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[0.81] fix: Unicode Text length Calculation #16185

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Merged
vineethkuttan merged 2 commits into from
May 26, 2026
+17 −6
Merged

[0.81] fix: Unicode Text length Calculation #16185

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03f21c1
fix Unicode length Calculation
vineethkuttan May 26, 2026
c8a415b
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vineethkuttan May 26, 2026
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7 changes: 7 additions & 0 deletions change/react-native-windows-363573e0-b320-4ecb-a1c0-ad9eac1b6845.json
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Original file line number Diff line number Diff line change
@@ -0,0 +1,7 @@
{
"type": "patch",
"comment": "fix Unicode length Calculation in Text Component",
"packageName": "react-native-windows",
"email": "66076509+vineethkuttan@users.noreply.github.com",
"dependentChangeType": "patch"
}
12 changes: 8 additions & 4 deletions vnext/Microsoft.ReactNative/Fabric/Composition/ParagraphComponentView.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -149,11 +149,13 @@ facebook::react::SharedViewEventEmitter ParagraphComponentView::eventEmitterAtPo
uint32_t textPosition = metrics.textPosition;

for (auto fragment : m_attributedStringBox.getValue().getFragments()) {
if (textPosition < fragment.string.length()) {
uint32_t utf16Length =
static_cast<uint32_t>(::Microsoft::Common::Unicode::Utf8ToUtf16(fragment.string).length());
if (textPosition < utf16Length) {
return std::static_pointer_cast<const facebook::react::ViewEventEmitter>(
fragment.parentShadowView.eventEmitter);
}
textPosition -= static_cast<uint32_t>(fragment.string.length());
textPosition -= utf16Length;
}
}
}
Expand Down Expand Up @@ -206,10 +208,12 @@ bool ParagraphComponentView::IsTextSelectableAtPoint(facebook::react::Point pt)

// Finds which fragment contains this text position
for (auto fragment : m_attributedStringBox.getValue().getFragments()) {
if (textPosition < fragment.string.length()) {
uint32_t utf16Length =
static_cast<uint32_t>(::Microsoft::Common::Unicode::Utf8ToUtf16(fragment.string).length());
if (textPosition < utf16Length) {
return true;
}
textPosition -= static_cast<uint32_t>(fragment.string.length());
textPosition -= utf16Length;
}
}
}
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2 changes: 1 addition & 1 deletion vnext/Microsoft.ReactNative/Fabric/Composition/TextDrawing.cpp
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Expand Up @@ -66,7 +66,7 @@ void RenderText(
unsigned int position = 0;
unsigned int length = 0;
for (auto fragment : attributedString.getFragments()) {
length = static_cast<UINT32>(fragment.string.length());
length = static_cast<UINT32>(::Microsoft::Common::Unicode::Utf8ToUtf16(fragment.string).length());
DWRITE_TEXT_RANGE range = {position, length};
if (fragment.textAttributes.foregroundColor &&
(fragment.textAttributes.foregroundColor != textAttributes.foregroundColor) ||
Expand Down
2 changes: 1 addition & 1 deletion ...ReactNative/Fabric/platform/react/renderer/textlayoutmanager/WindowsTextLayoutManager.cpp
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Expand Up @@ -262,7 +262,7 @@ void WindowsTextLayoutManager::GetTextLayout(
attachments.push_back(attachment);
position += 1;
} else {
unsigned int length = static_cast<UINT32>(fragment.string.length());
unsigned int length = static_cast<UINT32>(Microsoft::Common::Unicode::Utf8ToUtf16(fragment.string).length());
DWRITE_TEXT_RANGE range = {position, length};
TextAttributes attributes = fragment.textAttributes;
DWRITE_FONT_STYLE fragmentStyle = DWRITE_FONT_STYLE_NORMAL;
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