢úÛÇ* —SA =}Ïr(»ñµ≤w◊€YËà’|ÙÎŒç'óRï∂#SäÏÌü∞¢S‰Ì§ôRÌX }–É•åY Éçˆ BŒ H " *â´8™ˆZø6z⁄ÿ ”ú6ɀ੠"∫t˘‹;'¬ endstream endobj 21 0 obj << /Off 22 0 R /Yes 23 0 R >> endobj Note: No object references 21 0 obj in the PDF.

The Problem Push buttons (created as a PDFAnnotation using PDFKit) do not properly write the associated caption's key-value pair (within the annotation's appearance characteristics dictionary) to a PDF document. What is Happening Push button widget annotations can have a caption that is displayed as the button’s label. In the PDF 1.7 specification (ISO PDF32000-2008, s. 12.5.6.19), a widget annotation can have an ‘appearance characteristics dictionary’ (MK) with properties to construct the appearance of the widget. The caption property (CA) is used to construct a button’s caption/label. PDFKit uses the PDFAnnotation .caption property to set the value of a push button’s caption as a string. Observation 1: In an open PDF document (using PDFView), a push button widget annotation can be created and added to a PDFPage using the following code: let pushButton = PDFAnnotation(bounds: pushButtonBounds, forType: .widget, withProperties: nil) pushButton.widgetFieldType = .button pushButton.widgetControlType = .pushButtonControl pushButton.caption = "My Button" page.addAnnotation(pushButton) The PDFAnnotation .caption property is used to set the caption to the required string. As a result, the push button is correctly displayed on the PDFPage with the correct label being display on the button. While the PDF document remains open, the appearance characteristics dictionary (an PDFAppearanceCharacteristics object) retains a key-value pair for the caption with the correct value as expected. On saving/writing to the PDF file, however, the key-value pair for the caption in the appearance characteristics dictionary is not written to the PDF document’s file. Resulting PDF markup: 6 0 obj << /Rect [ 256 299.8977 356 399.8977 ] /Border [ 0 0 0 ] /T (button23) /F 4 /Subtype /Widget /DA (/.AppleSystemUIFont 13 Tf 0 g) /MK 8 0 R /C [ 0 ] /AP 9 0 R /V /Off /M (D:20250330154918Z00'00') /FT /Btn /Type /Annot /Ff 65536 >> endobj 9 0 obj << /N 10 0 R >> endobj 8 0 obj << /BG [ 0.75 ] >> endobj 10 0 obj << /Filter /FlateDecode /Type /XObject /Subtype /Form /FormType 1 /BBox [0 0 100 100] /Resources 11 0 R /Length 170 >> stream x }ê1 Ç0 Öw~≈ ahÈ KÈ q1q0\‚`ú Ÿ¿ 8¯Ôm% u0óª‰.Ô{yπ åP°H-}ª‡à y3 ¸ %≠¡‰ %› g¨$•µMVXø‡Hé†Ö ”î“¿˜® BI•L ˆ†b A pü‰Ã @ÓpB∫ †æœs ãÙ:d8Éwÿr»/}” €∂I÷Bõ B;'+gm Ô˝„ mÙ~ L*>• endstream endobj On closing the PDF document, the assigned value for the push button’s caption is not written to the file and is lost. Observation 2: On reopening the PDF document, and assigning a new value for the already-created push button’s caption, a key-value pair for the caption is again correctly added to the PDFAnnotation appearance characteristics dictionary. On saving/writing to the PDF file, this time, the caption key-value pair in the appearance characteristics dictionary is correctly written/saved to the PDF document file. Resulting PDF markup: 6 0 obj << /Border [ 0 0 0 ] /Rect [ 256 299.8977 356 399.8977 ] /T (button23) /F 4 /BS 8 0 R /Subtype /Widget /DA (/.AppleSystemUIFont 13 Tf 0 g) /MK 9 0 R /C [ 0 ] /AP 10 0 R /V /Off /M (D:20250330154918Z00'00') /FT /Btn /Type /Annot /Ff 65536 >> endobj 10 0 obj << /N 11 0 R >> endobj 9 0 obj << /BG [ 0.75 ] /CA (My Button) >> endobj 8 0 obj << /W 0 >> endobj 11 0 obj << /Filter /FlateDecode /Type /XObject /Subtype /Form /FormType 1 /BBox [0 0 100 100] /Resources 12 0 R /Length 163 >> stream x uè1 ¬@ Ö˜˛ä7∂√]ì´◊Î≠ ¡A 8à”a∑Vj·ø˜jë™ !ÅÑ|y/=ˆËA1òʺ]pDá|=0¬“Œb ø+Õ gùf2E≤∞Ê≈N` û·Xm©-BãZ†H Ÿ ¿≈ºPÄ= Ø míãp •¡ ÈÓÅ˙>é “kó· Ÿb#—¬ Ûã¶2∂Ñ2fiΠ;óDÌiÓ?ü>LÁûÊy;} endstream endobj Impact on User Experience: Push button captions may not be properly saved to the PDF document’s file. This may result in an application redrawing a push button without a caption/label. More so, an application that uses the caption value to “read” a button’s label (e.g., for accessibility purposes) will not be able to do so.

