[Unified Text Replacement] willBeginTextReplacementSession sometime…

…s does not return a context if the text lengths differ

https://bugs.webkit.org/show_bug.cgi?id=274325
rdar://128285414

Reviewed by Aditya Keerthi.

The length of the string produced by `editingAttributedString` and the character count produced by
`TextIterator` can sometimes differ. This can happen when there are images in the HTML, as `editingAttributedString`
handles them in a special case.

Fix by adding a new `TextIteratorBehavior` option that acts the same as `EmitsObjectReplacementCharacters`,
but only for images, and then use this behavior anywhere in UnifiedTextReplacementController that
needs character ranges or counts.

Also fix a few issues with attachments in attributed strings:

* When converting an `AttributedString` to an `NSAttributedString` with an attachment, if the attachment
does not have a "preferred" filename, an empty file wrapper will be created. Fix by always creating a file
wrapper.

* When converting HTML with an image to an attributed string, the position of the resulting attachment in
the produced attributed string is sometimes incorrect. This is because the length of the attachment itself
is never taken into account, and so consequent parts of the string will be inserted in too early of a position.
Fix by accounting for the length of the attachment.

* Source/WebCore/editing/TextIterator.cpp:
(WebCore::TextIterator::TextIterator):
(WebCore::TextIterator::handleReplacedElement):
* Source/WebCore/editing/TextIteratorBehavior.h:
* Source/WebCore/editing/cocoa/AttributedString.mm:
(WebCore::toNSObject):
* Source/WebCore/editing/cocoa/HTMLConverter.mm:
(WebCore::editingAttributedString):
* Source/WebKit/WebProcess/WebPage/Cocoa/UnifiedTextReplacementController.mm:
(WebKit::UnifiedTextReplacementController::characterRange):
(WebKit::UnifiedTextReplacementController::characterCount):
(WebKit::UnifiedTextReplacementController::resolveCharacterRange):
(WebKit::UnifiedTextReplacementController::plainText):
(WebKit::UnifiedTextReplacementController::willBeginTextReplacementSession):
(WebKit::UnifiedTextReplacementController::textReplacementSessionDidReceiveReplacements):
(WebKit::UnifiedTextReplacementController::textReplacementSessionDidReceiveTextWithReplacementRange):
(WebKit::UnifiedTextReplacementController::textReplacementSessionPerformEditActionForPlainText):
(WebKit::UnifiedTextReplacementController::contextRangeForSessionOrRangeWithUUID const):
(WebKit::UnifiedTextReplacementController::replaceContentsOfRangeInSessionInternal):
* Source/WebKit/WebProcess/WebPage/UnifiedTextReplacementController.h:

Canonical link: https://commits.webkit.org/279002@main

Source/WebCore/editing/TextIterator.cpp

@@ -37,6 +37,7 @@
 #include "HTMLBodyElement.h"
 #include "HTMLElement.h"
 #include "HTMLFrameOwnerElement.h"
+#include "HTMLImageElement.h"
 #include "HTMLInputElement.h"
 #include "HTMLLegendElement.h"
 #include "HTMLMeterElement.h"
@@ -350,6 +351,8 @@ static Node* firstNode(const BoundaryPoint& point)
 TextIterator::TextIterator(const SimpleRange& range, TextIteratorBehaviors behaviors)
     : m_behaviors(behaviors)
 {
+    ASSERT(!m_behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharacters) || !m_behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharactersForImagesOnly));
+
     range.start.protectedDocument()->updateLayoutIgnorePendingStylesheets();
 
     m_startContainer = range.start.container.ptr();
@@ -772,7 +775,17 @@ bool TextIterator::handleReplacedElement()
 
     m_hasEmitted = true;
 
-    if (m_behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharacters)) {
+    auto shouldEmitObjectReplacementCharacter = [&] {
+        if (m_behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharacters))
+            return true;
+
+        if (m_behaviors.contains(TextIteratorBehavior::EmitsObjectReplacementCharactersForImagesOnly) && is<HTMLImageElement>(m_currentNode.get()))
+            return true;
+
+        return false;
+    }();
+
+    if (shouldEmitObjectReplacementCharacter) {
         emitCharacter(objectReplacementCharacter, m_currentNode->protectedParentNode(), protectedCurrentNode(), 0, 1);
         // Don't process subtrees for embedded objects. If the text there is required,
         // it must be explicitly asked by specifying a range falling inside its boundaries.

