Android: textAlign: "justify" is silently ignored on ColorOS 15 (Realme/OPPO) — RN sets JUSTIFICATION_MODE_INTER_WORD but the OEM discards it

[kaushaldarji29]

Description

On ColorOS 15 (Realme / OPPO), textAlign: "justify" on a plain <Text> renders
left-aligned. There is no error, no warning and no fallback — the app has no way to know
justification did not happen.

React Native itself does the right thing. TextLayoutManager.getTextJustificationMode()
maps the "justified" alignment attribute to Layout.JUSTIFICATION_MODE_INTER_WORD, and
createLayout() passes it to StaticLayout.Builder.setJustificationMode() on API >= 26.
The OEM text engine accepts the call and does not apply it.

This is not the New Architecture path: enablePreparedTextLayout defaults to false, so
this goes through the shared ReactTextView / StaticLayout route.

It is also not a library, font or styling problem. I tested 13 variants on both devices —
bare justify, textBreakStrategy simple/highQuality/balanced, with and without
lineHeight, four fonts (system default, sans-serif, and two bundled asset fonts),
includeFontPadding: false, android_hyphenationFrequency: "normal", and nested <Text>.

• Stock Android: all 13 justify correctly.
• ColorOS 15: none justify, including the simplest possible case — a plain <Text>
  with only fontSize and textAlign: "justify", no custom font and no other styling.

A textAlign: "left" control was included throughout and correctly reads unjustified on
both devices, confirming the measurement distinguishes the two states.

Why this is worth an RN-level issue even though the root cause is the OEM: apps
currently have no way to detect that justification was dropped, so the only options are an
OEM allowlist or shipping silently broken layout. Either a way to query whether
justification was actually applied, or a documented caveat on textAlign, would let apps
fall back deliberately.

Steps to reproduce

1. Clone and install the reproducer:

   git clone https://github.com/ilalgtc/ColorOSJustifyRepro.git
   cd ColorOSJustifyRepro
   npm install
   

2. Run it on a ColorOS 15 device (tested: Realme RMX3686, Android 15, API 35):

   npx react-native run-android
   

   Everything is in App.tsx. There is one screen and no extra dependency.

3. Read the summary line at the top of the screen. On ColorOS it reports:

   JUSTIFIED on this device: none
   

4. Look at probe A — a plain <Text> with only fontSize and
   textAlign: "justify", no custom font, no HTML renderer, no third-party library.
   It renders left-aligned with a ragged right edge and reports NOT JUSTIFIED,
   with a shortfall of tens of px against the container.

5. Run the same build on stock Android (an emulator is enough). The summary line
   reports:

   JUSTIFIED on this device: A, B, C, D, E, F, G
   

   and probe A renders flush to both margins, reporting shortfall 0.0px.

Each probe renders the same paragraph in the same container and measures itself via
onTextLayout, so the screen prints its own verdict — nothing has to be judged by eye.

Probe Z is a control using textAlign: "left". It must read NOT JUSTIFIED on
every device, including stock Android. It is there to prove the measurement can tell
the two states apart rather than always reporting "justified" — if Z ever reads
JUSTIFIED, the measurement is broken and the app says so on screen.

React Native Version

0.87.1

Affected Platforms

Runtime - Android

Output of npx @react-native-community/cli info

System:
  OS: macOS 26.3
  CPU: (8) arm64 Apple M2
  Memory: 123.92 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 24.3.0
    path: /Users/kaushal/.nvm/versions/node/v24.3.0/bin/node
  Yarn:
    version: 1.22.22
    path: /opt/homebrew/bin/yarn
  npm:
    version: 11.4.2
    path: /Users/kaushal/.nvm/versions/node/v24.3.0/bin/npm
  Watchman:
    version: 2026.01.12.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.2
      - iOS 26.2
      - macOS 26.2
      - tvOS 26.2
      - visionOS 26.2
      - watchOS 26.2
  Android SDK: Not Found
IDEs:
  Android Studio: 2026.1 AI-261.26222.65.2613.16025427
  Xcode:
    version: 26.2/17C52
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.18
    path: /usr/bin/javac
  Ruby:
    version: 2.6.10
    path: /usr/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.2.0
    wanted: 20.2.0
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native:
    installed: 0.87.1
    wanted: 0.87.1
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: Not found
  newArchEnabled: false

Stacktrace or Logs

No crash. This is a rendering/layout defect, so the "log" is the line geometry the
reproducer measures with onTextLayout and prints on screen.

Reproducer: probe A = <Text style={{ fontSize: 16, textAlign: "justify" }}>
Probe Z    = the same text with textAlign: "left" (control)
React Native 0.87.1, new architecture enabled.

--- Emulator, stock Android 16 (API 36) -----------------------------------------
Summary line: "JUSTIFIED on this device: A, B, C, D, E, F, G"

  A (justify only)  box 394.7 · 12 lines · shortfall  0.0px · overflow 4.3px
                    widths 398.6, 395.9, 397.5, 398.6, 398.9, 397.2, ...
  Z (control, left) box 394.7 · 12 lines · shortfall 41.8px · overflow 0.0px
                    widths 352.9, 369.4, 358.6, 385.5, 354.9, 376.7, ...

  Probes B-G report identical geometry to A. The control behaves as expected.

--- Realme RMX3686, ColorOS 15, Android 15 (API 35) -----------------------------
Summary line: "JUSTIFIED on this device: none"

  A (justify only)  box <FILL> · <FILL> lines · shortfall <FILL>px · overflow <FILL>px
                    widths <FILL>
  Z (control, left) box <FILL> · <FILL> lines · shortfall <FILL>px · overflow <FILL>px
                    widths <FILL>

---------------------------------------------------------------------------------
Probe A on ColorOS measures tens of px short and its line widths vary line to line —
the signature of left-aligned text — while the identical probe on stock Android is
flush to within 0.0px. Probe Z is unjustified on both, confirming the measurement
separates the two states rather than always reporting "justified".

Secondary observation: where justification does work, lines measure ~4px WIDER than
their container (overflow 4.3px above), which clips the trailing glyph. Visible on
stock Android too and independent of the ColorOS problem.

MANDATORY Reproducer

https://github.com/kaushaldarji29/ColorOSJustifyRepro

Screenshots and Videos