The Problem In the Preview app in macOS (or the Files app in iOS and iPadOS), when a user selects a radio button to "On", the radio button appears to behave as expected (with related radio buttons, sharing the same parent form field, appearing to turn "Off"). Also, as expected, the app indicates that the user has edited the PDF and, as such, is able to save and close the file as normal. On re-opening the file, the radio buttons seem to have been reset and user input lost. What is Happening Related radio button annotation widgets share the same parent form field. In the PDF 1.7 specification (ISO PDF32000-2008, s. 12.7.4.2.4), the parent form field object holds the field name property (T), the name object of the appearance state of the kid object currently selected (V), as well as an array of the references to the related radio button kid objects (Kids). Each kid object holds a reference to the parent object (Parent). When the user selects a radio button to be on, the V property is updated in the parent object accordingly. On saving the PDF, an incremental update to the file is made with an updated copy of the kid object, corresponding to the selected radio box, created. The kid object created for the updated radio box, however, is updated incorrectly with the Parent object reference removed and the properties that ought to reside with the parent object (for V, T, and FT), instead, incorrectly written/merged into the kid object itself. The original parent object (belonging to the shared field form) is not updated with the incremental update in any way. Impact on User Experience Radio buttons are not functional, with user-input not properly saved. As such, using Preview to complete a PDF form with radio buttons is not possible. On re-opening the PDF, user input to the state of radio buttons appear not to have been saved. Affected Apps/OSs: Preview (macOS 12 and above) and Files (iOS 16 and iPadOS 16) Related Sample of Code Radio button annotation widget object (11 0 obj) and form field parent object (16 0 obj) in original PDF file: 11 0 obj << /Border [ 0 0 0 ] /Rect [ 433 405 453 425 ] /F 4 /BS 13 0 R /Subtype /Widget /DA (/Helvetica 13 Tf 0 g) /MK 14 0 R /C [ 0 ] /AP 15 0 R /M (D:20230803164805Z00'00') /AS /Off /Parent 16 0 R /Type /Annot /Ff 32768 >> endobj 16 0 obj << /V / /Kids [ 10 0 R 11 0 R ] /T (button2) /FT /Btn >> endobj 15 0 obj << /N 17 0 R >> endobj 17 0 obj << /Ted 18 0 R /Off 20 0 R >> endobj Copy of object (11 0 obj) created with incremental update of PDF, included in saved file following user selection: 11 0 obj << /C [ 0 ] /FT /Btn /F 4 /BS << /W 0 >> /Subtype /Widget /DA (//Helvetica 13 Tf 0 g) /Type /Annot /Border [ 0 0 0 ] /M (D:20230803164805Z00'00') /Rect [ 433 405 453 425 ] /MK << /BG [ 0.75 ] >> /AP << /N << /Off 53 0 R /Ted 57 0 R >> >> /T (button2) /AS /Ted /Ff 32768 /V /Ted >> endobj A bug report, describing as much, was submitted to Apple (FB9978281).