Source/WebCore/editing/TextIteratorBehavior.h

@@ -63,6 +63,8 @@ enum class TextIteratorBehavior : uint16_t {
     EntersImageOverlays = 1 << 10,
 
     IgnoresUserSelectNone = 1 << 11,
+
+    EmitsObjectReplacementCharactersForImagesOnly = 1 << 12,
 };
 
 using TextIteratorBehaviors = OptionSet<TextIteratorBehavior>;

Source/WebCore/editing/cocoa/AttributedString.mm

@@ -194,14 +194,15 @@
         return attachment;
     }, [] (const TextAttachmentFileWrapper& value) -> RetainPtr<id> {
         RetainPtr<NSData> data = value.data ? bridge_cast((value.data).get()) : nil;
-        RetainPtr<NSFileWrapper> fileWrapper = nil;
-        if (!value.preferredFilename.isNull()) {
-            fileWrapper = adoptNS([[NSFileWrapper alloc] initRegularFileWithContents:data.get()]);
+
+        RetainPtr fileWrapper = adoptNS([[NSFileWrapper alloc] initRegularFileWithContents:data.get()]);
+        if (!value.preferredFilename.isNull())
             [fileWrapper setPreferredFilename:filenameByFixingIllegalCharacters((NSString *)value.preferredFilename)];
-        }
+
         auto textAttachment = adoptNS([[PlatformNSTextAttachment alloc] initWithFileWrapper:fileWrapper.get()]);
         if (!value.accessibilityLabel.isNull())
             ((NSTextAttachment*)textAttachment.get()).accessibilityLabel = (NSString *)value.accessibilityLabel;
+
         return textAttachment;
 #if ENABLE(MULTI_REPRESENTATION_HEIC)
     }, [] (const MultiRepresentationHEICAttachmentData& value) -> RetainPtr<id> {

Source/WebCore/editing/cocoa/HTMLConverter.mm

@@ -2399,8 +2399,11 @@ AttributedString editingAttributedString(const SimpleRange& range, IncludeImages
     for (TextIterator it(range); !it.atEnd(); it.advance()) {
         auto node = it.node();
 
-        if (RefPtr imageElement = dynamicDowncast<HTMLImageElement>(node); imageElement && includeImages == IncludeImages::Yes)
-            [string appendAttributedString:attributedStringWithAttachmentForElement(*imageElement).get()];
+        if (RefPtr imageElement = dynamicDowncast<HTMLImageElement>(node); imageElement && includeImages == IncludeImages::Yes) {
+            RetainPtr attachmentAttributedString = attributedStringWithAttachmentForElement(*imageElement);
+            [string appendAttributedString:attachmentAttributedString.get()];
+            stringLength += [attachmentAttributedString length];
+        }
 
         auto currentTextLength = it.text().length();
         if (!currentTextLength)

Source/WebKit/WebProcess/WebPage/Cocoa/UnifiedTextReplacementController.mm

@@ -47,6 +47,30 @@
 
 namespace WebKit {
 
+// MARK: Static utility helper methods.
+
+WebCore::CharacterRange UnifiedTextReplacementController::characterRange(const WebCore::SimpleRange& scope, const WebCore::SimpleRange& range)
+{
+    return WebCore::characterRange(scope, range, { WebCore::TextIteratorBehavior::EmitsObjectReplacementCharactersForImagesOnly });
+}
+
+uint64_t UnifiedTextReplacementController::characterCount(const WebCore::SimpleRange& range)
+{
+    return WebCore::characterCount(range, { WebCore::TextIteratorBehavior::EmitsObjectReplacementCharactersForImagesOnly });
+}
+
+WebCore::SimpleRange UnifiedTextReplacementController::resolveCharacterRange(const WebCore::SimpleRange& scope, WebCore::CharacterRange range)
+{
+    return WebCore::resolveCharacterRange(scope, range, { WebCore::TextIteratorBehavior::EmitsObjectReplacementCharactersForImagesOnly });
+}
+
+String UnifiedTextReplacementController::plainText(const WebCore::SimpleRange& range)
+{
+    return WebCore::plainText(range, { WebCore::TextIteratorBehavior::EmitsObjectReplacementCharactersForImagesOnly });
+}
+
+// MARK: UnifiedTextReplacementController implementation.
+
 UnifiedTextReplacementController::UnifiedTextReplacementController(WebPage& webPage)
     : m_webPage(webPage)
 {
@@ -83,11 +107,11 @@
     auto selectedTextRange = document->selection().selection().firstRange();
 
     auto attributedStringFromRange = WebCore::editingAttributedString(*contextRange);
-    auto selectedTextCharacterRange = WebCore::characterRange(*contextRange, *selectedTextRange);
+    auto selectedTextCharacterRange = UnifiedTextReplacementController::characterRange(*contextRange, *selectedTextRange);
 
     if (session) {
         auto attributedStringCharacterCount = attributedStringFromRange.string.length();
-        auto contextRangeCharacterCount = WebCore::characterCount(*contextRange);
+        auto contextRangeCharacterCount = UnifiedTextReplacementController::characterCount(*contextRange);
 
         // Postcondition: the selected text character range must be a valid range within the
         // attributed string formed by the context range; the length of the entire context range
@@ -140,12 +164,12 @@
 
         auto locationWithOffset = replacementData.originalRange.location + additionalOffset;
 
