react / react/react-native

[Android] Using adjustsFontSizeToFit=true sometimes causes font size to be too small.

Ouverte
#56,799 5 commentaires 2 réactions 0 personnes assignées Voir sur GitHub

Personne n'a encore pris cette issue.

Needs: Triage :mag: Platform: Android
Langage dominant
C++
Étoiles
127k
Forks
25.3k
Merge moyen
1 j 23 h
PR mergées (30 j)
4

Description

Description

Even when there is no need to shrink the font, there is sometimes a difference in the font sized used when adjustsFontSizeToFit is true vs. when it is false (or not included as a prop on a <Text> component). In other words, the font size is reduced when it should not be. This problem was introduced by the fix for #54715.

Specific font sizes needed to show this bug vary depending on the dp-to-font ratio of the test system or emulator, which points to rounding as the root cause of this bug.

Steps to reproduce
  1. Use two components, one with adjustsFontSizeToFit={true} and one without.
  2. Experiment with different fontSize values until you find one or more where the rendered size differs (even though there is no need to reduce the font to accommodate the text).

The provided reproducer demonstrates the problem.

React Native Version

0.85.2

Affected Platforms

Runtime - Android

Output of npx @react-native-community/cli info
info Fetching system and libraries information...
System:
  OS: macOS 15.7.5
  CPU: (16) x64 Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
  Memory: 829.41 MB / 40.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 24.11.1
    path: /Users/USER/.nvm/versions/node/v24.11.1/bin/node
  Yarn:
    version: 1.22.22
    path: /Users/USER/.nvm/versions/node/v24.11.1/bin/yarn
  npm:
    version: 11.6.2
    path: /Users/USER/.nvm/versions/node/v24.11.1/bin/npm
  Watchman:
    version: 2026.03.30.00
    path: /usr/local/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /usr/local/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:
    API Levels:
      - "27"
      - "28"
      - "29"
      - "30"
      - "31"
      - "34"
      - "35"
      - "36"
      - "36"
    Build Tools:
      - 30.0.3
      - 31.0.0
      - 33.0.0
      - 33.0.2
      - 34.0.0
      - 35.0.0
      - 35.0.1
      - 36.0.0
    System Images:
      - android-27 | Google APIs Intel x86 Atom
      - android-27 | Google Play Intel x86 Atom
      - android-29 | Google APIs Intel x86 Atom
      - android-30 | Google Play Intel x86 Atom
      - android-31 | Google Play Intel x86 Atom_64
      - android-34 | Google APIs Intel x86_64 Atom
      - android-34 | Google Play Intel x86_64 Atom
      - android-35 | Google Play Intel x86_64 Atom
      - android-36.1 | Google Play Intel x86_64 Atom
    Android NDK: Not Found
IDEs:
  Android Studio: Not Found
  Xcode:
    version: 26.2/17C52
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.10
    path: /usr/bin/javac
  Ruby:
    version: 2.6.10
    path: /usr/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.1.0
    wanted: 20.1.0
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native:
    installed: 0.85.2
    wanted: 0.85.2
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

info React Native v0.85.3 is now available (your project is running on v0.85.2).
info Changelog: https://github.com/facebook/react-native/releases/tag/v0.85.3
info Diff: https://react-native-community.github.io/upgrade-helper/?from=0.85.2&to=0.85.3
info For more info, check out "https://reactnative.dev/docs/upgrading?os=macos".
Stacktrace or Logs
N/A
MANDATORY Reproducer

https://github.com/MarkCSmith/react-native-issues/blob/master/Android-adjustsFontSizeToFit/RNTesterPlayground.js

Screenshots and Videos

Notice the text rendering differences for the following font sizes: 10, 11, 18, 22.

Image

Guide de contribution

Ouvrir le guide de contribution

Par où commencer

  1. Lisez l'issue en entier, puis le guide de contribution du projet.
  2. Signalez en commentaire que vous la prenez — cela évite que deux personnes fassent le même travail.
  3. Forkez le dépôt et travaillez sur une branche.
  4. Ouvrez une pull request qui référence le numéro de l'issue.

Piste de recherche

Commencez par le reproducer obligatoire dans RNTesterPlayground.js et comparez le rendu Android des composants Text avec et sans adjustsFontSizeToFit aux tailles de police signalées. Suivez l’implémentation Android de cette prop, en vous concentrant sur le comportement d’arrondi introduit par #54715. C’est terminé lorsque les tailles de police rendues sont identiques lorsqu’aucune réduction n’est nécessaire, y compris pour les cas du reproducer.

Rédigé par le modèle d'indexation à partir du texte de l'issue.

Évaluation

Stack technique
android, react-native
Domaine
mobile
Type d'issue
Bug
Difficulté
4/5
Temps estimé
3-5 jours
Activité
Calme
Clarté
Plutôt claire
Accessibilité débutants
52/100

Recevez les nouvelles issues par e-mail

Un résumé court des issues GitHub adaptées aux débutants.