[UnifiedPDF] Cursor updates are incorrect over text/image elements fo…

…r untagged PDFs.

https://bugs.webkit.org/show_bug.cgi?id=265908
rdar://119217538

Reviewed by Tim Horton.

The CGPDFPageLayoutGetAreaOfInterestAtPoint interface does not correctly
identify text/image elements on Untagged PDF files. This made our hit
test results incomplete on said PDF files. To address this issue, we
adopt new PDFPage API `areaOfInterestAtPoint`, which not only hit tests
for annotations, but also for text and image on a page, thus subsuming
both -[PDFPage annotationAtPoint:] and CGPDFPageLayoutGetAreaOfInterestAtPoint
while maintaining correctness across tagged and untagged PDFs.

* Source/WebKit/Platform/spi/Cocoa/PDFKitSPI.h:
* Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/UnifiedPDFPlugin.mm:
(WebKit::UnifiedPDFPlugin::pdfElementTypesForPluginPoint const):

Canonical link: https://commits.webkit.org/275287@main

Source/WebKit/Platform/spi/Cocoa/PDFKitSPI.h

@@ -37,7 +37,9 @@
 #endif // PLATFORM(IOS_FAMILY)
 
 #import <PDFKit/PDFDocumentPriv.h>
+#import <PDFKit/PDFPagePriv.h>
 #import <PDFKit/PDFSelectionPriv.h>
+
 #if __has_include(<PDFKit/PDFActionPriv.h>)
 #import <PDFKit/PDFActionPriv.h>
 #else
@@ -122,6 +124,23 @@
 @end
 #endif
 
+#if HAVE(PDFPAGE_AREA_OF_INTEREST_AT_POINT)
+#define PDFAreaOfInterest NSInteger
+
+#define kPDFTextArea        (1UL << 1)
+#define kPDFAnnotationArea  (1UL << 2)
+#define kPDFLinkArea        (1UL << 3)
+#define kPDFControlArea     (1UL << 4)
+#define kPDFTextFieldArea   (1UL << 5)
+#define kPDFIconArea        (1UL << 6)
+#define kPDFPopupArea       (1UL << 7)
+#define kPDFImageArea       (1UL << 8)
+
+@interface PDFPage (Staging_119217538)
+- (PDFAreaOfInterest)areaOfInterestAtPoint:(PDFPoint)point;
+@end
+#endif
+
 #if HAVE(PDFDOCUMENT_SELECTION_WITH_GRANULARITY)
 typedef NS_ENUM(NSUInteger, PDFSelectionGranularity);
 

Source/WebKit/WebProcess/Plugins/PDF/UnifiedPDF/UnifiedPDFPlugin.mm

@@ -1624,6 +1624,38 @@ static BOOL annotationIsLinkWithDestination(PDFAnnotation *annotation)
 
     PDFElementTypes pdfElementTypes { PDFElementType::Page };
 
+#if HAVE(PDFPAGE_AREA_OF_INTEREST_AT_POINT)
+    if ([page respondsToSelector:@selector(areaOfInterestAtPoint:)]) {
+        PDFAreaOfInterest areaOfInterest = [page areaOfInterestAtPoint:pointInPDFPageSpace];
+
+        if (areaOfInterest & kPDFTextArea)
+            pdfElementTypes.add(PDFElementType::Text);
+
+        if (areaOfInterest & kPDFAnnotationArea)
+            pdfElementTypes.add(PDFElementType::Annotation);
+
+        if ((areaOfInterest & kPDFLinkArea) && annotationIsLinkWithDestination([page annotationAtPoint:pointInPDFPageSpace]))
+            pdfElementTypes.add(PDFElementType::Link);
+
+        if (areaOfInterest & kPDFControlArea)
+            pdfElementTypes.add(PDFElementType::Control);
+
+        if (areaOfInterest & kPDFTextFieldArea)
+            pdfElementTypes.add(PDFElementType::TextField);
+
+        if (areaOfInterest & kPDFIconArea)
+            pdfElementTypes.add(PDFElementType::Icon);
+
+        if (areaOfInterest & kPDFPopupArea)
+            pdfElementTypes.add(PDFElementType::Popup);
+
+        if (areaOfInterest & kPDFImageArea)
+            pdfElementTypes.add(PDFElementType::Image);
+
+        return pdfElementTypes;
+    }
+#endif
+
     if (auto annotation = [page annotationAtPoint:pointInPDFPageSpace]) {
         pdfElementTypes.add(PDFElementType::Annotation);
 
@@ -1658,8 +1690,6 @@ static BOOL annotationIsLinkWithDestination(PDFAnnotation *annotation)
     }
 #endif
 
-    // FIXME: <https://webkit.org/b/265908> Cursor updates are incorrect over text/image elements for untagged PDFs.
-
     return pdfElementTypes;
 }