-        auto resolvedRange = resolveCharacterRange(*sessionRange, { locationWithOffset, replacementData.originalRange.length });
+        auto resolvedRange = UnifiedTextReplacementController::resolveCharacterRange(*sessionRange, { locationWithOffset, replacementData.originalRange.length });
 
         replaceContentsOfRangeInSession(session, resolvedRange, replacementData.replacement);
 
         auto newRangeWithOffset = WebCore::CharacterRange { locationWithOffset, replacementData.replacement.length() };
-        auto newResolvedRange = resolveCharacterRange(*sessionRange, newRangeWithOffset);
+        auto newResolvedRange = UnifiedTextReplacementController::resolveCharacterRange(*sessionRange, newRangeWithOffset);
 
         auto originalString = [context.attributedText.nsAttributedString() attributedSubstringFromRange:replacementData.originalRange];
 
@@ -329,7 +353,7 @@
 
     document->selection().clear();
 
-    auto sessionRangeCharacterCount = WebCore::characterCount(*sessionRange);
+    auto sessionRangeCharacterCount = UnifiedTextReplacementController::characterCount(*sessionRange);
 
     if (UNLIKELY(range.length + sessionRangeCharacterCount < contextTextCharacterCount)) {
         RELEASE_LOG_ERROR(UnifiedTextReplacement, "UnifiedTextReplacementController::textReplacementSessionDidReceiveTextWithReplacementRange (%s) => the range offset by the character count delta must have a non-negative size (context range length: %u, range.length %llu, session length: %llu)", session.uuid.toString().utf8().data(), contextTextCharacterCount, range.length, sessionRangeCharacterCount);
@@ -386,7 +410,7 @@
         ASSERT(!characterRanges->isEmpty());
 
         auto replaceCharacterRange = subCharacterRange(range, characterRanges->last().range);
-        return WebCore::resolveCharacterRange(*sessionRange, replaceCharacterRange);
+        return UnifiedTextReplacementController::resolveCharacterRange(*sessionRange, replaceCharacterRange);
     }();
 
 #if PLATFORM(MAC)
@@ -401,7 +425,7 @@
         return;
     }
 
-    auto replacedRangeAfterReplace = WebCore::resolveCharacterRange(*sessionRangeAfterReplace, characterRangeWithDelta);
+    auto replacedRangeAfterReplace = UnifiedTextReplacementController::resolveCharacterRange(*sessionRangeAfterReplace, characterRangeWithDelta);
 
     auto finalTextIndicatorUUID = createTextIndicator(replacedRangeAfterReplace, TextIndicatorStyle::Final);
 
@@ -464,7 +488,7 @@
     markers.forEach<WebCore::DocumentMarkerController::IterationDirection::Backwards>(*sessionRange, { WebCore::DocumentMarker::Type::UnifiedTextReplacement }, [&](auto& node, auto& marker) {
         auto rangeToReplace = WebCore::makeSimpleRange(node, marker);
 
-        auto currentText = WebCore::plainText(rangeToReplace);
+        auto currentText = UnifiedTextReplacementController::plainText(rangeToReplace);
 
         auto oldData = std::get<WebCore::DocumentMarker::UnifiedTextReplacementData>(marker.data());
         auto previousText = oldData.originalText;
@@ -689,7 +713,7 @@
         if (!sessionRange)
             continue;
 
-        return WebCore::resolveCharacterRange(*sessionRange, characterRanges[index].range);
+        return UnifiedTextReplacementController::resolveCharacterRange(*sessionRange, characterRanges[index].range);
     }
 
     return std::nullopt;
@@ -810,9 +834,9 @@
         return;
     }
 
-    auto sessionRangeCount = WebCore::characterCount(*sessionRange);
+    auto sessionRangeCount = UnifiedTextReplacementController::characterCount(*sessionRange);
 
-    auto resolvedCharacterRange = WebCore::characterRange(*sessionRange, range);
+    auto resolvedCharacterRange = UnifiedTextReplacementController::characterRange(*sessionRange, range);
     document->selection().setSelection({ range });
 
     replacementOperation(document->editor());

Source/WebKit/WebProcess/WebPage/UnifiedTextReplacementController.h

@@ -91,6 +91,11 @@ class UnifiedTextReplacementController final {
         WebCore::CharacterRange range;
     };
 
+    static WebCore::CharacterRange characterRange(const WebCore::SimpleRange& scope, const WebCore::SimpleRange&);
+    static WebCore::SimpleRange resolveCharacterRange(const WebCore::SimpleRange& scope, WebCore::CharacterRange);
+    static uint64_t characterCount(const WebCore::SimpleRange&);
+    static String plainText(const WebCore::SimpleRange&);
+
     std::optional<std::tuple<WebCore::Node&, WebCore::DocumentMarker&>> findReplacementMarkerContainingRange(const WebCore::SimpleRange&) const;
     std::optional<std::tuple<WebCore::Node&, WebCore::DocumentMarker&>> findReplacementMarkerByUUID(const WebCore::SimpleRange& outerRange, const WTF::UUID& replacementUUID) const;